Objective: Combined small cell lung cancer(C-SCLC) is an uncommon subgroup of small cell lung cancer(SCLC) and few clinical data can be referred.Our study is to investigate the clinical features and prognostic factors of C-SCLC, as well as the role of multimodality treatment.Methods: Between January 2004 and December 2012, patients with histologically diagnosed C-SCLC were retrospectively analyzed.The survivals were evaluated with the Kaplan-Meier method.Univariate and multivariate analyses were used to evaluate potential prognostic factors.Results: One hundred and fourteen patients were enrolled, with a median age of 59(range: 20-79) years old.The most common combined component was squamous cell carcinoma(52.6%).Among these patients, the disease was stage Ⅰ, Ⅱ, Ⅲ and Ⅳ in 9.6%, 19.3%, 46.5% and 24.6% of the patients, respectively.Eighty patients(70.2%)received at least two of the three modalities containing chemotherapy, radiotherapy and surgery.The median follow-up was 32.5 months.The median time of overall survival(OS) was 26.2 months.On univariate analysis,smoking(P=0.029), Karnofsky performance score(KPS) <80(P=0.000), advanced TNM stage(P=0.000), no surgery(P=0.010), positive resection margin(P=0.000), positive lymph nodes ≥4(P=0.000), positive lymph node ratio >10%(P=0.000) and non-multimodality treatment(P=0.004) were associated with poor OS.Multivariate analysis confirmed that smoking, advanced TNM stage, positive resection margin and positive lymph nodes ratio>10% were poor prognostic features.Conclusions: C-SCLC has a relatively early stage and good prognosis, which may due to the underestimated diagnosis in non-surgical patients.Multimodality therapy is recommended, especially for limited disease.Smoking,advanced TNM stage, positive resection margin and positive lymph nodes ratio >10% are poor prognostic factors. Objective: Combined small cell lung cancer (C-SCLC) is an uncommon subgroup of small cell lung cancer (SCLC) and few clinical data can be referred. Our study is to investigate the clinical features and prognostic factors of C-SCLC, as well as the role of multimodality treatment. Methods: Patients with histologically diagnosed C-SCLC were retrospectively analyzed. survivals were evaluated with the Kaplan-Meier method. Univariate and multivariate analyzes were used to evaluate potential prognostic factors. Results: One hundred and fourteen patients were enrolled with a median age of 59 (range: 20-79) years old. The most common combined components were squamous cell carcinoma (52.6%). Among these patients, the disease was stage I, Ⅱ, Ⅲ and Ⅳ in 9.6%, 19.3%, 46.5% and 24.6% of the patients, respectively. Lighty patients (70.2%) received at least two of the three modalities containing chemotherapy, radiotherapy and surgery.The median follow-up was 32.5 m (P = .029), Karnofsky performance score (KPS) <80 (P = .000), advanced TNM stage (P = .000), no (P = 0.010), positive resection margin (P = 0.000), positive lymph nodes ≧ 4 (P = 0.000), positive lymph node ratio> 10% (P = 0.000) and non-multimodality treatment associated with poor OS. Multivariate analysis confirmed that smoking, advanced TNM stage, positive resection margin and positive lymph node ratio> 10% were poor prognostic features. Conclusions: C-SCLC has a relatively early stage and good prognosis, which may due to the underestimated diagnosis in non-surgical patients. Multimodality therapy is recommended, especially for limited disease. moking, advanced TNM stage, positive resection margin and positive lymph node ratio> 10% are poor prognostic factors.