Blood test for tailored prostate cancer treatment
A blood test could help identify which advanced prostate cancer patients are likely to fail on abiraterone (Zytiga) or enzalutamide (Xtandi), according to new research (Ann Oncol 2017;doi: 10.1093/annonc/mdx155).
The test, developed by scientists at The Institute of Cancer Research (ICR) and Royal Marsden Hospital, analyses DNA released by cancer cells into the bloodstream and identifies tumours whose cells carry multiple copies of the androgen-receptor gene. It is these patients who do less well on the two drugs.
Researchers analysed blood samples from men with advanced prostate cancer on three different clinical trials, taking samples before receiving abiraterone or enzalutamide, and after the disease progressed.
In an initial group of 171 patients, men with high levels of the gene in their blood samples were four times more likely to die over the course of the study than those with lower levels. The findings were confirmed in a second study of 94 men.
Dr Gerhardt Attard, study lead at the ICR, says: ‘While abiraterone and enzalutamide are both excellent treatments for advanced prostate cancer, they don’t work for everyone and the disease can rapidly return’.
‘Identifying patients who may not benefit from these drugs could spare them unnecessary treatment and side-effects.’