RESUMEN
Objective: To evaluate the effect of depth of remission of induction chemotherapy on the overall prognosis of limited stage small cell lung cancer (L-SCLC). Methods: The study was a retrospective, L-SCLC patients who contained complete imaging data and underwent consecutive standardized treatments at the Department of Thoracic Radiation and Medical Oncology, Zhongnan Hospital of Wuhan University between January 2013 and June 2021 were included. To delineate the volume of tumor before and after induction chemotherapy and to calculate the depth of remission caused by the induced chemotherapy. The time receiver operating characteristic (timeROC) method was used to determine the optimal predictors for prognosis, multi-factor analysis using Cox risk proportional model. Results: A total of 104 patients were included in this study. The median PFS and OS of this cohort were 13.7 months and 20.9 months, respectively. It was observed by timeROC analysis that residual tumor volume after induction chemotherapy had the optimal predictive value of PFS at 1 year (AUC=0.86, 95% CI: 0.78~0.94) and OS at 2 years (AUC=0.76, 95% CI: 0.65~0.87). Multivariate analysis showed residual tumor volume after induction chemotherapy was the independent prognostic factor to PFS (HR=1.006, 95% CI: 1.003~1.009, P<0.01) and OS (HR=1.009, 95% CI: 1.005~1.012, P<0.001). For those whose residual tumor volume remitted to less than 10 cm(3) after induction chemotherapy, the favorable long-term outcomes could be achieved, regardless of their initial tumor load. Conclusion: The depth of remission of induction chemotherapy could be a promising prognostic predictor to the L-SCLC and provide the individualized treatment guidance.