Lack of association between interleukin-22 gene polymorphisms and cancer risk: a case-control study and a meta-analysis.

BACKGROUND: Interleukin-22 (IL22) has been implicated in inflammation and tumorigenesis. The association between IL22 gene polymorphisms and cancer risk has been widely explored. However, the limited sample sizes of previous studies may produce inadequate statistical power and conflicting results, which calls for further investigations. In this study, we recruited a total of 1490 cancer patients (480 liver cancer patients, 550 lung cancer patients, and 460 gastric cancer patients) and 800 normal controls to explore the associations between IL22 gene polymorphisms (rs1179251, rs2227485, rs2227511, and rs2227473) and cancer risk. METHOD: The genotyping was performed with polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and Sanger sequencing. RESULTS: Our results showed that none of the four IL22 gene polymorphisms was associated with the risk of liver, lung or gastric cancer in Hubei Han Chinese population. To improve the statistical strength, a meta-analysis was further conducted. The results further confirmed our present findings and showed that rs1179251, rs2227485, and rs2227473 were not associated with cancer risk in total or stratified analysis. CONCLUSION: Consequently, the rs1179251, rs2227485, rs2227511, and rs2227473 polymorphisms may not be associated with cancer risk. However, further investigations using larger samples in different ethnic populations are required.