Prognostic Significance of Time to Castration Resistance in Patients With Metastatic Castration-sensitive Prostate Cancer

BACKGROUND/AIM: It is important to delay the emergence of castration-resistant phenotype to improve the prognosis in patients with metastatic castration-sensitive prostate cancer (mCSPC). The objective of this study was to investigate the prognostic impact of time to castration resistance (TTCR) in mCSPC patients. PATIENTS AND METHODS: This study included 437 consecutive mCSPC patients whose primary androgen deprivation therapy was judged to have failed. Prognostic outcomes in these patients were investigated by dividing them into the following 4 groups of 82, 104, 133 and 118 patients with TTCR 0-6, 6.1-12, 12.1-18 and ≥18.1 months, respectively. RESULTS: The mean value of TTCR in the 437 patients was 18.7 months. Of several baseline parameters, significant differences among the 4 groups were noted in the performance status, prostate-specific antigen (PSA) level, lactate dehydrogenase (LDH) level, alkaline phosphatase (ALP) level and Gleason score, all of which favored longer TTCR groups. Furthermore, despite the lack of a significant difference in time from the development of castration-resistant disease to death among the 4 groups, there was a significant difference in overall survival (OS) from diagnosis among these groups, showing prolonged OS proportional to TTCR. Univariate analysis identified the age, PSA level, LDH level, ALP level, Gleason score, visceral metastasis and TTCR as significant predictors of OS, of which only age, ALP level and TTCR were shown to be independently associated with OS on multivariate analysis. CONCLUSION: mCSPC patients with a longer TTCR are likely to achieve a more favorable OS.