Long-term Outcomes of Undifferentiated-Type Early Gastric Cancer with Positive Horizontal Margins after Endoscopic Resection

Abstract

Background/Aims: This study examined the long-term outcomes of undifferentiated-type early gastric cancer (UD EGC) with positive horizontal margins (HMs) after endoscopic resection (ER) and compared them between additional surgery and nonsurgical management. Methods:From 2005 to 2015, a total of 1,124 patients with UD EGC underwent ER at 18 tertiary hospitals in Korea. Of them, 92 patients with positive HMs as the only noncurative factor (n=25) or with both positive HMs and tumor size >2 cm (n=67) were included. These patients underwent additional surgery (n=40), underwent additional endoscopic treatment (n=6), or were followed up without further treatment (n=46).Results: No lymph node (LN) metastasis was found in patients who underwent additional surgery. During a median follow-up of 57.7 months (interquartile range, 27.6 to 68.8 months), no LN or distant metastases or gastric cancer-related deaths occurred in the overall cohort. At baseline, the residual cancer rate was 57.8% (26/45) after additional surgery or ER. The 5-year local recurrence rate was 33.6% among patients who were followed up without additional treatment. The 5-year overall survival rates were 95.0% and 87.8% after additional surgery and nonsurgical management (endoscopic treatment or close follow-up), respectively (log-rank p=0.224). In the multivariate Cox regression analysis, nonsurgical management was not associated with an increased risk of mortality.Conclusions: UD EGC with positive HMs after ER may have favorable long-term outcomes and a very low risk of LN metastasis. Nonsurgical management may be suggested as an alternative, particularly for patients with old age or chronic illness.

Korean Practice Guidelines for Gastric Cancer 2022: An Evidence-based, Multidisciplinary Approach

“…Seven retrospective studies compared the recurrence rate of endoscopic treatments including re-ESD and APC, with gastrectomy or close observation [ 188 189 190 191 192 193 194 ]. The mean follow-up period for the 6 studies was 60 months, and these studies included both differentiated and undifferentiated cancers.…”

“…Therefore, close observation could be considered a selective treatment option in cases of positive lateral margins in differentiated-type EGC. Recently, a retrospective study comparing gastrectomy and nonsurgical treatments (endoscopic treatment [6/52] and close observation [46/52]) in undifferentiated-type EGC has also been published [ 194 195 ]. The local recurrence rate was 0% in the surgical group and 21.2% (11/52) in the nonsurgical group, and the 5-year survival rate was 87.8% in the nonsurgical group, lower than the 95.0% in the surgical group, but without statistical significance.…”

Early gastric cancer recurrence after endoscopic submucosal dissection: Not to be ignored!

“…Previous research found that a cancer-positive horizontal margin (HM) more significant than 6 mm had been identified as an independent risk factor in the local GC recurrence[ 12 ]. However, subsequent studies have also shown that, without additional treatment, positive HM patients still have a comparable long-term prognosis and a low risk of lymphatic metastasis despite a non-low recurrence rate[ 13 ]. Furthermore, published research has found a higher GC recurrence risk in post-ESD patients with unevaluable or positive vertical margins than those with unevaluable or positive HM[ 14 ].…”

Should All Undifferentiated Early Gastric Cancer Patients Undergoing Noncurative Endoscopic Resection Be Sent to the Operating Room?

“…In last issue of Gut and Liver, Yang et al 9 conducted an external validation of the eCura system for UD EGC using a large number of cases, and their study findings are reported herein. The authors collected data from 634 patients with noncurative endoscopic resection, of whom 270 underwent radical surgery and 364 received no additional treatment, from 18 institutions in Korea.…”