Blood test flags failing prostate cancer treatment weeks earlier

The study, published in Nature Cancer, shows that men could switch or intensify treatment much sooner than is currently possible if their cancer is not responding to treatment, potentially saving precious time and improving outcomes for patients.

Researchers found that detecting tiny fragments of tumour DNA in the blood can reveal whether prostate cancer is continuing to grow, even when current tests show little change. This can allow clinicians to greatly accelerate treatment personalisation and clinical research.

Around 10,000 men are diagnosed with advanced prostate cancer every year, but currently there is no way to quickly tell which men will respond well to hormone therapy alone, or which will need additional treatments like chemotherapy.

Currently, clinicians look for a drop in PSA (Prostate-Specific Antigen) levels, to check if a treatment is working. But PSA can linger in the blood for months, so it can take time to detect these changes. As tumour DNA leaves the blood very quickly, it can act as an early warning sign that the cancer is still growing. This means it could also be used in clinical trials to show if new treatments are effective much more quickly.

Professor Gert Attard (UCL Cancer Institute), who led the study, 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 hormone-sensitive advanced cancer. By using it alongside PSA blood tests, we can personalise treatments and help find the right balance between reducing side effects and giving men more time with their loved ones.

“The next step is to show that we can reproduce this and how it can be used in practice. That’s why we’re implementing it across all our clinical trials for advanced prostate cancer to get the evidence we need to roll this out as soon as possible.”

The study assessed 117 men with newly diagnosed metastatic prostate cancer treated at 14 NHS centres across the UK, and found that:

• 3 in 10 men studied had detectable levels of tumour DNA in their blood after 6-12 weeks of treatment.
• These men had a dramatically lower life expectancy, with just half living more than two years, compared to 85% of men where tumour DNA was not detectable.
• Combining tumour DNA and PSA blood tests identified a group who were 20x more likely to die than men with undetectable tumour DNA and very low PSA levels and may therefore greatly benefit from more intensive treatment.

Prostate cancer is now the most common cancer in the UK, with more than 64,000 men diagnosed and 12,000 men dying from the disease each year. One in eight men will develop the disease in their lifetime, and the risk is higher for Black men, and those with a family history of prostate cancer.

Dr Hayley Luxton, Head of Research Impact & Engagement at Prostate Cancer UK, which funded the study alongside Movember, said: “Thousands of men are diagnosed with advanced, incurable prostate cancer every year, and right now, we can’t say which treatment will be best for which man until much later on. By showing if treatments are effective so much sooner, this test could not only help men with advanced prostate cancer live longer and better but could also massively speed up prostate cancer research in future.”

Links

• The paper in Nature Cancer
• Professor Gert Attard's academic profile
• UCL Cancer Institute
• UCL Medical Sciences

Image

• Credit: Jacob Wackerhausen via istockphoto

Media contact

Tom Cramp

E: t.cramp@ucl.ac.uk