The ECLIPSE study conducted on nearly 8,000 people showed that a new home blood test for colorectal cancer is as effective as current home tests using stool samples. This new test, which detects circulating tumor DNA in blood shed by tumors, is about 83% accurate for average-risk individuals without symptoms, similar to stool tests but less accurate than colonoscopies. Colorectal cancer is the second most common cause of cancer deaths in adults in the United States, expected to kill 53,000 people in 2024, with increasing rates among younger adults. Experts hope that the availability of a blood-based test for colorectal cancer will encourage more people to get screened early, as early detection greatly improves treatment outcomes.
Dr. William Grady, a study author and gastroenterologist at Fred Hutchinson Cancer Center, emphasized the importance of offering more convenient screening options to increase participation rates. While colonoscopies are still considered the most accurate method of detection, the new blood test offers a less unpleasant alternative for those who dislike the home stool test. The new test showed higher sensitivity for colorectal cancers, including early stage cancers, but was less sensitive for advanced precancerous lesions. Younger individuals under 50 are increasingly being diagnosed with colorectal cancer, making early screening crucial to improving survival rates.
Dr. Jeremy Kortmansky, clinical director of the GI Medical Oncology Division at Yale Cancer Center, noted the challenge of improving accuracy rates in home-based tests, as the sensitivity of stool tests correlates with the size of the polyp or cancer. Smaller lesions may not shed enough DNA to be detected in a stool sample, affecting the accuracy of the test. Dr. Anton Bilchik, a surgical oncologist, highlighted the potential link between disruptions in the microbiome and the development of colon cancer, as well as the significance of specific bacteria in tumor growth. The technology described in the study could be used to evaluate other bacteria that may prevent colorectal cancer and provide targets for future therapies.
Symptoms of colon cancer include abdominal pain or cramping, changes in stool habits, blood in the stool, weight loss, and low iron levels in the blood. Screening for colorectal cancer aims to detect cancers or precancerous lesions early, when they are more treatable and potentially curable. The new blood test offers a less unpleasant option for screening, potentially increasing participation rates among individuals who are hesitant to undergo stool tests or colonoscopies. Despite the challenges in improving accuracy rates for home-based tests, the use of circulating tumor DNA detection in blood samples provides a promising method for early detection of colorectal cancer, which is crucial for improving survival outcomes. Early screening is especially important for younger adults, as rates of colorectal cancer among individuals under 50 continue to rise.
