III.4 Tamoxifen and the uterus: Potential uterine risks of anti- oestrogens. The approach of the European Institute of Oncology

Tamoxifen has been widely used as adjunctive therapy for women with breast cancer because it acts as an excellent anti-oestrogen for breast tissue. However, tamoxifen has been found to be associated with various endometrial pathologies, such as endometrial hyperplasia, endometrial polyps and endometrial carcinoma [De Muylder and colleagues. Int J Crynecol Pathol 1991, 36, 127-129]. Transvaginal ultrasonography has been found to be an accurate diagnostic method in assessing endometrial thickness in correlation with various physiological and pathological endometrial conditions. Consistently, an endometrial thickness less than 4-5 mm has been associated with inactive endometrium on biopsy [Granberg S and colleagues. Am J Obstet Gynecol 1991, 164, 47-52]. However, transvaginal ultrasonography has limited use in the diagnosis of specific abnormalities because of many false positive monographic findings in patients receiving tamoxifen. Some patients taking tamoxifen show heterogeneous centrally located uterine changes when initially viewed with vaginal probe ultrasound. When such patients are viewed with a technique of fluid enhancement (sonohysterography), some changes thought to be in the endometrium were actually in the proximal myometrium, probably due to reactivation of adenomyosal foci in the form of microcysts [Goldstein SR. Am J Obstet Gynecol 1994, 170, 447-451]. The aim of this study is to assess the clinical value of sonohysterography in identifying endometrial diseases among asymptomatic, postmenopausal breast cancer patients treated with tamoxifen 20 mg/day, and to compare its accuracy with that of transvaginal ultrasonography, hysteroscopy and endometrial sampling.