New blood test can spot when breast cancer has become resistant to treatment – and exactly which drugs doctors should use next

bEING able to quickly switch drugs could dramatically slow cancer’s spread

A smart blood test developed by scientists dramatically slows the spread breast cancer, scientists have revealed.

The new test, developed by experts in London, spots when the most common form of breast cancer has stopped responding to standard treatments.

It then tells doctors exactly which drug to treat patients with next, matching the treatment to the genetic make-up of the tumour.

A smart blood test developed by scientists dramatically slows the spread breast cancer, scientists have revealed.

A trial of 783 women showed that using precisely matched drugs doubled the length of time for which doctors were able to halt the progression of the disease.

Being able to rapidly switch drugs is crucial in the treatment of cancer, because tumours evolve and become resistant to medicines.

When a certain drug stops working, doctors switch onto a different form of medication.

But until now they only been able to do this when a patient starts getting sick again, or by using a painful biopsy to analyse the tumour.

The new test, which could be available within three years, allows doctors to act far more quickly, alerting them as soon as the cancer starts resisting the drug’s effect.

It is one of the first in a battery of ‘liquid biopsies’ that experts think will revolutionise the treatment of cancer.

Breast cancer patients could be spared the misery of chemotherapy with test to predict if their tumour will return

A genetic test could spare thousands of breast cancer patients each year the ordeal of unnecessary chemotherapy, research suggests.

By analysing the genetic make-up of a tumour, scientists can accurately predict how likely cancer is to return after surgery.

A new genetic test, called Mammaprint, could spare 14 per cent of breast cancer patients – one in every seven – from having to undergo chemotherapy after their tumour is removed.

Chemotherapy can cause gruelling side effects including nausea, hair loss and exhaustion.

A team of Belgian scientists found that they could accurately pinpoint patients whose tumours were unlikely to return, even if they do not have chemotherapy.

The sensitive tests pick up minute strands of DNA that are shed by a tumour as it grows.

Trials carried out by the Institute of Cancer Research and the Royal Marsden hospital in London found that by using the tests, and then moving patients onto a drug matched to its genetic make-up, doctors were able to halt the progress of breast cancer for six months.

Women who were treated with a drug that had not been DNA matched only had two and a half months before the tumour started spreading again.

Researchers analysed blood samples from 783 women with oestrogen receptor positive breast cancer – the most common form of the disease, accounting for three quarters of cases.

By using the test, scientists identified a single gene called ESR1, which mutates when a breast tumour has stopped responding to standard hormone treatment.

The researchers randomly divided patients into two groups and gave them each one of two drugs.

One group was given a drug called exemestane – which works by blocking oestrogen synthesis.

The others were given a drug called fulvestrant, which degrades the oestrogen receptor protein so it can’t ‘feed’ the tumour.

The results, published in the Journal of Clinical Oncology, showed that patients with the ESR1 mutation responded far better to fulvestrant, which delayed progression of the disease for 5.7 months, compared to 2.6 months on exemestane.

Culled from Daily Mail