The Effect of Time to Castration Resistance on Overall Survival and Success of Docetaxel Treatment in Castration Resistant Prostate Cancer Patients

To investigate the prognostic role of time to castration resistance(TTCR) in patients who have received solely Docetaxel chemotherapy regimen(DCR) for castration resistant prostate cancer(CRPC).

Between Jan 2004 and Dec 2015, data of 162 patients who have received DCR for CRPC were gathered. Patients were divided into three groups according to TTCR: Group 1(≤ 12 months), group 2(13-24 months), and group 3(>24 months). Data of age, clinical stage, Gleason grade(GG), previous treatments, site of metastases, Prostate-specific antigen (PSA) values, TTCR, overall survival, biochemical progression free survival(PFS) and PSA response to docetaxel were recorded.

The mean age of the 162 patients was 74.4 ± 8.5 years. Data on mean age, type of castration, adding estramustine to docetaxel, secondary hormonal manipulation, Gleason grade, clinical T stage at initial diagnosis and site of metastases were comparable between three groups. PSA values were higher in group 1 than other groups. PSA response to docetaxel was 59.2% in all patient and it was worse in group 1 than other groups (P = .009). Two years overall survival rates were 7.6%, 25% and 32.3% in group 1, 2 and 3, respectively. Median survival rates were 7, 14 and 23 months in group 1, 2 and 3, respectively, and this difference was statistically significant (P=.016). On multivariate analysis, TTCR was found to be independent prognostic factor for overall survival and response to docetaxel treatment.