An open, randomized, multicentre, phase III trial comparing the efficacy of two tamoxifen (T) schedules in preventing gynecomastia (gy) induced by bicalutamide monotherapy (BM) in prostate cancer patients (pca pts)

e16080 Background: BM is a valuable option for pca pts who wish to avoid the consequences of androgen deprivation and to mantain sexually active.BM is commonly well tolerated:however gy and mastalgia virtually develop in all pts and represent a major cause of treatment discontinuation. We had previously demonstrated that T is safe and effective in preventing breast events induced by BM without affecting B tumor activity (Boccardo, J Clin Oncol. 2005;23:808). However possible interferences between B and T,especially after prolonged administration, remain a matter of concern.In order to reduce the exposure to T,we considered the putative advantages of a weekly administration based on T effects being dose -dependent and on drug long half-life. Methods: This was a non inferiority trial. 80 pts with localized, locally advanced or biochemically recurrent pca were randomly assigned to receive daily B (150 mg) plus T 20 (mg) continuously (d group: n = 41) or same but with T at 20 mg/weekly after the first 8 weeks...