Thousands of women with deadliest form of breast cancer could be saved by a simple test that tells doctors in 24 hours how well they will respond to chemotherapy
- Triple negative breast cancer is so aggressive it can resist chemotherapy
- Around a third of women will see their cancer come back within three years
- Test can detect a protein which blocks the chemo with results in 24 hours
- It could be available within a decade following trials, researchers said
Women with the most deadly type of breast cancer have hope from a simple test which shows if they will respond to treatment.
‘Triple-negative’ breast cancer, most common in women under the age of 40 and affecting more than 8,000 women every year in the UK, is so aggressive it can survive chemotherapy.
About a third of women see the standard chemotherapy fail and the cancer come back within three years.
However, scientists have discovered a test which identifies these women, so that they can be given a different type of chemotherapy likely to work better.
The test is for a protein called NUP98, which is thought to switch on genes that help cancer cells survive chemotherapy.
It can be found using a simple biopsy of breast tissue, with results available to doctors within 24 hours.
Women with the most deadly type of breast cancer – triple negative – have hope from a simple test which shows if they will respond to treatment
Women with high levels of the protein are 10 times more likely to see their cancer come back, raising their risk of dying, and are half as likely to benefit from the standard chemotherapy, researchers who looked at results for more than 500 women found.
They say the test could be available for women within a decade, following trials on the first breast cancer patients in five years.
Dr Niamh Buckley, who led the study of breast cancer patients from Queen’s University Belfast, said: ‘We know that triple-negative breast cancer is a very aggressive form of the disease.
‘For women who have been diagnosed, we want to tailor their treatment to give them the best possible chance of survival.
‘This test will hopefully help us to identify women who should be given an alternative form of chemotherapy and could stop breast cancer coming back in these women, saving their lives.’
Around one in seven breast cancers are triple-negative, meaning they are negative for ‘receptors’ on cancer cells which receive signals to divide.
Other types of breast cancer, like ‘oestrogen receptor-positive’ breast cancer, can be treated with wonder drugs like tamoxifen which damage the machinery allowing the cells to multiply.
But women with triple-negative breast cancer have no such drugs, meaning surgery and chemotherapy are their only chance of survival. That is why it is so important that the standard chemotherapy, using drugs called anthracyclines, works.
The newly discovered test, reported in the journal BMC Cancer, could help to identify the one in three women for whom this type of chemotherapy will not work.
It picks up those women with high levels of NUP98, which blocks the chemotherapy meant to kill off cancer cells by destroying their DNA.
It is not fully understood how the protein works, but it may switch on genes which repair the DNA damage or help cancer cells survive it by blocking the signal which kills them when they are damaged.
If these women can be singled out, they can be given a treatment more likely to work so that their cancer will not come back or spread to their liver or brain and become terminal.
They can instead have a different type of chemotherapy, such as one type using drugs called ‘taxanes’ to stop cancer cells dividing.
The test, found using breast tissue from more than 100 women with triple-negative breast cancer and confirmed using a database of another 450 patients, uses a substance which reacts with NUP98.
The protein is tagged with a brown dye in women’s breast tissue sample, so that it can be easily spotted in the laboratory.
Women with high, rather than low levels of NUP98 are seven to 10 times more likely to see their breast cancer come back after chemotherapy.
Baroness Delyth Morgan, chief executive of Breast Cancer Now, which funded the study, said: ‘This is a very promising discovery. It’s really encouraging that testing for levels of NUP98 could help ensure patients get the type of chemotherapy that’s most likely to be effective for them as early as possible.’