Interleukin 1β-511T gene (IL1β) polymorphism is correlated with gastric cancer in the Caucasian population: Results from a meta-analysis

The polymorphisms of interleukin-1β (IL1β) genes have been controversially correlated with gastric cancer risk. We examined all the available published studies through a meta-analysis approach. Twenty-one studies assessing the correlation between IL1β gene polymorphisms and gastric cancer were examined: 15 studies evaluated the role of IL1β-511T, 12 of IL1β-31T and 6 investigated both polymorphisms. The IL1β-511T polymorphism was correlated with an increased risk of developing gastric cancer in the global population (OR of 1.23, 95% CI 1.09-1.37, P=0.0002). The analysis of the population stratified for Caucasian and Asian ethnicities showed that the IL1β-511T polymorphism was correlated with a statistically significant increased risk of gastric cancer in the Caucasian (OR of 1.56, 95% CI 1.32-1.84, P<0.00001), but not in the Asian population (OR of 1, 95% CI 0.85-1.16, P=0.95). An analysis of patients with the IL1β-31T genotype did not show an increased risk of developing gastric cancer either on the overall or stratified population. The present data partially agree with the results of the two recently published meta-analyses. Our findings confirm the correlation between the IL1β-511T allele polymorphism and gastric cancer risk in the overall population. However, this correlation is not statistically significant in the Asian, but is strongly correlated in the Caucasian subgroup. The present analysis considered a more copious sample size of cases after taking into account all the studies published recently by searching the ‘PubMed’ and ‘MEDLINE’ databases until July 2007. Hence, the present study contributes to clarify the controversial results on IL1β polymorphisms and gastric cancer risk correlation evidencing the importance of ethnicity in the generation of the IL1β polymorphism analysis.