| Theme |
Selection of the therapeutic methods (EMR or ESD) for colorectal tumor |
| Title |
Characteristics of laterally spreading tumors (LST) in the colorectum |
| Author |
Shin-ei Kudo |
Digestive Disease Center, Showa University Northern Yokohama Hospital |
| Author |
Nobunao Ikehara |
Digestive Disease Center, Showa University Northern Yokohama Hospital |
| Author |
Takemasa Hayashi |
Digestive Disease Center, Showa University Northern Yokohama Hospital |
| Author |
Hiromasa Oikawa |
Digestive Disease Center, Showa University Northern Yokohama Hospital |
| Author |
Noriyuki Ogata |
Digestive Disease Center, Showa University Northern Yokohama Hospital |
| Author |
Hironari Shiaki |
Digestive Disease Center, Showa University Northern Yokohama Hospital |
| Author |
Yoshiki Wada |
Digestive Disease Center, Showa University Northern Yokohama Hospital |
| Author |
Hiroshi Kashida |
Digestive Disease Center, Showa University Northern Yokohama Hospital |
| Author |
Shigeharu Hamatani |
Department of Pathology, Showa University Northern Yokohama Hospital |
| [ Summary ] |
Laterally spreading tumors (LSTs) in the colorectum are defined as large circumferentially extending neoplasms (≤10mm) in diameter. There are usually good indications for endoscopic mucosal resection (EMR) because they are rather benign in spite of their large diameter. However, those with deep submucosal (SM) invasion should be carefully treated endoscopically because of a higher potential for invasion. A total of 29,291 early colorectal cancers and adenomas were resected endoscopically or surgically between April 2001 and June 2009. Of these, 1,713 (5.8%) lesions were determined to be LSTs. They were evaluated for magnifying endoscopic findings and were determinated to be association with submucosal invasion. The rate of submucosal invasion was significantly higher in LST-NG than in LST-G (15.7% v 6.3% ; p<0.01). The muscularis mucosae was more severely destroyed in LST-NG (PD). Residual adenomatous components were recognized in 65.7% of LST-G but only in 7.5% of LST-NG (PD). LST-G can be treated with piecemeal EMR techniques (EPMR), due to its low rate of submucosal invasion. In contrast, LST-NG (PD) type should be treated with ESD techniques because of the higher potential for invasion and greater difficulty in diagnosing depth of cancer. The clinicopathological characteristics of LSTs are different in individual subgroups; therefore, care should be taken when determining treatment. |