CHEK2 1100delC Variant and Breast Cancer Risk in Caucasians: A Meta-analysis Based on 25 Studies with 29,154 Cases and 37,064 Controls

Links between the CHEK2 1100delC heterozygote and breast cancer risk have been extensively explored.However, both positive and negative associations with this variant have been reported in individual studies. Fora detailed assessment of the CHEK2 1100delC heterozygote and breast cancer risk, relevant studies published asrecently as May 2012 were identified using PUBMED and EMBASE and selected using a priori defined criteria.The strength of the relationship between the CHEK2 1100delC variant and breast cancer risks was assessed byodds ratios (ORs) under the fixed effects model. A total of 29,154 cases and 37,064 controls from 25 case-controlstudies were identified in this meta-analysis. The CHEK2 1100delC heterozygote was more frequently detectedin cases than in controls (1.34% versus 0.44%). A significant association was found between CHEK2 1100delCheterozygote and breast cancer risk (OR=2.75, 95% CI: [2.25, 3.36]). The ORs and CIs were 2.33 (95% CI: [1.79,3.05]), 3.72 (95% CI: [2.61, 5.31]) and 2.78 (95% CI: [2.28, 3.39]) respectively in unselected, family, early-onsetbreast cancer subgroups. The CHEK2 1100delC variant could be a potential factor for increased breast cancerrisk in Caucasians. However, more consideration is needed in order to apply it to allele screening or other clinicalwork.