Is prophylactic breast radiotherapy necessary in all patients with prostate cancer and gynecomastia and/or breast pain?

PURPOSE

We investigated the efficacy of prophylactic radiotherapy for gynecomastia/breast pain induced by 150 mg bicalutamide in a prospective, randomized, multi-institutional trial.

MATERIALS AND METHODS

After definitive treatment for localized prostate cancer 125 patients were randomized to 12 Gy radiotherapy before bicalutamide as prophylactic radiotherapy (53) or bicalutamide only for nonprophylactic radiotherapy (72). The incidence of gynecomastia, breast pain and tenderness, and discomfort perceived by the patients was assessed by physical examination and direct questioning at 3, 6 and 12 months of followup.

RESULTS

At the end of 12 months the gynecomastia rate was 15.8% in the prophylactic group and 50.8% in the nonprophylactic group (p <0.001). On patient evaluation the breast enlargement rate was 34.4%. The severity of breast pain and tenderness was not different between the groups. The breast pain rate was 36.4% and 49.2% by 12 months in the prophylactic and nonprophylactic groups, and the rate of patients who felt discomfort from gynecomastia was 11.4% and 29.5%, respectively.

CONCLUSIONS

In this prospective study the incidence of gynecomastia was not as high as previously believed. Although prophylactic breast irradiation seemed to decrease the gynecomastia rate in patients on 150 mg bicalutamide, our study proves that not all patients need prophylaxis since only 52% were significantly bothered by gynecomastia. Thus, individual assessment is needed to select patients who need prophylactic radiation while on 150 mg bicalutamide.