CAS P8 -652 6N del polymorphism and breast cancer risk: a systematic review and meta-analysis

Many studies have investigated the association between CASP8-652 6N del polymorphism and the risk of breast cancer, but the result is still unclear owing to the obvious inconsistence among those studies. This study aims to quantify the strength of association between CASP8-652 6N del polymorphism and risk of breast cancer. We searched the electronic MEDLINE database for studies relating to the association between CASP8-652 6N del polymorphism and risk of breast cancer. We estimated summary odds ratios (ORs) with their 95% confidence intervals (95% CIs) to assess the association. Ten case-control studies with 13,220 cases and 13,750 controls were included into this meta-analysis. Meta-analysis of a total of ten studies showed that reduced breast cancer risk was associated with CASP8 -652 6N del polymorphism (homozygous: OR=0.85, 95% CI 0.93-0.98). After adjustment for heterogeneity, meta-analysis showed that reduced breast cancer risk was also associated with CASP8-652 6N del polymorphism (homozygous: OR=0.78, 95% CI 0.63-0.95, dominant: OR=0.93, 95% CI 0.88-0.99). For Caucasians, CASP8-652 6N del was associated with reduced breast cancer risk at a borderline level (homozygous: OR=0.94, 95% CI 0.86-1.02, heterozygous: OR=0.96, 95% CI 0.90-1.03, recessive: OR=0.96, 95% CI 0.90-1.03, dominant: OR=0.94, 95% CI 0.88-1.01). No evidence of publication bias was observed. Meta-analyses of the available data suggest that CASP8 -652 6N del polymorphism is associated with reduced breast cancer risk.