A nomogram with lymph node status predicts survival and the benefit of postoperative  adjuvant therapy 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 various postoperative adjuvant treatments (POAT) 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 POAT was evaluated 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. The prognosis of patients receiving POAT (POCT or PORT plus POCT) and patients receiving surgery alone was comparable in low-risk group, while POCT could significantly prolong survival for IIIA-N2 NSCLC patients after surgery in moderate-risk and high-risk groups. Only patients in high-risk group could benefit from the combination of postoperative radiotherapy (PORT) and postoperative chemotherapy (POCT).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. Surgery alone was recommended as the first choice of treatment to patients in low-risk group. POCT was recommended for patients in moderate-risk group, and the combination of PORT and POCT was recommended for patients in high-risk group. This study may provide additional integration, introspection, and improvement for therapeutic decision-making.