No association of single nucleotide polymorphisms involved in GHRL and GHSR with cancer risk: A meta-analysis
Ghrelin was associated with several of cancers. The conflict results of SNPs with GHRL and GHSR gene were demonstrated in different studies. Thus, this meta-analysis is to evaluate the associations.Systematic literature search was done on PubMed database up to October 2013. We used odds ratios (ORs) with 95% confidence intervals (CIs) to assess the strength of the association by a fixed-effect model and a random-effect model.A total of 7 studies, which included 3 studies for breast cancer, 2 for colorectal cancer, 1 for hepatocellular carcinoma, 1 for esophageal cancer and 1 for Non-Hodgkin lymphoma. When analyzed all the GHRL SNPs with all kinds of cancers, there was significantly difference with cancer patients compared with controls (Recessive model: OR 0.938, 95% CI 0.890-0.989, p=0.017), while no significant difference was existed in the additive model (OR 0.9903, 95% CI 0.957-1.024, p=0.558) and dominant model (OR 1.014, 95% CI 0.970-1.061, p=0.536). When analyzed all the GHSR SNPs with all kinds of cancers, no significant difference was observed.Our results suggest that the SNP with GHRL and GHSR might be weaker association with cancer risk, especially with breast cancer risk.