Genetic variants linked to breast cancer discovered
Tuesday October 24th, 2017
A major international study has identified 72 new genetic variants that contribute to the risk of developing breast cancer.
The study, which involved 550 researchers from 300 institutions across
the globe, almost doubles the number of known variants associated with
breast cancer to about 180.
Of the new variants, 65 are common variants that predispose to breast cancer, while seven predispose specifically to oestrogen-receptor negative breast cancer, which is the subset of cases that do not respond to hormonal therapies.
Writing in Nature and Nature Genetics, the researchers describe how they analysed genetic data from 275,000 women, 146,000 of whom had been diagnosed with breast cancer.
The researchers combined epidemiological data with other data from breast tissue to make predictions about the target genes. They also showed for the first time that these genes are often the same as those that are altered when a tumour develops.
Most of the variants found were located within regions of the genome that regulate the activity of nearby genes.
Professor Doug Easton from the Centre for Cancer Genetic Epidemiology and a Fellow at Homerton College, the University of Cambridge, UK, said: “These findings add significantly to our understanding of the inherited basis of breast cancer. As well as identifying new genetic variants, we have also confirmed many that we had previously suspected.
“There are some clear patterns in the genetic variants that should help us understand why some women are predisposed to breast cancer, and which genes and mechanisms are involved.”
About 70% of all breast cancer cases are oestrogen-receptor positive while others are oestrogen-receptor negative. These studies identified genetic regions specifically associated with either oestrogen-receptor positive or oestrogen receptor negative breast cancer, demonstrating that they are biologically distinct cancers.
Associate Professor Roger Milne at Cancer Council Victoria in Melbourne, Australia, said: “These findings may inform improved risk prediction, both for the general population and BRCA1 mutation carriers. A better understanding of the biological basis of oestrogen receptor negative breast cancer may lead to more effective preventive interventions and treatments.”
Professor Karen Vousden, Cancer Research UK’s chief scientist, added: “The results, gathered from around the world, help pinpoint the genetic changes linked to a women’s risk of breast cancer. Learning which women are at higher risk of breast cancer could help identify who may benefit from earlier screening, and spare women at a lower risk from having to attend screening if it’s unlikely to benefit them.”
Michailidou, K et al. Association analysis identifies 65 new breast cancer risk loci. Nature 23 Oct 2017; DOI: 10.1038/nature24284
Milne, RL et al. Identification of ten variants associated with risk of estrogen receptor negative breast cancer Nature Genetics. 23 Oct 2017; DOI: 10.1038/ng.3785
Tags: Cancer | Genetics | UK News | Women's Health & Gynaecology
Printer friendly page