Blood test 'improves' prostate cancer treatment'

4th May 2017 – An inexpensive blood test could help doctors tailor individual targeted treatments for men with advanced prostate cancer, say scientists.

The test, which could cost less than £50, looks for multiple copies of the androgen receptor gene, which many prostate cancers need to grow.

Men who are given abiraterone and enzalutamide – standard treatment for advanced prostate cancer which is resistant to traditional hormone blocking therapy – respond much less well if they have multiple copies of the gene compared to men who do not.

Alternative treatments

A reliable test could mean that men with multiple copies of the gene could be spared treatments that are unlikely to work for them and could be offered alternative options instead.

Details of the test, developed by scientists at The Institute of Cancer Research (ICR) and Royal Marsden NHS Foundation Trust, have been published in the journal Annals of Oncology.

The team analysed blood samples from men with advanced prostate cancer who were enrolled in 3 different clinical trials. The samples were taken before they were given abiraterone or enzalutamide, and after the disease began to get worse.

In an initial group of 171 patients, they found that men with high levels of the androgen receptor gene in their blood were 4 times more likely to die over the course of the study than those with lower levels.

These findings were confirmed in a second study of 94 men.

The androgen receptor is already known to play an important role in helping cancers to become resistant to abiraterone and enzalutamide.

A 'robust test'

Lead researcher Dr Gerhardt Attard from the Centre for Evolution and Cancer at the Institute of Cancer Research in London says in a statement: "Abiraterone and enzalutamide are excellent treatments for advanced prostate cancer and some men can take these drugs for years without seeing a return of their cancer. But in other men, these drugs do not work well and the disease rapidly returns.

"Currently there is no approved test to help doctors choose whether these are the best treatments for an individual.

"We have developed a robust test that can be used in the clinic to pick out which men with advanced prostate cancer are likely to respond to abiraterone and enzalutamide, and which men might need alternative treatments.

"Our method costs less than £50, is quick to provide results, and can be implemented in hospital laboratories across the NHS."

The test will need to be further assessed in clinical trials.

'A significant step'

In a statement, Dr Iain Frame, director of research at Prostate Cancer UK, says: "A man with incurable prostate cancer does not have time to waste taking drugs that will not work for him. To stop prostate cancer from being a killer, we need to move away from a one-size-fits-all approach to treatment.

"This test could be a significant step towards that and we'll be watching its development very closely."

Dr Emma Smith, science information manager at Cancer Research UK, which also helped fund the study, comments in a statement: "Developing tests that help doctors predict how likely a treatment is to work will prevent patients from suffering unnecessary side effects from treatments that are unlikely to benefit them.

"If further studies confirm this test is reliable, it could also help doctors choose better options for men whose prostate cancer is unlikely to respond to standard treatments."