New test offers prostate cancer hope

■ A new blood test can predict how men with advanced prostate cancer will respond to treatment and could replace painful surgical biopsies, British scientists have found. The test, which is minimally invasive, can also help identify men who are less likely to respond at the start of treatment, and those more likely to relapse later.

The type of blood test, known as a liquid biopsy, could lead to more precise patient care, allowing clinicians to tailor treatment for men with advanced prostate cancer, and prevent drugs being used that are unlikely to work.

Researchers at the Institute of Cancer Research, London, and The Royal Marsden NHS Foundation Trust analysed traces of cancer DNA that had entered the bloodstream. The team looked at more than 1,000 blood samples from 216 men with the disease and found those with high levels of tumour DNA at the start of treatment had a significantly worse outcome.

They monitored patients with blood tests during treatment to see whether liquid biopsies could help doctors predict responses to treatment. Men who responded to treatment had the greatest fall in the amount of cancer DNA in the bloodstream — a 23pc reduction — while those who partially responded had a reduction of 16pc. Those whose cancer continued to get worse or stayed the same only saw reductions of one per cent or four per cent, respectively. The research was presented at the American Society of Clinical Oncology annual conference.