Historical Controls

NTP has gathered a significant database of results collected on chronic toxicity and carcinogenicity studies, as well as developmental and reproductive studies. To evaluate study results and follow changes in the biology of our test species, we maintain a historical summary of the observations made on the untreated or control groups from individual studies. These data are divided into categories depending on the study type. Due to a variety of factors that can influence response, historical control data may be identified by:

• Species
• Sex
• Route of administration
• Vehicle
• Study type
• Laboratory

Chronic Toxicity & Carcinogenicity Studies

Chronic toxicity and carcinogenicity studies are labeled in the NTP Historical Controls database under study type as "Chronic." Specific information, including pathology tables, body weights, survival curves, and chemicals by sex/species may be viewed from the database. The data for control animals are compiled from the most recent five-year window.

• Within the pathology tables, tumor incidence is defined as the number of animals exhibiting a tumor type divided by the number of animals examined and is expressed as both raw counts and percent.
• The pathology tables present the mean and standard deviation of tumor incidence among studies, along with the number of studies summarized.
• The growth and survival curves present the mean for each route, species, and sex group of control animals along with the 5th and 95th percentile.

Developmental & Reproductive Toxicity Studies

Users can search data related to developmental and reproductive toxicity (DART) studies within the NTP Historical Controls database. The database includes information on fetal defects from stand-alone prenatal development (i.e., teratology) studies or modified one-generation studies (MOG). Files presenting data on fetal findings can be found in the database under "All Routes and Vehicles."

Fetal Findings

In the fetal findings file, under the "Summary" tab, fetal findings (Column C) are further delineated by exam type (Column A), followed by body area (Column B). Data are presented as the number of fetuses or litters with a finding and the percentage calculations are in parentheses.

• Rows in bold reflect the total number of fetuses or litters per finding. Columns labeled "TOTAL_FETUS" and "TOTAL_LITTER" indicate the total number of findings per fetus and per litter in all studies presented here.
• Columns labeled "MIN_FETUS," "MIN_LITTER," "MAX_FETUS," and "MAX_LITTER" indicate the minimum and maximum number of fetuses or litters with that finding.

NTP Historical Controls Database

Download Earlier Historical Controls