EXPANSIVE UTERINE FIBROMYOMAS IN 11 WOMEN TREATED WITH TAMOXIFEN

Tamoxifen, a non-steroid anti-oestrogen derivative of diethylstilboest rol, is the main drug used for hormone therapy for hormone-dependent b reast cancer, This ambivalent drug has both antagonist and agonist eff ects. While tamoxifen blocks tumour growth it can also have an undersi rable agonist effect on the genital tract, The uterus is a target orga n for this paradoxical action due to pro-oestrogenic stimulation of th e endometrium and the myometrium. We observed eleven cases of uterine fibromyoma during treatment with tamoxifen which required hysterectomy due to increased tumour volume, The pathology report on the surgical specimens did not show any evidence of malignancy. Differential diagno sis is based on sarcomatous degeneration of the fibromyoma and presenc e of intra-myomatous metastases from the breast. Hysterectomy is indic ated in menopaused patients with a symptomatic fibromyomatous uterus b efore starting long-term anti-oestrogen therapy for hormone-dependent breast cancer.