Abstract
＜BACKGROUND＞Endoscopic mucosal resection (EMR) or laparoscopic wedge resection have been performed for patients with mucosal gastric cancer, resulting in preservation of their stomach, keeping QOL. However indication of minimal surgery remains to be discussed, especially for undifferentiated type of gastric cancer, since undifferentiated type is known to invade into deep layer of gastric wall and lymph nodes. ＜PURPOSE＞Clinico-pathological features of undifferentiated type of gastric cancer were considered, retrospectively, objecting early gastric cancer diagnosed by pre-operative examination. ＜PATIENTS AND METHODS＞We retrospectively investigated 293 patients who were diagnosed as early gastric cancer before surgery, and performed gastrectomy between January, 1994 and December, 1997. Two subgroups were divided into either differentiated type (pap., tub1., tub2 ; 202 cases) or undifferentiated type (por 1., por 2., sig ; 91 cases) , and accuracy rates of pre-operative diagnosis for cancer invasion depth, incidence of mis-diagnosis of cancer margin, and distribution of lymph node metastasis were evaluated. ＜RESULTS＞According to accuracy rates of pre-operative diagnosis for cancer invasion depth, differentiated and undifferentiated type resulted in 94.6% and 91.2%, respectively. We also showed 3 undifferentiated type which were histologically diagnosed as positive marginal of cancer after surgery, while we experienced no such case in differentiated type. In addition, positive rate of lymph nodes in undifferentiated mucosal cancer was statistically higher than in differentiated mucosal cancer (P＝0.02) . ＜CONCLUSIONS＞While small surgical procedure is a promising technique to preserve patients' QOL cancer therapy must be cautious to eliminate undesirable outcome like recurrence or cancer death caused by minimal surgery. In the study, we concluded that indication of minimal surgery should be considered properly, based on the risks of the difficulties of diagnosis for cancer invasion depth, surgical margin and lymph node metastasis in undifferentiated type of gastric cancer.
