Endoscopic Submucosal Dissection (ESD) for Early Gastric Cancer (GC) - Long-Term Outcomes of a Prospective Study in Its Expanded Indication

Abstract

Introduction: Endoscopic mucosal resection (EMR) is recognized as a minimally invasive treatment for superficial GC without metastasis. ESD is a new technique developed to obtain en bloc resection even for large and/or ulcerative lesions. The aim of this study was to assess efficacy and safety of ESD against some conditions of GC which are hardly associated with nodal metastasis, as proposed by Soetikno R., Gotoda T., et al. (J Clin Oncol.23: 4490-98, 2005). Aims 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 enrolled and 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 our hospitals, 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 Sep. 2008 ESD was performed in 624 patients. Among them 543 were enrolled, and the followed-up period was median 36 months. Complete resection was achieved in 513 patients (94%), and perforation and bleeding were encountered in 6% and 5%, respectively. No emergent surgery and no immediate mortality were noted. Six patients (1.3%) recurred locally during follow-up period of median 18 months (range: 3-32). In all cases histological evaluation of the margin were tumor-positive or not evaluable because of piecemeal resection. No distant metastasis was noted. The remaining 81 patients were advised to receive additional operation mainly because of massive submucosal invasion or lymphovascular involvement. Nodal metastasis was recognized in 3 of 49 patients who were actually operated on, and local recurrence occurred in 3 of 32 patients who rejected operation and were followed up. Totally 9 recurrent lesions were managed to treat by repeated ESD in spite of severe fibrosis in the submucosa, and histologically they were all mucosal cancer. Conclusion: ESD achieves complete resection even in large or ulcerative GC, providing the precise histological assessment. However, the long-term prognosis such as 5-year survival should continuously be investigated.