Gynecomastia and breast pain induced by adjuvant therapy with bicalutamide after radical prostatectomy in patients with prostate cancer: the role of tamoxifen and radiotherapy.

PURPOSE We investigated the role of tamoxifen and radiotherapy (RT) for the prevention and treatment of gynecomastia and breast pain during adjuvant bicalutamide monotherapy after radical prostatectomy (RP) in patients with prostate cancer. Also, we evaluated their effects on patient hormonal status, quality of life (QOL), sexual function and prostate specific antigen relapse-free survival. MATERIALS AND METHODS This was a multicenter prospective trial. From January 2002 to February 2004, 102 patients who had undergone RP for localized or locally advanced prostate cancer were recruited and randomized into 3 groups, namely group 1-those receiving only 150 mg bicalutamide as adjuvant hormonal therapy, group 2-those receiving bicalutamide and 10 mg tamoxifen, and group 3-those receiving bicalutamide and RT. Patients in group 1 in whom gynecomastia or breast pain developed were subsequently randomized to receive tamoxifen or RT soon after symptoms started. Gynecomastia, breast pain, prostate specific antigen, QOL, sexual function and hormonal levels were assessed. Minimum followup was 12 months. RESULTS Of group 1 patients 67% had gynecomastia compared with 8% in group 2 and 34% in group 3. Breast pain was more frequent in group 1 than in groups 2 and 3 (58% vs 7% and 30%, respectively). Differences were significant between groups 1 and 2 (OR 0.12 p <0.001), and groups 1 and 3 (OR 0.52 p < 0.01). In patients in group 1 who had gynecomastia or breast pain a significant decrease in symptoms was achieved in those receiving tamoxifen (p <0.05). Treatments were well tolerated in the 3 groups. No differences in QOL between groups 2 and 3 were found. At a median followup of 26 months we observed 12 biochemical relapses. CONCLUSIONS Gynecomastia and breast pain induced by bicalutamide monotherapy after RP can be prevented and treated. Tamoxifen has been shown to be more effective and safe than RT in this setting. QOL and sexual function are not negatively influenced by these 2 treatment options.