Environment and Breast Cancer: Science Review
AboutCancer studies: Experimental details
National Toxicology Program Technical Report 288, 1984
Notes
Increased malignant mammary tumors. Highly tumorogenic at other sites. Study had to be terminated early due to high mortality. 0, 625, 1250ppm, 6 hr/d, 5 d/wk for 60 wks (males) or 61 wks (females). Female mice: 0/50, 2/50, 6/50 acinar cell carcinoma; 0/50, 4/49, 0/49 adenosquamous carcinoma
Increased malignant mammary tumors. Highly tumorogenic at other sites. Study had to be terminated early due to high mortality. 0, 625, 1250ppm, 6 hr/d, 5 d/wk for 60 wks (males) or 61 wks (females). Female mice: 0/50, 2/50, 6/50 acinar cell carcinoma; 0/50, 4/49, 0/49 adenosquamous carcinoma
Route
Route of chemical administration: dermal, inhalation, gavage (delivery directly into the
stomach), in feed, subcutaneous injection (under the skin), or intraperitoneal injection (into the
cavity that contains the abdominal organs).
inhalation
Doses
Dosage, frequency, and duration of treatment; the sizes of the groups of animals
involved and what age the animals were at the beginning of the study.
0, 625, 1250ppm, 6 hr/d, 5 d/wk for 60 wks (males) or 61 wks (females). 50 animals of each sex were in each dose group. Animals were 8-9 wks old when exposure began.
Time after cessation of dosing
How long the animals were observed after the chemical was no
longer being administered and before death of the animals.
none
Mammary tumors, malignant
Development of malignant mammary gland tumors follows the
same format as for benign, as described above.
0/50, 2/50, 6/50 acinar cell carcinoma
0/50, 4/49, 0/49 adenosquamous carcinoma
Comments
This field contains information on the survival rates of the animals and the body
weight trends in order to evaluate whether these factors were likely to have affected the
generation of mammary gland tumors. Mammary gland tumors tend to develop later in an
animal’s life, so studies with lowered survival could mean that animals died before mammary
gland tumors could develop. Decreased weight (perhaps due to toxicity of the chemical) can
decrease the development of tumors. This field may also contain other comments about the
design or outcome of the study.
Originally planned for 103 wk, but severe mortality caused early termination of study at 60 wks. Body weights were similar to controls.
Other tumors
A list of other tumors that developed in the study that were treatment related.
heart, lymphoma, lung, forestomach, liver, ovary, preputial (barely)
Endocrine related toxicities
This field reports endocrine related toxicities that appeared in the
study such as testicular atrophy.
atrophy of the ovary 2/49, 40/45, 40/48; involution of the uterus 0/49, 7/46, 14/49; testicular atrophy 0/50, 19/47, 11/48
CPDB TD50 (mg/kg-d)
Data excerpted from the CPDB database that is defined as the "dose-rate in
mg/kg body wt/day which, if administered chronically for the standard lifespan of the species,
will halve the probability of remaining tumorless throughout that period". The CPDB
calculated values for all tumor endpoints listed as well as for total tumors. The range of
mammary gland tumors TD50s is provided, as well as an overall range.
Mammary: 1030, Overall: 28-1590