['Platinum doublets are standard chemotherapy for advanced non-small-cell lung cancer (NSCLC). The aim of this study was to assess whether neutropenia is: (1) an indicator for treatment efficacy, or (2) associated with specific polymorphisms.', 'Four hundred ninety-four patients, treated with cisplatin-docetaxel were retrospectively analyzed. Relative dose intensity (RDI) was assessed for both drugs. Neutrophil counts were assessed only on Day 21 of each cycle. Genotyping was performed for 4 different polymorphisms in ERCC1, XRCC3, XPD-23, and XPD-10.', 'The median overall survival was 9 months. The mean RDI was 0.94 for cisplatin and 0.93 for docetaxel. Four hundred three patients received ≥ 3 cycles of chemotherapy, and 239 received ≥ 6 cycles. Thirty-one percent developed neutropenia, and 19% had Grade (G)3-4 neutropenia. RDI was lower in patients with neutropenia (G1-4; 0.87-0.93) when compared with those without (G0; 0.94-0.95; P < .02). Male patients (P = .02) had inferior survival when compared with female patients, and ECOG (Eastern Cooperative Oncology Group) 1-2 patients (P < .001) had worse survival when compared with ECOG 0. There was no significant survival difference with respect to Grade of neutropenia (G0, 8.7 vs. G1-2, 11.6 vs. G3-4, 9.6 months; P = .41). In ECOG 0 patients, survival was significantly better for neutropenic G1-4 (hazard ratio [HR], 0.55; 95% confidence interval [CI], 0.31-0.96; P = .034) when compared with non-neutropenic (G0) patients. No association was observed between examined polymorphisms and neutropenia.'] Does chemotherapy-induced neutropenia correlate with DNA repair gene polymorphisms and treatment efficacy in advanced non-small-cell lung cancer patients?