No significant impact of patient age and prior treatment profile with docetaxel on the efficacy of cabazitaxel in patient with castration-resistant prostate cancer.

The correlation of the oncological outcomes of docetaxel and cabazitaxel in Japanese metastatic castration-resistant prostate cancer (mCRPC) patients has not been unclear. This study included a total of 47 consecutive Japanese mCRPC patients treated with cabazitaxel and assessed the prognostic significance of cabazitaxel, focusing on patient age and the correlation of efficacy between docetaxel and cabazitaxel. Prostate-specific antigen (PSA) decline was observed in 27 patients (57.4%), including 19 (40.0%) achieving the response defined by PSA decline ≥ 30%. The median overall survival (OS) periods after the introduction of cabazitaxel was 16.1 months. Twenty (42.6%) were judged to have responded to cabazitaxel with a PSA decrease ≥ 30% from the baseline. A 30% PSA response to cabazitaxel was achieved in 4 (50.0%) patients with ≧ 75 years (n = 8) and 16 (41.0%) patients with less than 75 years (n = 39). There was no significant correlation between the PSA response and patients' age (p = 0.707). A 30% PSA response to cabazitaxel was achieved in 13 (46.4%) and 7 (36.8%) patients with and without that to docetaxel, respectively. A 30% PSA response to cabazitaxel was achieved in 5 (16.6%) and 7 (41.2%) patients who had treated with less than 10 cycles docetaxel or 10 ≦ cycles, respectively. Univariate and multivariate analyses revealed that there were no significant correlation of patient age (p = 0.537), the response to prior docetaxel therapy (p = 0.339) or cycles of docetaxel therapy (p = 0.379) with shorter OS. These results indicate that the introduction of cabazitaxel for Japanese mCRPC patients could result in oncological outcomes without any association with patient's age and the profiles of previous docetaxel therapy.