Follicle-Stimulating Hormone (FSH) Levels During Androgen Deprivation Therapy Are Not Associated With Survival or Development of Castration-Resistant Prostate Cancer

Background Follicle-stimulating hormone (FSH) dysregulation plays a potential role in prostate cancer progression. The objective of this study was to evaluate whether higher FSH levels during androgen deprivation therapy (ADT) for recurrent prostate cancer could predict the development of castration-resistant prostate cancer (CRPC), prostate cancer-specific survival (CSS), and overall survival (OS). Methods Serum FSH levels were measured in cryopreserved samples of the continuous ADT arm of the PR.7 trial, supplemented with analogous samples from a large contemporaneous biobank. Univariate and multivariate analyses assessed the relationship between FSH tertiles and time to CRPC, as well as CSS, and OS. Results A total of 172 patients were included in our analysis. Of these, 54 patients (31%) developed CRPC during the 9-year follow-up. Median FSH for the tertiles was 4.35, 6.13, and 11.32 mIU/mL. FSH tertiles were not significantly associated with the time to CRPC, or with CSS or OS. FSH levels were not a significant prognostic factor for these oncologic outcomes. Conclusion As previously reported, the use of gonadotropin-releasing hormone (GnRH) antagonists for ADT has significantly more suppression of FSH levels than GnRH agonists. Our results do not suggest that differences in circulating FSH 1 year following ADT initiation influence long-term oncologic outcomes or development of CRPC.