title: Viable Cancer Cells in the Remnant Stomach are a Potential Source of Peritoneal Metastasis after Curative Distal Gastrectomy for Gastric Cancer.
abstract: The mechanisms underlying peritoneal metastasis (PM) after curative gastrectomy for gastric cancer (GC) are not well elucidated. This study assessed whether viable cancer cells, including cancer stemlike cells (CSCs), were present in the remnant stomach immediately before gastrointestinal (GI) tract reconstruction because these could be a source of PM after gastrectomy.
  
  
  
  Saline fluid used for remnant stomach lumen irrigation before GI reconstruction was prospectively collected from 142 consecutive patients undergoing distal gastrectomy for GC and cytologically examined. Proliferative activity (Ki67 staining) and stemness (expression of the CSC surface markers CD44s or CD44v6) were evaluated in detected cancer cells.
  
  
  
  Viable cancer cells were detected in 33 (23.2 %) of the 142 remnant stomachs. These cells formed clusters and stained positively for Ki67, indicating proliferation. Cancer cells in remnant stomachs and surface cancer cells in primary GCs from 10 (30.3 %) of these 33 cases also stained positively for CD44s or CD44v6. In a multiple logistic regression analysis, advanced cancer (odds ratio [OR], 4.65; 95 % confidence interval [CI], 1.32-16.4; P = 0.017), tumor size of 40 mm or larger (OR, 3.78; 95 % CI, 1.12-12.8; P = 0.033), and histologic differentiation (OR, 3.10; 95 % CI, 1.30-7.40; P = 0.011) were associated independently with the presence of cancer cells in the remnant stomach.
  
  
  
  Viable, proliferative, and clustered cancer cells, including CSCs, were found in remnant gastric lumens immediately before GI reconstruction, indicating a possible cellular source of PM after curative gastrectomy for GC. Dissemination of gastric contents into the peritoneal cavity should be avoided during GI reconstruction.
authors.affiliation: Department of Surgery, Shiga University of Medical Science, Otsu, Shiga, Japan. satoshi1@belle.shiga-med.ac.jp.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Murata
authors.affiliation: Department of Surgery, Shiga University of Medical Science, Otsu, Shiga, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Yamamoto
authors.affiliation: Department of Surgery, Shiga University of Medical Science, Otsu, Shiga, Japan.
authors.forename: Tsuyoshi
authors.initials: T
authors.lastname: Yamaguchi
authors.affiliation: Department of Surgery, Shiga University of Medical Science, Otsu, Shiga, Japan.
authors.forename: Sachiko
authors.initials: S
authors.lastname: Kaida
authors.affiliation: Division of Diagnostic Pathology, Department of Clinical Laboratory Medicine, Shiga University of Medical Science, Otsu, Shiga, Japan.
authors.forename: Mitsuaki
authors.initials: M
authors.lastname: Ishida
authors.affiliation: Department of Surgery, Shiga University of Medical Science, Otsu, Shiga, Japan.
authors.forename: Hirokazu
authors.initials: H
authors.lastname: Kodama
authors.affiliation: Department of Surgery, Shiga University of Medical Science, Otsu, Shiga, Japan.
authors.forename: Katsushi
authors.initials: K
authors.lastname: Takebayashi
authors.affiliation: Department of Surgery, Shiga University of Medical Science, Otsu, Shiga, Japan.
authors.forename: Tomoharu
authors.initials: T
authors.lastname: Shimizu
authors.affiliation: Department of Surgery, Shiga University of Medical Science, Otsu, Shiga, Japan.
authors.forename: Toru
authors.initials: T
authors.lastname: Miyake
authors.affiliation: Biomedical Innovation Center, Shiga University of Medical Science, Otsu, Shiga, Japan.
authors.forename: Tohru
authors.initials: T
authors.lastname: Tani
authors.affiliation: Division of Diagnostic Pathology, Department of Clinical Laboratory Medicine, Shiga University of Medical Science, Otsu, Shiga, Japan.
authors.forename: Ryoji
authors.initials: R
authors.lastname: Kushima
authors.affiliation: Department of Surgery, Shiga University of Medical Science, Otsu, Shiga, Japan.
authors.forename: Masaji
authors.initials: M
authors.lastname: Tani
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000032:analysis; D005260:Female; D005743:Gastrectomy; D018530:Gastric Stump / Q000473:pathology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010534:Peritoneal Neoplasms / Q000556:secondary; D011446:Prospective Studies; D012307:Risk Factors; D013274:Stomach Neoplasms / Q000473:pathology* / Q000601:surgery*; D015996:Survival Rate; D007507:Therapeutic Irrigation; D016896:Treatment Outcome
chemical_list: D014408:Biomarkers, Tumor