Clinical Outcomes And Prognostic Factors In Limited-stage Small Cell Lung Cancer Patients Treated With Intensive Modified Radiotherapy

Purpose:To investigate the clinical efficacy and prognosis of intensity-modulated radiotherapy(IMRT)combined with chemotherapy for limited-stage small cell lung cancer(LS-SCLC).Methods:A retrospective analysis was performed on the clinical data of 484 LS-SCLC patients treated with chemotherapy and IMRT in Cancer Hospital of Chinese Academy of Medical Sciences from August 2006 to May 2014 All patients were primarily managed with concurrent or sequential chemoradiotherapy,followed by prophylactic cranial irradiation(PCI)in patients with complete or partial response.IMRT was adopted in all patients.The Kaplan-Meier method was used for survival analysis,and log-rank test and Cox regression were used for univariate and multivariate analysis of prognostic factors.Results:Follow-up rate was 93%for all patients.The median overall survival time(MST)was 23.8 months;the 2-,3-,and 5-year overall survival(OS)rates were 48.7%,39.8%,and 28.6%,respectively.The median progression-free survival(PFS)time was 14.1months;the 2-,3-,and 5-year PFS were 34.4%,30.5%,and 28.3%,respectively.The acute toxicity after chemotherapy and thoracic IMRT was tolerable.The incidence rates of grade ≥3 bone marrow suppression,grade ≥2 radiation esophagitis,and grade ≥2 radiation pneumonitis were 26.9%,24.8%,and 18.4%,respectively.The rates of CR,PR,SD,PD after thoracic radiation were 15.5%,69.0%,5.6%,7.0%,respectively.Response information of 14 patients were lost and objective response rate was 84.5%.The univariate analysis showed that age,smoking history,TNM stage,PCI and the number of induction chemotherapy cycles were significant prognostic factors for OS of LS-SCLC(P=0.006,0.001,0.047,<0.001,0.046).The multivariate analysis showed that smoking history and PCI were independent factors affecting the prognosis for the LS-SCLC patients(P=0.001,<0.001).Conclusions:IMRT combined with chemotherapy achieves satisfactory clinical outcomes in the treatment of LS-SCLC.Smoking history and PCI are independent prognostic factors for OS of LS-SCLC patients.