The Impact of N2 Lymph Node Positivity on Survival Rates Among Patients Undergoing Surgery for Non-Small Cell Lung Cancer

Abstract

ABSTRACT Objective: In this study, our aim was to examine the impact of unexpected N2 and potentially resectable N2 groups, which were categorized based on the clinical approach to N2 lymph node involvement, on the survival outcomes of patients who underwent lung resection for non-small cell lung cancer. Specifically, we focused on identifying patients with ipsilateral mediastinal metastatic lymph nodes (N2) and assessing their survival rates. Material and Method: A retrospective cohort study was conducted at a single center, comprising a total of 953 patients who underwent anatomical lung resection and mediastinal lymph node dissection for non-small cell lung cancer (NSCLC) between the years 2011 and 2017. Results: Between January 2011 and December 2017, a retrospective review was conducted on 953 patients who underwent lung resection for non-small cell lung cancer (NSCLC) at our hospital. Patients were categorized into three groups: patients without initial clinical N2 involvement but with postoperative pathological N2 involvement (group 1), patients with initial clinical N2 involvement who underwent immediate surgery (group 2), and patients with initial clinical N2 involvement who demonstrated stable pathological N2 involvement or partial regression after receiving neoadjuvant chemotherapy or chemoradiotherapy and subsequently underwent surgery (group 3). A total of 71 patients (7.45% of the cohort) with postoperative pN2 were included in this study. Among these 71 patients, 41 (57.74%) did not have initial cN2 involvement and were categorized as postoperative pN2 (group 1). Twenty patients (28.16%) with a single cN2 were considered as carefully selected patients and underwent surgery (group 2). Ten patients (14.08%) were selected patients who received neoadjuvant treatment and subsequently had a single N2 involvement, and they underwent anatomical resection (group 3). Statistical analysis revealed no significant differences in survival between the three groups (p=0.882). Conclusion: No consensus currently exists regarding the role of surgery in the management of patients with NSCLC and mediastinal lymph node metastases. Existing evidence suggests that studies encompassing larger patient cohorts are necessary to comprehensively investigate the subgroups of patients with N2 disease.