Page URL:

Gene test could improve prediction of breast cancer risk

16 October 2017
Appeared in BioNews 922

A new genetic test to accurately predict an individual's risk of developing breast cancer will soon be rolled out at two hospital clinics in Manchester.

The research team believe the test could reduce the number of women opting for pre-emptive mastectomy by as much as one-third in those with a BRCA mutation, and give breast cancer patients the chance to make more informed decisions.

'With more accurate genetic testing, we can better predict a woman's risk of developing the disease and therefore offer the appropriate advice and support, rather than a "one size fits all" approach,' said Lester Barr, chairman of Prevent Breast Cancer, a UK charity based in Manchester which part-funded the research.

Breast cancer has been shown to be linked to mutations in the BRCA1 and BRCA2 genes, however mutations in these genes only account for 15-20 per cent of cases of hereditary cancer.

The new test assesses an individual's risk of developing breast cancer by analysing genetic variations at 18 positions within their DNA code. These variants are known as SNP (single nucleotide polymorphism) and have been shown to be indicative of breast cancer risk in women who do not carry BRCA mutations. While they showed minimal effects individually, when data on the SNPs was combined together, it affected a person's risk considerably.

The case-control study group consisted of 451 women with a family history of breast cancer, who had also developed breast cancer. Of these, 112 carried BRCA mutations. The researchers compared genetic profiles of these women against a control group of 1605 women (691 of whom carried BRCA mutations).

Researchers also took into account other factors when calculating risk, including age at first assessment, height and weight, and family history of breast cancer.

Many women who had previously been classified as high risk (with a 30 percent chance or higher of developing the disease during their lifetimes) were reclassified as lower risk, a group in which mastectomy is not recommended. 

The predictions devised during this research have been confirmed by Prevent Breast Cancer's 'Predicting Risk of Cancer at Screening' (PROCAS) study, in which 10,000 women underwent SNP testing, and 455 then went on to be diagnosed with breast cancer.

Initially this new test will only be available at St Mary's and Wythenshawe hospitals in Manchester, however Prevent Breast Cancer is hopeful this will be available to the whole population 'in the next one to two years'.

'This new test will help women at risk of familial breast cancer to make more informed decisions about their care,' said Professor Gareth Evans, at the University of Manchester and St Mary's Hospital, who led the study.

'BRCA1 and BRCA2 are just part of what we should be looking for when assessing risk and in Manchester we plan to incorporate screening for these new genetic markers in clinical practice within the next six months,' he added.

Gene test 'narrows down breast cancer risk'
BBC |  8 October 2017
New genetic tests to predict risk brings us closer to a breast cancer-free future
Prevent Breast Cancer |  28 November 2021
New test set to transform breast cancer prevention
University of Manchester |  9 October 2017
Test for breast cancer risk could reduce pre-emptive mastectomies
The Guardian |  8 October 2017
9 April 2018 - by Anna Mallach 
Estonia is offering a free DNA test to 10 percent of its population to identify people at risk of developing certain diseases, in the first state-sponsored personal genetic information service...
13 November 2017 - by Dr Loredana Guglielmi 
Researchers have introduced new criteria to screen for BRCA gene mutations that could prevent more than 10,000 cases of cancer and save more than 2000 lives in the next decade...
30 October 2017 - by Annabel Slater 
Two studies have discovered 72 new genetic variants associated with the risk of developing breast cancer...
13 February 2017 - by Dr Hannah Somers 
A study has indicated that US doctors may not be recommending genetic testing to a sufficient number of high-risk breast cancer patients...
16 January 2017 - by Annabel Slater 
Canadian scientists have identified a genetic fingerprint that indicates which prostate cancer tumours may develop into a more aggressive form of the disease after treatment...
19 December 2016 - by Anastassia Bolotkova 
Angelina Jolie's 2013 public announcement that she has the BRCA1</i> breast cancer gene led to a 64 percent increase in women seeking genetic testing for breast cancer...
11 July 2016 - by Antony Starza-Allen 
Genetic mutations on several genes including BRCA2 have been associated with prostate cancer; while in a separate study, a BRCA1 mutation has been linked to a particular form of uterine cancer...
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.