A Nomogram with Lymph Node Status Predicts Survival and the Benefit of Postoperative Radiotherapy in IIIA-N2 Non-small Cell Lung Cancer Patients after Surgery

Abstract

Objective: This study aimed at establishing a novel nomogram predicting overall survival and investigating the survival benefit of postoperative radiotherapy in IIIA-N2 Non-small cell lung cancer (NSCLC) patients after surgery.Methods: Data of IIIA-N2 NSCLC patients between 2004 and 2016 were collected from the Surveillance, Epidemiology, and End Results (SEER). Patients were excluded if the information regarding follow-up time and clinicopathological features were incomplete. Through Univariate and multivariate analyses, independent prognostic factors were identified and integrated into the construction of nomogram. The survival benefit of PORT was investigated in model-defined low-risk, intermediate-risk, and high-risk subgroups, respectively.Results: In total, 4389 patients were finally included for analysis. Patients’ age, sex, T stage, differentiation grade, examined lymph nodes number (ELN), metastatic lymph nodes number (MLN), and metastatic lymph nodes ratio (LNR) were identified as independent prognostic factors and were integrated into the construction of nomogram. The C-index and calibration curves indicated that the predictive performance of the nomogram was satisfactory. Patients were then categorized into three prognostic groups with the increasing risk of all-cause of death. Only patients in high-risk group could benefit from PORT.Conclusion: In this large-cohort retrospective study, A survival-predicting nomogram and risk stratification model were established to estimate prognosis in IIIA-N2 NSCLC patients. PORT was recommended for those patients in high-risk group. This study may provide additional integration, introspection, and improvement for therapeutic decision-making.