Metachronous gastric cancers after endoscopic resection: how effective is annual endoscopic surveillance?

Endoscopic resection (ER) has been widely accepted in Japan as a less invasive treatment for early gastric cancer, but the incidence of subsequent metachronous gastric cancer (MGC) and the appropriate endoscopic follow-up interval after ER have not been determined as yet. In this study, we investigated the incidence of MGC after ER and assessed our annual endoscopic surveillance program after ER.

We studied the clinicopathological features of 633 consecutive ER patients (575 with a single lesion and 58 with synchronous multiple lesions) treated at our institution from 1987 through 2002, after excluding 158 patients who underwent additional surgery due to noncurative ERs, 180 patients whose surveillance periods were less than 1 year, 1 patient with hereditary non-polyposis colorectal cancer, and 1 patient with gastric tube cancer. We defined a second cancer found within 1 year after ER as "synchronous" and a second cancer found after 1 year as "metachronous."

First MGCs had an overall incidence of 8.2% (52 out of 633 patients); the annual incidence was constant, and the cumulative 3-year incidence was 5.9%. The average time to the discovery of a first MGC after the initial ER was 3.1 +/- 1.7 years (range, 1-8.6 years). Almost all first MGCs (96.2%, 50 out of 52 lesions) were treated curatively with repeat ER.

In order to detect MGC at a stage early enough for a curative repeat ER, an annual endoscopic surveillance program is both practical and effective for post-ER patients.