A simple blood test has shown promise in accurately detecting colon cancer, the deadly disease growing exponentially among youth. The experimental blood test not only helps detect colon cancer effectively but also can accurately rule it out among healthy people. The test is quite convenient considering it's less invasive compared to traditional methods like colonoscopies and stool-based tests, according to a study presented at the 2025 American Society of Clinical Oncology Gastrointestinal Cancers Symposium.
The test identified colon cancer with 81% accuracy among those diagnosed with the disease and correctly ruled it out for 90% of healthy individuals. Researchers believe this breakthrough could significantly increase screening rates, particularly among those who avoid colonoscopies due to their invasive nature.
The researchers noted, about 22% of people eligible for colon cancer screening have never received it, with this percentage climbing to 40% in certain states. Colonoscopy can be inconvenient, as patients need to undergo unpleasant bowel preparation and often must be anesthetized during the procedure. Stool tests are also used for screening colon cancer, but those must be done every year under current guidelines.
How the study was carried out was quite thorough; over 40,000 people aged 45 to 85 participated at 200 sites across the U.S. Blood was drawn for the test, followed by standard colonoscopy. Researchers compared results to determine the efficiency of the blood test.
This blood test, described by Dr. Pamela Kunz, chief of GI medical oncology at Yale School of Medicine, "represents a new tool in our toolbox of colorectal cancer screening options." She added, the results show the blood test “may provide a convenient and effective option for colorectal cancer screening in the average-risk U.S. population.”
Colon cancer typically impacts older adults and begins at the colon—a part of the large intestine. Alarmingly, it is on the rise among individuals under 50. The disease often starts as small clumps of cells called polyps, which can turn cancerous over time. Symptoms of colon cancer can include changes in bowel habits, blood in the stool, and abdominal discomfort such as cramps or gas, along with unintended weight loss or fatigue.
Given the distressing trends of colon cancer cases, particularly among younger populations, the introduction and validation of this blood test could bridge the gap for many who are reluctant to undergo traditional screening methods. With growing awareness and increasing dialogue on preventive health measures, this blood test offers hope for improved outcomes through earlier detection.
Overall, the promising results from the study may stimulate discussions around how best to implement the new screening method, focusing on increasing access and encouraging participation among those eligible for colon cancer screenings. If adopted widely, it could mark a significant transformation in colorectal cancer prevention, ensuring higher rates of detection and treatment options being made readily available.