British Genomic Study Finds Fifteen New Breast Cancer Loci

A much smaller group comprising about 0.7% of women have genetic variations that make them three times more likely to develop the disease. The purpose of this study was to find genetic markers that can help identify women at high-risk and lead to improved cancer screening and prevention.

Investigators at the University of Cambridge (United Kingdom) and colleagues in the Breast Cancer Association Consortium, part of the Collaborative Oncological Gene-environment Study, performed a meta-analysis of 11 GWAS (genome-wide association study), comprising 15,748 breast cancer cases and 18,084 controls together with 46,785 cases and 42,892 controls from 41 studies genotyped on a 211,155-marker custom array (iCOGS). Analyses were restricted to women of European ancestry.

The investigators generated genotypes for more than 11 million SNPs (single nucleotide polymorphisms) by imputation using the 1000 Genomes Project reference panel and identified 15 new loci associated with breast cancer.

The 1000 Genomes Project, launched in January 2008, is an international research effort to establish a detailed catalogue of human genetic variation. The project unites multidisciplinary research teams from institutes around the world, including China, Italy, Japan, Kenya, Nigeria, Peru, the United Kingdom, and the United States. Each team contributes to the enormous sequence dataset and to a refined human genome map, which is freely accessible through public databases to the scientific community and the general public alike. By providing an overview of all human genetic variation, not only what is already known to be bio-medically relevant, the consortium generates a valuable tool for all fields of biological science, especially in the disciplines of genetics, medicine, pharmacology, biochemistry, and bioinformatics.

Senior author Dr. Doug Easton, professor of public health and primary care at the University of Cambridge, said, “Our study is another step towards untangling the breast cancer puzzle. As well as giving us more information about how and why a higher breast cancer risk can be inherited, the genetic markers we found can help us to target screening and cancer prevention measures at those women who need them the most. The next bit of solving the puzzle involves research to understand more about how genetic variations work to increase a woman’s risk. And we are sure there are more of these variations still to be discovered.”

The study was published in the March 9, 2015, online edition of the journal Nature Genetics.

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