Long-term risk of metachronous gastric neoplasms after curative endoscopic submucosal dissection for early gastric cancer.

BACKGROUND

There is currently no consensus on long-term risk stratification for metachronous gastric neoplasms (MGNs) occurring beyond 5 years following endoscopic submucosal dissection (ESD).This study aimed to investigate the time-dependent changes in predictive factors for MGN after curative ESD for early gastric cancer (EGC) and analyze the clinicopathological features of late MGNs.

METHODS

We retrospectively reviewed patients who underwent ESD for early gastric neoplasms between March 2005 and June 2020. MGN was defined as a new gastric neoplasm detected at a different site >12 months following ESD. Survival data were collected and analyzed using multivariable and time-split Cox hazard regression models.

RESULTS

Among 5,571 patients treated with ESD, 876 were included with a median follow-up of 58 months. The cumulative incidence of MGN was 10.79% at 5 years and continued to accumulate beyond 5 years (26.65% at 10 years). All MGNs were stage I and there was no gastric cancer-related mortality. Cox regression analysis identified family history of gastric cancer (adjusted hazard ratio [aHR] 2.12, 95% confidence interval [CI] 1.32 - 3.41) and extensive intestinal metaplasia (aHR 6.50, 95% CI 3.73 - 11.36) as independent predictors of MGN. Histological upgrade was not associated with MGN during the first 5 years but emerged as a significant risk factor in the late period (interaction P value = 0.005).

CONCLUSION

MGNs may develop even beyond 5 years following ESD with curative resection in patients with EGC. These findings highlight the long-term risk of MGN after ESD, providing a framework for clinical risk estimation.