Segmentectomy versus lobectomy in small-sized peripheral non-small-cell lung cancer with radiologically pure-solid appearance in Japan (JCOG0802/WJOG4607L): a post-hoc supplemental analysis of a multicentre, open-label, phase 3 trial

Background Although segmentectomy was better than lobectomy in terms of overall survival for patients with nonsmall-cell lung cancer (NSCLC) with a pure -solid tumour appearance on thin-section CT in the open-label, multicentre, randomised, controlled, phase 3 JCOG0802/WJOG4607L trial, the reasons why segmentectomy was associated with better overall survival were unclear. We aimed to compare the survival, cause of death, and recurrence patterns after segmentectomy versus lobectomy in trial participants with NSCLC with a pure -solid appearance Methods We conducted a post -hoc supplemental analysis of the JCO0802/WJOG4607L randomised, controlled, noninferiority trial for the patients (aged 20-85 years) with small-sized NSCLC with radiologically pure -solid appearance on thin-section CT (<= 2 cm, consolidation tumour ratio 1 center dot 0). The primary aim was to compare the overall and relapsefree survival, cause of death, and recurrence patterns associated with segmentectomy and lobectomy for patients with radiologically pure -solid NSCLC to determine why the overall survival of segmentectomy was superior to that of lobectomy, even for oncologically invasive lung cancers. JCO0802/WJOG4607L is registered with the UMIN Clinical Trials Registry, UMIN000002317, and is complete. Findings Between Aug 10, 2009, and Oct 21, 2014, 1106 patients were randomly assigned to undergo either lobectomy or segmentectomy. Of these participants, 553 (50%) had radiologically pure -solid NSCLC and were eligible for this posthoc supplemental analysis. Of these 553 participants, 274 (50%) patients underwent lobectomy and 279 (50%) underwent segmentectomy. Median patient age was 67 years (IQR 61-73), 347 (63%) of 553 patients were male and 206 (37%) were female, and data on race and ethnicity were not collected. As of data cutoff (June 13, 2020), after a median follow-up of 7 center dot 3 years (IQR 6 center dot 0-8 center dot 5), the 5 -year overall survival rate was significantly higher after segmentectomy than after lobectomy (86 center dot 1% [95% CI 81 center dot 4-89 center dot 7] in the lobectomy group, with 55 deaths vs 92 center dot 4% [88 center dot 6-95 center dot 0] in the segmentectomy group, with 38 deaths; hazard ratio (HR) 0 center dot 64 [95% CI 0 center dot 41-0 center dot 97]; log -rank test p=0 center dot 033), whereas the 5 -year relapse-free survival was similar between the groups (81 center dot 7% [95% CI 76 center dot 5-85 center dot 8], with 34 events vs 82 center dot 0% [76 center dot 9-86 center dot 0], with 52 events; HR 1 center dot 01 [95% CI 0 center dot 72-1 center dot 42]; p=0 center dot 94). Deaths after a median follow-up of 7 center dot 3 years due to lung cancer occurred in 20 (7%) of 274 patients after lobectomy and 19 (7%) of 279 after segmentectomy, and deaths due to other causes occurred in 35 (13%) patients after lobectomy compared with 19 (7%) after segmentectomy (lung cancer death vs other cause of death, p=0 center dot 19). The locoregional recurrence was higher after segmentectomy (21 [8%] vs 45 [16%]; p=0 center dot 0021). In subgroup analyses, better 5 -year overall survival after segmentectomy than after lobectomy was observed in the subgroup of patients aged 70 years or older (77 center dot 1% [95% CI 68 center dot 2-83 center dot 8] with lobectomy vs 85 center dot 6% [77 center dot 5-90 center dot 9] with segmentectomy; p=0 center dot 013) and in male patients (80 center dot 5% [73 center dot 7-85 center dot 7] vs 92 center dot 1% [87 center dot 0-95 center dot 2]; p=0 center dot 0085). By contrast, better 5 -year relapse-free survival after lobectomy than after segmentectomy was observed in the subgroup younger than 70 years (87 center dot 4% [95% CI 81 center dot 2-91 center dot 7] with lobectomy vs 84 center dot 4% [77 center dot 9-89 center dot 1] with segmentectomy; p=0 center dot 049) and in female patients (94 center dot 2% [87 center dot 6-97 center dot 4] vs 82 center dot 2% [73 center dot 2-88 center dot 4]; p=0 center dot 047). Interpretation This post -hoc analysis showed improved overall survival after segmentectomy in patients with puresolid NSCLC compared with lobectomy. However, survival outcomes of segmentectomy depend on the patient's age and sex. Given the results of this exploratory analysis, further research is necessary to determine clinically relevant indications for segmentectomy in radiologically pure -solid NSCLC. Copyright (c) 2024 Elsevier Ltd. All rights reserved.