Page URL:

Scientists find five times more genes linked to breast cancer than were previously known

13 January 2020
Appeared in BioNews 1030

A major international study on the genetics of breast cancer published in Nature Genetics has identified more than 350 genetic variants that increase a person's risk of developing the disease.

The researchers, from over 450 departments and institutions worldwide, say the findings will help provide the most detailed picture yet of how differences in our DNA put some women at greater risk than others of developing breast cancer.

'This incredible haul of newly-discovered breast cancer genes provides us with many more genes to work on, most of which have not been studied before,' said co-author Dr Alison Dunning from the University of Cambridge. 'It will help us build up a much more detailed picture of how breast cancer arises and develops. But the sheer number of genes now known to play a role emphasises how complex the disease is.'

Breast cancer is a polygenic disease, meaning no single genetic variant or gene causes the disease, instead it is a combination of a number of genetic variants that act together to increase the likelihood of developing the disease.

In this new study, researchers collaborated to compare the DNA of 110,000 breast cancer patients against that of 90,000 healthy patient controls. The large sample allowed them to identify 352 genetic variants that are associated with an increased risk of breast cancer. It is not yet clear exactly how many genes these variants affect, but the researchers have identified 191 genes with reasonable confidence, with less than one in five of these being previously recognised.

Previous genome-wide association studies, which also compared the DNA of patients against that of healthy controls, had identified 150 regions of the genome that clearly affect breast cancer risk as well as changes within these regions that affect the risk of developing cancer. Yet the researchers of this latest study point to the importance of identifying the specific variants or genes involved. 

'We know from previous studies that variants across our DNA contribute towards breast cancer risk, but only rarely have scientists been able to identify exactly which genes are involved,' said co-author Dr Laura Fachal, of the University of Cambridge. 'We need this information as it gives us a better clue to what is driving the disease and hence how we might treat or even prevent it.'

Of the newly discovered genetic variants, a third predispose women towards developing hormone-responsive breast cancer: the type affecting four out of five breast cancer patients, which responds to hormonal treatments such as tamoxifen. Fifteen percent of the genetic variants predispose women to the rarer type, oestrogen-receptor-negative breast cancer, with the remaining genetic variants playing a role in both types.

Furthering our understanding of the genetic risk of developing breast cancer will allow doctors and clinicians to provide advice on the best treatment strategy for both reducing a person's risk and also preventing the onset of the disease.

15 March 2021 - by Dr Charlott Repschlager 
Breast cancer brain metastases can be targeted with a new approach using stem cells as a delivery system...
7 September 2020 - by Dr Laura Riggall 
Women with high risk single-gene variants in the BRCA gene may have a lower risk of developing breast cancer than previously reported...
20 July 2020 - by Dr Molly Godfrey 
Screening all women over 30 for the most common breast and ovarian cancer causing mutations could prevent millions of cancer deaths worldwide, according to a new study...
24 February 2020 - by Dr Melanie Krause 
Scientists from the University of Bristol have found a potential connection between the intake of statins and a reduction in ovarian cancer risk...
17 February 2020 - by Sandy Starr 
This film documents a debate about polygenic risk scores chaired by the deputy director of the Progress Educational Trust at the Battle of Ideas festival...
7 October 2019 - by Dr Loredana Guglielmi 
Multigene testing for all women diagnosed with breast cancer would save thousands of lives each year in the UK and USA, suggests new research...
27 August 2019 - by Dr Charlott Repschlager 
An influential health group in the USA has concluded that more women could benefit from wider gene screening for hereditary breast or ovarian cancer...
5 August 2019 - by Dr Molly Godfrey 
A newly developed blood test can spot breast cancer relapses almost a year before they are clinically detectable...
24 June 2019 - by Georgia Everett 
A large international study has identified the cancer risk associated with hundreds of mutations in BRCA genes. The findings will help improve accuracy when interpreting genetic test information on BRCA genes...
to add a Comment.

By posting a comment you agree to abide by the BioNews terms and conditions

Syndicate this story - click here to enquire about using this story.