Tamoxifen and malignant epithelial-nonepithelial tumours of the endometrium: report of six cases and review of the literature

Aims: To review the use of tamoxifen in malignant epithelial-nonepithelial tumours of the endometrium. Tamoxifen has been widely used for almost 20 ye ars as adjuvant therapy for breast cancer. Large clinical trials have point ed out that long-term tamoxifen therapy increases the risk of uterine cance rs. These tumours include endometrial carcinomas, stromal sarcomas, leiomyo sarcomas as well as malignant mixed (epithelial-nonepithelial) tumours. Methods: We report here six more cases of malignant epithelial-nonepithelia l tumours which, in addition to those reported in the literature, makes a t otal of 36 presented cases. The pathogenesis of such tumours remains unclea r, but it has been claimed that unopposed oestrogenic stimulation due to th e agonistic effect of tamoxifen might be involved, as in the case of endome trial carcinomas. Pelvic irradiation has also been incriminated, especially in women under 55 years of age. Results: Among 21 endometrial malignant epithelial-nonepithelial tumours as sociated with tamoxifen, seven occurred in women less than 55 years old. Fi ve of them had previous pelvic irradiation. The data from the literature an d from our series suggest that tamoxifen might favour the occurrence of mal ignant epithelial-nonepithelial tumours in women with breast cancer aged ov er 55 years, whereas in younger women both pelvic irradiation and tamoxifen might participate.