Performance of endoscopic submucosal dissection for undifferentiated early gastric cancer: a multicenter retrospective cohort

Background and study aims Undifferentiated early gastric cancer (UD-EGC) represents an extended indication for endoscopic submucosal dissection (ESD) based on the existing guidelines. This study evaluated the prevalence of UD-EGC recurrence after ESD, and potentially implicated risk factors. Patients and methods Data from 17 centers were collected retrospectively including demographics, endoscopic and pathological findings, and follow-up data from UD-EGC cases treated by ESD. Patients with incomplete resection or advanced disease were excluded. Descriptive statistics quantified variables and calculated the incidence of recurrence. Chi-square test was applied to assess any link between independent variables and relapse; significantly associated variables were inserted to a multivariable regression model. Results Seventy-one patients were eligible, with 2:1 female to male ratio and age of 65.8 +/- 11.8 years. Mean lesion size was 33.5 +/- 18.8mm and the most frequent histological subtype was signet ring-cells UGC (2:1). Patients were followed-up every 5.6 +/- 3.7 months with a mean surveillance period of 29.3 +/- 15.3 months until data collection. Four patients (5.6%) developed local recurrence 8.8 +/- 6.5 months post-ESD, with no lymph node or distal metastases been reported. Lesion size was not associated with recurrence (P = 0.32), in contrast to lymphovascular and perineural invasion which were independently associated with local recurrence ( P = 0.006 and P < 0.001, respectively). Conclusions ESD could be considered as the initial step to manage UD-EGC, providing at least an entire-lesion biopsy to guide therapeutic strategy. When histology confirms absence of lymphovascular and perineural invasion, this modality could be therapeutic, providing low recurrence rates.

Automated summary

This study evaluated the recurrence rate of undifferentiated early gastric cancer (UD-EGC) after endoscopic submucosal dissection (ESD) and identified potential risk factors. The results showed that 5.6% of patients had local recurrence after ESD, with no lymph node or distant metastases reported. Lesion size was not associated with recurrence, while lymphovascular and perineural invasion were independent risk factors for local recurrence.