Reduced Estriol Excretion in Patients With Breast Cancer Prior to Endocrine Therapy

Cancer of the breast develops in nearly 6% of all white women. Age-adjusted mortality rates for this neoplasm have changed very little during the past four decades in spite of improved lay education and improved methods of surgical, radiological, and medical therapy. The decreased risk of mammary cancer occurrence in the Japanese and the ameliorating influence of pregnancy upon this risk, in proportion to the number of gestations, have suggested to many investigators that genetic and endocrine factors have a role in its pathogenesis. No major qualitative or quantitative differences from normal have thus far been identified in estrogen or progestin metabolism characteristic of breast cancer patients, but suggestive abnormalities have been reported for excretion of androgen metabolites in relationship to 17-hydroxysteroid excretion.¹

Thus far, scant attention has been paid to the possible protective role of "impeded" or blocking estrogenic steroids in modifying the carcinogenicity of estrone or estradiol