A groundbreaking blood test could enable doctors to identify failing prostate cancer treatment earlier, a trial found.

Experts believe this discovery could lead to personalised therapies and extend the lives of men with advanced disease.

The University College London study investigated whether tests for tiny fragments of tumour DNA in the blood could detect ongoing cancer growth. It involved 117 men with newly diagnosed metastatic prostate cancer , which had spread, across 14 NHS sites.

Researchers found that three in 10 men had detectable tumour DNA in their blood after six to 12 weeks of treatment.

Crucially, combining these DNA tests with prostate specific antigen (PSA) levels identified men 20 times more likely to die than those with undetectable tumour DNA and low PSA.

Professor Gerhardt Attard, who led the study at University College London, said: “This is so exciting because it’s the first time we’ve ever seen such a clear link between tumour DNA in the blood and outcomes for men with…