Lobectomy vs Sublobar Resection in The Society of Thoracic Surgeons Database: Importance of Patient Factors and Lymph Node Evaluation

Background

Prospective randomized trials have demonstrated noninferior survival between sublobar resection and lobectomy in healthy patients with non-small cell lung cancer with tumors ≤2 cm. However, some patient attributes are not well represented in randomized trials, and uncertainty remains in the widespread applicability of randomized trial nodal dissection protocols.

Methods

Patients with ≤2 cm, node-negative non-small cell lung cancer (cT1 N0) in The Society of Thoracic Surgeons prospective database were linked to Medicare survival data by using a probabilistic matching algorithm. Survival was assessed by propensity score–weighted Kaplan-Meier analysis.

Results

Overall, 20,031 patients were identified, including 11,976 patients who underwent lobectomy, 2586 who underwent segmentectomy, and 5469 who underwent wedge resection. Fewer lymph nodes were sampled in the sublobar resection group (mean, 5.5 vs 12.8), and pathologic upstaging was less common (7.1% vs 14.2%). Overall survival after sublobar and lobar resection was similar within groups understudied in recent trials, including age ≥75 years (P = .07), forced expiratory volume in 1 second of 10% to 59% (P = .14), and Zubrod performance status 2 to 3 (P = .23). When sublobar resection was performed with inadequate nodal evaluation (<2 nodes removed), survival was inferior to survival after lobectomy (P < .001). Among patients with nodal upstaging, lobectomy was not associated with improved survival over sublobar resection (P = .42).

Conclusions

The clinical trial finding that sublobar resections achieve survival similar to that seen with lobectomy in early-stage lung cancer appears to apply to older, less healthy patients in a real-world setting, provided adequate lymph node resection is performed. Performing a lobectomy in the setting of nodal upstaging does not obviously improve survival. Further study is warranted to clarify the role of sublobar resection in the general population.