Interleukin-1beta and interleukin-1 receptor antagonist gene polymorphisms and gastric cancer: a meta-analysis.
BACKGROUND
Polymorphisms of interleukin-1B (IL1B) and its receptor antagonist (IL1RN) genes have been inconsistently associated with gastric cancer risk. We examined these associations by performing meta-analyses.


METHODS
Twenty-five studies testing the association between IL1B and/or IL1RN gene polymorphisms and gastric cancer were examined: 14 studies of IL1B-511, 14 studies of IL1B-31, 8 studies of IL1B+3954, and 23 studies of IL1RN. Overall and ethnicity-specific summary odds ratios and corresponding 95% confidence intervals for gastric cancer associated with these polymorphisms were estimated using fixed- and random-effects models. Heterogeneity and publication bias were evaluated.


RESULTS
IL1B-511T and IL1RN*2 were associated with gastric cancer risk in Caucasians, but not in Asians. For IL1B-511T, the association in Caucasians was stronger when intestinal-subtype and noncardia gastric cancer cases were examined. A nonsignificant trend was observed between IL1B-31C and gastric cancer in Caucasians. No significant association of IL1B+3954T and gastric cancer risk was detected. Studies with better methodologic characteristics reported stronger effects. There was no evidence of publication bias.


CONCLUSIONS
IL1B-511T is associated with gastric cancer susceptibility in Caucasians. The meta-analyses suggest that the conflicting results among studies may be explained by variation in allele frequencies among the ethnic groups and variation in tumor types, as well as by the methodologic quality of the studies.
Camargo
M Constanza
MC
Division of Gastroenterology, Hepatology, and Nutrition, Vanderbilt University Medical Center, 2215 Garland Avenue, 1005 MRB IV, Nashville, TN 37232-0252, USA. maria.c.camargo@vanderbilt.edu
Mera
Robertino
R
Correa
Pelayo
P
Peek
Richard M
RM
Fontham
Elizabeth T H
ET
Goodman
Karen J
KJ
Piazuelo
M Blanca
MB
Sicinschi
Liviu
L
Zabaleta
Jovanny
J
Schneider
Barbara G
BG
D005787:Gene Frequency; D020022:Genetic Predisposition to Disease; D005838:Genotype; D006801:Humans; D053590:Interleukin 1 Receptor Antagonist Protein; D007375:Interleukin-1 / Q000235:genetics*; D018598:Minisatellite Repeats; D011110:Polymorphism, Genetic; D020641:Polymorphism, Single Nucleotide; D012795:Sialoglycoproteins / Q000235:genetics*; D013274:Stomach Neoplasms / Q000209:etiology / Q000235:genetics*
C507763:IL1RN protein, human; D053590:Interleukin 1 Receptor Antagonist Protein; D007375:Interleukin-1; D012795:Sialoglycoproteins