몬치료가표준치료방법이되었다. 2000년대에들어서면서선 Purpose: The aim of this study is to evaluate the relationship of menopause and serum follicle stimulating hormone (FSH) level and estradiol (E2) in Korean women with breast cancer. Methods: We reviewed 1,404 women aged from 20to 82year-old (median 47 years) with breast cancer who had got surgery at Asan Medical Center in 2008. All patients were checked serum FSH before the operation. Three hundred fifty-three patients were in postmenopause state at the time of surgery. Their ages were from 40to 60-year-old (median 50.3 years). Results: The proportion of postmenopausal status in each age-group were 5.1% (45to 49-year-old), 41% (50to 54-year-old), 86.1% (55to 59-year-old), and 100% over the age of 60, respectively. And the proportion of the patients with FSH over 30 mUI/mL were 68.6% (45to 49-year-old), 87.5% (55to 59-year-old), 75.0% (55to 59-year-old) and 30.0% (over the age of 60), respectively. Conclusion: Our study shows that even though patients had been in amenorrhea over 1 year, not all patients have their FSH level over 30 mUI/mL. And this finding is more prominent in age group from 45to 49-year-old.