Long-term outcome and surveillance policy after endoscopic therapy for early gastric cancer

Abstract

endoscopic therapy are conducted more rigorously. Thus, we can expect state-of-the-art clinical data on quality assurance after endoscopic therapy for early gastric cancer. Uedo and colleagues [3] from the Osaka Medical Center for Cancer and Cardiovascular Diseases have analyzed the long-term outcome of early gastric cancer after successful EMR. The subjects enrolled in their study were treated for cancer that fully met the criteria for EMR according to the guidelines established by JGCA: well-differentiated histology, no evidence of submucosal invasion, and smaller size (less than 2cm) without ulceration [2]. Early gastric cancers fulfilling these criteria are considered to be curable by ER alone because of negligible risk of metastatic spread. Patients with such lesions will benefit most from endoscopic treatment if the conditions mentioned above are met. According to the data of Uedo et al., long-term diseasespecific survival rates at 5 or 10 years were both 99%, providing assurance of long-term survival benefit for endoscopic therapy. However, it should be noted that two patients among their subjects died of gastric cancer. One of them actually had a lymphatic invasion that had been misclassified in a completely resected group in their database. This patient, therefore, should have been operated on immediately after endoscopic resection. The other patient had cancer foci in a hyperplastic polyp that had been removed by endoscopy. It is quite unlikely that inadequate polypectomy was the cause of death, because complete resection was confirmed by pathological examination of the resected specimen. Rather, it would be reasonable to assume that a cancer that had developed elsewhere in the stomach may have been responsible for the death, which occurred more than 10 years after resection, because this patient was lost to follow-up. This possibility conveys a very important message in advocating the necessity of continuous follow-up. It is well known that the risk of developing gastric cancer is high in patients with atrophy and In Japan, nationwide mass screening programs and easy access to endoscopic examinations by experienced gastroenterologists have enabled detection of gastric cancer at very early stages. In recent years, more than half the gastric cancers detected by screening programs are in their early stages, and many of them are amenable to endoscopic resection (ER) [1]. Several techniques for endoscopic mucosal resection (EMR) have been developed, and recent introduction of endoscopic submucosal dissection (ESD) has enabled resection of more extensive lesions beyond the criteria proposed by the Japanese Gastric Cancer Association (JGCA) [2]. Although these endoscopic therapies are now being performed in a large number of institutions throughout Japan, the quality assurance in each institution or comparisons of outcomes among hospitals has not been scrutinized. It should be kept in mind, however, that the conditions for these endoscopic treatments for early gastric cancer compared with surgical operation should be (1) similar or better curative rate, (2) earlier recovery and better quality of life, and (3) cost-effective advantage. Excellent long-term results (5-year survival rate exceeding 95%) after surgical operation for early gastric cancer have been achieved in major institutions in Japan. To be compatible with the first condition, longterm outcome of endoscopic therapy for early gastric cancer with more limited disease extension should theoretically be superior to surgical results. Unfortunately, very few studies have been conducted to verify this premise that is vital for critical evaluation of the indication of ER for early gastric cancer. In this issue of Gastric Cancer, two articles that address the subject in part are published by authors from two leading institutions [3,4]. In these institutions, a large number of ERs are routinely performed by highly experienced endoscopists and their surveillance programs after