To encourage robust and honest debate about difficult issues, STAT publishes a selection of letters to the editor received in response to First Opinion essays. Today’s issue is a little different. An essay about a blood test to detect hidden colorectal cancer and a letter from the essay’s author regarding a response.Submit a letter to the editor hereor find the submission form at the end of the First Opinion Essay.
“Balancing Hope and Reality: The Promises and Risks of Blood-Based Colorectal Cancer Screening” Written by Folasade P. May
I have been following with interest recent data releases on blood-based colorectal cancer screening tests. This first opinion essay by Dr. May accurately characterizes the potential pitfalls of blood-based strategies. That is, it has the potential to shift the clinical performance of colorectal cancer screening programs from cancer prevention to cancer detection. This is a step backwards from current solutions and could increase the burden on patients and healthcare systems.
A strategy for screening average-risk individuals that Dr. May did not mention is noninvasive stool-based testing. This includes both multi-target fecal DNA testing (mt-sDNA) and fecal immunochemical testing (FIT). (Disclosure: My employer, PolyMedco, conducts such tests for colorectal cancer.) These well-established, U.S. Preventive Services Task Force-supported methods are Colonoscopies performed on patients are more sensitive in detecting precancerous lesions. Therefore, it is suitable for effective methods. prevention program.
However, the major difference between mt-sDNA testing and FIT is cost. Annual FIT costs only a few tens of dollars, is easy and convenient for patients, and is a highly cost-effective approach to identifying patients most likely to benefit from colonoscopy. This is supported by many clinical studies. sDNA tests also have a high false-positive rate, which could lead to more people undergoing unnecessary colonoscopies. The so-called “FIT-first” approach, which uses FIT in combination with colonoscopy, is an accurate and cost-effective way to screen populations for colorectal cancer that should not be missed.
As the cliché goes, the best test is the one completed. There may be some utility if blood-based screening is a more attractive option for certain patients. However, as the number of individuals targeted for screening increases, we must focus on expanding the use of proven, cost-effective solutions already in place, such as FIT.
— Dr. Todd W. Kelly, Vice President of Medical Affairs, Polymedco
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Dr. Folasade May responds:
Stool-based colorectal cancer screening tests like the one Dr. Kelly describes are powerful tools for prevention and early detection, and I strongly support their use. However, those who utilize stool-based tests or other non-colonoscopy tests should be aware that these tests are her two-step test if the results are abnormal. You will need to undergo a colonoscopy to complete the screening process. Recent national data show that only about 50% of people with an abnormal stool-based test complete a colonoscopy in a timely manner.
The adage quoted by Dr. Kelly, “The best test is the test that gets done,” suggests that all screening options are equivalent. With the introduction of blood-based screening options, we may need to consider whether that is still the case. Screening options such as stool tests, colonoscopies, and CT colonography, currently recommended by the U.S. Preventive Services Task Force, can help prevent cancer by removing precancerous polyps before they become cancerous. provides a unique opportunity to both detect and prevent . With the blood-based tests I’ve seen the data on, that’s not possible. What we should say is that the best test is one that can detect both polyps and cancer.
— Dr. Folasade P. May, a gastroenterologist, is director of quality for gastroenterology at UCLA Health.
