Long-term survival data of patients with limited disease small cell lung cancer: a retrospective analysis

Introduction: In patients with limited disease small cell lung cancer (LD-SCLC) treated with concurrent chemoradiotherapy (CCRT), long-term survival data have not been fully evaluated. Moreover, the association between long-term prognosis and prognostic factors has not been sufficiently investigated. Methods: In this retrospective study, we evaluated the efficacy of CCRT in 120 patients with LD-SCLC with a plan for curative CRT using concurrent accelerated hyperfractionated radiotherapy. Results: The patients had a median age of 65.5 years, predominantly male (73%), and had clinical stage III disease (80%). The median follow-up time for overall survival (OS) was 72.2 months, median OS was 42.5 months, and the 3-year and 5-year survival rates were 52.4% and 41.8%, respectively. The median progression-free survival (PFS) was 12.5 months, and the 3-year and 5-year PFS rates were 37.6% and 33.6%, respectively. The 5-year OS rates of patients who achieved PFS at each time point were 70.9%, 83.6%, and 91.9% at 12, 24, and 36 months, respectively. The gradual increase in the 5-year OS rate following PFS extension and initial depression of the Kaplan-Meier curve showed disease progression frequently occurred in the first 2 years after initiation of CCRT. The Cox proportional hazards model showed no significant factors correlated with long-term survival through univariate and multivariate analyses. Although the prognostic factors associated with long-term prognosis in LD-SCLC were not identified, the 5-year survival rate was 41.8%, and among patients without disease progression at 2 years, the 5-year survival rate was 83.6%. Conclusion: These data suggested that the prognosis of patients with LD-SCLC was improving.