The International Association for the Study of Lung Cancer Staging Project for Lung Cancer: Proposals for the...

Area of Science:

• Oncology
• Medical Diagnostics
• Cancer Staging

Background:

• Non-small cell lung cancer (NSCLC) staging relies on the TNM classification.
• The M component of TNM classification requires refinement for improved accuracy.
• Current M categories may not fully capture prognostic differences in advanced NSCLC.

Purpose of the Study:

• To analyze metastatic categories in NSCLC for proposed modifications to the TNM classification's M component.
• To enhance the prognostic accuracy of NSCLC staging for the upcoming ninth edition.
• To evaluate the prognostic impact of metastatic lesion burden and organ involvement.

Main Methods:

• Analysis of a large database (124,581 patients, 2011-2019) focusing on advanced NSCLC (stages IVA-IVB).
• Utilized Kaplan-Meier method for overall survival analysis.
• Employed multivariable-adjusted Cox proportional hazards regression to assess prognosis.

Main Results:

• The eighth edition M categories showed good discrimination in the analyzed dataset.
• Increasing number of metastatic lesions correlated with decreasing prognosis, but a specific number was not suitable for staging.
• Involvement of multiple extrathoracic organ systems significantly worsened prognosis compared to single organ involvement.
• M1c patients with single extrathoracic organ metastasis were prognostically distinct from those with multiple extrathoracic organ involvement.

Conclusions:

• The M1a and M1b categories of the eighth edition TNM classification are validated and recommended for continuation.
• A proposal is made to subdivide the M1c category into M1c1 (single extrathoracic organ system) and M1c2 (multiple extrathoracic organ systems).
• This subdivision aims to provide more precise prognostic stratification for advanced NSCLC patients.