© Georg Thieme Verlag KG Stuttgart · New York
Upper gastrointestinal tumors
13 January 2011 (online)
Lymph node metastasis from intestinal-type early gastric cancer: experience in a single institution and reassessment of the extended criteria for endoscopic submucosal dissection (Kang et al., Gastrointest Endosc 2010 )
Improvements in both endoscopic detection methods and treatment techniques such as endoscopic mucosal resection (EMR) and endoscopic submucosal dissection (ESD) have been readily applied in the treatment of early gastric cancers (EGC), notably in Asia. The risk of lymph node metastases have been largely based on Japanese series. Proposed extended criteria for ESD in treating intestinal-type EGC include  :1) differentiated mucosal cancer of any size without ulcer; 2) differentiated mucosal cancer ≤ 3 cm with ulcer; and 3) submucosal cancer ≤ 3 cm (sm1 < 500 µm), without lymphovascular invasion. This large retrospective Korean cohort described by Kang et al. included 478 patients who were naive to endoscopic therapies and who were undergoing gastrectomy and lymph node dissection for EGC (intramucosal 56 %, submucosal 44 %). Risk factors for lymph node invasion were analyzed and also compared with the extended criteria used for ESD of intestinal-type EGC. Similar to previous reports, the incidence of lymph node metastasis (13 %) was higher for submucosal EGCs than for mucosal EGCs (25 % vs. 3 %; P < 0.001), increased size (P < 0.001), depth of invasion (P < 0.001), and lymphovascular invasion (P < 0.001). In contrast to other reports, an elevated morphology (grouping Paris classification types I, IIa, IIa + IIb, IIa + IIc) was strongly associated with the risk for lymph node metastasis for the entire cohort (P < 0.001) and remained significant on multivariate analysis when restricted to intestinal-type lesions (n = 296) (P < 0.006). When the authors compared their results to the established extended criteria permitting ESD, seven patients with intestinal-type EGCs were found to have lymph node metastasis: 2 / 146 patients (1.4 %) with small (≤ 3 cm) non-ulcerated mucosal cancer; 2 / 126 patients (1.6 %) with cancer ≤ 3 cm with no lymphovascular emboli and irrespective of the presence of ulceration; and 3/20 patients (15.0 %) with intestinal-type submucosal cancer (sm1 ≤ 500 mm) without lymphovascular invasion and measuring ≤ 3 cm in size.
Endoscopic morphological aspects may need to be revisited prior to stratifying patients for ESD; however, it is important to remember that ESD or EMR in itself, although of curative therapeutic potential, forms part of an important staging tool for superficial carcinomas, and definitive therapies can obviously be modified accordingly.