Survival Outcomes For Patients With Surgery And Postoperative Radiotherapy In Stages ?-? Small-Cell Lung Cancer

Background:Lung cancer is one of the most common cause of cancer-related death worldwide.Small cell lung cancer(SCLC),which accounts for approximately 15%of all lung cancer cases,has a poor prognosis because of its very aggressive clinical course and early metastasis.Based on earlier pivotal findings,chemotherapy and radiotherapy were recommended as appropriate therapies for SCLC,and the use of surgical resection was essentially discontinued.Currently,an increasing amount of research supports the fact that surgical resection can improve survival outcomes in patients with SCLC,especially in limited-stage patients.This study was performed to evaluate the survival outcomes of surgery for stage ?-? SCLC.Methods:Data from 4,780 patients who had been diagnosed with histologically confirmed SCLC from 2004 to 2014 were extracted from the SEER database.The baseline characteristics of all subjects identified through the SEER database included age,gender,race,primary site,surgery and surgery type,postoperative radiotherapy(PORT)or not,tumor-node-metastasis(TNM)stage,grade,number of nodes,year of diagnosis,overall survival(OS)and lung cancer-specific survival(LCSS).The Pearson's chi-squared test and Fisher s exact probability tests were used to analyze differences between qualitative data of surgery and no-surgery groups.OS and LCSS were determined by Kaplan-Meier analysis and compared using the log-rank test.The proportional hazards model was used to estimate OS and LCSS hazard ratios for prognostic factors including age,gender,race,and neoplastic grade.The primary endpoint was OS and secondary endpoint was LCSS.All data were analyzed using the SPSS software package,version 20.0(IBM,SPSS Statistics,Chicago,IL,USA).Results:A total of 4,780 histologically confirmed patients were identified from the SEER database,comprising 1,018 patients(21.3%)with stage ? disease;295(6.2%)with stage ?;and 3,467(72.5%)with stage ? disease.Among all of the patients,520 had been treated with surgery,the majority(n= 344;66.2%)of whom had stage ?disease.The baseline characteristics and key prognostic factors of patients in the surgery and no-surgery groups including age,primary tumor site,radiation sequence with surgery,TNM stage,tumor grade,and number of nodes examined and positive.The hazard ratio(HR)for OS and LCSS,in patients who underwent surgery,according to stage were as follows:OS,0.369 and LCSS,0.335 in stage ?;OS,0.549 and LCSS,0.506 in stage ?;and OS,0.477 and LCSS,0.456 in stage ?(all p<0.001).The multivariate Cox analysis for OS and LCSS in stages ? to ? SCLC.Increased age(?65 years)and diagnosis at stages ? or ? were both significant risk factors for SCLC(HRs>1,all p<0.001).Surgical resection was associated with a favorable prognosis for SCLC(HRs<1,p<0.001).Patients who underwent surgery had significantly better OS,and lobectomy was associated with the best outcome.Kaplan-Meier survival analysis for OS and LCSS showed that PORT did not significantly improve survival compared to surgery alone in patients with SCLC.Conclusions:Surgical resection was associated with significantly improved OS outcomes and should be considered in the management of stage ?-? SCLC.PORT did not improve survival compared to treatment with surgery alone in patients with stages ? to ? SCLC.