Androsterone long chain fatty acid esters in human breast cyst fluid.

We reported previously that incubation of [3H] androsterone in homogenates of human breast tumor resulted in production of long chain fatty acid esters of androsterone (A-LCFE). To identify the individual A-LCFE, breast tumor homogenates were incubated with androsterone, then submitted to solvent extraction, Celite chromatography, high pressure liquid chromatography and OH- negative chemical ionization mass spectrometry. The (M-1)-ions of the oleate, linoleate, palmitoleate, palmitate, arachidonate, and stearate esters of androsterone were produced. The first 3 cited unsaturated esters accounted for over 90% of the total. Since fibrocystic disease of the breast is a reported risk factor for the development of breast cancer, breast cyst fluids were analyzed for A-LCFE as part of an overall program to relate endocrine profiles in cyst fluid to the incidence of cancer. Breast cyst fluids were analyzed for total A-LCFE by a method involving solvent extraction, saponification, purification of the liberated androsterone, and then quantification of the steroid by RIA. The 10 fluids analyzed contained 0.52-3.79 ng/ml fatty acid esters, measured as androsterone. In 4 of these samples, the individual A-LCFE were analyzed by mass spectrometry. As in the incubation study, the unsaturated fatty acid esters predominated. In 3 samples, palmitoleate and in 1 sample, oleate predominated. The palmitate varied from undetectable to 25% of the total. The divergent total concentrations and profiles of A-LCFE indicate potential parameters for correlations with the subsequent course of fibrocystic disease of the breast.