Evaluation of patient-reported gynecomastia following neoadjuvant androgen deprivation therapy and stereotactic body radiotherapy for localized prostate cancer.

Abstract

e17125 Background: Androgen deprivation therapy (ADT) is commonly combined with stereotactic body radiotherapy (SBRT) for localized prostate cancer. Agents such as leuprolide and relugolix are associated with hormone-related side effects, including gynecomastia. The incidence and severity of bothersome breast tenderness or enlargement following short-course ADT and SBRT remain poorly characterized. This study aimed to assess gynecomastia burden in prostate cancer patients treated with ADT and SBRT, and its association with testosterone recovery. Methods: Institutional IRB approval (IRB#: 2009-510) was obtained for a retrospective review of prospectively collected data. Gynecomastia was measured via Question 13b of the Expanded Prostate Index Composite (EPIC)-26 (EPIC Q13b), which assesses breast enlargement/tenderness. Survey responses and serum testosterone were recorded at ADT initiation and every 3 months, with a median follow-up of 9 months. Follow-up varied due to missed visits or incomplete surveys. EPIC Q13b responses ranged from 0 to 4, and were grouped as 0 (none), 1-2 (mild), and 3-4 (moderate to severe). Results: From 2009 to 2024, 281 localized prostate cancer patients (12 low-risk, 180 intermediate-risk, and 89 high-risk) were treated with short-course ADT (3-6 months) and SBRT (35-36.25 Gy) at Georgetown University Hospital. Patients received either leuprolide (n = 166) or relugolix (n = 115). The median age was 72 years, and 42% of patients were non-white. At baseline, 9.8% of men reported mild gynecomastia symptoms, while 2.2% experienced moderate to severe symptoms. The incidence of mild symptoms peaked at 15.4% at 6 months before declining to below baseline by 24 months. Moderate to severe symptoms reached the highest incidence of 5.8% at 12 months and decreased to 0% at 24 months, with a cumulative incidence of 10.3%. There was no significant difference in symptoms between patients treated with leuprolide versus relugolix. Testosterone recovery ( > 230 ng/dL) occurred in approximately 65% of patients by 12 months in those with follow-up. Conclusions: Bothersome gynecomastia occurs at low rates in men treated with neoadjuvant ADT. Resolution of symptoms occurred in most patients within two years after treatment. The temporary nature of gynecomastia may be important to include in patient counseling regarding hormone therapy side effects. Incidence and severity of breast enlargement/tenderness assessed by EPIC Q13b at different follow-up time points. Time Point (months) Total N Grade 0 Grade 1-2 Grade 3-4 0 183 162 (88.5%) 17 (9.3%) 4 (2.2%) 1 133 111 (83.5%) 16 (12%) 6 (4.5%) 3 217 188 (86.6%) 22 (10.1%) 7 (3.2%) 6 221 177 (80.1%) 34 (15.4%) 10 (4.5%) 9 178 156 (87.6%) 16 (9%) 6 (3.4%) 12 156 132 (84.6%) 15 (9.6%) 9 (5.8%) 18 138 121 (87.7%) 15 (10.9%) 2 (1.4%) 24 124 119 (96%) 5 (4%) 0 (0%) 30 78 72 (92.3%) 6 (7.7%) 0 (0%)