Washington’s latest wolf in sheep’s clothing is a Medicare proposal to cover blood-based colorectal cancer screening tests. On the surface, it sounds like progress—more options, more innovation, more access for seniors and people with disabilities. Look closer, and it’s a shift toward a test that is simply worse at detecting cancer where it matters most.
There is a simple way to think about cancer screening: the goal is not just to find cancer but to stop it before it starts. That distinction is what separates truly preventive care from care that reacts after the fact. When it comes to colon cancers, colonoscopies work by finding and removing precancerous polyps before they become dangerous. Stool-based tests, though less comprehensive, still detect a meaningful share of those early warning signs and therefore are meaningful preventative tests.
In contrast, the newer blood-based tests are primarily designed to detect cancer once it already exists. Their clinical efficacy in identifying the precancerous changes that make screening valuable is notably lower, with one test catching advanced precancerous polyps just 13% of the time. This shifts the system away from prevention and toward later detection in a way that is difficult to justify as an improvement.
Coverage decisions shape behavior in predictable ways, as doctors tend to recommend what is easiest for patients to complete and patients tend to choose what is most convenient. When Medicare elevates a test that is convenient but demonstrates lower efficacy in early-stage prevention, it does not merely sit alongside existing options, it begins to displace them.
This dynamic reflects an unfortunate pattern in Washington where policies are framed as improving efficiency while quietly weakening incentives for high-quality results. What ultimately matters is not how many options are technically available, but the clinical performance of those options and whether they lead to better health results.
Colorectal cancer remains one of the clearest examples of a disease where prevention works when the system is aligned properly, and catching and removing polyps early can increase the odds of preventing cancer entirely. The performance gap between different screening methods is not a minor technicality; it is a central question of whether we prioritize the most effective tools available. Missing early warning signs leaves patients facing a disease that could have been avoided.
An approach aligned with the "Make America Healthy Again" (MAHA) agenda should be grounded in the idea that new technologies must earn their place through demonstrated results. Prevention should take priority over convenience when the two are in tension. This proposal moves in the opposite direction by lowering the bar for coverage in a way that risks normalizing a lower standard of efficacy.
There is a straightforward alternative that does not reject innovation but instead insists on evidence. Blood-based screening tests will likely play a major role in preventive care if they can demonstrate an ability to reliably detect precancerous disease at rates comparable to current standards. However, covering them before that standard is met does not accelerate progress; it risks locking in weaker outcomes across the system.
Healthcare policy often revolves around abstractions such as coverage categories and reimbursement structures, but the measure that ultimately matters is whether more disease is being prevented or less. If a policy prioritizes a less effective test, resulting in fewer precancerous conditions being addressed early, then it is not making the country healthier.
What is needed is not a longer list of covered options but a clearer focus on outcomes. In cancer screening, the difference between prevention and delayed detection is not theoretical and it is not marginal. Policy decisions that blur that distinction risk producing exactly the kind of results that a prevention-focused healthcare agenda is supposed to avoid.
