Neutropenia as a prognostic factor in advanced gastric cancer patients undergoing second-line chemotherapy with weekly paclitaxel

Background: Neutropenia during chemotherapy has been reported to be a predictor of better survival in patients with several types of cancers, although there are no reports in pretreated patients.Methods: We retrospectively analyzed 242 patients with advanced gastric cancer (AGC) who received weekly paclitaxel (Taxol) as second-line chemotherapy. Background characteristics and neutropenia as time-varying covariates (TVCs) were analyzed as prognostic factors.Results: Of the 242 patients, mild neutropenia (grades 1-2) occurred in 101 patients (41.7%) and severe neutropenia (grades 3-4) occurred in 63 patients (26.0%). The other 78 patients (32.2%) did not experience neutropenia. According to a multivariate Cox model with neutropenia as a TVC, hazard ratios of death were 0.61 [95% confidence interval (CI) 0.43-0.85; P = 0.004] for patients with mild neutropenia and 0.61 (95% CI 0.41-0.88; P = 0.009) for those with severe neutropenia. Among the patients in landmark analysis (landmark of 2.5 months; median time to treatment failure of paclitaxel), mild and severe neutropenia remained significant prognostic factors.Conclusions: Our results indicate that neutropenia during chemotherapy is associated with improved survival in patients with AGC who received weekly paclitaxel as second-line chemotherapy. Prospective trials are required to assess whether dosing adjustments based on neutropenia may improve chemotherapy efficacy.