Recently, in addition to standard surgical operations, reduction therapy (endoscopic mucosal resection and endoscopic gastrectomy) is indicated for early gastric cancer. However, the indication should be limited to the casesof early gastric cancer without lymph node metastases.
During the past 25 years, we have surgically treated 2, 246 cases of early gastric cancer. The percentage of lymph node metastasis in 1, 242 mucosal cancer cases was 1.8% and that in 1, 004 submucosal cancer cases was 16.9%. In the mucosal cancer cases, lymph node metastasis did not occur in the depressedtumors with a diameter of less than 10mm and the elevated tumors with a diameted of less than 20mm. In the submucosal cancer cases, lymph node metastasis did not occur in the elevated tumors less than 10mm in diameter. So, the cases of gastric cancerof these types require the reduction therapy.
However, in the mucosal cancers that have been diagnosed during the last 5 years, the percentage of preoperative correct diagnosis as for thedepth of invasion was 69.4%. In the submucosal cancers, the rate was 60.1%. Many of the cases diagnosed incorrectly had ulcers in the lesion. As for the infiltration type, INFβ and γ were noticeable in these cases. As for the histological type, most of the cases wereof the undifferentiated type.
Moreover, if should be noted, the percentage that the histological type of preoperative ensoscopic biopsy specimens agrees with that of postoperative ones is 50-60% except for tubl of mucosal cancers.