Metachronous Gastric Cancer Occurring after Endoscopic Resection of Early Gastric Cancer

Abstract

Endoscopic resection (ER) has been widely used as a curative treatment for early gastric cancers (EGCs). Especially endoscopic submucosal dissection has several merits such as high en bloc and curative resection rates for EGCs and preservation of the entire stomach. However, ER has the inevitable limitation that the possibility of newly developing gastric cancers in the preserved stomach is still present. Metachronous gastric cancer (MGC) is defined as a newly developed gastric cancer occurring at a previously uninvolved site ≥1 year after the index ER of EGCs. The incidence of MGC is 3.3~15.6% and increases over time after ER. Old age, male sex, current smoking, severe atrophy and intestinal metaplasia, persistent Helicobacter pylori (H. pylori) infection, differentiated-type histology, and multiple initial gastric cancers are risk factors of MGC. As H. pylori eradication could reduce the risk of MGC after ER of EGCs, H. pylori eradication is strongly recommended for the prevention of MGC after ER of EGCs. Most MGCs are found at an early stage on regular surveillance endoscopy after ER and successfully treated with ER, with excellent long-term outcomes.