The purpose of this study is to evaluate the relationship between extracapsular extension (ECE) and clinicopathology, and its influence on the prognosis in non-small cell lung cancer (NSCLC) patients. Clinical data from 388 stage IIA-IIIA NSCLC patients who underwent curative resection and confirmed ECE positive were reviewed. The Fisher's exact or Chi-square test was used to analyze the associations between ECE and the clinical pathology. The log-rank test and Cox regression model were used to evaluate the factors influencing disease-free survival (DFS) and overall survival (OS). ECE was detected in 85 (21.9%) patients, and it had a significant correlation with advanced T stage, pathological stage and histologic type of adenocarcinoma. For the whole population, the median OS was 39.0 months, and the 5-year OS rate was 33.9%. In multivariate analysis, both ECE status and postoperative chemotherapy were significant factors for OS. The median DFS for all patients was 26.0 months, and the 5-year DFS rate was 21.7%. In multivariate analysis, pathologic stage, ECE, and postoperative chemotherapy were the independent predictor factors for DFS. Further analysis found that the locoregional recurrence-free survival and the distant recurrence-free survival rates in ECE negative group were also significantly higher than in the ECE positive group. For NSCLC patients with lymph node metastasis, the presence of ECE occurs more frequently in advanced stage and histologic type of adenocarcinoma and it may be a powerful prognostic factor which reflects the aggressive biological behavior.
Keywords: Non-small cell lung cancer; extracapsular extension; prognosis; surgery.