A polygenic risk score for breast cancer risk in a Taiwanese population
Several genome-wide association studies on breast cancer (BC) have reported similar findings of a new susceptibility locus, 5p12. After that, a number of studies reported that the rs10941679, rs4415084, and rs981782 polymorphism in chromosome 5p12 has been implicated in BC risk. However, the studies have yielded contradictory results. To derive a more precise estimation of the relationship, a meta-analysis of 131,983 BC cases and 200,314 controls from 24 published case-control studies was performed. Overall, significantly elevated BC risk was associated with rs10941679, rs4415084, and rs981782 risk allele when all studies were pooled into the meta-analysis. In the subgroup analysis by ethnicity, significantly increased risks were found for the rs10941679 and rs4415084 polymorphism among Caucasians and East Asians, while no significant associations were observed for the two polymorphisms in African and other ethnic populations. For 5p12-rs981782, significant associations were only detected among Caucasians. In addition, we found that rs10941679 and rs4415084 on 5p12 confer risk, exclusively for estrogen receptor (ER)-positive tumors with per-allele OR of 1.16 (95% CI: 1.11-1.21; P<10(-5)) and of 1.14 (95% CI: 1.09-1.19; P<10(-5)) respectively. Ethnicity was identified as a potential source of between-study heterogeneity. In conclusion, this meta-analysis demonstrated that common variations are a risk factor associated with increased BC susceptibility, but these associations vary in different ethnic populations.