Investigation of Endoscopic and Pathologic Features for Safe Endoscopic Treatment of Superficial Spreading Early Gastric Cancer

Superficial spreading early gastric cancer (EGC) is a rare disease that is treated mainly by surgery. There are few studies on the safety of endoscopic treatment for patients with superficial spreading EGC. The aims of this study were to (1) investigate the risk of lymph node metastasis of superficial spreading EGC and (2) investigate the potential criteria for endoscopic treatment of superficial spreading EGC using surgical specimens. Between 2000 and 2010, patients who received curative surgery of R0 resection at Severance Hospital (Seoul, Korea) for early gastric cancer were enrolled. The superficial spreading EGC was defined as cancer in which the longest tumor length was ≥6cm. The medical records of the patients were reviewed retrospectively. Of the 3813 patients with EGC, 140 (3.7%) had lesions ≥ 6cm, whereas 3673 (96.3%) had lesions<6cm. Patients with superficial spreading EGC had higher rates of submucosal cancer (59.3% vs 45.7%, P=0.002), lymphovascular invasion (18.6% vs 9.8%, P<0.001), and lymph node metastasis (15.7% vs 10.1%, P=0.033) compared with patients with common EGC (< 6cm). Multivariate analysis revealed that a tumor ≥ 6cm was not strongly associated with lymph node metastasis in EGC, as compared with a tumor<6cm, but submucosal invasion and lymphovascular invasion were strongly associated with lymph node metastasis in EGC. In mucosal cancer without ulcers, tumors ≥ 6cm had a higher rate of lymph node metastasis than tumors ≤ 2cm; however, this trend was not significant (7.7% vs 5.3%, P=0.455). Superficial spreading EGC was not associated with an increased risk of lymph node metastasis compared with common EGC. We suggest that differentiated intramucosal superficial spreading EGC without ulceration can be treated by endoscopic submucosal dissection.