D. Wang1, A. Castillo2, B. Rettner1,3, A. Zhu1,4, C.J. Yang1 1Massachusetts General Hospital, Thoracic Surgery, Boston, MA, USA 2Boston College, Chestnut Hill, MA, USA 3Morristown Medical Center, Surgery, Morristown, NJ, USA 4University Of California – San Diego, Surgery, San Diego, CA, USA
Introduction:
The landmark multicenter, international, randomized control trial CALGB 140503 demonstrated that sublobar resection was noninferior to lobectomy for overall survival and disease-free survival in patients with peripheral, stage IA (≤ 2 cm) non-small cell lung cancer (NSCLC). In this study, most patients had adenocarcinoma or squamous cell carcinoma histology. Other major clinical trials investigating sublobar versus lobar resection, such as JCOG0802, are also enriched in primarily adenocarcinoma histology. The objective of this study is to evaluate overall survival for patients undergoing sublobar versus lobar resection for stage IA (≤ 2 cm) NSCLC by histology.
Methods:
Patients diagnosed with stage IA (≤ 2 cm) NSCLC between 2010 and 2020 undergoing sublobar resection (wedge resection or segmentectomy) or lobectomy with extensive lymph node sampling (>9 nodes) were identified in the National Cancer Database (NCDB). The association between extent of resection and 5-year overall survival was evaluated using multivariable logistic regression and Cox proportional hazards modeling. Histology subtypes evaluated include adenocarcinoma, squamous cell carcinoma, large cell carcinoma, neuroendocrine/carcinoid, and bronchioloalveolar carcinoma. Covariates used for adjusting include age, sex, race, Charleson Deyo score, distance from hospital, education, income, insurance status, facility type, year of diagnosis, tumor size, tumor location, tumor grade, clinical tumor stage, and adjuvant therapy.
Results:
From 2010 to 2020, a total of 32,464 patients were diagnosed with stage IA (≤ 2 cm) NSCLC and underwent sublobar or lobar resection with extensive lymph node sampling. Patients undergoing sublobar resection had noninferior overall survival when compared to those undergoing lobar resection for squamous cell (65.5% vs 70.9%; p=0.22), large cell (65.0% vs 65.3%; p=0.86), adenosquamous cell (59.2% vs 67.6%; p=0.68), and neuroendocrine/carcinoid (92.5% vs 93.5%; p=0.33) histologic subtypes. Patients undergoing sublobar resection for adenocarcinoma (77.5% vs 81.8%; p<0.01) and bronchioloalveolar carcinoma (83.5% vs 84.8%; p=0.03) had worse overall survival when compared to those undergoing lobar resection.
Conclusion:
In this national analysis, there was no statistically significant difference in 5-year overall survival for patients with stage IA (≤ 2 cm) NSCLC undergoing sublobar or lobar resection for squamous cell, large cell, adenosquamous, and neuroendocrine/carcinoid histology subtypes. However, this study demonstrates that sublobar resection was associated with worse overall survival for patients with adenocarcinoma and bronchioloalveolar carcinoma in contrast with the findings of CALGB 140503.