AI-powered blood test detects 90% of colorectal cancer cases

A groundbreaking blood test utilizing artificial intelligence can detect colorectal cancer with remarkable accuracy, according to a study by South Korean researchers. The test identifies 90% of colorectal cancer cases by analyzing cell-free DNA (cfDNA) in blood samples, offering a less invasive alternative to current screening methods.

Developed by a team from Asan Medical Center and GC Genome, the test demonstrated a 90.4% sensitivity rate in identifying colorectal cancer. Crucially, it also showed a high sensitivity of 84.2% for Stage 1 cancer, the earliest stage where treatment is most effective. For early-stage cancers treatable with endoscopic resection, the detection rate was 90%.

Colorectal cancer is the third most common cancer in South Korea, with over 32,000 new cases reported in 2023. Despite high survival rates when detected early, screening participation remains low due to the discomfort associated with traditional methods. The national screening program, which involves a fecal occult blood test followed by a colonoscopy if positive, had a participation rate of only 44.4% in 2025.

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We have presented the possibility of conveniently screening for colorectal cancer with just a blood test, reducing the burden felt during existing screening processes.

The new blood test analyzes short DNA fragments released into the bloodstream from dying cells, including those from cancer cells. AI algorithms are trained to identify subtle differences in these DNA fragments, such as length and structural patterns, to indicate the presence of cancer.

While the results are promising, researchers caution that further studies are needed to confirm the test's performance in asymptomatic individuals and its effectiveness as a primary screening tool. Currently, it is seen as a potential new pre-screening method to encourage more people to undergo colonoscopies, rather than a complete replacement for them. The test also showed a 58.3% sensitivity for advanced colorectal polyps, which are pre-cancerous lesions.

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Early detection of colorectal cancer can lead to treatment through endoscopic resection, contributing to improved survival rates and quality of life after treatment.