A simple blood test could help to identify men with prostate cancer who are less likely to respond to treatment or more likely to relapse, research has suggested.

The liquid biopsy – a non-invasive, less painful test than commonly-used tissue biopsies – could lead to tailored treatment for those in the advanced stages of the disease, scientists said.

Researchers at The Institute of Cancer Research (ICR) in London and The Royal Marsden NHS Foundation Trust looked at more than 1,000 blood samples from 216 men with advanced prostate cancer.

They said the tests can detect traces of cancer in the bloodstream and could help track how the disease evolves and responds to treatment.

The study focused on men who were part of a clinical trial looking at the benefit of the targeted drug abiraterone with or without an experimental drug, ipatasertib, and the results showed that men with high levels of tumour DNA at the start of treatment had a significantly worse outcome.

They also found, after monitoring patients with repeat blood tests, that those who responded to treatment had the greatest fall in the amount of cancer DNA in their bloodstream.

Scientists also found, through analysis of DNA from the blood tests, that there were specific genetic changes associated with drug resistance, indicating risk of early relapse.

Prostate cancer is the most common cancer in men in the UK, with more than 47,500 men diagnosed every year, according to Prostate Cancer UK.

Professor Johann de Bono, professor of experimental cancer medicine at the ICR and consultant medical oncologist at The Royal Marsden trust, said: “Our study shows that a simple blood test could help us track how cancer evolves and responds to treatment – initially as part of clinical trials and eventually in routine care.

“These so-called liquid biopsy tests are minimally invasive, cost-effective and can be performed often and with ease.

“Tracking prostate cancer with a blood test instead of a painful surgical biopsy could significantly improve patients’ quality of life.”

Professor Paul Workman, chief executive of the ICR, said: “These simple blood tests detect traces of cancer circulating in the bloodstream and help us anticipate cancer’s next move.

“They can help doctors come up with personalised treatment plans and to stay one step ahead of the disease.

“This study showcases the value of liquid biopsies for guiding therapy. They are a faster, kinder, more flexible alternative to traditional tissue biopsies and are set to become a gold standard for cancer treatment.”

The research, presented at the American Society of Clinical Oncology (ASCO) virtual annual meeting, was funded by Roche and Genentech, the trial sponsors, as well as Cancer Research UK, Prostate Cancer UK, the Movember Foundation and the Prostate Cancer Foundation.