内視鏡による食道表在癌の診断と予後推定

Diagnosis and Prediction of Prognosis by Endoscopy in Superficial Type of Esophageal Cancer

　食道における早期癌も，この数年全国各地で報告されてきたが，その数は胃における早期癌に比べれば遙かに少なく，遠隔成績など多くが今後の検討にまたねばならない点が多い．

　食道の早期癌は食道癌取扱い規約¹⁾により「癌の浸潤が粘膜下層までで，リンパ節転移のないもの」と定義されている．癌の深達度が粘膜下層までのもので，リンパ節転移のあるものは表在癌とよんで，早期癌（つまりstage 0癌）と区別し，さらに，術前合併療法として放射線治療や化学療法をおこなったときには，それぞれR-早期癌，Ch-早期癌の様に符号をつけることにしている．

　Superficial type of esophageal cancer confined at most to the submucosa has been quite few in number of reported cases. For the past 11 years only 27 cases, representing 4 per cent of all resected cancer of the esophagus, have been described. Prior to surgical intervention superficial type was endoscopically confirmed in 58 per cent. Tne reminders were mistaken for advanced cancer. Characteristic changes of this variety of cancer in its whole aspect are a very important clue to its endoscopic diagnosis, but its dynamic observation is also effective.

　In superficial type of cancer, neoplasms less than 3 cm in diameter accounted for 52 per cent, while in advanced cancer such small tumors were seen in only 10 per cent. Almost all of these small neoplasms belonged to early cancer with no lymph node metastasis. Turbidity, corseness and thickening of the mucosa accounted for m cancer, seen either as flatelevated type or erosive variety. Cancers elevated more than 3 mm above the mucosal surface in resected specimen or those with grossly ulcerated change belonged all to sm cancer.

　A definite difference in the prognosis of superficial type of cancer was seen between early cancer free of lymph node metastasis and superficial cancer involving lymph node. Study of the deceased either of early cancer or of superficial cancer shows that vascular invasion plays an important role in mortality. There is also a closs relationship between the histologic types of cancer, early or superficial, and vascular invasion. the latter was recognized in almost all cases of poorly differentiated carcinoma, while in cases of moderately differentiated carcinoma it was seen in 67 per cent and in well differentiated cancer in only 17 per cent. In this respect, preoperative determination of the histologic types by means of biopsy seems necessary in predicting prognosis.

　It has been suggested here that combination of elevated and erosive types confirmed by endoscopy is clinically more malignant than others not only from the histologic type and frequency of vascular invasion but from postoperative end-results as well.