Segmentectomy vs Lobectomy in Small-Sized Peripheral NSCLC

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In a Japanese phase III trial (JCOG0802/WJOG4607L) reported in The Lancet, Saji et al found that segmentectomy was both noninferior and superior to lobectomy as measured by overall survival in patients with small-sized peripheral non–small cell lung cancer (NSCLC).

Study Details

In the open-label multicenter noninferiority trial, 1,106 patients with clinical stage IA disease (tumor diameter ≤ 2 cm; consolidation-to-tumor ratio > 0.5) were randomly assigned between August 2009 and October 2014 to undergo segmentectomy (n = 552) or lobectomy (n = 554).

The primary endpoint was overall survival in the intention-to-treat population, with a noninferiority margin of 1.54 for the upper limit of the 95% confidence interval (CI) of the hazard ratio (HR) using a stratified Cox regression model. Superiority was confirmed if the upper limit of the confidence interval was < 1.

Overall Survival

In the segmentectomy group, 22 patients were switched to receive lobectomy and 1 patient received wide wedge resection. Adjuvant therapy was received by 47 patients in the segmentectomy group, including tegafur/uracil by 22 and cisplatin/vinorelbine by 13, and by 67 patients in the lobectomy group, including tegafur/uracil by 39 and cisplatin/vinorelbine by 11.    

At a median follow-up of 7.3 years (range = 0.0–10.9 years), 5-year overall survival was 94.3% (95% CI = 92.1%–96.0%) in the segmentectomy group vs 91.1% (95% CI = 88.4%–93.2%) in the lobectomy group (HR = 0.663, 95% CI = 0.474–0.927, P < .0001 for noninferiority and P = .0082 for superiority).


  • Segmentectomy was found to be noninferior and superior to lobectomy in overall survival.
  • Overall survival at 5 years was 94.3% vs 91.1%.

At 5 years, relapse-free survival was 88.0% (95% CI = 85.0%–90.4%) in the segmentectomy group vs 87.9% (95% CI = 84.8%–90.3%) in the lobectomy group (HR = 0.998, 95% CI = 0.753–1.323, P = .9889). The proportions of patients with local relapse were 10.5% vs 5.4% (P = .0018).

At 1 year, median reduction in forced expiratory volume in 1 second was 8.5% in the segmentectomy group vs 12.0% in the lobectomy group (difference = 3.5%, P < .0001); however, the difference did not meet the predefined threshold for clinical significance of 10%.

Adverse Events

Grade 2 or worse intraoperative complications occurred in nine patients (2%) in the segmentectomy group vs six patients (1%) in the lobectomy group. Grade 2 or worse postoperative complications occurred in 148 patients (27%) vs 142 patients (26%). No 30-day or 90-day mortality was observed.

The investigators concluded, “To our knowledge, this study was the first phase III trial to show the benefits of segmentectomy vs lobectomy in overall survival of patients with small-peripheral NSCLC. The findings suggest that segmentectomy should be the standard surgical procedure for this population of patients.”

Hisashi Saji, MD, of the Department of Chest Surgery, St. Marianna University School of Medicine, Kawasaki, is the corresponding author for The Lancet article.

Disclosure: The study was funded by the National Cancer Center Research and the Ministry of Health, Labour, and Welfare of Japan. For full disclosures of the study authors, visit


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