TRAP: Precise radiotherapy to delay chemotherapy and protect quality of life

Grant information

Why did we fund this project?

• In many men with advanced prostate cancer, the cancer has spread to other parts of the body, such as the lymph nodes, bones and lungs. These new cancers are called metastases. 
• Whilst hormone therapy can often slow the growth and spread of metastases, some of the metastases eventually become resistant and stop responding. When this happens, men's next best treatment option is often chemotherapy, which can cause side effects that can be difficult to deal with.
• Dr Alison Tree and team wanted to test whether a new precise radiotherapy treatment called stereotactic body radiotherapy (SBRT) could slow the growth and spread of metastases that are resistant to hormone therapy.
• SBRT involves hitting cancer with beams of radiation from different directions, so that while the cancer receives a high dose of radiotherapy, the surrounding tissues experience much lower doses, which reduces side effects.
• The team hoped this new treatment might slow the progression of prostate cancer metastases to help men avoid chemotherapy for longer, protecting their quality of life.

What did the team do?

• The team recruited 86 men to take part in the TRAP trial. All had advanced prostate cancer with metastases that were not responding to hormone therapy.
• Each man received SBRT to treat either 1 or 2 of their metastases, delivered over 5 sessions.
• The team monitored the men using blood tests and scans to see how the metastases were responding to the treatment. If men were not responding, they were offered different treatments.

What did the team achieve?

• The team found that after the SBRT treatment, men had an average of 6 months where their metastases didn't grow. 40% of men remained stable after 1 year.
• Impressively, on average men on the study avoided other treatments such as chemotherapy for just under 2.5 years. As SBRT has much fewer side effects compared to chemotherapy, this helped protect the men's quality of life, helping them live better for longer.

What does this mean for men?

• The team have shown that SBRT can slow the growth of metastases in men with advanced prostate cancer who are resistant to hormone therapy.
• Importantly, this could help men avoid chemotherapy for longer, helping them live with fewer treatment side effects and significantly improving their quality of life.
• The team now need to confirm their ground-breaking findings in a larger trial with more men, and they are doing this through a new Prostate Cancer UK-funded project called STAR-TRAP.
• With the evidence from this larger study, we hope that this treatment model will eventually be approved as a treatment option to help men with advanced prostate cancer live better for longer.