Diminished ratio of estrogen receptors to progesterone receptors in breast carcinomas of women who have had multiple miscarriages.

We examined the relationship of a history of miscarriage to the ratio of tumor estrogen receptors to progesterone receptors in 74 women with breast carcinoma evaluated between 1988 and 1990. Only women who had been pregnant and whose tumor contained both estrogen and progesterone receptors were included. Women with breast carcinoma and a history of two to four miscarriages had significantly lower ratios (less than 1) of tumor estrogen receptors to progesterone receptors than women with a history of zero or one miscarriage (greater than 1). This finding may be the result of a genetic anomaly in breast cancer patients that also affects the uterine environment during the reproductive years.