Gastric epithelial cell proliferation and ras oncogene p21 expression in first-degree relatives of gastric cancer patients: a case???control study

Abstract

Individuals with a family history of gastric cancer have an increased risk of developing such neoplasia. This study aimed to assess epithelial cell proliferation and ras oncogene mutation in such individuals. Twenty dyspeptic, first-degree relatives of patients with gastric cancer and 20 matched controls were enrolled. Endoscopy with biopsies was performed in all cases. Gastric specimens were used to look for Helicobacter pylori infection and to assess both epithelial cell proliferation and ras oncogene expression by immunohistochemistry. Cell proliferation values were not significantly different between the patient and control groups (18.1 +/- 7.1 versus 18.9 +/- 7.4; P = 0.7). Overall, ras mutation was detected in five out of 40 cases, and its distribution was similar between patients and controls (20 versus 10%; P = 0.9), as well as between H. pylori-positive and negative patients (22 versus 9%; P = 0.2). Cell proliferation values tended to be higher in cases with ras mutation than in those without (25.2 +/- 9.4 versus 16.8 +/- 5.8; P = 0.08). Cell proliferation values were significantly higher in H. pylori-positive cases compared with uninfected cases, in both patient (24.7 +/- 4.7 versus 12.5 +/- 2.4; P = 0.0003) and control (25.9 +/- 4.8 versus 13.3 +/- 2.8; P = 0.0003) groups. Both gastric cell proliferation values and ras mutation prevalence did not differ between first-degree relatives of gastric cancer patients and controls. H. pylori infection similarly increased the proliferation index of gastric mucosa in both groups.