Does Prophylactic Radiation Therapy to Avoid Gynecomastia in Patients With Prostate Cancer Increase the Risk of Breast Cancer?

In this registry-based study, we did not find an increased risk of BC in PC patients who received PRT. The number of BC cases in our study was low, and the risk of secondary BC after PRT seems to be negligible. The incidence of BC could, however, increase with additional follow-up. Also, 2 patients who had received PRT developed a malignant phyllodes tumor, an extremely rare type of BC associated with gynecomastia.