Long-term local recurrence and survival after colorectal endoscopic submucosal dissection: a prospective multicenter real-world cohort study

Background: Information on long-term outcomes of colorectal endoscopic submucosal dissection (ESD) in real-world clinical practice remains limited. This study aimed to evaluate long-term local recurrence and its predictors after colorectal ESD. Methods: This prospective, multicenter study was conducted at 11 institutions in Hiroshima, Japan, and included all consecutive colorectal ESD cases (1838 lesions from 1732 patients) between 2014 and 2018. The primary outcome was the cumulative local recurrence rate. The secondary outcomes included factors associated with local recurrence, overall survival, and cancer-specific survival. Factors associated with local recurrence were evaluated using cause-specific Cox proportional hazards models using Firth's penalized partial likelihood. Results: The cumulative local recurrence rates at 1, 3, and 5 years were 0.06%, 0.64%, and 0.75%, respectively. The longest interval to recurrence was 52 months. No local recurrence was observed in patients who achieved curative resection. Rectal lesions (hazard ratio [HR] 3.93; P = 0.04), high-risk pathologic features (HR 14.3; P < 0.001), R1 resection (HR 7.59; P = 0.003), and delayed bleeding (HR 7.72; P = 0.009) were associated with local recurrence. The 5-year overall survival and cancer-specific survival rates were 95.3% and 100%, respectively; however, 1/10 patients with local recurrence developed liver and lung metastases and subsequently died 64 months after ESD. Conclusions: Colorectal ESD had a very low long-term local recurrence rate in real-world clinical settings. No recurrence was observed in patients who underwent curative resection. Long-term surveillance is warranted after noncurative resection.