Colonoscopy has been revolutionary in reducing and preventing the incidence and survival of one of the most dangerous cancers that occur. The quality and safety of the exam has improved over time in a methodological way which has been a public health success delivering the benefits in studies to the real world..
However, we have also learned from these successes that colonoscopy utilization has been excessive. Data over time shows that small lesions called "adenomas" may not be as significant as previously thought, and guidelines to lengthen the interval between exams were recently altered in 2021. And a recent study shows that only 1 in 5 physicians are adhering to this new guideline, one that would move up to 40% of patients into a 7-10 year interval instead of 5!
Further, a shift in the ages recommended to be screened has shifted downwards, to help capture some lesions in patients as young as 45 and prevent unnecessary exams over age 75.
But barriers to colon cancer screening persist. The cost and commitment required for colonoscopy, including the preparation and time involved contribute to ongoing evidence that only 40% of appropriate patients have the test when it is recommended. And non-invasive testing such as stool tests for blood, though improving, require annual at-home testing and strict adherence to a follow-up colonoscopy within 30 days for a positive test. Patients only adhere to these non-invasive tests 60-70%. We also realize that no matter how easy a test, many patients simply do not seek preventive medical care.
Yet the development of non-invasive stool and blood tests are well underway. These tests look for molecular markers and more accurate assessments for microscopic blood. Modeling shows that the success of these types of tests, should they meet key performance and cost metrics, could entirely shift the cost-effectiveness of screening recommendations. Many of these tests are approaching the sensitivity, specificity, cost and less frequent intervals suggested in models. There are over 170 companies working on these solutions, many along side other cancer screening molecular and genetic markers. Cologuard, one of the best stool tests so far, is improving on accuracy even for pre-cancerous polyps and a lower cost with their 2.0 version under study. Epi proColon is a blood test that when combined with other non-invasive tests gets close to some of these proposed performance metrics. There are also many great studies underway looking closer at why pre-cancerous polyps and cancers occur, including links to the microbiome.
So what does the future hold for improvement? Hybrid models. It makes intuitive sense that a combination of non-invasive testing and appropriate use of colonoscopy could best address the need to continue to prevent the occurrence of colon cancer, while helping reduce the cost and complexity of doing so. Finding cancer early is still important, as the outcomes are becoming more favorable even when found. Increasing population screening rates where possible enhances the success of our programs.
How should we think about this?
How soon will colonoscopy use for cancer screening decline due to non-invasive testing advances?
It depends on all three of these variables:
2. Test performance
Patient adherence to recommendations improves the easier the test gets. Non-invasive wins when infrequent (2-3 years?) and around $1-200. Cologuard is currently $5-600 however the price is market based and somewhat arbitrary.
Test performance is improving, and there is a sweet spot in sensitivity vs specificity that is interrelated to cost. And newer targets and novel targets are imminent (microbiome, metabolome, liquid biopsy/blood based methylation, multi target sDNA stool test expansion).
Cost decline follows the tech learning curves, and is demonstrable. Thus an inflection point can be projected in the coming few years that will upend cost-effectiveness.
Recent analyses show that very soon, we may see a reduction in need for colonoscopy by 30-40%. Combine this with data showing that small adenomas do not require increased surveillance, and that it may be unnecessary to screen as much or as late in life as we have been.
Another recent study shows a 70% costs savings in these non-invasive test scenarios with better outcomes in QALY saved. Even for Cologuard 1.0.
(Is this the reason many Gastroenterologists are selling their colonoscopy based practices to Private Equity? Is the market is speaking!)
The last piece of this puzzle is really a combination of the science and art of medicine vs bureaucracy. The consensus guidelines always take years to change, and public health measures that might be best overall don't always mean those guidelines are the best for individuals. And the big push for artificial intelligence use during colonoscopy? Well, I'll break that down in another post as the positive spin is without a lot of substance.
There is good reason to think that colonoscopy in earlier age groups provides significant benefit over later age groups who have had multiple negative colonoscopies. (for average risk individuals without symptoms, of course). Helping identify individuals who do have lesions of concern and may benefit from a colonoscopy based screening regimen focuses resources and appropriate utilization. This is an opportune time to undergo this risk assessment, as the intervals now suggested for follow-up colonoscopy exams provide many years for non-invasive testing to come to the forefront. For those that are unsure of their past colonoscopy results, seeing a provider that can update your risks and need for procedures with up to date guidelines makes a lot of sense!
Guess which test Pearl Health Partners will always advocate?
The best one.