Prognostic Factors for Resected Non-Small Cell Lung Cancer with pN2 Status: Implications for Use of Postoperative Radiotherapy

Background. For non-small cell lung cancer (NSCLC) patients with pN2 status, the use of postoperative radiotherapy (PORT) remains controversial. Here, we investigated the association between different clinicopathological features and postoperative therapy and local control and survival in patients with resected pN2 NSCLC. Methods. We retrospectively analyzed 83 patients with pN2 NSCLC who underwent resection at Vanderbilt University Medical Center between 1994 and 2004. The relationship between 10 prognostic factors-gender, age at diagnosis, histology, tumor size, number of nodal stations involved, positive node number, surgical margin, extracapsular extension (ECE), and use of postoperative chemotherapy and PORT-and 2-year local recurrence-free survival (LRFS), distant recurrence-free survival (DRFS), recurrence-free survival (RFS), and overall survival (OS) rates was evaluated. Univariate and multivariate analyses were conducted using the Kaplan-Meier method and Cox proportional hazards ratios, respectively. Results. On univariate analysis, PORT was significantly associated with greater LRFS, RFS, and OS rates, whereas chemotherapy was associated with a trend toward a higher OS rate. Negative surgical margins were predictive of a higher OS rate, and negative ECE was associated with higher LRFS and RFS rates. On multivariate analysis, only PORT and negative ECE were associated with a higher LRFS rate. On subgroup analysis, in negative ECE patients, PORT was significantly associated with a higher OS rate. Conclusions. PORT is associated with a higher OS rate for patients with resected pN2 NSCLC with negative ECE but not with positive ECE. The absence of ECE may serve as a useful prognostic variable in the selection of pN2 NSCLC patients for PORT and warrants further investigation in randomized clinical trials. The Oncologist 2009;14:1106-1115