Chemotherapy-Induced Neutropenia and Outcome in Patients With Metastatic Castration-Resistant Prostate Cancer Treated With First-Line Docetaxel

The aim of the study was to retrospectively investigate the association between chemotherapy-induced neutropenia and survival in metastatic castration-resistant prostate cancer (mCRPC) patients receiving first-line docetaxel treatment. Docetaxel-induced neutropenia is associated with better overall and progression-free survival in mCRPC. These findings support the hypothesis that chemotherapy-induced neutropenia might be a surrogate indicator of the biological activity of chemotherapy in patients with mCRPC. Neutropenia is a common side effect associated with docetaxel use. We retrospectively investigated the association between chemotherapy-induced neutropenia and survival in metastatic castration-resistant prostate cancer (mCRPC) patients receiving first-line docetaxel. Metastatic castration-resistant prostate cancer patients treated with first-line docetaxel, with known neutrophils value 10 days after first administration, were included in this retrospective analysis. Neutropenia was categorized in Grade 0 to 1 (G0-1), Grade 2 to 3 (G2-3), and Grade 4 (G4). Outcome measures were progression-free survival (PFS) and overall survival (OS). Eighty patients were analyzed. Median PFS was 5.4 months in patients with G0-1 neutropenia, 6.9 months with G2-3 neutropenia (hazard ratio [HR] vs. G0-1, 0.69; 95% confidence interval [CI], 0.35-1.35; P = .27) and 9.5 months with G4 neutropenia (HR vs. G0-1, 0.30; 95% CI, 0.16-0.57; P < .0001). Median OS was 11.6 months in patients with G0-1 neutropenia, 25.5 months in patients with G2-3 neutropenia (HR vs. G0-1, 0.36; 95% CI, 0.16-0.80; P = .012) and 39.3 months in patients with G4 neutropenia (HR vs. G0-1, 0.19; 95% CI, 0.09-0.41; P