Association of 2-methoxyestradiol levels with the occurrence and development of endometrial cancer in humans*

Abstract

Abstract Objective The aim of the study was to determine the association of urinary levels of estradiol (E2) and 2-methoxyestradiol (2-MeOE2) with the occurrence and development of endometrial cancer. Methods In this case-control study, 24-h urine specimens were collected from 28 postmenopausal patients with endometrial cancer and 28 postmenopausal healthy female controls. The concentration of 2-MeOE2 was determined using liquid chromatography-mass spectrometry with hollow fiber liquid-phase microextraction. The concentration of E2 was determined using an enzyme-linked immunosorbent assay. Results Estrogen levels were different between the patients with endometrial cancer and controls. The relative quantity of E2 in the case group was higher than that in the control group (P < 0.05), whereas that of 2-MeOE2 was lower in the case group than that in the control group (P < 0.05). The ratio of E2-to-2-MeOE2 in the case group was significantly higher than that in the control group (P < 0.05). Conclusion The results of this study indicate an imbalance of estrogen metabolites in endometrial carcinogenesis. Reduced 2-MeOE2 levels and elevated E2-to-2-MeOE2 ratio may be used as potential biomarkers for the risk assessment of estrogen-induced endometrial cancer.