New blood test shows strong potential for detecting colorectal cancer in asymptomatic adults
A recent study reports that a blood test can correctly identify colorectal cancer in about eight out of ten asymptomatic individuals, achieving 83 percent accuracy. The findings were published in a leading medical journal and add to the growing evidence that blood-based cancer detection can complement existing screening methods.
Involving nearly 8,000 participants aged 45 to 84, the research compared the blood test against colonoscopy, which is widely regarded as the gold standard for colorectal cancer screening. The analysis centers on tumor DNA circulating in the blood, a technology commonly referred to as a liquid biopsy. The study noted that tumor DNA was detectable in the blood of many patients whose colorectal cancer was later confirmed by colonoscopy, highlighting the test’s potential role in identifying cancer early when treatment is most effective.
Among the group with confirmed colorectal cancer, the blood test yielded a positive result in about 83 percent of cases. For others who did harbor a tumor according to colonoscopy, a negative blood test occurred in a subset, indicating room for improvement in sensitivity. Importantly, the test showed higher sensitivity for early stage bowel cancer and was less sensitive for precancerous lesions that could develop into cancer over time.
The new blood test performs comparably to at home stool tests in accuracy, but it offers a distinct advantage in convenience. A simple blood draw can be more acceptable to some patients and may encourage broader participation in screening programs, ultimately supporting earlier detection and intervention.
Experts emphasize that colorectal cancer remains common but is highly preventable through routine screening. They note that screening uptake remains suboptimal, with only half to six-tenths of eligible individuals actually completing recommended tests. The implication is clear: expanding access to blood-based screening options could bolster overall screening rates and cancer control efforts.
In addition to these findings, emerging research suggests that microbial factors in the gut may influence cancer outcomes. While the exact mechanisms require further study, scientists are examining how gut microbiota might interact with cancer therapies and affect survival. This line of inquiry could eventually inform personalized approaches to prevention and treatment, alongside established screening strategies.
As the landscape of colorectal cancer screening evolves, clinicians and patients alike may benefit from a broader toolkit. Liquid biopsy offers a promising alternative or complement to existing methods, with the potential to increase detection in populations that currently face barriers to screening. Ongoing studies will help clarify the role of blood-based testing in routine practice, including how best to integrate it with colonoscopy and stool-based approaches for optimized prevention and early treatment outcomes.
Overall, the recent results underscore the promise of blood-based colorectal cancer detection and the importance of expanding access to reliable screening options for people in North America and beyond.