Urinary estrogen metabolites and breast cancer risk in Chinese population

Abstract

Background: In China, the association between estrogen metabolism and breast cancer risk and the differences in metabolic pattern between breast cancer patients and controls are poorly understood. Methods: A total of 84 patients with invasive breast cancer and 47 controls with benign breast diseases were included in this study. Estrogen metabolites from their morning urine were determined by HPLC-MS/MS and evaluated in both groups, and the predictive value of each estrogen metabolite in the malignant group according to their menstrual status was analyzed. Results: Urinary concentration of estrogen metabolites 2-OHE1, 2-OHE2, 4-OHE2, 4-MeOE1, and 16ɑ-OHE1 were lower in postmenopausal patients with breast cancer, compared with benign controls, In logistic regression model, breast cancer risk increased with the decline in the levels of 4-OHE2 and 4-MeOE1. In premenopausal patients,, a difference in the level of 2-OHE2 was observed between both groups, and 2-OHE2 was found to have predictive value for breast cancer. Additionally, urinary 2-OHE2 level in premenopausal HR+ patients was considerably higher compared with HR- patients. Conclusions: We found that lower urinary levels of 4-OHE2 and 4-MeOE1had predictive value for breast cancer, and higher 2-OHE1 were associated with HR+ breast cancer in premenopausal women.