Helicobacter pylori infection and risk of intestinal metaplasia in first-degree relatives of gastric cancer patients: a population based study.

Background: HP infection and family history (FH) of gastric cancer (GC) seem to be risk factors for GC. Aim and methods: to study if Hp infection is associated with an increased risk of intestinal metaplasia (IM)in relatives of GC patients. In the frame of the ongoing Loiano-Monghidoro Project (APT 2001; 15:10017), inhabitants are re-invited to undergo upper gastrointestinal endoscopy with biopsies, [sup 13]C-UBT, medical interview and questionnaire. Odds ratio (OR), as an estimate of the relative risk for IM, was calculated by logistic regression analysis. Results: of 892 subjects enrolled histological evaluation is available for 672 subjects. 104 subjects had FH+ and 568 subjects had a FH-. The prevalence of IM was 32% (140/437) vs 17.4% (41/235), (p<0.0001), in HP+ and HP- subjects, respectively (OR= 2.2, 95% CI 1.5-3.3); the risk however appeared to be greater in HP+ FH+ (OR= 2.6, 95% CI 1.0-7.3) than HP+ FH- subjects (OR= 2.0, 95% CI 1.3-3.2). The prevalence of IM was 36.5% (38/104) vs. 25.2% (143/568) (p< 0.02)in FH+ and FHsubjects respectively(OR=1.7, 95% CI 1.1-2.6). The prevalence of IM was 42.1%(32/76) vs 29.9%(108/361), (p< 0.04), in HP+ FH+ and HP+FHsubjects respectively (OR= 1.7, 95% CI 1.0-2.8). Differently the prevalence of IM was similar in HP- FH+ 21.4% (6/28) and HP- FH- 16.9% (35/207) (p= ns) (OR= 1.3, 95% CI 0.5-3.5). Conclusions: The risk of developing IM associated with HP infection is increased in first-degree relatives of GC patients and a FH+ for GC is a risk factor of IM only in HP+ subjects. [ABSTRACT FROM AUTHOR]