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.