We’re launching a £3.2 million clinical trial to help men with advanced prostate cancer by reducing the debilitating side effects of hormone therapy (sometimes known as HRT).

The ENHANCE trial, jointly funded by Cancer Research UK and Prostate Cancer UK, will investigate whether lower doses of hormone therapies like abiraterone and enzalutamide offer the same life-extending benefits with fewer side effects.

Abiraterone and other hormone treatments stop advanced prostate cancer from spreading or growing by depriving the cancer cells of testosterone, which they use as a fuel. They can make it possible for people with incurable prostate cancer to live long lives without the disease progressing.

However, the side effects of the hormone therapy doses used to treat advanced prostate cancer can have a big impact on people’s quality of life. Issues like fatigue, hot flushes, and high blood pressure can be so severe that some men struggle to continue treatment.

HRT has already helped triple prostate cancer survival in the UK since the 1970s. If ENHANCE shows that lower doses have the same ability to stop advanced prostate cancer growing or spreading further, it could change prostate cancer treatment guidelines as early as 2030, improving care for thousands of men and reducing costs for the NHS.

The benefits of lowering hormone therapy doses

Prostate cancer is now the most common cancer in UK men, with around 55,900 men diagnosed each year. Thanks to the advances we’ve already made in treating prostate cancer, more than 8 in 10 of these men will survive their disease for 10 years or more.

And, for some recently diagnosed men, the benefits of reduced-dose treatment are already clear.

Retired solicitor Jonathan Edwards, 80, was one of a group of patients whose positive responses showed what could be possible with lower HRT doses and set the stage for ENHANCE.

Diagnosed with prostate cancer at the end of 2024, Jonathan struggled badly with the side effects of the hormone-blocking drug enzalutamide. When his nurse reduced his dose, his quality of life improved dramatically and his cancer remained under control.

Enhancing quality of life for men with advanced prostate cancer

Professor Ananya Choudhury, ENHANCE’s lead researcher, works at the University of Manchester and the Christie NHS Foundation Trust, where Jonathan is being treated. Her experience with men receiving hormone therapy has directly influenced her work.

“Patient experience has been central to the design of this trial,” Choudhury explained. “We know these drugs can be life-extending, but for many men the side effects are extremely challenging. Cases like Jonathan’s demonstrate why this trial is crucial to the future of prostate cancer care.

“Throughout the study, we will closely monitor survival and side effects, with a particular focus on fatigue and quality of life. By making treatment more tolerable, we hope more men will be able to stay on therapy for longer and gain the full benefit.”

The trial will test half-dose treatments of the hormone therapies abiraterone, enzalutamide, darolutamide and apalutamide in 1,500 patients from hospitals across the UK.

“ENHANCE is a patient-driven trial, shaped with the help of patient and public involvement groups,” said Choudhury. “It has the potential to make a real difference to people’s lives in a relatively short period of time and even have a global impact.”

Crucially, at least 10% of the trial’s participants will be Black men, who have been historically underrepresented in clinical trials and are often treated based on data that may be less applicable to them. Data also shows that Black men are more likely to develop prostate cancer, although more evidence is needed to understand their risk of aggressive disease and the role of overdiagnosis.

The trial, which is being run jointly with University College London, will also collect tissue, blood and urine samples from participants. This will help researchers identify biomarkers that could help determine if reduced-dose treatments work better for some men than others, helping shape more personalised care in the future.