The purpose of this study was to investigate factors predicting the sensitivity to cabazitaxel therapy in metastatic castration-resistant prostate cancer (mCRPC) patients with phosphatase and tensin homolog deleted from chromosome 10 (PTEN) alterations. This single-institution, retrospective study included 12 mCRPC patients with PTEN alterations who had received cabazitaxel therapy. Five patients (41%) responded to cabazitaxel therapy with a prostate-specific antigen (PSA) level decline of ≥30% from baseline, and all of them had responded to prior docetaxel therapy with a PSA decline of ≥30%. None of the patients with a poor response to prior docetaxel therapy responded well to cabazitaxel therapy. Of the seven patients who did not respond to cabazitaxel and whose PSA declined from baseline was <30%, five (71%) were also refractory to prior docetaxel therapy. The PSA responses to docetaxel and cabazitaxel were significantly correlated (p = 0.027). Kaplan–Meier analysis revealed that progression-free survival (PFS) for cabazitaxel was significantly shorter for prior docetaxel nonresponders (3.3 versus 9.1 months, p = 0.028). Multivariate analysis revealed that a poor response to prior docetaxel (PSA decline < 30%) (hazard ratio [HR] = 6.382, 95% confidence interval [CI] 1.172–34.750, p = 0.032) and baseline PSA of ≥20 ng/ml (HR = 33.584, 95% CI 2.332–483.671, p = 0.010) were independent prognostic factors for PFS with cabazitaxel therapy. These results demonstrate cross-resistance between docetaxel and cabazitaxel. The response to prior docetaxel therapy can influence the sensitivity to cabazitaxel therapy in mCRPC patients with PTEN alterations.
- castration-resistant prostate cancer
- genetic alteration
- prostate-specific antigen response
ASJC Scopus subject areas
- Cancer Research