Clinicopathological significance of intestinal metaplasia in endoscopically resected early gastric carcinoma

Objective: To investigate the clinicopathological and prognostic significance of intestinal metaplasia (IM) in endoscopically resected early gastric carcinoma (EGC).Methods: Altogether 136 consecutive cases with EGC resected by endoscopic submucosal dissection over 5 years were included and divided into the early gastric cardiac (EGCC; n = 60) and non-cardiac carcinoma (EGNCC; n = 76) groups. Goblet cell IM and subtypes were determined with histology and immunostaining. Recurrence-free survival (RFS) was compared among various IM groups.Results: IM was identified in 128 (94.1%) EGC cases, including complete IM (n = 39), incomplete IM (n = 27), and mixed IM (n = 62). Incomplete IM was significantly more common in EGCC and exhibited a lower frequency of en bloc resection than the complete subtype. The frequency of synchronous or metachronous gastric tumor was significantly more common in EGCC with complete IM than in those with incomplete IM. Compared to EGC without IM, EGC with IM showed a significantly higher frequency of non-poorly cohesive carcinoma, en bloc resection, and non-eCuraC-1 grade. EGNCC with IM was significantly associated with negative resection margins and en bloc resection. The 5-year RFS was significantly lower in EGNCC patients with incomplete IM compared with those with mixed IM. The independent risk factors for RFS included tumor size >2 cm and eCuraC-1 grade.Conclusions: Subtyping IM in EGC helped predict endoscopic resectability, prognosis, and risk of synchronous or metachronous gastric tumor. The significance of IM differed between EGCC and EGNCC. Large studies with longer follow-up are warranted to validate our findings.