title: Peroxisome proliferator-activated receptor gamma (PPARG) polymorphisms and breast cancer susceptibility: a meta-analysis.
abstract: BACKGROUND
  Peroxisome proliferator-activated receptor gamma (PPARG), a nuclear hormone receptor, plays a critical role in the lipid and glucose homeostasis, adipocyte differentiation, as well as intracellular insulin-signaling events. Several studies have been conducted to explore the associations of PPARG polymorphisms with breast cancer (BC), yet the findings are inconsistent.
  
  
  METHODS
  Databases of Pubmed and Embase were searched until October 5, 2014. The association between PPARG polymorphisms and BC risk was determined by crude odds ratios (ORs) with their 95% confidence intervals (CIs).
  
  
  RESULTS
  Finally, there are nine publications involving 3,931 BC cases and 5,382 controls included in this meta-analysis. No significant association was observed between PPARG rs1801282 C>G variants and overall BC risk in all genetic comparison models. However, in a subgroup analysis by ethnicity, significant association was observed between PPARG rs1801282 C>G variants and decreased BC risk in three genetic models: GG+CG vs. CC (OR, 0.83; 95% CI, 0.71-0.96; P = 0.011), CG vs. CC (OR, 0.82; 95% CI, 0.71-0.96; P = 0.011) and G vs. C (OR, 0.85; 95% CI, 0.75-0.97; P = 0.016) in Caucasians and in a subgroup analysis by menopausal status, significantly decreased BC risk was also found in two genetic models: GG+CG vs. CC (OR, 0.79; 95% CI, 0.67-0.95; P = 0.011) and CG vs. CC (OR, 0.77; 95% CI, 0.64-0.92; P = 0.005) in post-menopause subgroup. For PPARG rs3856806 C>T, we found no significant association between PPARG rs3856806 C>T polymorphism and breast cancer.
  
  
  CONCLUSIONS
  In summary, despite some limitations, the results suggest that PPARG rs1801282 C>G polymorphism may be a protective factor for BC in Caucasians and in post-menopause women.
authors.affiliation: Department of Thoracic Surgery, The Union Clinical Medical College of Fujian Medical University Fuzhou, Fujian Province, China.
authors.forename: Weifeng
authors.initials: W
authors.lastname: Tang
authors.affiliation: Department of Thoracic Surgery, Fujian Provincial Cancer Hospital Fuzhou, Fujian Province, China.
authors.forename: Yuanmei
authors.initials: Y
authors.lastname: Chen
authors.affiliation: Department of Cardiology, The People's Hospital of Xishuangbanna Dai Autonomous Prefecture Jinghong, Yunnan Province, China.
authors.forename: Yafeng
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Department of Cardiothoracic Surgery, Affiliated People's Hospital of Jiangsu University Zhenjiang, Jiangsu Province, China.
authors.forename: Haiyong
authors.initials: H
authors.lastname: Gu
authors.affiliation: Department of Thoracic Surgery, The Union Clinical Medical College of Fujian Medical University Fuzhou, Fujian Province, China.
authors.forename: Shuchen
authors.initials: S
authors.lastname: Chen
authors.affiliation: Department of Thoracic Surgery, The Union Clinical Medical College of Fujian Medical University Fuzhou, Fujian Province, China.
authors.forename: Mingqiang
authors.initials: M
authors.lastname: Kang
keywords: Breast cancer; meta-analysis; peroxisome proliferator-activated receptor gamma; polymorphism