P3.04-013 The Role of Extent of Surgical Resection and Lymph Node Assessment for Clinical Stage I Pulmonary Lepidic Adenocarcinoma: Topic: Miscellaneous I

Abstract

This study examined the association of extent of lung resection, pathologic nodal evaluation, and survival for patients with clinical stage I (cT1-2N0M0) adenocarcinoma with lepidic histology in the National Cancer Database (NCDB). The association between extent of surgical resection and long-term survival for patients in the NCDB between the years of 2003-2006 with clinical stage I lepidic adenocarcinoma who underwent lobectomy or sublobar resection was evaluated using Kaplan-Meier and Cox proportional hazards regression analyses. Of the 1,991 patients with cT1-2N0M0 lepidic adenocarcinoma who met study criteria, 1,544 patients underwent lobectomy and 447 underwent sublobar resections. Patients treated with sublobar resection were older, more likely to be female, had higher Charlson/Deyo comorbidity scores, but had smaller tumors and lower T-status. Of patients treated with lobectomy, 6% (n=92) were upstaged due to positive nodal disease, with a median of 6 lymph nodes sampled (IQR: 3,10). In an analysis of the entire cohort, lobectomy was associated with a significant survival advantage over sublobar resection in univariate analysis (median survival 9.2 vs. 7.5 years, p=0.022; 5-year survival 70.5% vs. 67.8%) and following multivariable adjustment (hazard ratio [HR]: 0.81 [95% [CI]: 0.68-0.95], p=0.011), (Figure 1). However, lobectomy was no longer independently associated with improved survival when compared to sublobar resection (HR: 0.99 [95% CI: 0.77-1.27], p= 0.905) in a multivariable analysis of a subset of patients that compared only those patients who underwent sublobar resection that included lymph node sampling to patients treated with lobectomy. Surgeons treating patients with stage I lung adenocarcinoma with lepidic features should cautiously utilize sublobar resection rather than lobectomy and must always perform adequate pathologic lymph node evaluation.