What Are Multi-Cancer Early Detection Blood Tests?

For most people, the thought of having cancer provokes feelings of fear and dread. It can be a cruel, grueling disease that affects millions of Americans. Just last year there were 1.9 million new cancer diagnoses in the U.S. And statistics suggest that one in two American men and one in three American women will be diagnosed with some form of cancer during their lifetime.  

Unfortunately, more than half of all cancers are diagnosed at an advanced stage. Cancers diagnosed in later stages require stronger treatment regimens, which don’t always work and can very taxing, leading to complications and long-term side effects. As a result, advanced cancer cases have much lower survival rates. 

This is why cancer early detection is so important. Early detection screenings are available for five types of cancer – breast, cervical, colorectal, prostate and high-risk lung (high-risk lung cancer screening is recommended for patients who currently smoke or have a history of smoking). Patients are advised to follow a screening schedule.

Unfortunately, there are more than 200 types of cancer. Many of these cancers develop unnoticed until symptoms begin appearing. By then, the cancer may have progressed to a later stage and may have spread to other parts of the body. This is why cancers like pancreatic and ovarian are so deadly — these diseases are generally very advanced when symptoms finally show. In fact, 70 percent of cancer deaths come from cancers for which there are no screening tests.

But there is a new type of cancer screening on the market that looks for these harder to find cancers. The screenings go by several names: multi-cancer detection, multi-cancer early detection (MCED) and, more colloquially, liquid biopsies. This type of blood test may help fill the gaps left by the five standard cancer screenings. It can also be combined with those standard screenings to better provide a more comprehensive approach to early detection.  

About 20 companies offer or are in the process of developing MCED screenings. Many MDVIP-affiliated practices offer the Galleri test, which is produced by GRAIL.

In general, an MCED test seeks pieces of DNA or proteins in the blood sample that come from cancer cells. If these are found, it might mean that the person has cancer and might also show where the cancer began. Not all tests work exactly the same; some MCED tests only look for the likelihood that there is cancer somewhere in the body.

The tests do not diagnose cancer. Follow up screenings like imaging tests and biopsies may be needed to verify what the MCED is suggesting. At this point, the tests are not approved by the Food and Drug Administration, though a few like Galleri have been granted waivers by the FDA and are available by prescription. (GRAIL is currently seeking fully FDA approval for Galleri.) The FDA is working with these companies to determine what is needed to be approved.

Researchers still have a lot to learn about the ability of these tests to detect cancer and individual types of cancer. More clinical trials are underway.

Who are the tests designed for? Right now, there aren’t industry-wide standards for these screenings. Galleri is generally designed for people who are older than 50 because they have a higher risk for cancer.

What do physicians consider with the information generated by the tests? The tests may indicate cancer but there can also be false positives. About 50% of people with a positive test likely will not have cancer. Your physician can do a workup. If no cancer is found, they may request you repeat it in about 6 months. (Galleri users can get this retest from maker GRAIL for free.)

That said, the tests are a major breakthrough for early cancer screenings. Galleri, for example, can help identify more than 50 types of cancers by recognizing a signal emitted from cancer cells that shed abnormal DNA into the bloodstream. The origin of that signal can be identified with almost 90 percent accuracy, according to studies. And the blood draw for the test can be done during a normal office visit.

If Galleri produces a positive result, patients should consider additional diagnostic testing such as imaging or a biopsy to confirm whether is cancer.

Currently, Medicare does not cover MCED tests and commercial insurance doesn’t either, even though Congress has introduced legislation to change that. That means patients must pay out of pocket to cover the tests.

If you’re interested in this kind of early cancer screening, talk to your MDVIP-affiliated physician. If they offer it, they can help you determine if these tests make sense for you.