Page URL:

DNA test may benefit women with hard-to-treat breast cancer

8 May 2018
Appeared in BioNews 948

Genetic testing could reveal a subset of patients with aggressive breast cancer who would benefit from a non-standard treatment, a clinical trial has found. 

Patients with certain genes responded twice as well to treatment with the alternative drug carboplatin, according to the trial, published last week in the journal Nature Medicine. The study was a randomised controlled phase III trial, with 376 patients taking part in the study from 74 hospitals across the UK. 

The usual hormone drugs and targeted therapies for breast cancer act on three surface proteins. Tumours that lack all three receptors are known as triple-negative breast cancers and are among the hardest to treat. The standard treatment for triple-negative patients in the UK is the chemotherapy drug docetaxel. 

These results, however, show that triple negative patients with mutations in their BRCA1 or BRCA2 genes – which increase the risk of developing breast cancer – did better when receiving carboplatin. 

In this trial, two-thirds of triple-negative patients with faulty BRCA1 or BRCA2 genes showed a positive response to carboplatin, compared with only a third to docetaxel. A third of patients who did not have the faulty genes responded to carboplatin. This finding could help some triple-negative breast cancer patients. 

The researchers believe that the differences are due to how the two drugs work. Docetaxel attacks part of the machinery that cells use to divide, while carboplatin directly binds to and interferes with DNA itself. As the BRCA1 and BRCA2 genes are usually involved in repairing damaged DNA, the researchers believe that a tumour in a patient with a less functional version of either BRCA gene is more susceptible to carboplatin, as less of the DNA damage it causes can be repaired.

About 15 percent of breast cancer cases are triple negative, of which five to 15 percent are likely to have BRCA1 or BRCA2 mutations. It is not currently standard practice to test women with triple-negative breast cancer for BRCA mutations, something that the authors of this study believe should change.  

'Using this simple test enables us to guide treatment for women within this type of breast cancer,' said Professor Andrew Tutt of the Institute of Cancer Research in London and lead author of the study. 'This is a great example of using personalised genetics to repurpose a chemotherapy drug into a targeted treatment.'

Carboplatin in BRCA1/2-mutated and triple-negative breast cancer BRCAness subgroups: the TNT Trial
Nature Medicine |  30 April 2018
Gene test might benefit women with hard-to-treat breast cancer
Cancer Research UK |  30 April 2018
New approach for hard-to-treat BRCA breast cancer shrinks tumours twice as fast
The Telegraph |  30 April 2018
13 August 2018 - by Jen Willows 
A study has identified five genes that are associated with an aggressive form of breast cancer...
11 June 2018 - by Grace O'Regan 
Chemotherapy is not necessary to treat the most common type of breast cancer in 69 percent of cases, a new study has shown...
21 May 2018 - by Christie Whitehouse 
A new study indicates that an important drug used to treat breast cancer is just as effective when the course of treatment is shortened by half.
14 May 2018 - by Julianna Photopoulos 
Every day, about 10 new genetic tests come to market in the US, a study has found...
14 May 2018 - by Hannah Tippett Simpson 
DNA mutations that give tumours resistance to a new class of breakthrough breast and ovarian cancer drugs have been discovered...
22 January 2018 - by Dr Molly Godfrey 
The blanket screening of all women over 30 for genetic mutations which cause breast and, or ovarian cancer could prevent more cancers and be more cost effective than current approaches, according to a new study...
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...
12 June 2017 - by Dr Loredana Guglielmi 
A drug treatment for ovarian cancer has shown success against inherited breast 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.