Figure 1.

Study design. Among 283 EGC patients who underwent ESD at the Yamagata University Hospital between January 2009 and December 2012 (A), we selected ten patients who had developed MGC more than a year after curative ESD and successful HP eradication (the M group). We then selected ten patients with no MGC developments for more than 3 years after ESD and successful HP eradication (the N group). The somatic variants in initial EGC and adjacent non-cancerous mucosa were compared between the samples obtained from the M group and those obtained from the N group (B). We used the term “initial EGC” to differentiate the condition from MGC, which is also called “secondary cancer”. *The patients in the N group matched the ten patients in the M group in terms of age, gender, location, size, and histological type of the initial EGC. EGC early gastric cancer, ESD endoscopic submucosal dissection, MGC metachronous gastric cancer, HP Helicobacter pylori.