Survival of patients with unsuspected pN2 non-small cell lung cancer after an accurate preoperative mediastinal staging

Abstract

Background: The aim of this study is to analyze the survival of patients with non-small cell lung cancer (NSCLC) without clinical suspicion of mediastinal lymph node involvement who underwent complete resection and whose tumors were finally proven to be pathologic N2 (pN2).

Methods: This is a retrospective study of a prospective database from January 2004 to December 2010. A total of 621 patients with NSCLC were staged and operated according to the European Society of Thoracic Surgeons guidelines. After exclusions (previous induction treatment, carcinoid tumors, small cell carcinomas), 540 patients were analyzed; 406 (75%) required surgical exploration of the mediastinum and 134 (25%) underwent surgery directly. Survival analysis was performed by the Kaplan-Meier method and the log-rank test was used for comparisons.

Results: Thirty (5.5%) patients had unsuspected pN2 and complete resection was achieved in 27 (90%). Three- and 5-year survival rates were 87% and 81%, respectively, for patients with a true negative result of the protocol (pN0-1), and 79% and 40%, respectively, for those with a false negative result (unsuspected pN2) (p < 0.0001).

Conclusions: The rate of unsuspected pN2 in patients whose tumors were staged according to the European Society of Thoracic Surgeons guidelines was low. The survival of this group of patients was better than expected. Therefore, resection of properly staged unsuspected pN2 NSCLC is reasonable and should not be avoided if complete resection can be achieved.