Colorectal cancer is a major global health concern, with 1.9 million new cases and 935,000 deaths annually. Early detection and interception is the best way to reduce these alarming numbers. Population based screening with FIT is the most widely used approach for this purpose. After a positive FIT result, polyps are removed in more than 60% of screened individuals, who then undergo regular surveillance colonoscopies to monitor for cancer or precancerous growths.
Over the last decade, stool tests have been widely implemented for colorectal screening, but their use for surveillance after polypectomy has hardly been investigated. This observational study aimed to evaluate whether three stool tests—the multitarget stool DNA (mt-sDNA) test and two types of FITs—could serve as safe alternatives to colonoscopy in this context. The study included 3,830 participants aged 50-75 who were scheduled for colonoscopy surveillance at 18 endoscopy centers across the Netherlands. Participants provided stool samples before their colonoscopy, which were analyzed for their ability to detect advanced neoplasia, i.e. colorectal cancer or its advanced precursors, often larger polyps. Using mathematical modeling, each test’s accuracy was used to predict long-term efficacy and colonoscopy burden of a range of surveillance scenarios.
For all three tests, possible scenarios were found where equal efficacy was achieved as colonoscopy surveillance, demonstrating that stool tests may be a safe alternative for colonoscopy in surveillance. The highest reduction in the number of necessary colonoscopies (41%) and the highest cost-effectiveness were achieved with annual FIT surveillance. This scenario both reduces patient burden and healthcare cost. “Our findings suggest that stool-based tests, particularly FIT, could significantly reduce unnecessary colonoscopies without missing high-risk cases.”, says Veerle Coupé, the health-economic modeller of the team. “Given the current challenges in health care, such as the lack of personnel and steeply increasing costs, this is an important finding that may contribute to a more efficient healthcare system.”
Next step
To confirm these findings, the researchers plan to evaluate the effectiveness of annual FIT monitoring after polyp removal in practice. This could pave the way for a new, less invasive form of follow-up care, where people undergo colonoscopy only if they are truly at high risk for colorectal polyps or cancer.
This research was financially supported by Alpe d’Huzes and the Dutch Cancer Society