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.