Guidelines for monitoring patients taking tamoxifen treatment

Tamoxifen is the most important anti-breast cancer drug in clinical use and has the potential to be used as a chemopreventive breast cancer agent. Usi ng outpatient hysteroscopy and based on 2 case control and 2 cohort follow- up studies in our department, we were able to demonstrate that 50% of women receiving long term tamoxifen experienced some sort of adverse endometrial effects. Although many women retain an atrophic endometrial layer, tamoxif en intake can lead to extensive senile cystic atrophia of the human endomet rium, to endometrial hyperplasia and to endometrial polyp formation. Based on a critical review of the literature, we have shown that tamoxifen double s the risk for developing endometrial cancer in postmenopausal women, altho ugh this increased risk may be higher and is duration (i.e. time of use)-de pendent. Screening patients with breast cancer for endometrial abnormalities while t hey are taking tamoxifen is feasible and uterine morbidity related to tamox ifen intake is preventable. Although screening may increase drug compliance it may not be cost-beneficial. However, uterine safety becomes important w hen only a small benefit of the treatment is to be expected as in the use o f tamoxifen in healthy women for boast cancer prevention. The aim of this report is to discuss methods and guidelines for detecting e ndometrial adverse effects of tamoxifen and to provide the clinician with a current opinion on timing and frequency of screening patients taking tamox ifen for the development of endometrial cancer. In summary those who advocate screening should start with pretreatment uter ine assessment using transvaginal ultrasonography or outpatient hysteroscop y. Symptom-free women with a normal pretreatment uterine cavity can be scre ened annually with transvaginal sonography from 2 to 3 years after the star t of tamoxifen. Hysteroscopy or saline infusion sonography will be required if there is endometrial thickening because the only value of transvaginal ultrasonography is a normal finding being a thin rectilinear endometrium.