早期胃癌臨床診断の実態―内視鏡的立場より

Current Status in Endoscopic Diagnosis for Early Gastric Cancer

　私共の施設が開かれたのは，1964年末であり，その後1970年末までの6年間に約200例の早期胃癌が発見され，治療の対象となった．これらにつき内視鏡的立場より，いかに術前診断が的確になされたかを検討した．

　Approximate 200 cases of early gastric cancer were found from 1965 to 1970. The final endoscopic diagnosis was made by reviewing the gastrophotographs after obtaining results of direct vision cytology and biopsy.

　Of 224 cases preoperatively interpreted as early gastric cancer on endoscopic examination, 165 (74％) were histologically confirmed. On the other hand, a correct diagnosis was made in 165 (86％) of 191 proven early gastric cancers endoscopically examined prior to surgery. No patients were submitted to surgery without a histological proof of malignancy in our series. Benign appearing lesion was, however, seen in 22 (11％) of the 191 early gastric cancers, prior to biopsy or cytology.

　Diagnostic accuracy based on endoscopic interpretation varies through the six year period and there was no evidence that the diagnostic ability in endoscopy had grown up at our clinic. Two major reasons were considered for it. First, endoscopists participating in the final diagnosis were not always the same during the period. Secondly, the endoscopic interpretation largely depends upon subjective impression. It may, however, be said that diagnostic criteria having an accuracy of 75 to 85 percent would be satisfactory. It is a clinician's major concern that early performance of biopsy with proper technique is required for avoiding a long-term follow-up in cases with false-negative diagnosis for malignancy.

　Biopsy procedure does not help to determine the depth of cancerous invasion, since a biopsy forceps at most can get only to the muscularis mucosae.

　Thus, one has to rely on re-evaluation of endoscopic findings, in order to determine whether or not a lesion is of early malignancy.