Thousands of men with prostate cancer could live longer thanks to a breakthrough by British experts.

Scientists have developed a new form of immunotherapy to delay resistance to hormone treatment and help the body's immune system to target the tumour.

For many diagnosed with prostate cancer, androgen deprivation therapy (ADT) is a powerful first-line treatment. While it is initially effective, some patients' tumours can develop resistance to it.

Immunotherapy has had huge success in other cancers, but this has not translated to prostate cancer. 

Now researchers from the University of Sheffield have published findings in the Journal for Immunotherapy of Cancer showing that a new form of the treatment using nanoparticles could help men live longer.

The team found that a type of white blood cell called a macrophage accumulates in tumours during ADT treatment.

They then developed a way of using nanoparticles to target delivery of a drug that boosts immunity levels in these cells. When released inside tumours, it stimulates other immune cells – called T cells – to kill cancer cells. When done with ADT, it delayed tumour resistance.

Professor Claire Lewis, who led the study, said she was 'excited' by the therapy's impact and hoped to conduct clinical trials 'as soon as possible'.

Some 52,000 cases of prostate cancer are diagnosed in the UK every year. The Daily Mail has campaigned for more than two decades for better diagnosis and treatment of the disease.

Dr Hayley Luxton, research impact manager at Prostate Cancer UK, which funded the study, said: ‘Over 12,000 men die from prostate cancer each year in the UK, and we desperately need new and more effective treatments.

‘Immunotherapy has completely changed the way other cancers are treated, but we haven’t yet seen anything even close to that success for men with prostate cancer.

‘We’re thrilled to have funded this research which shows a new form of immunotherapy could give men much more time before their cancer becomes resistant to hormone therapy.

‘It will be really exciting to see how it performs in future clinical trials, and we hope it will play a pivotal role in finally unlocking the potential of immunotherapy for men with prostate cancer.’