£50 blood test could predict prostate cancer drug response

Researchers have developed a blood test that could better tailor the treatment of patients with prostate cancer.

A team at The Institute of Cancer Research, London, and The Royal Marsden NHS Foundation Trust, along with colleagues in Europe, looked at blood samples from 265 men with advanced prostate cancer being treated with abiraterone or enzalutamide, either before or after docetaxel chemotherapy.

In a primary trial involving 171 patients, they found that men in whom a blood test detected multiple copies of the gene that codes for the androgen receptor - known to play an important role in helping cancers to become resistant to treatment with abiraterone and enzalutamide - were four times more likely to die over the course of the study than those who did not.

This was then confirmed in a smaller group of patients (94), in which men with multiple copies of this gene had an eight-fold shorter response to treatment than men with one or two copies of the gene.

Dr Gerhardt Attard, team leader in the Centre for Evolution and Cancer at the ICR and Consultant Medical Oncologist at The Royal Marsden, noted that 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 that "in other men, these drugs do not work well and the disease rapidly returns.

"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."

Furthermore, the test costs just £50 and gives quick results, he said. "We are now looking to assess our test in prospective clinical trials and would hope it can become part of standard patient care."

"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," said Dr Iain Frame, Director of Research at Prostate Cancer UK .

"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," added Dr Emma Smith, science information manager at Cancer Research UK.