[Endoscopic therapy of digestive cancer]

We have treated early gastric cancer by means of endoscopical photocoagulation using a Nd-YAG laser since December 1980, particularly in inoperable cases due to other complications or old age. Forty-seven lesions found in 41 patients have so far been photocoagulated and followed up. By this treatment, cancer cells disappeared in 42 out of 47 lesions, although 2 cases died of other diseases and recurrence was experienced in 3 cases. In addition to photocoagulation therapy using a laser, we have recently developed a large-biopsy technique called strip biopsy in order to get sufficient tissue for diagnosis in comparison with bite biopsy. By this method, we are able to resect the full thickness of the mucosa including the submucosal layer up to a size of about 4 cm, without any severe complication such as hemorrhage and perforation. We succeeded in resecting the early gastric cancer in 34 lesions in 31 patients. Of course, the combination therapy of endoscopical photocoagulation and strip biopsy seems to be reasonable for the therapy of early gastric cancer. For the purpose of improving endoscopy therapy for early gastric cancer, accurate diagnosis particularly with regard to the depth of invasion of cancer cells must be performed. In this sense, we have attempted to improve the resolution of the ultrasonic endoscope. Ultrasonic endoscopy can yield more accurate information about the depth of invasion and its metastasis to the lymph nodes. Therefore, ultrasonic endoscopy is excellent, not only for making sure of the grade of gastric cancer, but also for the detection of its recurrence, which can not be observed by ordinary endoscopy. It is obvious that surgical resection is a superior therapy for gastric cancer. In this sense, endoscopic therapy could be regarded as an "orphan" in this field. However, in the combination of endoscopic therapy and ultrasonic endoscopy, endoscopic therapy for gastric cancer should be acknowledged to be equal to surgical therapy.