Exogenous estrogens and breast cancer in women with natural menopause.

ABSTRACT

PIP: 90 breast cancer patients aged 50-64 were compared with 83 controls matched for age, race, and socioeconomic class to determine the relationship between administration of exogenous estrogens and breast cancer when the factors of age, age at menopause, and calendar year were controlled. No harmful effect of estrogen administration was demonstrat ed, but a previous finding by the authors of a beneficial effect was neg ated. It is suggested, however, that there are still too many confounding factors in a study of this type for a harmful association to be revealed, and it is recommended that a case-control study be carried out in a large prepaid medical care system.