Cancer Res Treat.  2025 Jan;57(1):95-104. 10.4143/crt.2024.120.

Differences in the Prognostic Impact between Single-Zone and Multi-Zone N2 Node Metastasis in Patients with Station-Based Multiple N2 Non–Small Cell Lung Cancer

• Kim S
• Lee GD
• Choi S
• Kim HR
• Kim YH
• Kim DK
• Park SI
• Yun JK

• KMID: 2564584
• DOI: http://doi.org/10.4143/crt.2024.120

Abstract

Purpose
The International Association for the Study of Lung Cancer suggests further subdivision of pathologic N (pN) category in non–small-cell lung cancer (NSCLC) by incorporating the location and number of involved lymph node (LN) stations. We reclassified patients with the station-based N2b disease into single-zone and multi-zone N2b groups and compared survival outcomes between the groups.
Materials and Methods
This retrospective study included patients with pN2 NSCLC who underwent lobectomy from 2006 to 2019. The N2 disease was subdivided into four categories: single-station N2 without N1 (N2a1), single-station N2 with N1 (N2a2), multiple-station N2 with single zone involvement (single-zone N2b), and multiple-station N2 with multiple zone involvement (multi-zone N2b). LN zones included in the subdivision of N2 disease were upper mediastinal, lower mediastinal, aortopulmonary, and subcarinal.
Results
Among 996 eligible patients, 211 (21.2%), 394 (39.6%), and 391 (39.3%) were confirmed to have pN2a1, pN2a2, and pN2b disease, respectively. In multivariable analysis after adjustment for sex, age, pT category, and adjuvant chemotherapy, overall survival was significantly better with single-zone N2b disease (n=125, 12.6%) than with multi-zone N2b disease (n=266, 26.7%) (hazard ratio [HR], 0.67; 95% confidence interval [CI], 0.49 to 0.90; p=0.009) and was comparable to that of N2a2 disease (HR, 1.12; 95% CI, 0.83 to 1.49; p=0.46).
Conclusion
Prognosis of single-zone LN metastasis was better than that of multiple-zone LN metastasis in patients with N2b NSCLC. Along with the station-based N descriptors, zone-based descriptors might ensure optimal staging, enabling the most appropriate decision-making on adjuvant therapy for patients with pN2 NSCLC.

Keyword

Lung neoplasms; Staging; Non-small-cell lung carcinoma; N descriptors; Lymph node; Metastasis

Figure

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  Fig. 1. Kaplan-Meier estimates of overall survival (A) and freedom from recurrence (B) in patients with pathologic N2 subdivided into N2a1, N2a2, multi-zone N2b, and single-zone N2b. CI, confidence interval; MST, median survival time.

• 

  Fig. 2. Multivariate Cox proportional hazards regression adjusted for age, sex, bovine serum albumin, and adjuvant therapy in patients with pathologic N2 subdivided N2a1, N2a2, multi-zone N2b, and single-zone N2b. (A) N2a1 vs. N2a2. (B) N2a1 vs. single-zone N2b. (C) N2a1 vs. multi-zone N2b. (D) N2a2 vs. single-zone N2b. (E) N2a2 vs. multi-zone N2b. (F) Single-zone N2b vs. multi-zone N2b. CI, confidence interval; HR, hazard ratio.

Reference

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