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 CAnpolymorphism with breast cancer risk in Caucasian postmenopausal women and performed a meta-analysis of published data. The IGF-I CAnpolymorphism 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 CAnpolymorphism 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 CA19non-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 CA19non-carriers versus CA19homozygous carriers. According to these results, the IGF-I CA19promoter polymorphism is not likely to predict the risk of breast cancer.