This international study was set up to look at the epidemiology of Helicobacter pylori infection, low levels of serum pepsinogen A (indicative of severe chronic atrophic gastritis) and lymphocytic alkyl-DNA adducts and to relate these biological entities to the occurrence of gastric cancer worldwide.
An international study was set up to look at the epidemiology of Helicobacter pylori infection, low levels of serum pepsinogen A (indicative of severe chronic atrophic gastritis) and lymphocytic alkyl deoxyribonucleic acid (DNA) adducts and to relate these biological entities to the occurrence of gastric cancer worldwide.
There was a statistically significant relationship between the prevalence of H. pylori seropositivity and log cumulative rates for both gastric cancer mortality (coefficient = 2.68 probability = 0.001) and incidence (coefficient = 1.79 probability = 0.002). There was also a highly significant association between the percentage prevalence of low serum pepsinogen A levels (less than 25 ng/ml) and gastric cancer rates in males (coefficients 0.43 (probability = 0.006) for mortality and 1.001 (probability = 0.0001) for incidence) but not in females. The prevalence of methyl DNA adducts in 55 to 64 year old nonsmokers was significantly higher in centres with a high risk of gastric cancer in comparison with those with a low risk (12.3% versus 1.1% probability less than 0.0001).
H. pylori seropositivity was more common in the 55 to 64 year age group than in the 25 to 34 year age group (62.4% versus 34.9%) and in subjects with a lower standard of education (61.6% versus 46.9% in those with secondary education and 34.1% in those with a higher education). There was no difference between men and women and seropositivity was not related to tobacco smoking or alcohol consumption. There was a strong correlation between the prevalence of H. pylori seropositivity and low pepsinogen A levels in the 55 to 64 age group at the population level (correlation = 0.79 probability versus 0.001).
In order to examine the epidemiology of chronic gastritis with atrophy and its association with gastric cancer, an ecological study, EUROGAST, was organised using these markers as a Concerted Action of the European Community Medical and Health Research Programme IV.
The original objectives of the EUROGAST study were:
1 To investigate the variability in serum pepsinogen A and C levels and the presence of serum IgG antibodies to H.pylori in representative samples of 12 geographically defined populations throughout Europe.
2 To examine the degree of association between the incidence and mortality from gastric cancer and the levels of serum pepsinogens and the prevalence of H.pylori antibodies.
3 To examine the extent and variability of the formation of alkyl-DNA adducts in peripheral lymphocytes and to relate the presence of adducts to gastric cancer rates and, within each population, to the presence of serologically defined atrophic gastritis (defined using pepsinogen levels).
The study was subsequently extended firstly by including additional populations in non-EC Europe, Africa, Japan and the US. This was to extend the range in cancer risk within the study populations. Secondly an additional objective became evident during the study:
4 To establish a biological resource of blood fractions, from different defined populations, collected, processed and stored under standardised conditions with accompanying socio-demographic data and comparable vital statistics about cancers of the stomach, colon, oesophagus, lung, breast (female) and prostate.