Persistent N2 After Induction Is Not a Contraindication to Surgery for Lung Cancer

Surgical management for potentially resectable stage IIIA-N2 non-small cell lung cancer (NSCLC) is controversial. For some, persistent N2 disease after induction therapy is a contraindication to resection. We examined outcomes of a well-selected surgical cohort of postinduction IIIA-N2 NSCLC patients with persistent N2 disease.

We retrospectively reviewed all resected clinical IIIA-N2 NSCLC patients from 2001 to 2018. Thorough preoperative staging, including invasive mediastinal staging, was performed. Those with nonbulky N2 disease, appropriate restaging, and potential for a margin-negative resection were included. After resection, patients were classified as having persistent N2 disease or mediastinal downstaging (N2 to >N0/N1). Persistent N2 patients were further classified as uncertain resection (R[un]) or complete resection (R0) according to the International Association for the Study of Lung Cancer definition. Kaplan-Meier survival analysis was used.

Fifty-four patients met inclusion criteria. After induction, 31 patients (57%) demonstrated persistent N2 disease, and 23 patients (43%) had mediastinal downstaging. Preinduction invasive mediastinal staging was performed in 98.1%. Most had clinical single-station N2 disease (75.9%). Margin-negative resections were performed in 100%. Eight patients were reclassified as R(un) due to positive highest sampled mediastinal station. The median overall survival for persistent N2 was 26 months for R(un) and 69 months for R0. Overall survival for the downstaged group was 67 months (P = .31).

Overall survival for patients with non-R(un) or persistent N2 (true R0) was similar to those with mediastinal downstaging. Well-selected patients with persistent N2 disease experience reasonable survival after resection and should have surgery considered as part of their multimodality treatment. This study underscores the importance of classifying the extent of mediastinal involvement for persistent N2 patients, supporting the proposed International Association for the Study of Lung Cancer R(un) classification.