Role of interleukin-12 gene polymorphisms in the onset risk of cancer: a meta-analysis

// Yi Zheng 1, 2, * , Meng Wang 2, * , Tian Tian 2, * , Kang Liu 2 , Xinghan Liu 2 , Yajing Zhai 1 , Shuai Lin 2 , Pengtao Yang 2 , Shanli Li 2 , Zhijun Dai 2 , Jun Lu 1 1 Clinical Research Center, First Affiliated Hospital of Xi’an Jiaotong University, Xi’an, Shaanxi, 710061, China 2 Department of Oncology, Second Affiliated Hospital of Xi’an Jiaotong University, Xi’an, Shaanxi, 710004, China * These authors contributed equally to this work Correspondence to: Jun Lu, email: lujun2006@xjtu.edu.cn Zhijun Dai, email: dzj0911@126.com Keywords: interluekin-12, cancer risk, polymorphism, meta-analysis Received: December 31, 2016      Accepted: February 27, 2017      Published: March 10, 2017 ABSTRACT Many molecular epidemiologic studies have explored the possible links between interleukin-12 (IL-12) polymorphisms and various cancers. However, results from these studies remain inconsistent. This meta-analysis is aimed to shed light on the associations between three common loci (rs568408, rs2243115, rs3212227) of IL-12 gene and overall cancer risk. Our meta-analysis finally included 33 studies comprising 10,587 cancer cases and 12,040 cancer-free controls. Odds ratios (ORs) and 95% confidence intervals (CIs) were used to assess the cancer risk. We observed a significant association between IL-12B rs3212227 and overall cancer risk, especially in hepatocellular carcinoma, nasopharyngeal cancer, and among Asians. IL-12A polymorphisms (rs2243115 and rs568408) were found no influence on overall cancer risk. Nevertheless, stratification analyses demonstrated that rs568408 polymorphism contributed to increasing cancer risk of Caucasians and cervical cancer. And, rs2243115 may enhance the risk of brain tumor. These findings provided evidence that IL-12 polymorphisms may play a potential role in cancer risk.