Objective  Leukopenia is a common side effect of chemotherapy,which is the standard treatment for small-cell lung cancer(SCLC).This study determines whether chemotherapy-induced leukopenia could be a predictor of the curative effect and be associated with the survival of SCLC patients.

  Methods  Data from 445 SCLC patients who underwent standard chemotherapy from 4 to 10 cycles were retrospectively analyzed.Leukopenia during chemotherapy was graded according to the following classification by the World Health Organization: without(grade 0),mild(grades 1 and 2),and severe leukopenia(grades 3 and 4).The endpoint of the main study was the overall survival(OS).

  Results  Chemotherapy-induced leukopenia and OS time were found to be correlated.According to a multivariate Cox model with time-varying covariates,the hazard ratio of death was 0.687(from 0.506 to 0.943) and 0.901(from 0.669 to 1.214) for patients with mild and severe leukopenia,respectively.The median survival was 13 months for patients without leucopenia.By contrast,patients with mild and severe leukopenia had median survival of 17 and 14 months,respectively(P=0.047).

  Conclusion  s Leukopenia during chemotherapy is associated with the survival of the SCLC patients.Mild leukopenia is strongly associated with a longer survival time.