Does a phase III trial show sublobar resection is better than lobectomy for small peripheral non–small cell lung cancer?

For patients with small peripheral non–small cell lung cancer (NSCLC) — tumors 2 cm or smaller — a major phase III trial has directly compared sublobar resection (removing only part of a lung lobe) with lobectomy (removing an entire lobe). The short answer is yes: the trial showed that sublobar resection is noninferior to lobectomy for disease-free survival, meaning it is not worse in terms of preventing cancer return or death. This finding has shifted surgical practice for carefully selected early-stage patients.

What the research says

The landmark phase III trial CALGB 140503 (Alliance) randomly assigned 697 patients with clinical stage T1aN0 NSCLC (tumor ≤2 cm, node-negative) to sublobar resection or lobar resection ⁹. After a median follow-up of 7 years, sublobar resection was noninferior to lobectomy for disease-free survival (hazard ratio for recurrence or death, 1.01; 90% CI, 0.83 to 1.24) ⁹. Overall survival was also similar between the two groups (hazard ratio for death, 0.95; 95% CI, 0.72 to 1.26) ⁹. Five-year disease-free survival was 63.6% with sublobar resection and 64.1% with lobectomy; 5-year overall survival was 80.3% and 78.9%, respectively ⁹.

A 2023 narrative review confirms that the CALGB 140503 trial demonstrated the efficacy and noninferiority of sublobar resection (including wedge resection) for clinical stage IA NSCLC with tumor diameter <2 cm ¹⁰. The same review notes that another randomized trial, JCOG0802/WJOG4607L, found segmentectomy (a type of sublobar resection) superior to lobectomy in overall survival for stage IA NSCLC with tumors <2 cm and a consolidation-to-tumor ratio <0.5 ¹⁰.

A secondary analysis of CALGB 140503 looked at the rate of second primary lung cancer (SPLC) after surgery. The rate per patient per year was 3.8% in the sublobar arm and 3.1% in the lobectomy arm, and the 5-year cumulative incidence of SPLC was 17.2% versus 14.7%, respectively ¹¹. While slightly higher in the sublobar group, these differences were not statistically significant, and the overall noninferiority finding for disease-free survival remained ¹¹.

What to ask your doctor

• Based on my tumor size and location, am I a candidate for sublobar resection instead of lobectomy?
• What are the expected differences in lung function recovery between sublobar resection and lobectomy for my case?
• How does my overall health and lung reserve affect the choice of surgery?
• What is the risk of a second primary lung cancer after sublobar resection, and how will I be monitored?
• Should I consider segmentectomy or wedge resection specifically, and what does the evidence show for each?