Should Medicare cover blood tests for cancer screening?

Congress is considering passing the Medicare Multi-Cancer Early Detection Screening Coverage Act, which would require Medicare to pay for multi-cancer early detection screening tests. Detecting cancer early with blood tests before cancer has spread sounds sensible — but overuse experts warn that embracing this new technology without careful consideration could actually do more harm than good. As some patient advocates have pleaded with Congress to approve Medicare coverage, it’s worth looking at the potential downsides of these multi-cancer screening tests.

The promise of blood testing

By now most Americans are familiar with Elizabeth Holmes and her failed company Theranos. The company promised that with only a small drop of blood, they could test for and diagnose a large selection of diseases. It was a lie. It was exposed years later, causing a national scandal and damaging the lives of trusting patients along the way.  

Other companies are still attempting to do what Theranos could not – develop a way to test blood for a spectrum of illnesses ranging from genetic abnormalities to cancer. There are various avenues to approach this task, whether it be screening for related antigens or counting blood cells. 


Multi-cancer screening tests, sometimes called liquid biopsies, are growing in popularity. These screening tests use a small amount of blood to look for markers for a variety of cancers. Currently the FDA has approved these tests for people with advanced ovarian, lung, breast, or prostate cancer to detect the recurrence of cancer and to guide therapy. Companies looking to expand the use into screening – and expand their profits – are pushing for wider adoption of blood screening tests. Is this a good idea?

The delicate balance between early detection and overuse

Our bodies have abnormalities all the time. Our cells are constantly dividing and dying as we develop with age. Cellular reproduction is bound to have errors and cancer cells will grow – but with a healthy human body, other cells involved in the immune system will quickly take care of cancer cells without the human even noticing. Sometimes they don’t, of course, and the cancerous cells multiply into benign or malignant tumors. This is where the fine line between early detection and overuse appears.

Say a patient goes in for a standard appointment, is offered a screening test, and receives an abnormal finding on their blood test –  but it’s not definitive. They have no symptoms and would not have known anything was abnormal had they not gotten the screening test. A good physician would consult the patient, likely encouraging them to get more tests to try and narrow down the diagnosis and prognosis. The patient goes for another test; again, it’s not definitive. They’ve now spent time and money on two tests that have neither informed nor improved their health. They can keep going for tests and procedures to figure out the source, or they can stop. The wisdom in their decision depends on whether or not they truly do have something harmful going on in their bodies. Stress about their unknown health status is now latched deeply to the back of their minds. 

Did these tests help the patient? The answer is unclear, and we won’t be able to step back and accurately look at this from a systemic level until we see results from the randomized controlled trials currently in progress. However, by then it might already be considered the standard of care.

Profits first and foremost

Medical testing is an expensive, lucrative business. If we’re considering funding blood screening tests via Medicare, we need to consider the costs and the benefits of this choice. Susanna Quinn, an ovarian cancer survivor, recently published a piece in the Daily Beast urging Congress to sign the Medicare Multi-Cancer Early Detection Screening Coverage Act. She argues that screening tests are a necessity, using her personal experience to elucidate the agony of going through and surviving cancer treatment.

While Quinn’s story is moving, it’s important to view her piece in the context of her potential financial conflicts. Quinn sits on the board of the Prevent Cancer Foundation, a nonprofit dedicated to early detection that receives extensive funding from pharma and device companies — including more than $1 million from Amgen, Astrazeneca, Genentech, Gilead, Merck, and Pfizer in 2020.

If Medicare begins paying for universal screening, those investments will pay out a large return on the taxpayer dime. It’s not that these efforts are not in good-faith, but there are vested financial interests pushing for early detection screening for everyone. H. Gilbert Welch, an academic physician and cancer researcher, broke down his concerns in an op-ed for Stat News.

The only thing that is clear to me is that this will cost a lot of money. That’s another thing the companies and their investors are banking on. The Galleri test costs $949 a pop and is recommended every year in those 50 and older. With 100 million Americans in this age group, that’s about $100 billion a year — 15 times the budget of the Centers for Disease Control and Prevention. And that’s not even counting the cost of all the subsequent testing and treatment that will invariably follow.

H. Gilbert Welch, STAT News

Early detection can save lives. The potential problem with preemptive, one-stop-shop blood testing is when it “diagnoses” variability in the human body. Cascade events are well-documented in the medical field and pose a significant threat to those using cancer screening blood tests. Preventative care IS public health, but it should be weighed against the sworn oath to first do no harm. The fine line between early detection and overuse is a tough one to walk.