Clinicopathological Significance of Plasminogen Activator Inhibitor-1 Promoter 4G/5G Polymorphism in Breast Cancer: A Meta-analysis

Background and Aims Plasminogen activator inhibitor type 1 (PAI-1) is associated with poor prognosis in breast cancer. Transcriptional expression of the PAI-1 can be controlled by PAI-1 promoter 4G/5G polymorphism. However, the significance of PAI-1 promoter 4G/5G polymorphism in breast cancer patients is contentious. To address this controversy, we conducted a meta-analysis for the relationships between PAI-1 promoter polymorphism and clinicopathological characteristics of breast cancer. Methods Relevant published studies were identified using a search of PubMed, Embase, and the ISI Web of Science. The effect sizes of PAI-1 promoter 4G/5G polymorphism on breast cancer risk, lymph node metastasis, histologic grade, and overall survival were calculated by odds ratio (OR) or hazard ratio. The effect sizes were combined using a random-effects model. Results Individuals with 4G/4G genotype had a higher risk of breast cancer than those with the combined 4G/5G and 5G/5G genotypes (OR = 1.388; p = 0.031). Breast cancer patients with the 5G/5G genotype displayed lymph node metastasis more than patients with either the combined other genotypes (OR = 1.495; p = 0.027) or with the 4G/4G genotype (OR = 1.623; p = 0.018). However, the PAI-1 promoter 4G/5G polymorphism was not associated with histological grade or overall survival. Conclusions PAI-1 promoter 4G/5G polymorphism is associated with a relatively increased risk of breast cancer development and lymph node metastasis.