Association between an insertion/deletion polymorphism in IL-1A gene and cancer risk: a meta-analysis

Purpose: Previous studies have reported the association of an insertion/deletion (Ins/Del) polymorphism (rs3783553) in the 3' untranslated region of interleukin-1A (IL-1A) with the risk of cancer, such as oral squamous cell carcinoma, nasopharyngeal carcinoma, and cervical carcinoma. However, the results are still inconsistent. The present meta-analysis aimed to clarify the association of IL-1A rs3783553 polymorphism with cancer risk. Methods: All eligible studies were selected from PubMed, Web of Science, and Chinese National Knowledge Infrastructure up to September 2, 2015. Summary odds ratios (ORs) and 95% confidence intervals (CIs) were used to evaluate cancer risk. Results: A total of ten case-control studies with 4,514 cases and 6,689 controls were included this meta-analysis. We found that IL-1A rs3783553 polymorphism was significantly associated with cancer risk (Ins/Ins + Ins/Del vs Del/Del: OR = 0.79, 95% CI = 0.67-0.92; Ins/Ins vs Del/Del: OR = 0.61, 95% CI = 0.47-0.79; Ins/Ins vs Ins/Del + Del/Del: OR = 0.67, 95% CI = 0.55-0.83; Ins vs Del: OR = 0.81, 95% CI = 0.72-0.92). In the stratified analyses, significant effects were found among Asian populations (Ins/Ins + Ins/Del vs Del/Del: OR = 0.81, 95% CI = 0.69-0.95) and cervical carcinoma (Ins/Ins vs Del/Del: OR = 0.51, 95% CI = 0.34-0.76; Ins/Ins vs Ins/Del + Del/Del: OR = 0.52, 95% CI = 0.35-0.78). Conclusion: Our meta-analysis suggests that the IL-1A rs3783553 polymorphism contributes to susceptibility to cancer. However, well-designed studies with larger sample sizes are required to verify the results.