Quantitative determination of estrone by liquid chromatography–tandem mass spectrometry in subcutaneous adipose tissue from the breast in postmenopausal women

•We developed a reproducible LC–MS/MS method to quantify estrone in adipose tissue.•The method was applied to adipose tissue from the breast in postmenopausal women.•Tissue and serum estrone levels were positively related in women with breast cancer.

Estrone is the most abundant estrogen after the menopause. We developed a liquid chromatography-tandem mass spectrometric method (LC–MS/MS) for determination of estrone in adipose tissue. Subcutaneous adipose tissue from the breast was collected during elective surgery in postmenopausal women undergoing mastectomy for treatment of breast cancer (n = 13) or reduction mammoplasty (controls, n = 11). Homogenized adipose tissue was extracted with organic solvents and the estrone fraction was purified by LH-20 column chromatography from the excess of lipids. The concentration of estrone was analyzed by LC–MS/MS. The method was accurate with an intra-assay variation of 8% and an interassay variation of 10%. The median concentration of estrone in subcutaneous adipose tissue from the breast did not differ between breast cancer and control women, 920 pmol/kg and 890 pmol/kg, respectively. In breast cancer patients but not in the controls, breast adipose tissue estrone levels correlated positively with the serum estrone concentration. In conclusion, the new method provides a reliable means to measure estrone concentrations in adipose tissue in postmenopausal women.