National Toxicology Program

National Toxicology Program
https://ntp.niehs.nih.gov/go/2968

TDMS Study 05136-08 Pathology Tables

NTP Experiment-Test: 05136-08  INCIDENCE RATES OF NEOPLASMS BY ANATOMIC SITE (SYSTEMIC LESIONS ABRIDGED) (a)      Report: PEIRPT05
Study Type: CHRONIC                                            CHLOROPRENE                                        Date: 10/04/96
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 09:52:49

                                                           CORE STUDY




       Facility:  Battelle Northwest

       Chemical CAS #:  0000126-99-8

       Lock Date:  04/14/94

       Cage Range:  All

       Reasons For Removal:    All

       Removal Date Range:     All

       Treatment Groups:       Include All


































a  Number of animals examined microscopically at site and number of animals with lesion

                                                              Page   1

NTP Experiment-Test: 05136-08  INCIDENCE RATES OF NEOPLASMS BY ANATOMIC SITE (SYSTEMIC LESIONS ABRIDGED) (a)      Report: PEIRPT05
Study Type: CHRONIC                                            CHLOROPRENE                                        Date: 10/04/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 09:52:49  
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         B6C3F1 MICE FEMALE                        CONTROL      12.8 PPM     32 PPM       80 PPM                                    
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
DISPOSITION SUMMARY                                                                                                                 
  Animals Initially in Study                          50           50           50           50                                     
  Early Deaths                                                                                                                      
    Moribund Sacrifice                                13           27           38           41                                     
    Natural Death                                      2            6           11            5                                     
    Accidently Killed                                               1                         1                                     
  Survivors                                                                                                                         
    Terminal Sacrifice                                35           16            1            2                                     
    Moribund Sacrifice                                                                        1                                     
  Animals Examined Microscopically                    50           50           50           50                                     
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 ALIMENTARY SYSTEM                                                                                                                  
                                                                                                                                    
   Intestine Large, Colon                             (50)         (47)         (48)         (49)                                   
      Sarcoma                                                                    1 (2%)                                             
   Intestine Small, Duodenum                          (49)         (45)         (42)         (48)                                   
   Intestine Small, Ileum                             (50)         (45)         (46)         (49)                                   
   Liver                                              (50)         (49)         (50)         (50)                                   
      Hemangiosarcoma                                  1 (2%)                    1 (2%)                                             
      Hepatocellular Carcinoma                         4 (8%)      10 (20%)      7 (14%)     15 (30%)                               
      Hepatocellular Carcinoma, Multiple                            1 (2%)       7 (14%)      4 (8%)                                
      Hepatocellular Adenoma                          12 (24%)     12 (24%)      9 (18%)      7 (14%)                               
      Hepatocellular Adenoma, Multiple                 5 (10%)      7 (14%)      2 (4%)       9 (18%)                               
      Hepatocholangiocarcinoma                                      1 (2%)       1 (2%)                                             
      Histiocytic Sarcoma                              1 (2%)       2 (4%)       3 (6%)                                             
      Sarcoma, Metastatic, Mesentery                                1 (2%)       1 (2%)       2 (4%)                                
   Mesentery                                          (10)         (14)         (27)         (21)                                   
      Hemangioma                                                                 2 (7%)       1 (5%)                                
      Hemangiosarcoma                                               4 (29%)     13 (48%)      4 (19%)                               
      Hepatocholangiocarcinoma, Metastatic, Liver                   1 (7%)                                                          
      Histiocytic Sarcoma                                                        1 (4%)                                             
      Sarcoma                                                       4 (29%)      8 (30%)      3 (14%)                               
   Pancreas                                           (49)         (49)         (48)         (50)                                   
      Hemangiosarcoma                                  1 (2%)                                                                       
      Hemangiosarcoma, Metastatic, Mesentery                                     1 (2%)                                             
      Hepatocholangiocarcinoma, Metastatic, Liver                   1 (2%)                                                          
      Sarcoma, Metastatic, Mesentery                                2 (4%)       2 (4%)                                             
   Salivary Glands                                    (50)         (49)         (50)         (50)                                   
      Sarcoma, Metastatic, Skin                                                  1 (2%)                                             
   Stomach, Forestomach                               (50)         (49)         (49)         (50)                                   
      Squamous Cell Carcinoma                          1 (2%)                                                                       
      Squamous Cell Papilloma                                                                 4 (8%)                                
   Stomach, Glandular                                 (50)         (48)         (49)         (50)                                   
      Sarcoma, Metastatic, Mesentery                                1 (2%)       2 (4%)       1 (2%)                                
                                                             Page   2                                                               
NTP Experiment-Test: 05136-08  INCIDENCE RATES OF NEOPLASMS BY ANATOMIC SITE (SYSTEMIC LESIONS ABRIDGED) (a)      Report: PEIRPT05
Study Type: CHRONIC                                            CHLOROPRENE                                        Date: 10/04/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 09:52:49  
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         B6C3F1 MICE FEMALE                        CONTROL      12.8 PPM     32 PPM       80 PPM                                    
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 CARDIOVASCULAR SYSTEM                                                                                                              
                                                                                                                                    
   Heart                                              (50)         (49)         (50)         (50)                                   
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 ENDOCRINE SYSTEM                                                                                                                   
                                                                                                                                    
   Adrenal Cortex                                     (50)         (48)         (49)         (50)                                   
      Hemangiosarcoma, Metastatic, Mesentery                                     1 (2%)                                             
      Hepatocholangiocarcinoma, Metastatic, Liver                   1 (2%)                                                          
   Adrenal Medulla                                    (50)         (48)         (48)         (50)                                   
      Pheochromocytoma Malignant                                    1 (2%)                                                          
      Pheochromocytoma Benign                          1 (2%)                    1 (2%)                                             
   Islets, Pancreatic                                 (49)         (49)         (48)         (50)                                   
      Adenoma                                                       1 (2%)       2 (4%)                                             
   Pituitary Gland                                    (49)         (48)         (48)         (50)                                   
      Pars Distalis, Adenoma                           4 (8%)       6 (13%)      4 (8%)       4 (8%)                                
      Pars Intermedia, Adenoma                         1 (2%)                                 1 (2%)                                
   Thyroid Gland                                      (50)         (49)         (49)         (50)                                   
      Follicular Cell, Adenoma                         1 (2%)       1 (2%)       1 (2%)                                             
      Follicular Cell, Carcinoma                                    2 (4%)                                                          
      Thyroglossal Duct, Adenoma                                                 1 (2%)                                             
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 GENERAL BODY SYSTEM                                                                                                                
                                                                                                                                    
   None                                                                                                                             
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 GENITAL SYSTEM                                                                                                                     
                                                                                                                                    
   Ovary                                              (48)         (47)         (47)         (49)                                   
      Cystadenoma                                      1 (2%)       1 (2%)       1 (2%)                                             
      Hemangiosarcoma                                                                         1 (2%)                                
      Histiocytic Sarcoma                                           2 (4%)       1 (2%)                                             
      Luteoma                                                       1 (2%)                                                          
      Sarcoma, Metastatic, Mesentery                                             1 (2%)                                             
      Teratoma Malignant                                            1 (2%)                                                          
   Uterus                                             (50)         (49)         (50)         (50)                                   
      Hemangioma                                                                              2 (4%)                                
      Hemangiosarcoma                                                            2 (4%)                                             
      Histiocytic Sarcoma                              1 (2%)       2 (4%)       2 (4%)                                             
      Leiomyosarcoma                                                1 (2%)                                                          
      Polyp Stromal                                    2 (4%)       4 (8%)       2 (4%)       3 (6%)                                
      Sarcoma, Metastatic, Mesentery                                                          1 (2%)                                
   Vagina                                                                       (1)                                                 
                                                             Page   3                                                               
NTP Experiment-Test: 05136-08  INCIDENCE RATES OF NEOPLASMS BY ANATOMIC SITE (SYSTEMIC LESIONS ABRIDGED) (a)      Report: PEIRPT05
Study Type: CHRONIC                                            CHLOROPRENE                                        Date: 10/04/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 09:52:49  
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         B6C3F1 MICE FEMALE                        CONTROL      12.8 PPM     32 PPM       80 PPM                                    
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
GENITAL SYSTEM - cont                                                                                                               
      Sarcoma                                                                    1 (100%)                                           
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 HEMATOPOIETIC SYSTEM                                                                                                               
                                                                                                                                    
   Bone Marrow                                        (50)         (49)         (49)         (50)                                   
      Hemangiosarcoma                                               1 (2%)       1 (2%)                                             
   Lymph Node                                         (4)          (3)          (5)          (2)                                    
      Iliac, Hemangiosarcoma, Metastatic, Mesentery                              1 (20%)                                            
      Iliac, Sarcoma, Metastatic, Mesentery                                                   1 (50%)                               
   Lymph Node, Bronchial                              (32)         (31)         (34)         (38)                                   
      Histiocytic Sarcoma                                                        1 (3%)                                             
      Sarcoma, Metastatic, Mesentery                                                          1 (3%)                                
   Lymph Node, Mandibular                             (32)         (40)         (33)         (40)                                   
   Lymph Node, Mesenteric                             (48)         (45)         (48)         (46)                                   
      Hemangiosarcoma                                               2 (4%)       1 (2%)       1 (2%)                                
      Hemangiosarcoma, Metastatic, Mesentery                                     3 (6%)                                             
      Histiocytic Sarcoma                                                        2 (4%)                                             
      Sarcoma                                                                    1 (2%)                                             
      Sarcoma, Metastatic, Mesentery                                1 (2%)       4 (8%)                                             
      Sarcoma, Metastatic, Skin                                     1 (2%)                                                          
      Sarcoma, Metastatic, Intestine Large, Colon                                1 (2%)                                             
   Lymph Node, Mediastinal                            (38)         (44)         (45)         (40)                                   
      Alveolar/Bronchiolar Carcinoma, Metastatic,                                                                                   
           Lung                                        1 (3%)                                 1 (3%)                                
      Hepatocholangiocarcinoma, Metastatic, Liver                   1 (2%)                                                          
      Sarcoma, Metastatic, Mesentery                                                          1 (3%)                                
      Sarcoma, Metastatic, Skin                                                               1 (3%)                                
   Spleen                                             (50)         (49)         (49)         (50)                                   
      Hemangiosarcoma                                  1 (2%)       1 (2%)       1 (2%)                                             
      Histiocytic Sarcoma                              1 (2%)                    1 (2%)                                             
   Thymus                                             (44)         (35)         (39)         (39)                                   
      Alveolar/Bronchiolar Carcinoma, Metastatic,                                                                                   
           Lung                                                                               1 (3%)                                
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 INTEGUMENTARY SYSTEM                                                                                                               
                                                                                                                                    
   Mammary Gland                                      (49)         (49)         (50)         (50)                                   
      Adenoacanthoma                                                1 (2%)       3 (6%)       2 (4%)                                
      Adenoma                                                       1 (2%)       1 (2%)                                             
      Carcinoma                                        3 (6%)       4 (8%)       6 (12%)     11 (22%)                               
      Carcinoma, Multiple                                                        1 (2%)       1 (2%)                                
   Skin                                               (49)         (49)         (50)         (50)                                   
      Basal Cell Adenoma                               1 (2%)                                                                       
      Squamous Cell Papilloma                                                                 1 (2%)                                
      Subcutaneous Tissue, Hemangiosarcoma             2 (4%)       1 (2%)       2 (4%)       1 (2%)                                
                                                             Page   4                                                               
NTP Experiment-Test: 05136-08  INCIDENCE RATES OF NEOPLASMS BY ANATOMIC SITE (SYSTEMIC LESIONS ABRIDGED) (a)      Report: PEIRPT05
Study Type: CHRONIC                                            CHLOROPRENE                                        Date: 10/04/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 09:52:49  
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         B6C3F1 MICE FEMALE                        CONTROL      12.8 PPM     32 PPM       80 PPM                                    
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
INTEGUMENTARY SYSTEM - cont                                                                                                         
      Subcutaneous Tissue, Histiocytic Sarcoma                      1 (2%)                                                          
      Subcutaneous Tissue, Sarcoma                                 10 (20%)     10 (20%)     16 (32%)                               
      Subcutaneous Tissue, Sarcoma, Multiple                        1 (2%)       1 (2%)       2 (4%)                                
      Subcutaneous Tissue, Sarcoma, Metastatic,                                                                                     
           Mesentery                                                             1 (2%)                                             
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 MUSCULOSKELETAL SYSTEM                                                                                                             
                                                                                                                                    
   Bone                                               (50)         (49)         (50)         (50)                                   
      Alveolar/Bronchiolar Carcinoma, Metastatic,                                                                                   
           Lung                                                                               1 (2%)                                
   Skeletal Muscle                                                              (2)          (1)                                    
      Sarcoma, Metastatic, Mesentery                                             1 (50%)                                            
      Sarcoma, Metastatic, Skin                                                  1 (50%)      1 (100%)                              
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 NERVOUS SYSTEM                                                                                                                     
                                                                                                                                    
   None                                                                                                                             
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 RESPIRATORY SYSTEM                                                                                                                 
                                                                                                                                    
   Larynx                                             (50)         (49)         (50)         (50)                                   
   Lung                                               (50)         (49)         (50)         (50)                                   
      Adenoacanthoma, Metastatic, Mammary Gland                                  3 (6%)                                             
      Alveolar/Bronchiolar Adenoma                     2 (4%)      10 (20%)     17 (34%)     10 (20%)                               
      Alveolar/Bronchiolar Adenoma, Multiple                        6 (12%)     12 (24%)     16 (32%)                               
      Alveolar/Bronchiolar Carcinoma                   2 (4%)       8 (16%)      8 (16%)     11 (22%)                               
      Alveolar/Bronchiolar Carcinoma, Multiple                      6 (12%)      8 (16%)     17 (34%)                               
      Carcinoma, Metastatic, Harderian Gland           1 (2%)       1 (2%)                                                          
      Carcinoma, Metastatic, Mammary Gland                                       2 (4%)       2 (4%)                                
      Carcinoma, Metastatic, Zymbal's Gland                                                   2 (4%)                                
      Hemangiosarcoma, Metastatic, Mesentery                        1 (2%)       2 (4%)                                             
      Hepatocellular Carcinoma, Metastatic, Liver      1 (2%)       1 (2%)       1 (2%)       4 (8%)                                
      Hepatocholangiocarcinoma, Metastatic, Liver                   1 (2%)       1 (2%)                                             
      Histiocytic Sarcoma                              1 (2%)                    2 (4%)                                             
      Sarcoma, Metastatic, Mesentery                                             2 (4%)       1 (2%)                                
      Sarcoma, Metastatic, Skin                                     2 (4%)       1 (2%)       2 (4%)                                
      Mediastinum, Alveolar/Bronchiolar Carcinoma,                                                                                  
           Metastatic, Lung                                                      1 (2%)       2 (4%)                                
      Mediastinum, Hemangiosarcoma                                               1 (2%)                                             
      Mediastinum, Sarcoma, Metastatic, Mesentery                                1 (2%)       1 (2%)                                
      Mediastinum, Sarcoma, Metastatic, Skin                        1 (2%)                    1 (2%)                                
   Nose                                               (50)         (49)         (49)         (50)                                   
      Respiratory Epithelium, Adenoma                                            1 (2%)                                             
                                                             Page   5                                                               
NTP Experiment-Test: 05136-08  INCIDENCE RATES OF NEOPLASMS BY ANATOMIC SITE (SYSTEMIC LESIONS ABRIDGED) (a)      Report: PEIRPT05
Study Type: CHRONIC                                            CHLOROPRENE                                        Date: 10/04/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 09:52:49  
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         B6C3F1 MICE FEMALE                        CONTROL      12.8 PPM     32 PPM       80 PPM                                    
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 SPECIAL SENSES SYSTEM                                                                                                              
                                                                                                                                    
   Harderian Gland                                    (2)          (6)          (4)          (9)                                    
      Adenoma                                          1 (50%)      3 (50%)      3 (75%)      8 (89%)                               
      Carcinoma                                        1 (50%)      2 (33%)                   1 (11%)                               
   Zymbal's Gland                                                                            (3)                                    
      Carcinoma                                                                               3 (100%)                              
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 URINARY SYSTEM                                                                                                                     
                                                                                                                                    
   Kidney                                             (50)         (49)         (49)         (50)                                   
      Hemangiosarcoma, Metastatic, Mesentery                                     1 (2%)                                             
      Hepatocholangiocarcinoma, Metastatic, Liver                   1 (2%)                                                          
      Histiocytic Sarcoma                                                        1 (2%)                                             
      Sarcoma, Metastatic, Mesentery                                             2 (4%)                                             
   Urinary Bladder                                    (50)         (47)         (46)         (47)                                   
      Hemangiosarcoma                                                            1 (2%)                                             
      Histiocytic Sarcoma                                                        1 (2%)                                             
      Sarcoma, Metastatic, Mesentery                                             2 (4%)                                             
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 SYSTEMIC LESIONS                                                                                                                   
   Multiple Organs                                   *(50)        *(50)        *(50)        *(50)                                   
      Histiocytic Sarcoma                              1 (2%)       2 (4%)       3 (6%)                                             
      Lymphoma Malignant                               7 (14%)      7 (14%)      3 (6%)       1 (2%)                                
____________________________________________________________________________________________________________________________________
                                                                                                                                    
     *   Number of animals with any tissue examined microscopically                                                                 
                                                             Page   6                                                               
NTP Experiment-Test: 05136-08  INCIDENCE RATES OF NEOPLASMS BY ANATOMIC SITE (SYSTEMIC LESIONS ABRIDGED) (a)      Report: PEIRPT05
Study Type: CHRONIC                                            CHLOROPRENE                                        Date: 10/04/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 09:52:49  
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         B6C3F1 MICE FEMALE                        CONTROL      12.8 PPM     32 PPM       80 PPM                                    
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
TUMOR SUMMARY                                                                                                                       
                                                                                                                                    
   Total Animals with Primary Neoplasms (b)            34          47          50          48                                       
     Total Primary Neoplasms                           55         124         151         160                                       
                                                                                                                                    
   Total Animals with Benign Neoplasms                 22          32          38          42                                       
     Total Benign Neoplasms                            31          53          59          66                                       
                                                                                                                                    
   Total Animals with Malignant Neoplasms              20          42          49          48                                       
     Total Malignant Neoplasms                         24          71          92          94                                       
                                                                                                                                    
   Total Animals with Metastatic Neoplasms              3           8          23          15                                       
     Total Metastatic Neoplasm                          3          18          40          27                                       
                                                                                                                                    
   Total Animals with Malignant Neoplasms                                                                                           
   Uncertain Primary Site                                                                                                           
                                                                                                                                    
   Total Animals with Neoplasms Uncertain-                                                                                          
   Benign or Malignant                                                                                                              
     Total Uncertain Neoplasms                                                                                                      
                                                                                                                                    
____________________________________________________________________________________________________________________________________
a  Number of animals examined microscopically at site and number of animals with lesion                                             
b  Primary tumors: all tumors except metastatic tumors                                                                              
                                                             Page   7                                                               
NTP Experiment-Test: 05136-08  INCIDENCE RATES OF NEOPLASMS BY ANATOMIC SITE (SYSTEMIC LESIONS ABRIDGED) (a)      Report: PEIRPT05
Study Type: CHRONIC                                            CHLOROPRENE                                        Date: 10/04/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 09:52:49  
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         B6C3F1 MICE MALE                          CONTROL      12.8 PPM     32 PPM       80 PPM                                    
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
DISPOSITION SUMMARY                                                                                                                 
  Animals Initially in Study                          50           50           50           50                                     
  Early Deaths                                                                                                                      
    Moribund Sacrifice                                15           16           26           34                                     
    Natural Death                                      8            7           10            3                                     
  Survivors                                                                                                                         
    Terminal Sacrifice                                27           27           14           13                                     
  Animals Examined Microscopically                    50           50           50           50                                     
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 ALIMENTARY SYSTEM                                                                                                                  
                                                                                                                                    
   Gallbladder                                        (41)         (40)         (37)         (40)                                   
   Intestine Large, Cecum                             (48)         (44)         (45)         (48)                                   
      Hemangioma                                                    1 (2%)                                                          
      Muscularis, Leiomyoma                            1 (2%)                                                                       
   Intestine Small, Jejunum                           (46)         (43)         (47)         (49)                                   
   Intestine Small, Ileum                             (46)         (45)         (46)         (48)                                   
   Liver                                              (50)         (50)         (50)         (49)                                   
      Alveolar/Bronchiolar Carcinoma, Metastatic,                                                                                   
           Lung                                                                               1 (2%)                                
      Cholangiocarcinoma                                                         1 (2%)                                             
      Hemangiosarcoma                                  2 (4%)       5 (10%)      6 (12%)      8 (16%)                               
      Hepatoblastoma                                                2 (4%)       3 (6%)       1 (2%)                                
      Hepatocellular Carcinoma                        10 (20%)     18 (36%)     18 (36%)     16 (33%)                               
      Hepatocellular Carcinoma, Multiple              14 (28%)     10 (20%)     19 (38%)     17 (35%)                               
      Hepatocellular Adenoma                           8 (16%)     11 (22%)     12 (24%)     11 (22%)                               
      Hepatocellular Adenoma, Multiple                14 (28%)      5 (10%)      7 (14%)     10 (20%)                               
      Hepatocholangiocarcinoma                                      1 (2%)                    1 (2%)                                
      Histiocytic Sarcoma                              1 (2%)                    1 (2%)                                             
      Sarcoma                                                       1 (2%)                                                          
   Mesentery                                          (2)          (8)          (16)         (11)                                   
      Hemangioma                                                                 1 (6%)       2 (18%)                               
      Hemangiosarcoma                                               3 (38%)     13 (81%)      7 (64%)                               
      Hepatocholangiocarcinoma, Metastatic, Liver                   1 (13%)                                                         
      Sarcoma, Metastatic, Liver                                    1 (13%)                                                         
   Oral Mucosa                                                                               (1)                                    
      Gingival, Squamous Cell Carcinoma                                                       1 (100%)                              
   Pancreas                                           (50)         (48)         (49)         (50)                                   
      Hemangiosarcoma                                               1 (2%)                                                          
      Hemangiosarcoma, Metastatic, Mesentery                                     1 (2%)                                             
      Hepatocholangiocarcinoma, Metastatic, Liver                   1 (2%)                    1 (2%)                                
      Sarcoma, Metastatic, Liver                                    1 (2%)                                                          
   Stomach, Forestomach                               (50)         (48)         (49)         (50)                                   
      Squamous Cell Carcinoma                                                                 1 (2%)                                
                                                             Page   8                                                               
NTP Experiment-Test: 05136-08  INCIDENCE RATES OF NEOPLASMS BY ANATOMIC SITE (SYSTEMIC LESIONS ABRIDGED) (a)      Report: PEIRPT05
Study Type: CHRONIC                                            CHLOROPRENE                                        Date: 10/04/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 09:52:49  
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         B6C3F1 MICE MALE                          CONTROL      12.8 PPM     32 PPM       80 PPM                                    
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
ALIMENTARY SYSTEM - cont                                                                                                            
      Squamous Cell Papilloma                          1 (2%)                    2 (4%)       4 (8%)                                
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 CARDIOVASCULAR SYSTEM                                                                                                              
                                                                                                                                    
   Heart                                              (50)         (49)         (50)         (50)                                   
      Alveolar/Bronchiolar Carcinoma, Metastatic,                                                                                   
           Lung                                                                               2 (4%)                                
      Hemangioma                                                                 1 (2%)                                             
      Hepatocholangiocarcinoma, Metastatic, Liver                                             1 (2%)                                
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 ENDOCRINE SYSTEM                                                                                                                   
                                                                                                                                    
   Adrenal Cortex                                     (50)         (49)         (50)         (50)                                   
      Alveolar/Bronchiolar Carcinoma, Metastatic,                                                                                   
           Lung                                                                               2 (4%)                                
      Capsule, Adenoma                                 1 (2%)                                                                       
   Adrenal Medulla                                    (50)         (49)         (50)         (49)                                   
      Pheochromocytoma Malignant                       1 (2%)                                                                       
      Pheochromocytoma Benign                                                    1 (2%)       1 (2%)                                
   Pituitary Gland                                    (49)         (47)         (47)         (48)                                   
      Pars Distalis, Adenoma                           1 (2%)                                                                       
   Thyroid Gland                                      (50)         (49)         (50)         (50)                                   
      Follicular Cell, Adenoma                         1 (2%)       1 (2%)       1 (2%)       1 (2%)                                
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 GENERAL BODY SYSTEM                                                                                                                
                                                                                                                                    
   None                                                                                                                             
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 GENITAL SYSTEM                                                                                                                     
                                                                                                                                    
   Epididymis                                         (50)         (49)         (50)         (50)                                   
      Hemangiosarcoma, Metastatic, Mesentery                                     1 (2%)                                             
      Hepatocholangiocarcinoma, Metastatic, Liver                   1 (2%)                                                          
      Histiocytic Sarcoma                                                                     1 (2%)                                
      Leiomyoma                                                                  1 (2%)                                             
      Leiomyosarcoma                                                             1 (2%)                                             
   Preputial Gland                                    (50)         (47)         (47)         (50)                                   
      Hemangiosarcoma                                                                         2 (4%)                                
   Prostate                                           (49)         (48)         (48)         (49)                                   
      Hemangiosarcoma, Metastatic, Mesentery                                     1 (2%)                                             
   Seminal Vesicle                                    (49)         (48)         (49)         (48)                                   
      Sarcoma, Metastatic, Liver                                    1 (2%)                                                          
   Testes                                             (50)         (49)         (50)         (50)                                   
                                                             Page   9                                                               
NTP Experiment-Test: 05136-08  INCIDENCE RATES OF NEOPLASMS BY ANATOMIC SITE (SYSTEMIC LESIONS ABRIDGED) (a)      Report: PEIRPT05
Study Type: CHRONIC                                            CHLOROPRENE                                        Date: 10/04/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 09:52:49  
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         B6C3F1 MICE MALE                          CONTROL      12.8 PPM     32 PPM       80 PPM                                    
                                                                                                                                    
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GENITAL SYSTEM - cont                                                                                                               
      Hemangiosarcoma                                               1 (2%)                                                          
      Interstitial Cell, Adenoma                       1 (2%)                                                                       
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 HEMATOPOIETIC SYSTEM                                                                                                               
                                                                                                                                    
   Bone Marrow                                        (50)         (49)         (50)         (50)                                   
      Hemangiosarcoma                                               1 (2%)       2 (4%)       1 (2%)                                
      Histiocytic Sarcoma                              1 (2%)                                                                       
   Lymph Node                                                      (1)          (2)          (3)                                    
      Renal, Hemangiosarcoma                                                                  1 (33%)                               
   Lymph Node, Bronchial                              (32)         (23)         (33)         (28)                                   
      Alveolar/Bronchiolar Carcinoma, Metastatic,                                                                                   
           Lung                                                                               4 (14%)                               
      Hepatocholangiocarcinoma, Metastatic, Liver                                             1 (4%)                                
      Histiocytic Sarcoma                                                        1 (3%)                                             
   Lymph Node, Mandibular                             (32)         (28)         (27)         (34)                                   
      Histiocytic Sarcoma                                                        1 (4%)                                             
   Lymph Node, Mesenteric                             (47)         (48)         (46)         (48)                                   
      Hemangiosarcoma                                                            1 (2%)                                             
      Histiocytic Sarcoma                              2 (4%)                    1 (2%)                                             
   Lymph Node, Mediastinal                            (34)         (38)         (37)         (37)                                   
      Alveolar/Bronchiolar Carcinoma, Metastatic,                                                                                   
           Lung                                                                               1 (3%)                                
      Hepatocholangiocarcinoma, Metastatic, Liver                   1 (3%)                                                          
      Sarcoma, Metastatic, Liver                                    1 (3%)                                                          
   Spleen                                             (50)         (49)         (50)         (50)                                   
      Hemangiosarcoma                                               2 (4%)       2 (4%)       1 (2%)                                
      Histiocytic Sarcoma                              1 (2%)                    1 (2%)                                             
   Thymus                                             (34)         (28)         (25)         (34)                                   
      Alveolar/Bronchiolar Carcinoma, Metastatic,                                                                                   
           Lung                                                                               1 (3%)                                
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 INTEGUMENTARY SYSTEM                                                                                                               
                                                                                                                                    
   Skin                                               (49)         (48)         (50)         (50)                                   
      Subcutaneous Tissue, Hemangiosarcoma             1 (2%)       3 (6%)       1 (2%)       7 (14%)                               
      Subcutaneous Tissue, Hemangiosarcoma,                                                                                         
          Multiple                                                  1 (2%)                                                          
      Subcutaneous Tissue, Histiocytic Sarcoma         1 (2%)                    1 (2%)                                             
      Subcutaneous Tissue, Sarcoma, Multiple                                     1 (2%)                                             
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                                                             Page  10                                                               
NTP Experiment-Test: 05136-08  INCIDENCE RATES OF NEOPLASMS BY ANATOMIC SITE (SYSTEMIC LESIONS ABRIDGED) (a)      Report: PEIRPT05
Study Type: CHRONIC                                            CHLOROPRENE                                        Date: 10/04/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 09:52:49  
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         B6C3F1 MICE MALE                          CONTROL      12.8 PPM     32 PPM       80 PPM                                    
                                                                                                                                    
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 MUSCULOSKELETAL SYSTEM                                                                                                             
                                                                                                                                    
   Bone                                               (50)         (50)         (50)         (50)                                   
      Alveolar/Bronchiolar Carcinoma, Metastatic,                                                                                   
           Lung                                                                               1 (2%)                                
      Hemangiosarcoma                                  1 (2%)                                                                       
   Skeletal Muscle                                                                           (1)                                    
      Hepatocholangiocarcinoma, Metastatic, Liver                                             1 (100%)                              
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 NERVOUS SYSTEM                                                                                                                     
                                                                                                                                    
   None                                                                                                                             
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 RESPIRATORY SYSTEM                                                                                                                 
                                                                                                                                    
   Lung                                               (50)         (50)         (50)         (50)                                   
      Alveolar/Bronchiolar Adenoma                     8 (16%)     12 (24%)     15 (30%)     15 (30%)                               
      Alveolar/Bronchiolar Adenoma, Multiple                        6 (12%)      7 (14%)     13 (26%)                               
      Alveolar/Bronchiolar Carcinoma                   4 (8%)       8 (16%)     13 (26%)     13 (26%)                               
      Alveolar/Bronchiolar Carcinoma, Multiple         2 (4%)       4 (8%)      10 (20%)     15 (30%)                               
      Hemangiosarcoma, Metastatic, Mesentery                                                  1 (2%)                                
      Hemangiosarcoma, Metastatic, Skin                             1 (2%)                                                          
      Hepatoblastoma, Metastatic, Liver                                          1 (2%)       1 (2%)                                
      Hepatocellular Carcinoma, Metastatic, Liver      8 (16%)     10 (20%)      5 (10%)      4 (8%)                                
      Hepatocholangiocarcinoma, Metastatic, Liver                   1 (2%)                    1 (2%)                                
      Histiocytic Sarcoma                              1 (2%)                                                                       
      Sarcoma, Metastatic, Liver                                    1 (2%)                                                          
      Bronchiole, Adenoma                                                        1 (2%)                                             
      Mediastinum, Alveolar/Bronchiolar Carcinoma,                                                                                  
           Metastatic, Lung                                                                   4 (8%)                                
      Mediastinum, Hepatocholangiocarcinoma,                                                                                        
          Metastatic, Liver                                         1 (2%)                    1 (2%)                                
   Nose                                               (50)         (48)         (50)         (50)                                   
      Adenoma                                                                                 1 (2%)                                
      Alveolar/Bronchiolar Carcinoma, Metastatic,                                                                                   
           Lung                                                                               1 (2%)                                
      Carcinoma, Metastatic, Harderian Gland                                     1 (2%)                                             
      Respiratory Epithelium, Adenoma                                                         1 (2%)                                
   Trachea                                            (50)         (48)         (50)         (50)                                   
      Adenoma                                                       1 (2%)       1 (2%)                                             
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                                                             Page  11                                                               
NTP Experiment-Test: 05136-08  INCIDENCE RATES OF NEOPLASMS BY ANATOMIC SITE (SYSTEMIC LESIONS ABRIDGED) (a)      Report: PEIRPT05
Study Type: CHRONIC                                            CHLOROPRENE                                        Date: 10/04/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 09:52:49  
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         B6C3F1 MICE MALE                          CONTROL      12.8 PPM     32 PPM       80 PPM                                    
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 SPECIAL SENSES SYSTEM                                                                                                              
                                                                                                                                    
   Harderian Gland                                    (2)          (5)          (11)         (12)                                   
      Adenoma                                          2 (100%)     5 (100%)     8 (73%)      9 (75%)                               
      Carcinoma                                                                  2 (18%)      2 (17%)                               
      Bilateral, Adenoma                                                                      1 (8%)                                
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 URINARY SYSTEM                                                                                                                     
                                                                                                                                    
   Kidney                                             (50)         (49)         (50)         (50)                                   
      Alveolar/Bronchiolar Carcinoma, Metastatic,                                                                                   
           Lung                                                                               1 (2%)                                
      Hemangiosarcoma                                                                         1 (2%)                                
      Hemangiosarcoma, Metastatic, Mesentery                                     4 (8%)                                             
      Hepatocholangiocarcinoma, Metastatic, Liver                                             1 (2%)                                
      Histiocytic Sarcoma                              1 (2%)                    1 (2%)                                             
      Renal Tubule, Adenoma                                         1 (2%)       1 (2%)       3 (6%)                                
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 SYSTEMIC LESIONS                                                                                                                   
   Multiple Organs                                   *(50)        *(50)        *(50)        *(50)                                   
      Histiocytic Sarcoma                              3 (6%)                    2 (4%)       1 (2%)                                
      Lymphoma Malignant                               2 (4%)       2 (4%)       2 (4%)       4 (8%)                                
____________________________________________________________________________________________________________________________________
                                                                                                                                    
     *   Number of animals with any tissue examined microscopically                                                                 
                                                             Page  12                                                               
NTP Experiment-Test: 05136-08  INCIDENCE RATES OF NEOPLASMS BY ANATOMIC SITE (SYSTEMIC LESIONS ABRIDGED) (a)      Report: PEIRPT05
Study Type: CHRONIC                                            CHLOROPRENE                                        Date: 10/04/96  
Route: RESPIRATORY EXPOSURE WHOLE BODY                                                                            Time: 09:52:49  
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         B6C3F1 MICE MALE                          CONTROL      12.8 PPM     32 PPM       80 PPM                                    
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
TUMOR SUMMARY                                                                                                                       
                                                                                                                                    
   Total Animals with Primary Neoplasms (b)            48          48          50          50                                       
     Total Primary Neoplasms                           78         106         156         172                                       
                                                                                                                                    
   Total Animals with Benign Neoplasms                 31          31          38          43                                       
     Total Benign Neoplasms                            38          43          59          72                                       
                                                                                                                                    
   Total Animals with Malignant Neoplasms              34          40          50          47                                       
     Total Malignant Neoplasms                         40          63          97         100                                       
                                                                                                                                    
   Total Animals with Metastatic Neoplasms              8          13          12          12                                       
     Total Metastatic Neoplasm                          8          22          14          31                                       
                                                                                                                                    
   Total Animals with Malignant Neoplasms                                                                                           
   Uncertain Primary Site                                                                                                           
                                                                                                                                    
   Total Animals with Neoplasms Uncertain-                                                                                          
   Benign or Malignant                                                                                                              
     Total Uncertain Neoplasms                                                                                                      
                                                                                                                                    
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a  Number of animals examined microscopically at site and number of animals with lesion                                             
b  Primary tumors: all tumors except metastatic tumors                                                                              
                                                             Page  13                                                               
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                             ----------              END OF REPORT             ----------                                           
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NTP is located at the National Institute of Environmental Health Sciences, part of the National Institutes of Health.