Risk Prediction for Locoregional Recurrence in Epidermal Growth Factor Receptor-Mutant Stage III-pN2 Lung Adenocarcinoma after Complete Resection: A Multi-center Retrospective Study.

Abstract

Background: This study aimed to develop a predictive model based on the risk of locoregional recurrence (LRR) in epidermal growth factor receptor (EGFR)-mutant stage III-pN2 lung adenocarcinoma after complete resection. Methods: A total of 11,020 patients with lung surgery were screened to determine completely resected EGFR-mutant stage III-pN2 lung adenocarcinoma. Patients were excluded if they received preoperative therapy or postoperative radiation therapy (PORT). The time from surgery to LRR was recorded. Clinicopathological variables with statistical significance predicting LRR in the multivariate Cox regression were incorporated into the competing risk nomogram. Patients were then sub-grouped based on different recurrence risk as a result of the nomogram. Results: Two hundred and eighty-eight patients were enrolled, including 191 (66.3%) with unforeseen N2 (IIIA1-2), 75 (26.0%) with minimal/single station N2 (IIIA3), and 22 (7.6%) with bulky and/or multilevel N2 (IIIA4). The 2-year overall cumulative incidence of LRR was 27.2% (confidence interval [CI], 16.3%-38.0%). IIIA4 disease (hazard ratio, 2.65; CI, 1.15-6.07; P=0.022) and extranodal extension (hazard ratio, 3.33; CI, 1.76-6.30; P