Reclassifying the International Association for the Study of Lung Cancer Residual Tumor Classification According to the Extent of Nodal Dissection for NSCLC: One Size Does Not Fit All

J Thorac Oncol. 2022 Jul;17(7):890-899. doi: 10.1016/j.jtho.2022.03.015. Epub 2022 Apr 21.

Abstract

Introduction: The extent of nodal assessment may require risk-based adjustments in NSCLC. We reclassified the International Association for the Study of Lung Cancer Residual tumor classification according to the extent of nodal dissection and evaluated its long-term prognosis by tumor stage and histologic subtype.

Methods: We reclassified 5117 patients who underwent resection for clinical stages I to III NSCLC and had complete or uncertain resection by International Association for the Study of Lung Cancer classification into the following 3 groups according to compliance with three components (N1, N2, and subcarinal node) of systematic nodal dissection criteria: fully compliant group (FCG), partially compliant group (PCG), and noncompliant group (NCG). Recurrence-free survival (RFS) and overall survival (OS) were compared.

Results: Of the 5117 patients, 2806 (55%), 1959 (38%), and 359 (7%) were FCG, PCG, and NCG, respectively. PCG and NCG were more likely to be of lower clinical stage and adenocarcinoma with lepidic component than FCG. The 5-year RFS and OS were significantly better in NCG than in FCG or PCG (RFS, 86% versus 70% or 74%, p < 0.001; OS, 90% versus 80% or 83%, p < 0.001). In particular, NCG had better RFS and OS than FCG or PCG in clinical stage I and in lepidic-type adenocarcinoma.

Conclusions: In early stage NSCLC with low-risk histologic subtype, a less rigorous nodal assessment was not associated with a worse prognosis. Although surgeons should continue to aim for complete resection and thorough nodal assessment, a uniform approach to the extent and invasiveness of nodal assessment may need to be reconsidered.

Keywords: Inadequate nodal assessment; Non–small cell lung cancer; Residual tumor; Systematic nodal dissection; Uncertain resection.

MeSH terms

  • Adenocarcinoma* / pathology
  • Adenocarcinoma* / surgery
  • Carcinoma, Non-Small-Cell Lung* / pathology
  • Humans
  • Lung Neoplasms* / pathology
  • Neoplasm Staging
  • Neoplasm, Residual / pathology
  • Prognosis
  • Retrospective Studies