title: Further understanding of an uncommon disease of combined small cell lung cancer: clinical features and prognostic factors of 114 cases.
abstract: 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.
authors.affiliation: Department of Radiation Oncology.
authors.forename: Yu
authors.initials: Y
authors.lastname: Men
authors.affiliation: Department of Special Medical Services & Department of Radiation Oncology, National Cancer Center/Cancer Institute & Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100021, China.
authors.forename: Zhouguang
authors.initials: Z
authors.lastname: Hui
authors.affiliation: Department of Radiation Oncology.
authors.forename: Jun
authors.initials: J
authors.lastname: Liang
authors.affiliation: Department of Radiation Oncology.
authors.forename: Qinfu
authors.initials: Q
authors.lastname: Feng
authors.affiliation: Department of Radiation Oncology.
authors.forename: Dongfu
authors.initials: D
authors.lastname: Chen
authors.affiliation: Department of Radiation Oncology.
authors.forename: Hongxing
authors.initials: H
authors.lastname: Zhang
authors.affiliation: Department of Radiation Oncology.
authors.forename: Zefen
authors.initials: Z
authors.lastname: Xiao
authors.affiliation: Department of Radiation Oncology.
authors.forename: Zongmei
authors.initials: Z
authors.lastname: Zhou
authors.affiliation: Department of Radiation Oncology.
authors.forename: Weibo
authors.initials: W
authors.lastname: Yin
authors.affiliation: Department of Radiation Oncology.
authors.forename: Luhua
authors.initials: L
authors.lastname: Wang
keywords: Combined small cell lung carcinoma; diagnosis; multimodality therapy; prognosis