Predictive blood test hailed as ‘incredibly exciting’ breakthrough in breast cancer

A new blood test can predict the risk of breast cancer returning three years before tumors appear on scans. This is an ‘incredibly exciting’ breakthrough that could help more women beat the disease for good.

More than 2 million women are diagnosed with breast cancer every year, the most common form of the disease. Although treatment has improved in recent decades, the cancer often returns, and when it does, it is usually in a more advanced stage.

But now research presented at the world’s largest cancer conference has shown that a personalized liquid biopsy could be a very early warning sign that cancer is returning. Results from a trial of the tests, unveiled at the annual meeting of the American Society of Clinical Oncology in Chicago, suggest they could help reveal which women need preventive therapy and which patients could be spared from it.

The test detects tiny amounts of cancer DNA in the bloodstream. Trial results show that it is so sensitive that it can accurately predict the risk of cancer coming back months or even years before the usual signs or symptoms begin to manifest.

Researchers at the Breast Cancer Now Toby Robins research center in London were able to identify every patient in the study who later had a relapse. The mean time to relapse was 15 months; the longest 41 months.

“Early detection is one of our greatest weapons against breast cancer and these initial findings, which indicate that tests could be able to detect signs of breast cancer recurrence up to a year before symptoms emerge, are incredibly exciting,” said Simon Vincent , research director at Breast Cancer Now, which helped fund the trial.

“Although this research is still in its early stages, detecting a recurrence of breast cancer earlier means that the treatment is much more likely to destroy the cancer and stop it from spreading to other parts of the body, at which point the cancer becomes incurable is becoming.”

Experts hope the findings will result in a strategy where treatment can be started much earlier. The ultra-sensitive liquid biopsy works by finding circulating tumor DNA (ctDNA) released into the bloodstream by cancer cells.

“Breast cancer cells can remain in the body after surgery and other treatments, but there may be so few of these cells that they are undetectable on follow-up scans,” said Isaac Garcia-Murillas, lead author of the study at the Institute of Cancer Research. (ICR) in London. “These cells can cause breast cancer patients to relapse many years after their first treatment.”

Previous research has suggested that ctDNA blood tests can identify relapse before it can be seen on a scan. However, these tests usually use a technique called whole exome sequencing, which typically looks for between 16 and 50 mutations. The new test uses whole genome sequencing and looks for 1,800 mutations, making it much more sensitive.

Researchers analyzed blood from 78 patients with different types of breast cancer. The new test correctly identified a high risk of recurrence in all 11 patients who relapsed during the five-year trial. All 60 women whose test found no ctDNA did not relapse, meaning there were no false negatives.

In three other patients, ctDNA was once detected, but further investigation showed that it had disappeared. The ICR did not provide complete data for the remaining four patients.

Prof Kristian Helin, CEO of the ICR, said: “Breast cancer is much easier to treat before it spreads to other parts of the body, so it is crucial to be able to detect signs of a recurrence as early as possible to help people to provide the best treatment. chance of survival.

“It is very exciting to see technological advances that can detect cancer cells and DNA with greater sensitivity to pick up residual disease or detect the early signs of a breast cancer recurrence while still allowing a cure. These approaches are having a transformative effect on cancer diagnosis.”