Environment and Breast Cancer: Science Review
Cancer studies: Experimental details
Toth B. Hydrazine, methylhydrazine and methylhydrazine sulfate carcinogenesis in Swiss mice. Failure of ammonium hydroxide to interfere in the development of tumors. Int J Cancer 1972;9(1):109-18.
Notes
A study listed by CPDB 2005 that did not report mammary tumors.
A study listed by CPDB 2005 that did not report mammary tumors.
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).
in drinking water
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.
In drinking water over lifespan (up to 120 wks) beginning at 6 wks old. 50 mice of each sex in dosed group, 110 of each in controls.. Average daily dose calculated to be 0.056 mg for females and 0.069 mg for males.
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, 5/50- adenocarcinoma. Interpret with caution: numbers are given in the text without saying explicitly stating results of controls. Numbers are not reproduced in the tables.
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.
No survival problems.
Other tumors
A list of other tumors that developed in the study that were treatment related.
lung, liver, lymphoma
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: not calculated, Overall: 2.20-29.8