Research highlights

• New evidence helps reduce harm caused by prostate cancer treatment.
• Major impact on health policy.
• Patients and clinicians better informed when making treatment decisions. 

Prostate cancer kills over 11,000 men a year in the UK – but it can be treated effectively when detected early enough through surgery, radiotherapy or active monitoring treatments.

ProtecT, a collaboration between Bristol, Cambridge and Oxford Universities, has helped to compare the various risks and side effects associated with these treatments so clinicians and patients can make more informed decisions on the best course of action. The programme has also changed health policy in the UK and around the world.  

The search for new evidence 

The risks linked to prostate cancer treatments include secondary cancer spread, disease progression and harm to sexual, urinary and bowel function.  

Many prostate cancers remain small and grow slowly during a man’s lifetime, however, which has led to clinicians calling for the development of monitoring and surveillance programmes to avoid or delay radical treatment until it is needed.  

In response, the Bristol team was instrumental in creating ProtecT, the first and only randomised trial to compare active monitoring, radical surgery, and radical radiotherapy in 1,643 men diagnosed with localised prostate cancer. 

When the ProtecT outcomes were published in 2016, they showed very low levels of prostate cancer mortality (less than 1%) and no evidence of a difference between the three different treatment approaches 

Other findings included no differences between the groups in all-cause mortality, but there was a slightly higher rate of cancer spread in the active monitoring group compared with the surgery and radiotherapy groups.  

In the active-monitoring group, there was an expected gradual decline in sexual and urinary function with age, but serious problems were avoided unless men changed to a radical treatment during follow-up.

This meant the ProtecT results provided strong evidence about the comparative risks of harms to sexual, urinary and bowel function caused by radical treatments, balanced against the small increased risk of progression and cancer spread from active monitoring. 

Impact on policy, practice and care 

In the years following the publication of these findings,  ProtecT has helped to change health policy.  

In the UK, the National Institute for Health and Care Excellence (NICE) launched an exceptional review “to determine the clinical and cost-effectiveness of treatments for localised prostate cancer”, directly referring to ProtecT as “the only UK-based study, making it directly applicable to current practice in the NHS”.

NICE subsequently published an updated guideline in 2019 with changes to major recommendations including those for treatments for low and intermediate-risk cancer.  

Major international clinical guidelines also rapidly incorporated ProtecT results, including those issued by the American Urological Association, the  European Society for Radiation Oncology and the International Society of Geriatric Oncology.  

The research has also helped to transform clinical practice to avoid harm. In the UK, the 2016 National Prostate Cancer Audit commented that “the proportion of men with low-risk disease being potentially ‘over-treated’ is an area of concern, especially given the recent publication of the ProtecT study.”

In the years after the release of the ProtecT findings, over-treatment reduced to 8% in 2017, 4% in 2018 and 4% again in 2019. 

Men newly diagnosed with clinically localised prostate cancer and their clinicians can also now consider the comparative benefits and harms of the main treatment methods.

In particular, they can balance the clear risks of treatment harms and benefits in the context of similar very low levels of risk of dying. This affects the decision-making of over 23,000 men diagnosed each year with low or intermediate-risk prostate cancer in England alone.