Genetic modifiers of CHEK2*1100delC-associated breast cancer risk

Genet Med. 2017 May;19(5):599-603. doi: 10.1038/gim.2016.147. Epub 2016 Oct 6.

Abstract

Purpose: CHEK2*1100delC is a founder variant in European populations that confers a two- to threefold increased risk of breast cancer (BC). Epidemiologic and family studies have suggested that the risk associated with CHEK2*1100delC is modified by other genetic factors in a multiplicative fashion. We have investigated this empirically using data from the Breast Cancer Association Consortium (BCAC).

Methods: Using genotype data from 39,139 (624 1100delC carriers) BC patients and 40,063 (224) healthy controls from 32 BCAC studies, we analyzed the combined risk effects of CHEK2*1100delC and 77 common variants in terms of a polygenic risk score (PRS) and pairwise interaction.

Results: The PRS conferred odds ratios (OR) of 1.59 (95% CI: 1.21-2.09) per standard deviation for BC for CHEK2*1100delC carriers and 1.58 (1.55-1.62) for noncarriers. No evidence of deviation from the multiplicative model was found. The OR for the highest quintile of the PRS was 2.03 (0.86-4.78) for CHEK2*1100delC carriers, placing them in the high risk category according to UK NICE guidelines. The OR for the lowest quintile was 0.52 (0.16-1.74), indicating a lifetime risk close to the population average.

Conclusion: Our results confirm the multiplicative nature of risk effects conferred by CHEK2*1100delC and the common susceptibility variants. Furthermore, the PRS could identify carriers at a high lifetime risk for clinical actions.Genet Med advance online publication 06 October 2016.

MeSH terms

  • Breast Neoplasms / genetics*
  • Checkpoint Kinase 2 / genetics*
  • Female
  • Genes, Modifier
  • Genetic Predisposition to Disease
  • Humans
  • Odds Ratio
  • Penetrance
  • Sequence Deletion*

Substances

  • Checkpoint Kinase 2
  • CHEK2 protein, human