Relationship between steroid excretion patterns and breast cancer incidence in Israeli women of various origins.

A nationwide study of the steroid excretion patterns in postmenopausal Israeli migrant women demonstrated differences between high- and low-risk groups for breast cancer in the following variables: age at first parturition, number of pregnancies, number of live births, height, and weight. The direction of the differnces was in line with those observed for breast cancer patients. The groups also differed in the exretion of estriol, 17-ketosteroids, and allotetrahydrocortisol. Multiple regression analysis revealed that the exretion of estriol was significantly lower in population groups in whom breast cancer incidence was high. Possibly this trend--which has also been observed in adolescent and premenopausal women--reflected environmental influences on peripheral estrogen metabolism.