No association of single nucleotide polymorphisms involved in GHRL and GHSR with cancer risk: A meta-analysis

BACKGROUND: 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. METHODS: 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. RESULTS: 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. CONCLUSION: Our results suggest that the SNP with GHRL and GHSR might be weaker association with cancer risk, especially with breast cancer risk.