title: Promoter methylation ofBRCA1is associated with estrogen, progesterone and human epidermal growth factor receptor-negative tumors and the prognosis of breast cancer: A meta-analysis.
abstract: Aberrant methylation of the breast cancer susceptibility gene 1 (BRCA1) promoter is a mechanism for its functional inactivation. It may potentially be used as a prognostic marker in studies for patients with breast cancer and plays an important role in tumorigenesis. Numerous studies have suggested that the methylation of theBRCA1promoter is associated with the prognosis of breast cancer. However, the prognosis ofBRCA1promoter methylation in breast cancer patients of different ethnicities remains ambiguous. The present meta-analysis was performed to adjust and augment a previously published study, which estimated the correlations between promoter methylation ofBRCA1and the clinical outcomes of breast cancer patients. These results indicated thatBRCA1methylation was significantly correlated with a poor prognosis of breast cancer, particularly for Asian patients, but the correlation was over-estimated in the previous study. The combined hazard ratios (HRs) in the present study were 1.76 (1.15-2.68) and 1.97 (1.12-3.44) for univariate and multivariate analysis of overall survival, which were different from 2.02 (1.35-3.03) and 1.38 (1.04-1.84) in the previous study. For studies of disease-free survival, the univariate and multivariate analyses also have different pooled HRs: 2.89 (1.73-4.83) and 3.92 (1.49-10.32) in the previously published study and 1.28 (0.68-2.43) and 1.64 (0.64-4.19) in the present study. In addition, theBRCA1promoter regions used to detect the hypermethylation were different. All the studies using the Baldwin's primer reported that breast cancer patients withBRCA1promoter methylation had a better prognosis. There were also correlations betweenBRCA1promoter methylation and receptor-negativity of the estrogen receptors, progesterone receptor, human epidermal growth factor receptor 2 and a triple-negative status. Patients with the estrogen, progesterone and epidermal growth factor-related receptor-negative status were more likely to be negative for the BRCA1 protein.
authors.affiliation: Laboratory of Molecular Genetics of Aging and Tumor, Faculty of Medicine, Kunming University of Science and Technology, Kunming, Yunnan 650500, P.R. China.
authors.forename: Taiyan
authors.initials: T
authors.lastname: Guo
authors.affiliation: Laboratory of Medical Genetics and Pharmacogenomics, Faculty of Medicine, Kunming University of Science and Technology, Kunming, Yunnan 650500, P.R. China.
authors.forename: Yongyong
authors.initials: Y
authors.lastname: Ren
authors.affiliation: Laboratory of Molecular Genetics of Aging and Tumor, Faculty of Medicine, Kunming University of Science and Technology, Kunming, Yunnan 650500, P.R. China.
authors.forename: Boyuan
authors.initials: B
authors.lastname: Wang
authors.affiliation: Laboratory of Molecular Genetics of Aging and Tumor, Faculty of Medicine, Kunming University of Science and Technology, Kunming, Yunnan 650500, P.R. China.
authors.forename: Yingze
authors.initials: Y
authors.lastname: Huang
authors.affiliation: Laboratory of Molecular Genetics of Aging and Tumor, Faculty of Medicine, Kunming University of Science and Technology, Kunming, Yunnan 650500, P.R. China.
authors.forename: Shuting
authors.initials: S
authors.lastname: Jia
authors.affiliation: Laboratory of Molecular Genetics of Aging and Tumor, Faculty of Medicine, Kunming University of Science and Technology, Kunming, Yunnan 650500, P.R. China.
authors.forename: Wenru
authors.initials: W
authors.lastname: Tang
authors.affiliation: Laboratory of Molecular Genetics of Aging and Tumor, Faculty of Medicine, Kunming University of Science and Technology, Kunming, Yunnan 650500, P.R. China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Luo
keywords: BRCA1; breast cancer; estrogen receptors; human epidermal growth factor receptor 2; methylation; progesterone receptor; prognosis; survival