A study of blood samples collected up to nine years before a cancer diagnosis found changes in the DNA that captured the body's response to early traces of cancer development.
Routine screening tests remain limited to a few cancers, such as pap smears for cervical cancer and stool tests for bowel cancer.
DNA reveals markers for people at high riskCurrently, liquid biopsies are mainly used after a cancer diagnosis to find and analyse DNA from existing tumours or to track potential recurrence.
For this study, the researchers studied blood samples collected from individuals who were months or years away from a cancer diagnosis to understand whether their DNA would reveal the earliest biological changes associated with cancer development.
They used stored blood samples from 491 participants in the Ontario Health Study who were cancer-free when their blood was collected.
A study of blood samples collected up to nine years before a cancer diagnosis found changes in the DNA that captured the body's response to early traces of cancer development. The findings, which are published in Cell Genomics, build on other recent work by researchers at Oxford Population Health and the University of Toronto aimed at identifying the earliest signs of cancer development using highly sensitive blood profiling that captures DNA changes.
Cancer remains the second leading cause of death globally, with deaths often resulting from a late diagnosis. When cancers are detected early, treatment is more likely to be successful and patients have a better chance of surviving.
Routine screening tests remain limited to a few cancers, such as pap smears for cervical cancer and stool tests for bowel cancer. For other cancers, early detection through radiological imaging to look for tumours or examining a tissue sample to look for cellular abnormalities varies in effectiveness. Recent developments in the use of liquid biopsies offer the possibility of detecting cancer in its earliest stages using minimally invasive blood or urine tests.
DNA reveals markers for people at high risk
Currently, liquid biopsies are mainly used after a cancer diagnosis to find and analyse DNA from existing tumours or to track potential recurrence. For this study, the researchers studied blood samples collected from individuals who were months or years away from a cancer diagnosis to understand whether their DNA would reveal the earliest biological changes associated with cancer development.
They used stored blood samples from 491 participants in the Ontario Health Study who were cancer-free when their blood was collected. Some subsequently developed breast or prostate cancer, while others remained cancer-free. The researchers looked for differences in chemical patterns in the DNA known as methylation. These tiny chemical tags act like switches that control gene activity linked to functions such as cell growth, immune function, and inflammation.
