Alterations in DNA proliferation in gastric stump mucosa with special reference to topography

Abstract

Gastric stump carcinoma occurs more frequently at the anastomotic site than at other areas of the gastric remnant. This study was conducted to determine whether alterations in cell dynamics could be detected in the normal-looking gastric remnant mucosa and to ascertain any difference in cell dynamics between the anastomotic site and other area. Sixty-three patients who underwent curative subtotal gastrectomy for gastric adenocarcinoma were examined 8 to 130 months after operation. Mucosa at the anastomotic site and at the greater curvature were endoscopically biopsied. Cell dynamic changes were examined by flow cytometry, bromodeoxyuridine in vitro labeling, and oncogene (K-ras and c-myc) amplification and translocation by Southern blot analyses. Inflammatory changes were observed in more than 60% of the cases both at the anastomotic site and at the greater curvature both macroscopically and microscopically. Blood flow, measured by laser Doppler flowmeter, was significantly decreased at the anastomotic site compared with the greater curvature (25.0 +/- 8.1 and 32.2 +/- 9.4 mg/min/100 mg tissue, respectively; p < 0.05). Analysis of DNA histograms obtained by flow cytometry revealed a small peak at the right shoulder of 2N peak in 33% of the specimens obtained from the anastomosis site and in 15% of those from the greater curvature (p < 0.05). The number of cells at S phase measured by bromodeoxyuridine in vitro labeling was also significantly greater at the anastomotic site than at the greater curvature. None of the five patients with aneuploid DNA histograms at the anastomotic site had detectable amplification or translocation of K-ras or c-myc gene in mucosal tissue. More marked changes in the mucosal cell dynamics observed at the anastomotic site may partially explain the higher incidence of gastric stump carcinoma at the anastomotic site.