Source: CNN
Colorectal cancer is responsible for roughly 900,000 deaths each year worldwide, although it is considered highly treatable when detected early. Unfortunately, many adults avoid recommended routine screenings because of the inconvenience, discomfort, or fear associated with current methods.
While at-home stool-based tests are available, the gold standard for early colorectal cancer detection remains colonoscopy—a procedure that involves inserting a flexible tube equipped with a camera into the rectum to examine the entire colon. During the procedure, doctors can also remove or biopsy suspicious tissue and polyps for further evaluation.
That is why a new blood test currently being developed is being viewed as a potentially major breakthrough in colorectal cancer screening. The test may soon offer patients a less invasive alternative to stool-based exams and colonoscopy, and researchers say it could encourage more people to undergo screening before symptoms appear.
According to the study, published this week by the American Cancer Society, the blood-based test showed promising accuracy in detecting colorectal cancer, particularly among adults at average risk for the disease. The development could provide health workers with an easier and more accessible way to improve screening rates, especially among people reluctant to undergo colonoscopies or stool collection tests.
But how does it work? After blood is drawn from the patient, the sample is sent to a laboratory where fragments of tumor DNA circulating in the bloodstream are analyzed. Researchers say these molecular traces can act as early warning signs of cancer, even before symptoms begin to appear. In clinical testing, the blood exam successfully identified a significant proportion of colorectal cancer cases, offering what experts describe as a potentially important step toward expanding access to cancer screening.
Experts caution, however, that blood tests are not expected to completely replace colonoscopies. If a blood test returns a positive result, patients would still need to undergo additional diagnostic procedures and follow-up testing to confirm the presence of cancer or precancerous polyps. Researchers also noted that detecting early-stage precancerous lesions remains more difficult with blood-based methods compared to colonoscopy.
Still, physicians argue that the convenience of a simple blood draw may encourage more adults to undergo routine colorectal cancer screening, especially adults age 45 and older who are considered at higher risk. After all, prevention is better than a cure. For patients who avoid existing screening tools, an easier option could ultimately lead to earlier detection and better survival outcomes.
