Comparison of prognostic characteristics between vintage and novel androgen receptor-axis-targeted drug among Japanese patients with non-metastatic castration-resistant prostate cancer: A multi-institutional study of Japanese Urological Oncology Group (JUOG).

163 Background: We conducted a multicenter study, 1) to verify the prognostic difference between novel androgen receptor-axis–targeted (ARAT) drug and vintage drug (Vintage) and, 2) to identify the prognostic PSA doubling time (PSADT) among Japanese non-metastatic castration-resistant prostate cancer (nmCRPC) patients. Methods: Of 515 patients diagnosed and treated for nmCRPC at 25 JUOG participating centers, including Chiba University Hospital, 489 patients with complete clinical characteristics were included. The association between each clinical factor, including drug types, PSADT, progression-free survival (PFS), and overall survival (OS) were analyzed, retrospectively. Results: The median age at nmCRPC diagnosis was 72 years, PSA was 3.24 ng/ml, and the observation period was 980 days. nmCRPC PFS and OS were 22 and 95 months, respectively. nmCRPC first-line therapy included Vintage + LH-RH alone: 197 cases/ARAT: 285 cases /Docetaxel (DOC): 7 cases. In the search for optimal PSADT (3-12M), PFS and OS correlated best at 10M (HR 1.64, p=0.005) and 4M (HR 2.63, p<.0001), respectively. ARAT(DOC) significantly prolonged PFS (HR 3.15, p<.0001) compared to Vintage, however, did not affect OS (HR 1.09, p=0.697) nor combined PFS (HR 0.94, p=0.733). The result was consistent, even after adjustment of the patient`s background by the propensity score matched analysis (n=145 in each arm), such as PFS (HR 0.35, p<.0001), OS (HR 1.16, p=0.598) and Combined PFS (HR 0.66, p=0.133). Multivariate analysis showed that PSADT was an independent prognostic factor for PFS (PSADT 10M: HR 3.1 p<.0001) and OS (PSADT 4M: HR 2.8, p=0.002). Conclusions: ARAT(DOC) prolonged PFS, but not OS, compared to Vintage in Japanese nmCRPC patients. PSADT (4-10M) may represent a useful tool in predicting prognosis and constructing treatment strategies for Japanese nmCRPC patients. [Table: see text]