Carboplatin plus paclitaxel therapy after docetaxel in men with metastatic castrate resistant prostate cancer

Abstract 

Objectives

Docetaxel is considered first-line chemotherapy for patients with metastatic castrate resistant prostate cancer (CRPC). Carboplatin and paclitaxel have demonstrated activity in CRPC but published data are limited regarding use after docetaxel.

Methods

A retrospective, bi-institutional review was conducted of patients with advanced CRPC treated with carboplatin plus paclitaxel after docetaxel. Therapy was evaluated for tolerability, response, and survival. Endpoints used modified Prostate Cancer Working Group 2 criteria.

Results

Twenty-five patients were identified from February 2000 to March 2008. Median pretreatment PSA was 130.2 ng/ml [range 0.1–2100]. Sites of metastases included bone (88%), lymph nodes (52%), pelvis (32%), lung (28%), and liver (20%). A median 4.5 cycles of docetaxel [range 1–22] were given with a median progression-free survival (PFS) of 12 weeks [range 2–68]. Eighty-eight percent of patients (22/25) were docetaxel-refractory at the initiation of therapy with carboplatin (AUC 4–6) day 1 plus paclitaxel 60–80 mg/m² days 1, 8, and 21 recycled every 28 days. Patients received a median of 3.5 cycles [range 1–8] of carboplatin/paclitaxel with a median PFS of 12 weeks [range 2–35]. Sixty-four percent of patients (16/25) achieved ≥30% reduction in PSA with a median overall survival of 42 weeks [95% CI 30.6–53.5 weeks]. Grade 3 or 4 adverse hematologic events occurred in 11/25 (44%) patients, with no neutropenic fever or grade 3/4 non-hematologic toxicity.

Conclusion

Carboplatin/paclitaxel chemotherapy following docetaxel in metastatic CRPC is well tolerated with favorable PSA response rates and survival. This combination is a viable option after progression on docetaxel-based therapy.

Keywords: Prostate cancer, Docetaxel, Carboplatin, Paclitaxel, Metastatic, Castrate resistant, Chemotherapy