Oncological outcomes of endoscopic vs. surgical resection for poorly differentiated early gastric cancer: a Surveillance, Epidemiology, and End Results based retrospective propensity score study.

[BACKGROUND] For poorly differentiated early gastric cancer (PDEGC), the oncologic safety and outcomes of endoscopic resection vs. surgical resection remain controversial. This study aimed to evaluate the prognostic difference of endoscopic resection and surgical resection for PDEGCs.

[METHODS] We retrospectively collected data of PDEGC cases from the Surveillance, Epidemiology, and End Results (SEER) database. A final cohort of 558 PDEGC cases with highly complete clinical and follow-up records available for analysis. Cox multivariate analysis and univariate analysis after propensity score matching (PSM) were used to evaluate the prognostic differences. Cancer-specific survival (CSS) and overall survival (OS) were chosen as the endpoints of this study.

[RESULTS] In multivariate analysis of the raw dataset, surgical resection was observed as a relative protective factor for CSS [hazard ratio: 0.61, 95% confidence interval (CI): 0.28-1.33, P  = 0.215] and an independent protective factor for OS (hazard ratio: 0.56, 95% CI: 0.32-0.98, P  = 0.042). Survival curves based on post-PSM dataset exhibited significant differences in analysis on both CSS ( Plog-rank = 0.034) and OS ( Plog-rank = 0.033).

[CONCLUSION] In this retrospective study on PDEGC utilizing the SEER database, our analysis suggests that endoscopic resection for PDEGC was associated with significantly worse CSS and OS compared with surgical resection. These findings reinforce the current guideline recommendations favoring surgical resection as the treatment of choice for PDEGC to achieve optimal oncological safety.