New cancer blood test will identify ‘relapse patients’

AN “Ultra-sensitive” blood test can predict which breast cancer survivors will relapse years before scans show evidence of new tumours.

In the earliest case, scientists found the test flagged a cancer relapse three years and five months earlier than a scan would have picked it up.

Experts hope the breakthrough could have a “transformative effect”, allowing women to start treatment before the disease becomes incurable.

The new test uses whole genome sequencing to search for DNA mutations that indicate cancer has returned.

In an early trial of 74 women, it correctly identified all 11 patients who later relapsed.

Recurrence was typically predicted 15 months before scans – the current method used by the NHS to check for relapse – showed evidence of tumours.

Study leader Dr Isaac Garciamurillas, of The Institute of Cancer Research in London, presented the findings at the American Society of Clinical Oncology’s annual conference in Chicago.

He said: “Breast cancer cells can remain in the body after surgery and other treatments but there can be so few they are undetectable on scans.

“These cells can cause patients to relapse many years after initial treatment. Ultra-sensitive blood tests could offer a better approach for the monitoring of patients whose cancer is at high risk of returning.” The new test, developed by Us-based Personalis, uses whole genome sequencing to search for up to 1,800 mutations.

Dr Garcia-murillas added: “A more sensitive test is very important for this group of early breast cancer patients, as they tend to have a very low amount of cancer DNA in their blood. “This study lays the groundwork for better post-treatment monitoring and potentially lifeextending treatment in patients.” The women who relapsed in the study survived for an average of just over five years. If further studies confirm the findings, future patients could begin treatment as soon as signs of recurrence are detected, researchers said. This could significantly boost their chances of successful treatment.

Dr Simon Vincent, director of research, support and influencing at Breast Cancer Now, which partfunded the study, said: “Early detection is one of our greatest weapons.

“These initial findings are incredibly exciting. With around 11,000 people dying every year in the UK from secondary breast cancer, breakthroughs like these are urgently needed.”

‘It would allow treatment to start far earlier’