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.
The EUROGAST research project focuses on a condition known to frequently precede the onset of gastric cancer: chronic atrophic gastritis (GAG). Two potential serum markers for CAG have become available: the concentration of serum pepsinogen (which decreases with increasing CAG) and the presence of serum antibodies to the bacterium Helicobacter pylori. The EUROGAST study looking at these 2 indicators in a variety of populations throughout Europe, selected for their variability in mortality from gastric cancer. Biochemical and metabolic differences between these groups are also studied, so as to determine the physiological processes that increase the cancer risk CAG sufferers. The second major aspect of EUROGAST is to assess the level of alkyl deoxy-ribonucleic acid (DNA) adducts in lymphocyte preparations from these populations. Several animal and human studies have demonstrated the formation of DNA adducts after carcinogen exposure. The level of alkyl adducts is thought to be indicative of exposure to alkylating agents, especially N-nitroso compounds which may have an aetiological role in gastric cancer. The study is attempting to estimate lymphocyte adduct formation in relation to gastric cancer risk in the populations studied and, within each population, to correlate adduct formation with the presence of serologically defined CAG.
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.