CHOLESTEROL AND CHOLESTEROL EPOXIDES IN NIPPLE ASPIRATES OF HUMAN-BREAST FLUID

Abstract

In nipple aspirates of breast fluid from nonpregnant healthy women, cholesterol and cholesterol epoxide levels were determined with GLC and mass spectrometric techniques. Cholesterol levels were elevated above plasma levels averaging 2200 .+-. 1995 (SD) mg/dl and showing progressive increases in mean breast fluid cholesterol levels with advancing age, averaging 187, 1957 and 3554 mg/dl in women of age groups 20 to 29, 30 to 39 and 40 to 49 yr, respectively. Cholesterol epoxide was detected in a significant number of women who yielded high levels of breast fluid cholesterol. Cholesterol epoxide has been reported by other workers to have transforming activity for embryo hamster cells and to be carcinogenic in animals. The human breast apparently secretes mutagenic and cancer-promoting substances which may have relevance in studies of the etiology of benign breast disease and cancer.