Risk Factors for Poor Survival in Metastatic Castration-resistant Prostate Cancer Treated With Cabazitaxel in Japan.

Objective: Cabazitaxel (CBZ) is approved for docetaxel-resistant castration-resistant prostate cancer (CRPC). This retrospective study aimed at assessing the efficacy and prognostic markers of cabazitaxel treatment in Japanese CRPC patients.

Methods: The medical records of 44 consecutive Japanese patients with CRPC who started cabazitaxel at our Institution between January 2011 and February 2019 were reviewed and statistically analysed.

Results: The median follow-up period after cabazitaxel initiation was 13.2 [interquartile range (IQR)=6.9-21.5] months. The objective response rate, median progression-free survival period, and median overall survival period (OS) were 45.5%, 4.3 months, and 20.7 months, respectively. On multivariate analysis, higher prostate-specific antigen (PSA; >100 ng/ml), lower haemoglobin (<10 g/dl), and lower number of prior docetaxel therapy cycles (<10) were predictors for shorter OS.

Conclusions: Patients with anemia, high PSA, and lower number of docetaxel therapy cycles might have shorter survival period from introduction of cabazitaxel therapy. In addition, PSA decline might still be a useful indicator as a predictor of prognosis of the metastatic CRPC patients treated with cabazitaxel.