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https://ntp.niehs.nih.gov/go/32649

Target Organs and Levels of Evidence for TR-548

Toxicology and Carcinogenesis Studies of Ethinyl Estradiol (CASRN 57-63-6) in Sprague-Dawley Rats (Feed Studies)

Chemical (Study Title)
CASRN		 Peer Review Date Route/Exposure Levels Study Laboratory
Endocrine disruptor (Ethinyl estradiol)
57-63-6		 05/16/2007 Dosed-Feed
0, 2, 10, or 50 ppb		 National Center for Toxicological Research

Levels of Evidence

F1C Male Rats: No Evidence
Type Organ/Tissue (Lesion)
Non-Neoplastic Lesions
  • Mammary Gland: alveolar hyperplasia (1/44, 4/45, 6/47, 18/44); ductal hyperplasia (0/44, 0/45, 2/47, 3/44)
  • Liver: basophilic focus (1/49, 3/49, 3/50, 17/49); eosinophilic focus (3/49, 5/49, 8/50, 15/49)

F1C Female Rats: No Evidence
Type Organ/Tissue (Lesion)
Non-Neoplastic Lesions
  • Uterus: endometrial hyperplasia (17/51, 18/50, 22/49, 25/50); squamous metaplasia (2/51, 6/50, 8/49, 13/50); atypical focal hyperplasia (6/51, 14/50, 16/49, 20/50)
  • Liver: eosinophilic focus (1/51, 1/50, 1/49, 5/50)

Levels of Evidence

F1T140 Male Rats: No Evidence
Type Organ/Tissue (Lesion)
Non-Neoplastic Lesions
  • Liver: basophilic focus (1/49, 3/50, 11/48, 6/49); eosinophilic focus (3/49, 11/50, 5/48, 10/49)
  • Mammary gland: alveolar hyperplasia (1/44, 2/45, 6/47, 14/48); ductal hyperplasia (0/44, 0/45, 1/47, 3/48)

F1T140 Female Rats: Equivocal Evidence
Type Organ/Tissue (Lesion)
May Have Been Related
  • Uterus: stromal polyp (2/51, 5/50, 6/50, 7/50)
Non-Neoplastic Lesions
  • Liver: basophilic focus (1/51, 1/50, 1/50, 6/50)
  • Clitoral Gland: hyperplasia (2/50, 1/50, 2/49, 8/49)

Levels of Evidence

F3T21 Male Rats: Equivocal Evidence
Type Organ/Tissue (Lesion)
May Have Been Related
  • Mammary Gland: adenoma or adenocarcinoma (0/42, 0/42, 0/40, 3/45)
  • Preputial Gland: epithelial neoplasms (2/49, 4/49, 4/50, 8/49)
Non-Neoplastic Lesions
  • Mammary Gland: alveolar hyperplasia (2/42, 6/42, 4/40, 9/45)

F3T21 Female Rats: Equivocal Evidence
Type Organ/Tissue (Lesion)
May Have Been Related
  • Uterus: stromal polyp (1/52,7/50, 2/50, 5/50)
Non-Neoplastic Lesions
  • Clitoral Gland: hyperplasia (0/50, 1/50, 2/49, 3/48)
  • Uterus: squamous metaplasia (1/52, 4/50, 3/50, 11/50); atypical focal hyperplasia (6/52, 16/50, 15/50, 21/50)