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

In 2021, the Commission on Cancer implemented Standard 5.8 requiring lymph node sampling from ≥3 mediastinal and ≥1 hilar stations (3N2+1N1) during curative-intent lung cancer resections. Before Standard 5.8, sampling ≥10 lymph nodes was recommended. To date, the optimal nodal sampling strategy is still unknown, particularly for sublobar resections. We assessed 3N2+1N1 sampling patterns and potential associations with recurrence and mortality by resection type.

In this multicenter retrospective study, we evaluated early-stage non-small cell lung cancer (NSCLC) patients who underwent lobectomy or sublobar resection (2009-2019). We calculated the proportion with 3N2+1N1 sampled. Using multivariable Cox regression, we assessed associations of 3N2+1N1 sampling with 1-year recurrence and 5-year overall mortality, stratified by lobectomy vs sublobar resection.

Among 2096 lobectomy patients, 43% had 3N2+1N1 sampling. In contrast, among 386 sublobar resection patients, 23% had 3N2+1N1. We found 3N2+1N1 sampling was not significantly associated with 1-year recurrence or 5-year mortality after lobectomy, but was associated with reduced 1-year recurrence (adjusted hazard ratio, 0.62; 95% CI, 0.39-0.98) after sublobar resection.

A minority of lobectomy and sublobar resection patients had 3N2+1N1 sampling. Although 3N2+1N1 sampling was not associated with improvements across all outcomes, our findings suggest that Standard 5.8 may be a meaningful step toward improved quality of lymph node evaluations in some patients.