Increased incidence of secondary gastric neoplasia in patients with early gastric cancer and coexisting gastric neoplasia at the initial endoscopic evaluation

Background and aims Multiple synchronous gastric cancers are found in up to 14% of affected patients. The aim of this study was to determine the incidence of secondary gastric neoplasia including missed synchronous gastric neoplasia in this patient group compared with that after a single cancer resection. Patients and methods Four hundred and forty patients who underwent endoscopic resection for early gastric cancer (EGC) were divided into two groups: those with or without synchronous gastric neoplasia at the initial assessment. Secondary gastric neoplasia was defined as missed synchronous gastric neoplasia or metachronous gastric neoplasia. We compared the clinicopathological characteristics and the incidence of secondary gastric neoplasia between the two groups. Results Synchronous gastric neoplasias were found in 34 patients (7.7%) at the initial endoscopic examination of EGC. Secondary gastric neoplasias were found in 67 of 440 patients (15.2%) during the follow-up period (median 24.0 months). The incidence of secondary gastric neoplasia and missed synchronous gastric neoplasia was higher in those patients with synchronous gastric neoplasia than in those with a solitary EGC at the initial treatment (P<0.01). Between the two groups, the risk of the secondary neoplasia was significantly higher within 1 year after endoscopic resection (P<0.01), but not after 1 year (P=0.20). Conclusion EGC with synchronous gastric neoplasia at the initial endoscopic examination was associated with an increased risk of secondary gastric neoplasia. These patients should be evaluated carefully with a shorter interval after the initial treatment.