title: CAG repeat polymorphisms in the androgen receptor and breast cancer risk in women: a meta-analysis of 17 studies.
abstract: The association between polymorphic CAG repeats in the androgen receptor gene in women and breast cancer susceptibility has been studied extensively. However, the conclusions regarding this relationship remain conflicting. The purpose of this meta-analysis was to identify whether androgen receptor CAG repeat lengths were related to breast cancer susceptibility. The MEDLINE, PubMed, and EMBASE databases were searched through to December 2014 to identify eligible studies. Data and study quality were rigorously assessed by two investigators according to the Newcastle-Ottawa Quality Assessment Scale. The publication bias was assessed by the Begg's test. Seventeen eligible studies were included in this meta-analysis. The overall analysis suggested no association between CAG polymorphisms and breast cancer risk (odds ratio [OR] 1.031, 95% confidence interval [CI] 0.855-1.245). However, in the subgroup analysis, we observed that long CAG repeats significantly increased the risk of breast cancer in the Caucasian population (OR 1.447, 95% CI 1.089-1.992). Additionally, the risk was significantly increased in Caucasian women carrying two alleles with CAG repeats ≥22 units compared with those with two shorter alleles (OR 1.315, 95% CI 1.014-1.707). These findings suggest that long CAG repeats increase the risk of breast cancer in Caucasian women. However, larger scale case-control studies are needed to validate our results.
authors: Department of Thoracic Surgery, Nanjing Medical University Affiliated Cancer Institute of Jiangsu Province, Nanjing, People's Republic of China ; Fourth Clinical College of Nanjing Medical University, Nanjing, People's Republic of China ; Jiangsu Key Laboratory of Molecular and Translational Cancer Research, Nanjing, People's Republic of China.
authors: Qixing
authors: Q
authors: Mao
authors: Department of Thoracic Surgery, Nanjing Medical University Affiliated Cancer Institute of Jiangsu Province, Nanjing, People's Republic of China ; Fourth Clinical College of Nanjing Medical University, Nanjing, People's Republic of China ; Jiangsu Key Laboratory of Molecular and Translational Cancer Research, Nanjing, People's Republic of China.
authors: Mantang
authors: M
authors: Qiu
authors: Jiangsu Key Laboratory of Molecular and Translational Cancer Research, Nanjing, People's Republic of China.
authors: Gaochao
authors: G
authors: Dong
authors: Department of Thoracic Surgery, Nanjing Medical University Affiliated Cancer Institute of Jiangsu Province, Nanjing, People's Republic of China ; Fourth Clinical College of Nanjing Medical University, Nanjing, People's Republic of China ; Jiangsu Key Laboratory of Molecular and Translational Cancer Research, Nanjing, People's Republic of China.
authors: Wenjie
authors: W
authors: Xia
authors: Department of Thoracic Surgery, Nanjing Medical University Affiliated Cancer Institute of Jiangsu Province, Nanjing, People's Republic of China ; Jiangsu Key Laboratory of Molecular and Translational Cancer Research, Nanjing, People's Republic of China.
authors: Shuai
authors: S
authors: Zhang
authors: Department of Thoracic Surgery, Nanjing Medical University Affiliated Cancer Institute of Jiangsu Province, Nanjing, People's Republic of China ; Jiangsu Key Laboratory of Molecular and Translational Cancer Research, Nanjing, People's Republic of China.
authors: Youtao
authors: Y
authors: Xu
authors: Jiangsu Key Laboratory of Molecular and Translational Cancer Research, Nanjing, People's Republic of China.
authors: Jie
authors: J
authors: Wang
authors: Department of Thoracic Surgery, Nanjing Medical University Affiliated Cancer Institute of Jiangsu Province, Nanjing, People's Republic of China ; Jiangsu Key Laboratory of Molecular and Translational Cancer Research, Nanjing, People's Republic of China.
authors: Yin
authors: Y
authors: Rong
authors: Department of Thoracic Surgery, Nanjing Medical University Affiliated Cancer Institute of Jiangsu Province, Nanjing, People's Republic of China ; Jiangsu Key Laboratory of Molecular and Translational Cancer Research, Nanjing, People's Republic of China.
authors: Lin
authors: L
authors: Xu
authors: Department of Thoracic Surgery, Nanjing Medical University Affiliated Cancer Institute of Jiangsu Province, Nanjing, People's Republic of China ; Jiangsu Key Laboratory of Molecular and Translational Cancer Research, Nanjing, People's Republic of China.
authors: Feng
authors: F
authors: Jiang
keywords: CAG repeat polymorphism; androgen; breast cancer; meta-analysis; risk; women