DEHYDROEPIANDROSTERONE CONCENTRATION IN BREAST-CANCER TISSUE IS RELATED TO ITS PLASMA GRADIENT ACROSS THE MAMMARY-GLAND

Dehydroepiandrosterone (DHEA) has been shown to affect the growth of m ammary carcinomas both in vitro and in vivo. In humans, very high leve ls of DHEA and/or dehydroepiandrosterone sulfate (DHEAS) have been fou nd in breast tissues and secretions, and epidemiological studies sugge st a role of these steroids in the modulation of breast cancer growth. An uptake from plasma and a transformation from precursors can be bot h postulated, but the main source of the adrenal C19 steroids found wi thin the breast is debated. Attempting to clarify this point, in ten p atients undergoing surgery for breast cancer we studied: a) DHEAS and DHEA concentrations in tumor tissue; b) the differences between DHEAS (or DHEA) concentration in peripheral venous plasma and that draining the affected breast, that we assume to reflect the arteriovenous gradi ent of these steroids; c) DHEA sulfatase activity in tumor tissue. Res ults show that DHEA sulfatase activity is not related to DHEAS or DHEA concentrations in breast cancer tissue. A negative DHEA plasma gradie nt across the breast is unveiled, whereas DHEAS levels are not differe nt in blood supplying and draining the breast with cancer. The DHEA pl asma gradient across the breast is positively related to DHEA concentr ation in tumor tissue. Data are consistent with the hypothesis that th e plasma source contributes remarkably to DHEA found within breast can cer tissue.