Lobectomy, segmentectomy, or wedge resection for peripheral clinical T1aN0 non-small cell lung cancer: A post hoc analysis of CALGB 140503 (Alliance)

Abstract

Background: We have recently reported the primary results of CALGB 140503 (Alliance), a randomized trial in patients with peripheral cT1aN0 non-small cell lung cancer (American Joint Committee on Cancer seventh) treated with either lobar resection (LR) or sublobar resection (SLR). Here we report differences in disease-free survival (DFS), overall survival (OS) and lung cancer-specific survival (LCSS) between LR, segmental resection (SR), and wedge resection (WR). We also report differences between WR and SR in terms of surgical margins, rate of locoregional recurrence (LRR), and expiratory flow rate at 6 months postoperatively.

Methods: Between June 2007 and March 2017, a total of 697 patients were randomized to LR (n = 357) or SLR (n = 340) stratified by clinical tumor size, histology, and smoking history. Ten patients were converted from SLR to LR, and 5 patients were converted from LR to SLR. Survival endpoints were estimated using the Kaplan-Maier estimator and tested by the stratified log-rank test. The Kruskal-Wallis test was used to compare margins and changes in forced expiratory volume in 1 second (FEV1) between groups, and the χ² test was used to test the associations between recurrence and groups.

Results: A total of 362 patients had LR, 131 had SR, and 204 had WR. Basic demographic and clinical and pathologic characteristics were similar in the 3 groups. Five-year DFS was 64.7% after LR (95% confidence interval [CI], 59.6%-70.1%), 63.8% after SR (95% CI, 55.6%-73.2%), and 62.5% after WR (95% CI, 55.8%-69.9%) (P = .888, log-rank test). Five-year OS was 78.7% after LR, 81.9% after SR, and 79.7% after WR (P = .873, log-rank test). Five-year LCSS was 86.8% after LR, 89.2% after SR, and 89.7% after WR (P = .903, log-rank test). LRR occurred in 12% after SR and in 14% after WR (P = .295). At 6 months postoperatively, the median reduction in % FEV1 was 5% after WR and 3% after SR (P = .930).

Conclusions: In this large randomized trial, LR, SR, and WR were associated with similar survival outcomes. Although LRR was numerically higher after WR compared to SR, the difference was not statistically significant. There was no significant difference in the reduction of FEV1 between the SR and WR groups.

Keywords: lung cancer; randomized trial; sublobar resection.