Prognostic Value of Single Nodal Zone Metastasis in Non-Small-Cell Lung Cancer-A Multi-Institutional Study

Objectives: Lung cancer is the leading cause of cancer-related deaths worldwide and mediastinal lymph node involvement is an important negative prognostic factor. Nevertheless, the involvement of a single mediastinal nodal zone has been reported to have favorable outcomes. This study aims to assess whether the prognosis of non-small-cell lung cancer (NSCLC) with single-zone lymph node involvement varies by the affected lymph node zone. Methods: We retrospectively analyzed patients affected by NSCLC with a single lymph node zone involvement who underwent anatomical resection. The prognosis of patients was statistically compared based on the different affected lymph node zones. Results: A total of 135 patients were enrolled. All patients underwent anatomical lung resection and systematic lymph node dissection. Lymph node involvement was observed in 50 cases (37%) for the upper zone, 36 cases (27%) for the aorto-pulmonary (AP) zone, 41 cases (30%) for the subcarinal zone and 8 cases (6%) for the lower zone. The median follow-up was 37 months [ranging from 1 to 115 months]. Cancer recurrence was reported in 64 cases (52%) during this period. The 2-year and 4-year overall survival (OS) were 69% and 49%, respectively. The 2-year and 4-year relapse-free survival (RFS) were 55% and 41%. The OS and RFS change relating to the different involved lymph node zones (p < 0.01). Lower zone involvement predicts worse prognosis, upper zone and subcarinal zone better outcomes, and the AP zone involvement intermediate survival. Conclusions: The location of the affected lymph nodes appears to be an important prognostic factor in patients with NSCLC, with significant impacts on both OS and RFS. It may play a key role in the disease progression and patient survival by providing more personalized therapy.