| Theme |
New Development of Laterally Spreading Tumor |
| Title |
Indications and Outcomes of Endoscopic Resection for Laterally Spreading Tumors of the Colorectum |
| Author |
Shiro Oka |
Department of Endoscopy, Hiroshima University Hospital |
| Author |
Shinji Tanaka |
Department of Endoscopy, Hiroshima University Hospital |
| Author |
Yuzuru Tamaru |
Department of Gastroenterology and Metabolism, Hiroshima University Hospital |
| Author |
Yuki Ninomiya |
Department of Gastroenterology and Metabolism, Hiroshima University Hospital |
| Author |
Naoki Asayama |
Department of Gastroenterology and Metabolism, Hiroshima University Hospital |
| Author |
Kenjiro Shigita |
Department of Gastroenterology and Metabolism, Hiroshima University Hospital |
| Author |
Nana Hayashi |
Department of Endoscopy, Hiroshima University Hospital |
| Author |
Kazuaki Chayama |
Department of Gastroenterology and Metabolism, Hiroshima University Hospital |
| [ Summary ] |
Most colorectal tumors larger than 20 mm in size are laterally spreading tumor (LSTs). Endoscopic submucosal dissection (ESD) is used to treat large LSTs. Recently, the safety and standardization of colorectal ESD techniques have been established. However, recognition of the subtypes of LST and the use of magnifying endoscopy enables us to recognize the cancerous area in the LST‒G and the LST‒NG flat elevated types precisely. Therefore, adenomatous large LST‒G and the LST‒NG flat elevated type can be cured using planned piecemeal endoscopic mucosal resection (EMR). Several studies have reported that adenomatous large LST‒G can be cured by piecemeal EMR. To reduce the size of the residual tumor and reduce the risk of local recurrence after EMR, it is important to observe the margin of the ulcer by using magnifying endoscopy and to perform appropriate trimming. The LST‒G nodular mixed type with large nodules and the LST‒NG pseudo‒depressed type has a relatively high risk for submucosal invasion. However, it is difficult to correctly recognize the submucosal invasive area with magnifying observation. Therefore, en block resection is necessary in cases of the LST‒NG pseudo‒depressed type or the LST‒G nodular mixed type with large nodules. The rationale for choosing between piecemeal EMR and ESD for large LSTs should be based on the LST subtype, the endoscopist's skill level, and the patient's condition. |