Key points from article :
A groundbreaking study led by researchers at Johns Hopkins has found that cancer-related genetic material can be detected in the bloodstream up to three years before a formal cancer diagnosis. The study, published in Cancer Discovery and supported by the NIH, suggests that multicancer early detection (MCED) blood tests could transform cancer screening by identifying tumours at a more curable stage.
Researchers analysed blood samples from participants in the long-term Atherosclerosis Risk in Communities (ARIC) study. Using ultra-sensitive sequencing methods, they compared samples from individuals diagnosed with cancer within six months to those who remained cancer-free. Notably, they identified cancer-linked mutations in some blood samples collected over three years prior to diagnosis.
In eight participants, the MCED test flagged cancer signals close to diagnosis. For six of them, earlier blood samples were also available, and in four of those, tumour DNA was already detectable, suggesting cancer was silently developing years earlier.
Lead author Dr. Yuxuan Wang highlighted the potential for early intervention: detecting tumours when they are less advanced could greatly improve outcomes. Senior researcher Dr. Bert Vogelstein noted that this work sets a sensitivity benchmark for future blood-based screening technologies.
The findings raise the possibility of routine blood tests playing a major role in cancer prevention, though researchers stress the need for careful follow-up strategies after a positive result to ensure the best use of early detection tools.
