After endoscopic submucosal dissection of early gastric cancer, patients are at high risk for synchronous or metachronous multiple gastric cancers.
Dr Tetsuo Takehara and colleagues elucidated the time at which multiple cancers develop, and determined whether scheduled endoscopic surveillance might control their development.
A multicentre retrospective cohort study from 12 hospitals was conducted.
Patients with early gastric cancer who underwent endoscopic submucosal dissection with en bloc margin-negative curative resection were included.
The research team classified synchronous cancer classified as concomitant cancer or missed cancer.
The cumulative incidence of metachronous cancers and overall survival rate were calculated using the Kaplan–Meier method.
From 1999 to 2010, 1258 patients met the inclusion criteria.
Synchronous or metachronous multiple cancers were detected in 14% of patients during a mean of 27 months.
|Multiple cancers were detected in 14% of patients |
Among the 110 synchronous cancers, 21 were missed at the time of the initial endoscopic submucosal dissection.
The researchers found that many of the missed lesions existed in the upper third of the stomach, and the miss rate was associated with the endoscopist's inexperience.
The cumulative incidence of metachronous cancers increased linearly and the mean annual incidence rate was 4%.
The incidence rate did not differ between patients with or without Helicobacter pylori eradication.
The team observed that less than 1% of lesions were detected as massively invading cancers during the follow-up.
The researchers found that 19% of synchronous cancers were not detected until the initial endoscopic submucosal dissection.
Dr Takehara's team concludes, "The incidence rate of metachronous cancer after endoscopic submucosal dissection was constant."
"Scheduled endoscopic surveillance showed that almost all recurrent lesions were treatable by endoscopic resection."