Objective   This study aimed to analyze and compare the prognosis and the prognostic factors of combined small cell lung cancer (CSCLC) and pure small cell lung cancer (PSCLC) retrospectively.

  Methods   The clinicopathological characteristics of the 343 small cell lung cancer patients who were diagnosed in Tianjin Medical University Cancer Institute and Hospital between January 2006 and December 2012 were collected and reviewed. Survival analysis was performed and prognostic factors were assessed.

  Results   The median OS (overall survival) and PFS (progression free survival) of CSCLC were 31 and 21 months, respectively, and the median OS and PFS of PSCLC were 15 and 9 months, respectively. The Kaplan–Meier survival curves revealed that the prognosis of CSCLC was significantly better compared with that of PSCLC. COX analysis showed that disease stage, pathology, and therapy were independent prognostic factors of small cell lung cancer. Univariate analysis indicated that the small cell lung cancer group benefited from the surgery, particularly the CSCLC. NLR, therapy, and disease stage influenced the prognosis of PSCLC, and disease stage and therapy influenced the prognosis of CSCLC. Multivariate analysis revealed that disease stage and therapy were independent risk factors of CSCLC in regard to OS.

  Conclusions   The prognosis of CSCLC was better compared with that of PSCLC. Limited-stage small cell lung cancer should undergo surgery, particularly the CSCLC.