[Definition of the adaptation of endoscopic surgery for early gastric cancer. Special examination on the relationship between the histological differentiation of the intramucosal gastric cancer and the lymph node metastasis].

Out of five hundred and nineteen surgically resected lesions which were histologically shown to be intramucosal gastric cancer, 247 were well differentiated, 98 were moderately differentiated, and 176 were poorly differentiated lesions. The incidence of lymph node metastasis in the 247 well differentiated, 98 moderately differentiated, and 176 poorly differentiated intramucosal adenocarcinomas were 0.8% (= 2/247), 2.1% (= 2/98), and 8% (14/176), respectively. The cumulative survival rate of 5 years after gastrectomy was 94.2% for the 247 well, 93.3% for the 98 moderately, and 93.7% for the 176 poorly differentiated adenocarcinomas. A pathological study on the atypism of the gland of the cancer and the condition of the proprial space under the cancer cells was conducted on 100 lesions of well differentiated adenocarcinomas in order to define the criteria of non-surgical endoscopic removal resection for early gastric cancer. Out of the 100 lesions mentioned above, there were only two well differentiated adenocarcinomas with lymph node metastasis in which the boundary between the epithelium of the cancer and the proprial space under the cancer was very unclear and the interstitial space in the propria under the cancer was very small. On the other hand, we have resected 73 intramucosal gastric cancers using the endoscopic surgical method called strip biopsy since 1984, and have followed up these cases. The cancers resected by strip biopsy, and were histologically intramucosal well differentiated adenocarcinomas shown to have a moderately maintained interstitial space under the cancer cells. And, up to the present, there has been no incidence of recurrence after strip biopsy for the 73 lesions mentioned above. According to these results, we have defined the criterion for early gastric cancer endoscopic surgery, as follows. Intramucosal cancer which is shown to be well differentiated adenocarcinoma with a moderately maintained interstitial space under the cancer cells is considered to be sufficient for non-surgical endoscopic resection.