S1408 Endoscopic Submucosal Dissection versus Surgery for Early Gastric Cancer With Undifferentiated Type Histology: A Systematic Review and Meta-Analysis

Introduction: Endoscopic submucosal dissection (ESD) is considered a standard treatment for early gastric cancer (EGC). However, its indication for the management of undifferentiated EGC is controversial. We compared the short- and long-term outcomes of ESD vs. surgery in the management of undifferentiated EGC. Methods: We performed a systematic review until March 2021 for studies assessing patients with undifferentiated EGC that met expanded indication and who were treated with ESD or surgery. Databases included Medline, Embase, Scopus, and Web of Science. The primary outcome was all-cause mortality. Secondary outcomes were complete histological, overall complication and recurrence rate. Newcastle-Ottawa Quality Assessment Scale was used to assess the quality of studies. Random effects meta-analyses were conducted, and effects shown as relative risks (RR) and their 95% confidence intervals (CIs). Results: Seven studies were included in the final analysis, with 755 and 1882 patients treated by ESD and surgery, respectively. All studies were Asian (six from Korea and one from China). Use of ESD was associated with an increased all-cause mortality (RR, 2.17; 95% CI, 1.24–3.81; p < 0.01). Furthermore, surgery was associated with lower risk of any recurrence (RR, 5.24; 95% CI, 1.49–18.46; p=0.01). No significant difference was found in the complete histological resection rate (RR, 0.94; 95% CI, 0.89–1.00; p=0.05) and in overall complication rate (RR, 1.01; 95% CI, 0.27–3.69; p=0.99) between the ESD and surgery groups. The risk of all-cause mortality was not significant if only the two studies performing propensity score matching were included (RR, 2.28; 95% CI, 0.95–5.47; p=0.06). If studies enrolling only patients with curative resections are included (two studies), all-cause mortality wsas higher in the ESD group (RR, 2.28; 95% CI, 1.18–4.39; p=0.01), but the risk of recurrence was similar (RR, 8.44; 95% CI, 0.43–166.81; p=0.16). Conclusion: Surgical treatment appears to be preferable for undifferentiated EGC. However, a strict and careful patient selection for ESD and meticulous surveillance after a curative resection could propose ESD as an alternative treatment.Figure 1.: a. Forest plot of All-cause mortality comparing endoscopic submucosal dissection (ESD) and surgery. b. Forest plot of Any recurrence comparing ESD and surgery CI, confidence interval.