ABSTRACT
IGF-I CA repeat polymorphisms, especially the allele containing CA19 repeats, have been reported to be associated with the risk for various types of cancers. However, the results still remain controversial and ambiguous. This meta-analysis was performed to evaluate the association between IGF-I CA19 repeat polymorphisms and the risk of cancer. Total 18 studies with IGF-I CA19 repeat genotyping on 9,873 patients and 15,607 controls were analyzed. We used random-effects model with a pooled OR of 0.69 (95% CI = 0.60-0.79) for the recessive genetic model, 0.97 (95% CI = 0.86-1.10) for the dominant genetic model, 0.99 (95% CI = 0.86-1.14) for the homozygote comparison and 1.06 (95% CI = 0.91-1.23) for the heterozygote comparison. In the subgroup analysis of recessive model, OR (95% CI) was 0.65 (0.52-0.80) in breast cancer, 0.68 (0.53-0.86) in prostate cancer, and 0.71 (0.52-0.96) in Caucasian. In conclusion, IGF-1 CA19 repeat polymorphisms are unlikely to be a major determinant of susceptibility to cancer. However, the subgroup analysis of recessive model indicates that IGF-I CA19 repeat polymorphisms may reduce the risk of certain types of cancer or in a specific population.
ABSTRACT
Vascular endothelial growth factor (VEGF) polymorphisms, specifically +405G/C (rs2010963), reportedly influence the risk for various digestive cancers. However, the consequences of these polymorphisms remain controversial and ambiguous. Therefore, we performed a meta-analysis of 11 studies with VEGF +405G/C genotyping on 2,862 patients and 3,028 controls using the random effects model. We obtained a pooled odds ratio (OR) of 1.04 (95% confidence interval (CI) = 0.86-1.26) for the recessive genetic model, 1.07 (95% CI = 0.81-1.42) for the dominant genetic model, 1.09 (95% CI = 0.81-1.47) for the homozygote comparison, and 1.03 (95% CI = 0.83-1.27) for the heterozygote comparison. In the subgroup analysis of the recessive model, the OR was 1.20 (95% CI = 1.02-1.40) in colorectal cancer. These results show that VEGF +405G/C polymorphisms are unlikely to be a major determinant of susceptibility to digestive cancer. Furthermore, the subgroup analysis of recessive model indicates that VEGF +405G/C polymorphisms increase the risk for colorectal cancer.
