Blood test could spare men with prostate cancer from chemotherapy

A technician holds blood samples for testing /COURTESY
A technician holds blood samples for testing /COURTESY

A revolutionary new blood test promises to spare men with prostate cancer from months of gruelling chemotherapy.

Scientists at the Institute of Cancer Research in London have used the new test to analyse tumours in greater detail than ever before by filtering cancer cells from the blood.

The test enables them to spot when prostate cancer is beginning to evolve to become resistant to chemotherapy.

This allows them to quickly switch to other treatments such as hormone drugs or immunotherapy.

At the moment most chemotherapy is only stopped when cancer symptoms start to get worse – a sign that the tumour has evolved and is starting to spread again. But this means men can undergo months of debilitating treatment which is not actually working.

The Daily Mail is campaigning for urgent improvements to prostate cancer treatments and diagnosis, which are lagging years behind others such as breast cancer.

Some 10,000 men with prostate cancer receive chemotherapy every year, of the 47,000 men diagnosed in Britain annually.

The new test is one of the first ‘liquid biopsies’ experts think will revolutionise the treatment of cancer. Study leader Professor Johann de Bono said: ‘Using the new blood test before, during and after treatment will allow us to keep a close eye on the way a person’s cancer evolves in response to drugs.

"[It] could allow us to detect treatment failure at an earlier stage, so we can switch people with advanced prostate cancer to treatments more likely to work."

Eventually, this technology could enable doctors to accurately target cancers according to their genetic make-up, to closely monitor tumours as they evolve, and to switch drugs if cancer becomes resistant to certain treatment.

Experts believe patients will be able to skip unnecessary chemotherapy, the NHS will save hundreds of millions of pounds, and thousands of lives will be saved as drugs become more accurate.

The new test captures tumour cells in the blood – offering a detailed insight into their genetic make-up.

Until now that degree of insight has only been possible by taking biopsy samples – a painful procedure. As they are invasive, biopsies cannot be done often, meaning if the cancer mutates, it can take months to be noticed.

The new blood test, in comparison, takes 90 minutes, meaning doctors can repeat it every few days, and can instantly tell what the cancer is doing.

Doctors struggled to do this before as solid tumours, such as prostate cancer, are relatively stable so do not shed many cells into the blood stream.

The team today publish the results of the first use of the test, on 14 men with advanced prostate cancer at the Royal Marsden NHS cancer hospital.

The findings, in the Clinical Cancer Research medical journal, showed some 12,500 cancer cells were extracted per sample, compared with 167 by usual methods.

The team found they could even use these cells to start growing ‘mini-tumours’ – allowing them to carry out tests to see which drugs work. Professor de Bono is now embarking on a bigger trial on 1,000 men. He said: "This could stop chemotherapy probably two courses earlier."