Characteristics of Metachronous Remnant Gastric Cancer After Proximal Gastrectomy: A Retrospective Analysis.

Purpose: Despite annual endoscopy, patients with metachronous remnant gastric cancer (MRGC) following proximal gastrectomy (PG) are at times ineligible for endoscopic resection (ER). This study aimed to clarify the clinical risk factors for ER inapplicability.

Materials and methods: We reviewed the records of 203 patients who underwent PG for cT1 gastric cancer between 2006 and 2015. The remnant stomach was categorized as a pseudofornix, corpus, or antrum.

Results: Thirty-two MRGCs were identified in the 29 patients. Twenty MRGCs were classified as ER (ER group, 62.5%), whereas 12 were not (non-ER group, 37.5%). MRGCs were located in the pseudo-fornix in 1, corpus in 5, and antrum in 14 in the ER group, and in the pseudo-fornix in 6, corpus in 4, and antrum in 2 in the non-ER group (P=0.019). Multivariate analysis revealed that the pseudo-fornix was an independent risk factor for non-ER (P=0.014). In the non-ER group, MRGCs at the pseudo-fornix (n=6) had more frequent undifferentiated-type histology (4/6 vs. 0/6), deeper (≥pT1b2; 6/6 vs. 2/6) and nodal metastasis (3/6 vs. 0/6) than non-pseudo-fornix lesions (n=6). We examined the visibility of the region developing MRGC on an annual follow-up endoscopy one year before MRGC detection. In seven lesions at the pseudofornix, visibility was only secured in two (28.6%) because of food residues. Of the 25 lesions in the non-pseudo-fornix, visibility was secured in 21 lesions (84%; P=0.010).

Conclusions: Endoscopic visibility increases the chances of ER applicability. Special preparation is required to ensure the complete clearance of food residues in the pseudo-fornix.