Long-term outcome of regional cooperation pathway after endoscopic submucosal dissection for early detection of new gastric cancer.

Objectives: The Cancer Control Act requires the maintenance of regional cooperation pathways (RCP) for cancer treatment. In 2008, we started RCP for early detection of new gastric cancer after endoscopic submucosal dissection (ESD). In gastric cancer treatment, RCP after surgical resection had been widely used, but little is known about RCP after ESD. This study aimed to evaluate the effectiveness of RCP after ESD.

Methods: This study included 465 patients on whom our RCP was implemented from 2008 to 2018. A regional family physician performed surveillance endoscopy at 3 months and 1 year after ESD and annually thereafter. We retrospectively evaluated the cumulative incidence and treatment outcomes of new gastric cancer and compared them with previous reports.

Results: During a median follow-up period of 70.5 months (3-120 months), 58 patients developed new gastric cancers, and metachronous gastric cancer was detected in 55 patients more than 1 year after ESD. The 5-year cumulative incidence rate was 9.8%. Three patients did not want treatment. Among the remaining 55 patients, the initial treatment was ESD in 51 and surgical resection in 4. Eventually, 50 patients (48 in the ESD group and 2 in the surgical resection group) fulfilled the pathologic criteria for curative ESD. There were no deaths due to gastric cancer.

Conclusion: Our study was the first to reveal the incidence of new gastric cancer after ESD using RCP. Most lesions were cured with ESD, and no patients died of gastric cancer. Therefore, we consider RCPs to be an option for surveillance after ESD.