Effectiveness of Vintage Hormone Therapy as Alternative Androgen Deprivation Therapy for Non-metastatic Castration-resistant Prostate Cancer

Background/Aim: Vintage hormone therapy for non-metastatic castration-resistant prostate cancer (nmCRPC) is not recommended under the current guidelines, but is widely practiced in Japan. This study assessed effectiveness of vintage hormone therapy as alternative androgen deprivation therapy (AADT) for treatment of nmCRPC. Patients and Methods: In this retrospective study we examined patients with nmCRPC that received vintage hormone therapy as AADT between 1999 and 2018. Results: Of 53 patients with nmCRPC, 25 patients (47.2%) had stage 1 nodal disease (N1) at diagnosis of nmCRPC. Prostate specific antigen (PSA) reduction rate >= 30% was observed in 32 patients (72.7%). The median PSA nadir was 0.7, and the duration of the response was 14.3 months. The median metastasis-free survival (MFS) for the entire patient population was 62.2 months, and the median overall survival (OS) was not reached. In the multivariate analysis, the duration of response in AADT>18 months was a predictor of prolonged OS. Conclusion: There is a certain number of nmCRPC patients who respond well to vintage hormone therapy as AADT. Further studies are expected to differentiate such cases.