Endoscopic submucosal dissection as total excisional biopsy for clinical T1 colorectal carcinoma.

Background/aims: Only the depth of submucosal invasion can be estimated prior to determining the indications for endoscopic submucosal dissection (ESD) as a curative treatment for colorectal carcinoma (CRC). Here we evaluated the outcomes of ESD for clinical T1 CRCs.

Methods: Of 660 patients who underwent ESD for CRC at the Hiroshima University Hospital between June 2003 and December 2013, we examined the outcomes of 37 (6%; 26 men, 11 women; mean age ± SD, 68 ± 12 years) who underwent ESD as total excisional biopsy for various reasons, in spite of an endoscopic diagnosis of T1 CRC.

Results: The mean lesion size was 25 ± 14 mm; 14 lesions were protruding and 23 were superficial. The en bloc resection rate was 100% (37/37). The histological en bloc resection rate was 92% (34/37). ESD resulted in a positive vertical margin in 3 cases. Deep submucosal invasion was seen in 3 cases, 2 of which had severe submucosal fibrosis. Although severe submucosal fibrosis was not found in other cases, pathologic examination of the deepest invasive portion of the tumor revealed poorly differentiated adenocarcinoma. The rates of post-ESD bleeding and perforation were 8% (3/37) and 5% (2/37), respectively. All patients recovered under conservative therapy. No cases of recurrence were noted in patients without additional surgical resection when the lesions satisfied the curative conditions listed in the 2014 Japanese Society for Cancer of the Colon and Rectum guidelines.

Conclusion: En bloc resection by ESD as total excisional biopsy for clinical T1 CRC is a highly effective treatment and establishes a precise histological diagnosis.