Tahereh Ashrafganjoei - MD,Gynecologist oncologist, Associate proffesor Shahid Beheshti University of Medical sciences

According to statistics from the International Agency for Research on Cancer (IARC), there areapproximately 44 million people living with cancer worldwide . In the United States, the fiveyearsurvival rate for female breast cancer is approximately 90 percent. Tamoxifen hasantiestrogenic activity in breast tissue, as a chemopreventive agent.It increases risk forendometrial tumors.So,Regular gynecologic follow-up should be performed for women who have not undergone totalhysterectomy . This is particularly important in women who are receiving tamoxifen .Theelevated risk of endometrial cancer continues as long as the patient takes tamoxifen anddecreases after treatment is discontinued . Because tamoxifen leads to enlargement ofsubendometrial glands, endometrial thickness may be increased in the absence of malignancy;therefore, endometrial thickness alone should not prompt further intervention in womentaking tamoxifen. Tamoxifen does not appear to result in an increased EC risk in premenopausalwomen. Routine screening for EC is not performed for women on tamoxifen. Forpremenopausal women taking tamoxifen irregular bleeding should be evaluated withhysteroscopy, hysterosonography, and if the source of bleeding remains unclear, endometrialbiopsy.For postmenopausal women taking tamoxifen who experience vaginal bleeding, endometrialevaluation should be pursued with biopsy and appropriate follow-upDetermining menopausal status is of key importance in the evaluation of AUB. Based on thehigh prevalence of amenorrhea among women on tamoxifen, menstrual history is not a reliablemethod of determining menopausal status. For laboratory testing, we order serum estradiol(E2) and follicle-stimulating hormone (FSH) levels. These remain reliable endocrinologicmarkers in the setting of tamoxifen use. Tamoxifen slightly raises FSH levels, but typically notto postmenopausal levels.