Environment and Breast Cancer: Science Review
AboutCancer studies: Experimental details
Maltoni C, Lefemine, G., Ciliberti, A., Cotti, G., and Carretti, D. Experimental research on vinyl chloride carcinogenesis. Arch. Res. Ind. Carcinog. 1984;2:1-533. Review 1.
Notes
yes- updated in 1988 paper.
yes- updated in 1988 paper.
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.
Exp 1: 0, 50, 250, 500, 2500, 6000, 10000 ppm. 4 h/d, 5 d/wk for 52 wks. 60 animals of each sex/group. 13 wks old at start.
Exp 2: 0, 100, 150, 200 ppm. 4 h/d, 5 d/wk for 52 wks. 120-185 animals of each sex/group. 13 wks old at start.
Exp 3: 30000 ppm. 4 h/d, 5 d/wk for 52 wks. 30 animals of each sex/group. 17 wks old at start.
Exp 4: 0, 50 ppm. 4 h/d, 5 d/wk for 52 wks. 100-150 animals of each sex/group. 11 wks old at start.
Exp 5: 0, 1, 5, 10, 25 ppm. 4 h/d, 5 d/wk for 52 wks.. 60 animals of each sex/group. 13 wks old at start.
Exp 6: 0, 50, 250, 500, 2500, 6000, 10000 ppm. 4 h/d, 5 d/wk for 17 wks. 30-95 animals of each sex/group. 12 wks old at start.
Exp 7: 0, 6000, 10000 ppm. 4 h/d, 5 d/wk for 5 wks or 4 h/d, 1 d/wk for 25 wks or 1 h/d, 4 d/wk for 25 wks. 60-114 animals of each sex/group, 11 wks old at start.
Exp 8: 6000, 10000 ppm. 4 hr/d, for 7 days (12th-18th day of pregnancy). 30 breeders, 16-27 embryos of each sex/group. 19 wks old at start (breeders).
Exp 9: 6000, 10000 ppm. 4 h/d, 5d/wk for 5 wks. 6 breeders 21-23 animals/group. 21 wks (breeders) or 1 d old at start.
Exp 10: 0, 2500 ppm. 4-7 h/d, 5d/wk for 76 wks or 15 wks. 54-60 breeders per group (76 wks only), 60-153 embryos of each sex/group. 12 wks old (breeders) or 12 day of pregnancy (embryos) at start.
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.
All rats observed until end of life.
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.
Mammary gland not systematically included in the necropsy, only if it was "any other organ with pathological lesions". Author's opinion was that high mortality was due to vinyl chloride carcinogenic effects rather than the toxicity of the compound. Controls have very high rates of mammary tumors 41-49%. Use historical controls for their comparisons.