IGF-1 CA repeat variant and breast cancer risk in postmenopausal women

IGF-I is an important growth factor for the mammary gland. We evaluated the relationship of the IGF-I CAn polymorphism with breast cancer risk in Caucasian postmenopausal women and performed a meta-analysis of published data. The IGF-I CAn polymorphism was genotyped in 4091 from the Rotterdam Study. A disease-free survival analysis was performed along with a meta-analysis of all available data on IGF-I CAn polymorphism and breast cancer risk. During follow-up 159 women were diagnosed with breast cancer. The disease-free survival analysis adjusted for age at entry, age at menopause, body mass index and waist hip ratio yielded a HR = 0.97 (95% CI=0.59–1.58) for CA19 non-carriers against carriers. The meta-analysis using the random-effects model gave a pooled OR of 1.26 (95% CI = 0.95–1.82) for IGF-I CA19 non-carriers versus CA19 homozygous carriers.According to these results, the IGF-I CA19 promoter polymorphism is not likely to predict the risk of breast cancer.