Follicle stimulating hormone (FSH), estradiol (E2) and luteinizing hormone (LH) can serve as indicators in the determination of menopausal status. NCCN clinical practice guidelines for breast cancer recommend detecting the levels of FSH and E2 for amenorrhea patients less than 60 years of age. But the detection method and the corresponding reference ranges indicating postmenopausal status are not mentioned. In addition, the reference limits vary a lot among different equipments and methods when it comes to diagnosis of menopause, thus it is difficult to set universal criteria. So in this study, four widely used methods and instruments in China are used to detect plasma levels of FSH, E2 and LN of premenopausal and postmenopausal patients. Instruments and methods must be one of the following four categories: microparticle chemiluminescent(Beckman),acridinium ester chemiluminescence (Siemens),acridinium ester chemiluminescence (Abbott) and electrochemiluminescence（Roche）.
