Long-term prognosis of expanded-indication differentiated-type early gastric cancer treated with endoscopic submucosal dissection or surgery using propensity score analysis.

BACKGROUND AND AIMS: Although endoscopic submucosal dissection (ESD) for expanded-indication lesions of differentiated-type early gastric cancer (EGC) has been widely accepted, no prospective randomized study has been conducted on this subject. This study aimed to evaluate the long-term outcomes of ESD and surgery for expanded-indication lesions of differentiated-type EGC.

METHODS: Between 1997 and 2012, 1500 consecutive patients with EGC were treated in Osaka City University Hospital. Using propensity score matching and inverse probability of treatment weighting (IPTW), we retrospectively evaluated the long-term outcomes, risk factors for mortality, and adverse events for patients with expanded-indication lesions of differentiated-type EGC who underwent ESD or surgical treatments.

RESULTS: A total of 308 patients with expanded-indication lesions of differentiated-type EGC confirmed by pathologic examination after ESD or surgery met the eligibility criteria. After matching, the 5-year overall survival rate was higher in the ESD group than in the surgery group (97.1% vs 85.8%; P = .01). We also found that surgery was significantly associated with mortality using both the IPTW method (hazard ratio [HR], 10.89; 95% confidence interval [CI], 1.37-86.6; P < .01), and Cox analysis (HR, 8.60; 95% CI, 1.11-66.52; P = .04) after matching. Significantly fewer adverse events were associated with ESD than with surgery (6.8% vs 28.4%; P < .01). No cause-specific mortality was observed in either group.

CONCLUSIONS: Our results indicate that ESD might be an alternative treatment modality for expanded-indication lesions of differentiated-type EGC.