Endoscopic Mucosal Dissection (ESD) for Early Gastric Cancer (GC): A Prospective Study for Extension of the Indication of Endoscopic Mucosal Resection (EMR)

Abstract

Background: Minimally invasive treatment such as EMR is widely noticed as a therapy for early GC. ESD is a promising EMR method which enables us to resect lesions en bloc as we like. Recently, in Japan, a guideline of treatment for GC shows some conditions of GC which are hardly associated with nodal metastasis. The aim of this study was to assess efficacy and safety of ESD against those lesions. Patients and Methods: We designed a prospective study in which ESD was applied in patients with differentiated-type GC up to 30 mm in diameter regardless of ulceration or above 30 mm without ulceration, but definite signs of submucosal invasion. According to final diagnosis after the ESD, GCs below, considered to have hardly metastasis, were followed up and otherwise were advised to be operated on additionally; differentiated-type mucosal GC above 30 mm in diameter without ulceration, and GC up to 30 mm with ulceration and/or minute submucosal invasion. The protocol was approved by the ethics committee of Osaka National Hospital, and consent to take part in the study was obtained from patients. Complete resection was defined if the lateral and basal margins were free of tumor pathologically. Followed-up endoscopic examinations are performed 1, 3, 6 months later, and then every six months. Results: Between Nov. 2001 and Nov. 2004, 180 lesions were enrolled. The average size of GC resected was 20 mm (range: 2-70 mm). Of 180 lesions, 144 (84%) were completely resected. Twenty-seven patients were recommended to have additional operation mainly because of massive submucosal invasion or lymphovascular involvement, and nodal metastasis was recognized in two of 12 patients who were actually operated on. Two of the remaining 153 patients recurred locally during follow-up period of median 19 mos (range: 3-36), and both were successfully treated by repeated ESD. No distant metastasis was noted. Perforation and bleeding were encountered in 9% and 8% of the patients respectively, which both happened more frequently in case of GC with ulceration (p < 0.05). No emergent surgery and no immediate mortality was noted. Conclusions: These results suggest that ESD is feasible for large mucosal GC without ulceration or for GC with ulceration and/or minute submucosal invasion up to 30 mm in diameter. However, to extend the indication of EMR for GC, correct pathological diagnosis obtained by en bloc resection is essential and the long-term prognosis should be investigated. Background: Minimally invasive treatment such as EMR is widely noticed as a therapy for early GC. ESD is a promising EMR method which enables us to resect lesions en bloc as we like. Recently, in Japan, a guideline of treatment for GC shows some conditions of GC which are hardly associated with nodal metastasis. The aim of this study was to assess efficacy and safety of ESD against those lesions. Patients and Methods: We designed a prospective study in which ESD was applied in patients with differentiated-type GC up to 30 mm in diameter regardless of ulceration or above 30 mm without ulceration, but definite signs of submucosal invasion. According to final diagnosis after the ESD, GCs below, considered to have hardly metastasis, were followed up and otherwise were advised to be operated on additionally; differentiated-type mucosal GC above 30 mm in diameter without ulceration, and GC up to 30 mm with ulceration and/or minute submucosal invasion. The protocol was approved by the ethics committee of Osaka National Hospital, and consent to take part in the study was obtained from patients. Complete resection was defined if the lateral and basal margins were free of tumor pathologically. Followed-up endoscopic examinations are performed 1, 3, 6 months later, and then every six months. Results: Between Nov. 2001 and Nov. 2004, 180 lesions were enrolled. The average size of GC resected was 20 mm (range: 2-70 mm). Of 180 lesions, 144 (84%) were completely resected. Twenty-seven patients were recommended to have additional operation mainly because of massive submucosal invasion or lymphovascular involvement, and nodal metastasis was recognized in two of 12 patients who were actually operated on. Two of the remaining 153 patients recurred locally during follow-up period of median 19 mos (range: 3-36), and both were successfully treated by repeated ESD. No distant metastasis was noted. Perforation and bleeding were encountered in 9% and 8% of the patients respectively, which both happened more frequently in case of GC with ulceration (p < 0.05). No emergent surgery and no immediate mortality was noted. Conclusions: These results suggest that ESD is feasible for large mucosal GC without ulceration or for GC with ulceration and/or minute submucosal invasion up to 30 mm in diameter. However, to extend the indication of EMR for GC, correct pathological diagnosis obtained by en bloc resection is essential and the long-term prognosis should be investigated.