Breakthrough blood test detects cancer years before symptoms appear

Independent

17-06-2025

Scientists have developed a 'highly sensitive' blood test that could detect signs of cancerous tumours years before the first symptoms appear, an advance that could lead to better treatment outcomes for patients.
Researchers from the Johns Hopkins University in the US found that genetic material shed by tumours can be detected in the bloodstream much before patients get their first diagnosis.
The study, published in the journal Cancer Discovery, found that these genetic mutations caused by cancer, can be detected in the blood over three years in advance for some patients.
'Three years earlier provides time for intervention. The tumours are likely to be much less advanced and more likely to be curable,' said study co-author Yuxuan Wang.
In the research, scientists assessed blood plasma samples collected from participants of a large NIH-funded study to investigate risk factors for heart attack, stroke, heart failure and other cardiovascular diseases.
Researchers developed highly accurate and sensitive genome sequencing techniques to analyse blood samples from 52 of the earlier study's participants.
Twenty-six of the participants were diagnosed with cancer within six months after sample collection, and 26 who were not diagnosed served as the control group for comparison.
Eight of the 52 participants scored positively in a multicancer early detection (MCED) laboratory test conducted at the time their blood samples were taken.
The MCED test is designed to detect multiple cancers in their early stages from a single blood sample by analysing cancer-signature molecules in the blood, including DNA and proteins.
All eight were diagnosed with cancer within four months following blood collection.
For six of these 8 participants, additional blood samples were collected about 3 to 3.5 years before cancer diagnosis.
In four of these cases, mutations linked to tumour growth could be identified in their earlier blood samples.
The findings point to 'the promise of MCED tests in detecting cancers very early', researchers say.
It may lead to more standardised blood tests to screen people either annually or every two years, which could boost early detection and prevent cancers from becoming treatment-resistant tumours.
'These results demonstrate that it is possible to detect circulating tumour DNA more than three years prior to clinical diagnosis, and provide benchmark sensitivities required for this purpose,' scientists wrote.
'Detecting cancers years before their clinical diagnosis could help provide management with a more favourable outcome,' said Nickolas Papadopoulos, another author of the study.
Scientists hope the findings can be validated in a larger-scale trial involving more participants.