[Early esophageal cancer--concept, diagnosis and treatment]

In spite of the conventional definition of early esophageal cancer which includes mucosal and submucosal cancers without lymph node metastasis, esophageal mucosal cancers are now considered as the early cancer in clinical field. The esophageal mucosal cancers are subclassified into m1 (intraepithelial cancer), m2(lamina propria mucosae) and m3(muscularis mucosae) in clinical view points. M1 and m2 esophageal cancers which had no lymph node metastasis could be treated completely by endoscopic mucosal resection. On the other hand, the patients with m3 cancer which showed lymph node metastasis in 10% of the cases should be treated by esophagectomy with lymph node dissection. For the diagnosis of the depth of carcinoma invasion, now, endoscopy with dye iodine stain and toluisine blue stain were most useful. Fundamentally, macroscopic appearance of lesions classified by Japanese Society for Esophageal Diseases are well related to the depth of invasion. Almost all mucosal cancers showed the superficial and flat type (0-IIc type). Subclassification of m1, m2 and m3 were easily differentiated by endoscopic observation of their characteristic appearances. In the evaluation of the methods of treatment for mucosal cancer, endoscopic mucosal resection and esopagostomy showed a complete resectability. While, the former was superior in the quality of life after treatment.