Impact of Pulmonary Resection Extent on Nodal Upstaging in Clinical Stage IA1-2 NSCLC: Real-World Evidence of Low Detection Rates with Sublobar Resections.

[OBJECTIVE] Identification of regional lymph node involvement has an impact on prognosis and treatment after surgery for clinical stage IA1-2 non-small cell lung cancer (NSCLC). This study investigates nodal upstaging rates and associated factors, with a focus on sublobar resections.

[METHODS] The National Cancer Database (NCDB) was used to identify NSCLC patients with clinical T1a-b (≤ 2 cm), N0, M0 disease (stage IA1-2) who had sublobar resection or lobectomy from 2004 to 2021. Rates of nodal upstaging (cN0→pN+) were calculated over the study period according to the type of pulmonary resection. Factors associated with nodal upstaging were evaluated with multivariable logistic regression.

[RESULTS] The study included 58,626 patients. Nodal upstaging occurred in 6.4% of patients: 3.8% to pN1, 2.7% to pN2. Factors associated with nodal upstaging included male gender, larger tumor size, histology, higher tumor grade, positive resection margins, more regional lymph nodes examined, and type of pulmonary resection. Nodal upstaging rates were 2.9% for wedge resections, 3.7% for segmentectomies, and 8.3% for lobectomies (P < .001). Compared to lobectomy, sublobar resections had lower odds of nodal upstaging: wedge resection (adjusted OR 0.58, 95% CI, 0.51-0.65) and segmentectomy (adjusted OR 0.59, 95% CI, 0.49-0.70; P < .001). This gap in nodal upstaging between sublobar resections and lobectomy persisted over the study period.

[CONCLUSIONS] The extent of surgical resection and lymph node evaluation were independent factors in detecting patients with regional lymph node involvement, signaling more advanced disease. As sublobar resections establish themselves as a widespread, valid treatment, strategies to close the gap in the detection of nodal disease are needed.