Outcomes Linked to 3N2+1N1 Sampling by Surgery Type: A Commission on Cancer Lung Cancer Quality Metric

Area of Science:

• Thoracic Surgery
• Oncology
• Surgical Pathology

Background:

• The Commission on Cancer's 2021 Standard 5.8 mandates lymph node sampling from 3 mediastinal and 1 hilar station (3N2+1N1) for curative-intent lung cancer resections.
• Prior recommendations emphasized sampling at least 10 lymph nodes.
• Optimal nodal sampling strategies, especially for sublobar resections, remain under investigation.

Purpose of the Study:

• To assess 3N2+1N1 lymph node sampling patterns in lung cancer resections.
• To evaluate the association of 3N2+1N1 sampling with recurrence and mortality based on resection type.

Main Methods:

• A multicenter retrospective study of early-stage non-small cell lung cancer (NSCLC) patients undergoing lobectomy or sublobar resection (2009-2019).
• Calculation of the proportion of patients with 3N2+1N1 sampling.
• Multivariable Cox regression analysis to assess associations with 1-year recurrence and 5-year overall mortality, stratified by resection type.

Main Results:

• Among 2096 lobectomy patients, 43% had 3N2+1N1 sampling; 23% of 386 sublobar resection patients did.
• 3N2+1N1 sampling was not significantly associated with 1-year recurrence or 5-year mortality after lobectomy.
• 3N2+1N1 sampling was associated with reduced 1-year recurrence after sublobar resection (aHR, 0.62; 95% CI, 0.39-0.98).

Conclusions:

• A minority of patients undergoing lobectomy or sublobar resection met the 3N2+1N1 sampling criteria.
• While not universally improving outcomes, the 3N2+1N1 standard may enhance lymph node evaluation quality for some lung cancer patients.