The pill and the breast

Estrogen and progesterone, although of a synthetic type in contraceptive pills, play a major role in the development, growth and function of the breasts. There is no statistically valid evidence to indicate that the widespread use of estrogens for contraceptive purposes and for the menopausal syndrome has increased the incidence of benign, premalignant or malignant breast lesions. However, if a cancer is present in a woman's breast, estrogen can increase its rate of growth. Furthermore, while the effect of exogenous estrogen administration to the population as a whole may be null, there may be a subgroup in which their use may have different effects, with a possible increase in breast cancer incidence in nulliparous or late parous women and a decrease in those with early parity. Patients with a dominant lump, suspicious diagnostic aid changes, serous, serosanguineous, bloody or watery nipple discharge or other adverse breast changes should not receive exogenous estrogens unless the lesion is found to be completely benign on biopsy. Even then, patients with gross cystic disease will continue to have these changes as long as estrogens are administered, and so they should avoid the use of estrogens. Patients in the high rist group for developing breast cancer should be cautioned about the potential dangers of the use of estrogens, whether in birth control pills or in other preparations for the menopause, and if they use them, these patients should be followed carefully by breast self-examinations, periodic examinations by physicians and diagnostic aids. Finally, serious consideration should be given to the inclusion of estriol in all estrogen preparations for its impeding or blocking effect against the potential carcinogenic properties of estradiol and estrone and to the addition of progesterone for its estrogen-antagonistic effect.