International Agency for Research on Cancer (IARC) - Summaries & Evaluations
VOL.: 6 (1974) (p. 149)
5. Summary of Data Reported and Evaluation
(N.B.: This section should be read in conjunction with the section
'General Conclusions on Hormones'.)
5.1 Animal carcinogenicity data
Chlormadinone acetate was tested by the oral route in mice, rats and
dogs. In mice it was also tested in combination with oestrogen.
Given alone, it produced no increase in the incidence of tumours in
mice or in rats but resulted in mammary tumours in dogs. The
significance of the tumours in dogs is discussed in the section,
"General Remarks on the Sex Hormones", in this volume.
In combination with mestranol, the incidence of pituitary tumours was
increased in mice of both sexes; in combination with
ethinyloestradiol, it increased the incidence of mammary tumours in
intact and castrated males of one hybrid strain.
5.2 Human carcinogenicity data
No case reports or epidemiological studies on chlormadinone acetate
alone were available to the Working Group. Epidemiological studies on
steroid hormones used in oestrogen-progestin contraceptive
preparations have been summarized in the section, 'Oestrogens and
Progestins in Relation to Human Cancer', in this volume.
Subsequent evaluations: Vol. 21 (1979);
Suppl. 7 (1987) (Progestins;
Combined oral contraceptives)
Last updated: 18 March 1998