Purpose: Endoscopic submucosal dissection permits removal of colorectal epithelial neoplasms en bloc, but long-term clinical outcomes remain unknown.
Methods: Endoscopic submucosal dissection was performed in 282 patients having 296 colorectal tumors that fulfilled the inclusion criteria, which included lesions greater than 20 mm in size for which en bloc resection would be difficult with endoscopic mucosal resection, lesions with fibrotic scar due to previous endoscopic treatment or biopsies, locally residual lesions after endoscopic resection, or invasive carcinoma with slight submucosal penetration. En bloc or piecemeal resection, complete (en bloc with tumor-free lateral/basal margins) or incomplete resection, and complications were assessed, and factors related to each were analyzed using logistic regression. Patients with early colon cancer received endoscopic follow-up and metastatic surveys for a median of 34 months.
Results: En bloc resection was achieved in 89.2% (264/296) and 234 lesions (79.1%) were deemed to have undergone complete resection. A right-side colonic location was the significant contributor to incomplete resection. Perforation was seen in 24 cases (8.1%) in association with tumor size and the presence of fibrosis. There was 1 case of locally recurrent tumor with incomplete resection, whereas neither recurrence nor residual disease was observed in the complete resection group. Neither cancer-related nor cancer-unrelated death was observed.
Conclusions: Precise assessment of curability with successful en bloc resection may reduce tumor recurrence after endoscopic submucosal dissection. The prognosis of early colorectal cancer in patients treated by endoscopic submucosal dissection is likely to be excellent, although further longer follow-up studies are warranted.