Blood Test Identifies Early Breast and Prostate Cancer Signals Years Before Diagnosis

Breast and prostate cancers are among the most common cancers, yet many are detected only after tumors have become established. Identifying disease earlier could support closer monitoring and help distinguish people who may need further testing from those at lower risk. Blood-based testing offers a less invasive way to detect cancer-related signals than tissue biopsy. New findings now show that signs of breast and prostate cancer may be detectable in blood up to eight years before diagnosis.

Researchers at the Ontario Institute for Cancer Research (OICR; Toronto, Canada) and collaborating institutions analyzed blood samples from the Ontario Health Study to identify early molecular warning signs of cancer. The approach focused on DNA methylation patterns, which can emerge early in cancer development. Because the method relies on a simple blood draw, it represents a liquid biopsy approach that could potentially be used to screen otherwise healthy individuals.

The study analyzed samples from Ontario Health Study participants who appeared healthy when their blood was collected but were later diagnosed with cancer months or years afterward. The Ontario Health Study includes more than 225,000 participants who provide blood samples for biobanking and consent to long-term follow-up through questionnaires and clinical health records. The findings were published in Cell Genomics and involved OICR, the Ontario Health Study, Genairx, the Nuffield Department of Population Health at the University of Oxford, and CanPath.

The results showed that blood-based methylation signals associated with breast and prostate cancers could be detected as early as eight years before diagnosis. According to the investigators, such testing could eventually help identify higher-risk individuals who may benefit from closer monitoring with additional blood tests or imaging, while reducing unnecessary invasive testing in those at lower risk.

The researchers are planning a prospective clinical trial to validate the findings in other settings. They are also evaluating additional blood analysis technologies with the aim of improving the accuracy, speed, and affordability of early cancer detection.

“Most breast and prostate cancers are detected at Stage 1 or Stage 2, when tumours have had a chance to take hold. This method allows us to see cancers at Stage 0 and even earlier, when they can be treated very successfully or prevented altogether,” said Dr. Philip Awadalla, Professor of Molecular Genetics at the Nuffield Department of Population Health and former OICR Senior Investigator.

“The potential here goes beyond a stand-alone cancer detection test. It could be a whole new comprehensive approach to risk stratification that changes how we screen for cancer and monitor high-risk patients,” added Awadalla.

Related Links
Ontario Institute for Cancer Research