120 P - Chemoprevention of breast cancer: update of the Italian trial in hysterectomised women

Abstract

Three major studies are ongoing in the U.K., the U.S.A. and Italy in order to verify the efficacy of Tamoxifen to Inhibit or reverse breast carcinogenesis and to evaluate the risk/benefit ratio of its use in healthy women. The 3 studies are similar: double blind, randomised trials with Tamoxifen (20 mg/day) versus placebo, in healthy women, aged 35 to 70. The main difference with the Italian Study is in the target population, which is hysterectomised women only. As of December 31,1995 the Italian trial is run by 48 centers, under the coordination of the European Institute of Oncology in Milan, end the accrual has reached 4.320 subjects. Their median age is 51 and 18% of them have at least one first degree relative affected by breast cancer. Sixteen percent of the enrolled women are using estrogen replacement therapy, which is not a cause of exclusion in our study. We had 63% of the participants with some side-effects. which have been mainly of moderate intensity and especially menopausal symptoms like hot flushes and vaginal dryness. Twentyeight cases of phlebitis were reported, of which 3 assessed as deep venous thrombophlebitis. The number of drop-outs, so far, is reasonably low (15.9%). Thirtyone cases of cancer have been reported, including fourteen breast cancers. The Italian study is showing the feasibililty to run these chemoprevention trials in hysterectomised women, thus avoiding the risk of endometrial cancer, which seems to be the major side-effect of Tamoxifen.