Koichi Nakadoi

Clinical outcomes of endoscopic submucosal dissection and endoscopic mucosal resection for laterally spreading tumors larger than 20 mm.

Background and Aims:  Colorectal laterally spreading tumors (LST) > 20 mm are usually treated by endoscopic submucosal dissection (ESD) or endoscopic mucosal resection (EMR). Endoscopic piecemeal mucosal resection (EPMR) is sometimes required. The aim of our study was to compare the outcomes of ESD and EMR, including EPMR, for such LST.

Management of T1 colorectal carcinoma with special reference to criteria for curative endoscopic resection

Background and Aim:  In guidelines 2010 for the treatment of colorectal cancer from the Japanese Society for Cancer of the Colon and Rectum (JSCCR), the criteria for identifying curable T1 colorectal carcinoma after endoscopic resection were well/moderately differentiated or papillary histologic grade, no vascular invasion, submucosal invasion depth less than 1000 µm and budding grade 1 (low grade). We aimed to expand these criteria.

Risk analysis of submucosal invasive rectal carcinomas for lymph node metastasis to expand indication criteria for endoscopic resection

In the 2010 guidelines for the treatment of colorectal cancer from the Japanese Society for Cancer of the Colon and Rectum (JSCCR), the criteria for identifying curable submucosal invasive colorectal carcinoma after endoscopic resection is as follows: differentiated adenocarcinoma, no vascular invasion, submucosal invasion depth <1000 μm and budding grade 1 (low grade). A total of 118 rectal submucosal carcinomas, treated by primary surgical resection or additional surgical resection with lymph node (LN) dissection, were analyzed. Relationships between clinicopathological findings and LN metastasis were evaluated. LN metastasis was found in 11.0% (13/118). There were no significant differences between clinicopathological findings and LN metastasis except for budding grade. Multivariate logistic regressionanalysis showed budding grade 2/3 (high grade) to be the independent risk factor for LN metastasis. When cases that met the curative condition of histological grade, tumor budding grade and vessel invasion together according to JSCCR 2010 criteria, the incidence of LN metastasis was only 2.2% (1/46, 95% confidence interval: 0.06–11.5%), regardless of the degree of submucosal invasion depth. In conclusion, even in cases of rectal carcinoma with submucosal deep invasion, the risk of LN metastasis is minimal under certain conditions.

Endoscopic features and management of diminutive colorectal submucosal invasive carcinoma.

The vast majority of diminutive (∼5 mm) colorectal tumors consist of a very low prevalence of advanced neoplasia, and a predict‐resect‐and‐discard policy has been proposed recently in Western countries. The histology of some diminutive colorectal tumors reveals carcinoma, not adenoma, although the frequency is relatively low. Clarifying the endoscopic features of diminutive submucosal invasive colorectal carcinoma (CRC) during colonoscopy is important for managing diminutive lesions.

Clinical outcomes of endoscopic submucosal dissection for rectal tumor close to the dentate line

p r s f s L J m Endoscopic mucosal resection is a standard therapy for colorectal tumors. Although endoscopic submucosal dissection (ESD) is not a standard therapy, it has emerged as a feasible treatment option because of improved techniques and specialized devices.4-8 Lesions close to the dentate line can be difficult to remove endoscopically because of the risk of bleeding from the rectal venous plexus. In addition, sensory nerves in the squamous epithelium below the dentate line make pain likely during the procedure. Moreover, the proximity of the anal sphincter makes maintaining a good visual field difficult. Therefore, special approaches are necessary for treating lesions in this area. Generally, ESD proceeds by handling the submucosal blood vessels. The en bloc resection rate for large colorectal tumors is high. As such, ESD is a logical choice for lesions close to the dentate line. Recently, Sanchez-Yague et al9 reported the successful use of ESD for resecting a ectal polyp proximal to the dentate line by using local idocaine injection. However, no reports, to our knowldge, have summarized the clinical results of ESD for esions close to the dentate line among many patients. ere, we report our experience with ESD and clinical utcomes in patients after ESD for lesions close to the entate line.