International Agency for Research on Cancer (IARC) - Summaries & Evaluations
VOL.: 21 (1979) (p. 387)
5. Summary of Data Reported and Evaluation
(N.B. - This section should be read in conjunction with the General Remarks on Sex Hormones and with
the General Conclusions on Sex Hormones.)
5.1 Experimental data
Ethynodiol diacetate was tested in mice, rats and monkeys alone or in
combination with oestrogens by oral administration. In castrated male
mice, it increased the incidence of mammary tumours, and in male rats
it produced benign mammary tumours. In combination with oestrogens,
it increased the incidence of pituitary tumours in mice and of
malignant mammary tumours in male and female rats. The study in
monkeys is still in progress.
Ethynodiol diacetate was reported to be embryolethal for pre- and
postimplantation embryos and to have teratogenic effects in some
5.2 Human data
No case reports or epidemiological studies on ethynodiol diacetate
alone were available to the Working Group. Epidemiological studies on steroid
hormones used in oestrogen-progestin oral contraceptive preparations have been summarized
in the section, 'Oestrogens and Progestins in Relation to Human Cancer'.
There is limited evidence for the carcinogenicity of ethynodiol
diacetate in animals. In humans, oral contraceptives containing
oestrogens in combination with progestins have been related causally
to an increased incidence of benign liver adenomas and a decreased
incidence of benign breast disease.
For definition of the italicized terms, see Preamble Evaluation.
Previous evaluation: Vol. 6 (1974)
Subsequent evaluation: Suppl. 7 (1987) (Progestins;
combined oral contraceptives)
Last updated: 7 April 1998