A feasibility study on the expanded indication for endoscopic submucosal dissection of early gastric cancer

Background Endoscopic submucosal dissection (ESD) is the standard treatment for selected cases of early gastric cancer (EGC). Evolution of ESD techniques and accessories has expanded treatment indications. The aim of this study was to compare the therapeutic outcomes for conventional and expanded indications of ESD for EGC. Methods Eight hundred six EGC lesions in 780 patients were classified into two groups based on a pathological review: a conventional indication group (595 cases) and an expanded indication group (211 cases). The expanded indication group was classified further into subgroups according to tumor depth and tumor size. Therapeutic outcomes were compared between the conventional and expanded indication groups and between the expanded indication subgroups. Results The complete resection rate (97.3% vs. 81.0%, p<0.001) and en bloc complete resection rate (95.6% vs. 79.1%, p = 0.003) were higher in the conventional indication group than in the expanded indication group. Among the expanded indication patients, the complete resection rate (64.5% vs. 91.1%, p<0.001) and en bloc complete resection rate (63.2% vs. 89.6%, p<0.001) were lower in the submucosal invasion subgroup than in the mucosal invasion subgroup. The complete resection rate and en bloc complete resection rate did not differ between subgroups classified according to tumor size in the expanded indication group. The conventional indication group and expanded indication group did not differ with regard to the rates of local recurrence (0.7% vs. 0%), metachronous recurrence (3.6% vs. 3.3%), or cumulative disease-free survival. Survival outcome was similar in the subgroups classified by tumor depth and size. Perforation was more frequent in the expanded indication group than in the conventional indication group (6.6% vs. 2.4%, p<0.001). Conclusion ESD for expanded indication of EGC had acceptable clinical outcomes. ESD can be applied safely to properly selected patients with EGC.