Preceding endoscopic submucosal dissection for T1 colorectal carcinoma does not affect the prognosis of patients who underwent additional surgery: a large multicenter propensity score-matched analysis.

BACKGROUND: We analyzed the influence of preceding endoscopic submucosal dissection (ESD) on the prognosis of patients with T1 colorectal carcinoma (CRC) after additional surgery using propensity-score matching. METHODS: 1638 consecutive patients with T1 CRC were retrospectively identified between January 1998 and December 2016 at the Hiroshima GI Endoscopy Research Group. We assessed 602 patients with 602 T1 CRC who underwent additional surgery after ESD (n = 216) or surgery alone (n = 386). The enrolled patients were treated according to the Japanese Society for Cancer of the Colon and Rectum (JSCCR) guidelines 2016, and were defined as non-endoscopically curable (non-e-curable) when they did not satisfy its curative criteria. We analyzed the pathological characteristics and the prognosis of non-e-curable patients using propensity-score matching between the additional surgery after ESD and surgery alone groups. RESULTS: There were no cases of recurrence and lymph node metastasis among the e-curable patients. The rate of lymph node metastasis and recurrences in the non-e-curable patients were 10.8% and 2.6%, respectively. After propensity-score matching, there were no significant differences in the 5-year overall survival rates (96.9% vs. 92.0%), 5-year disease-free survival rates (96.7% vs. 96.7%) and 5-year disease-specific survival rates (100% vs. 98.6%) after treatment of T1 CRCs between the 2 groups in non-e-curable patients. CONCLUSIONS: Preceding ESD with histological en bloc resection for patients with T1 CRC did not affect their oncologic behavior adversely after additional surgery.