The evaluation of the endometrial thickness of amenorrhea breast cancer patients treated with tamoxifen

Breast cancer is one of the most common cancers in women worldwide and one of its most desirable treatments is tamoxifen. The reported side effect associated with tamoxifen is endometrial thickness and increased risk of endometrial cancer. The aim of this study was to assess the influence of tamoxifen on the endometrial thickness in amenorrhea breast cancer patients treated with tamoxifen. This descriptive-analytic, cross-sectional study was conducted in Radiotherapy Departments of Mashhad University of Medical Sciences over a period of seven years.162 patients treated with tamoxifen whose bleeding cycle had been disrupted were selected and the relationship between tamoxifen usage and endometrial thickness was investigated in them. In addition, the relationship between abnormal vaginal bleeding and the ultra sonographic findings was assessed. Data analysis was done by using t-test and Chi-square test. There was a significant relationship between tamoxifen usage and abnormal endometrial thickness while the greatest relationship was observed in the first year of treatment. The relationship between abnormal vaginal bleeding and abnormal endometrial sonographic findings was significant (P=0.001). The incidence of endometrial cancer in tamoxifen users was more than general population (0.61% vs. 0.1%). Considering the findings of this study, in the presence of abnormal sonographic and clinical observations indicating abnormal vaginal bleeding, pathological evaluation of the endometrial biopsy should be carried out for patients who use tamoxifen.