Résumé
BACKGROUND AND AIMS: A superficially invasive cancer in the colon is considered a candidate for an endoscopic resection. Therefore, detecting a superficially invasive cancer and differentiating it from a massively invasive cancer is an important key in selecting proper treatment. In order to accomplish this purpose, exact knowledge of the characteristics of submucosal invasive cancers is required. In this study, attempts to define those endoscopic features and draw guidelines for treatment were made. METHODS: Recently, 23 submucosal invasive cancers were experienced. All of them were detected by an endoscopic examination, and were treated by endoscopic therapy and/or surgical resection. These cancers were reviewed and analyzed with emphasis on size, configuration, differentiation, and treatment. RESULTS: The most common sizes ranged from 10 mm to 19 mm (47.8%). There were two minute lesions below 5 mm. The most common type of lesions was sessile (43.5%). Most lesions showed redness and 60.9% showed hardness. Many cases had characteristic features such as nodules (47.8%), bleeding easily upon touch (39.1%), erosion (39.1%), and white spots (34.8%). Other characteristic features were expanded figures, depressions, and mucosal convergence. Moderately-differentiated adenocarcinomas were predominant (8/15, 53.3%), and there were four polypoid cancers (4/17, 23.5%). In 43.5% of the lesions, only endoscopic treatment was enough. Forty-four percent of all patients treated endoscopically needed additional surgical resections because of uncertainty with respect to complete excision of the cancer and/or a poorly-differentiated adenocarcinoma with lymphatic invasion. There was no lymph node metastasis in any of the patients who underwent surgical resections, and three of them had no residual tumors, as the endoscopic treatment had completely excised the cancer. CONCLUSIONS: Accurate information on submucosal invasive cancers and recognition of the endoscopic characteristics of submucosal invasive cancers are necessary for their detection and management in an early stage. Moreover, it is possible to differentiate superficially invasive cancers from massively invasive ones by their characteristic features. Therefore, in selected patients with superficially invasive cancers, surgical resections can be avoided.