Javascript is not enabled.

Javascript must be enabled to use this site. Please enable Javascript in your browser and try again.

Skip to content
Content starts here


Leaving Website

You are now leaving and going to a website that is not operated by AARP. A different privacy policy and terms of service will apply.

Can a Blood Test That Detects Early Cancers Save Lives?

The promise of Multi-Cancer Early Detection blood test has stirred hopes, but concerns about false positives remain

spinner image illustration of blood vessels and an inset of a test tube showing that Lab work can identify DNA shed by malignant tumors.

The news is full of “promising” developments that may “one day” lead to a brighter, healthier future. But for our annual AARP survey focusing on “game-changing” medical breakthroughs in vision, heart health and more, we decided to focus on game changers improving lives today. Each of these astounding new technologies and treatments is available, or will be in the near future, to make your life, and the lives of millions of other Americans, better.

Joyce Ares’ cancer journey began with a shock — but just as surprising was how quickly it ended. Diagnosed with stage 1 Hodgkin’s lymphoma after an experimental blood test in 2020, she underwent short rounds of chemotherapy and radiation. Now, with no signs of cancer, she’s back to cooking for weekend dinner parties and visiting her grandchildren and great-grandchildren. “I am thrilled they found it early,” says Ares, 76, a retired real estate broker from Canby, Oregon. “I know there are folks who say, ‘What’s going to happen is going to happen.’ That doesn’t mean you have to die early or have a horrible experience trying to get rid of the devil of cancer in your body. You can find out earlier, get it dealt with and have a beautiful life.”​​

spinner image Early detection helped Joyce Ares become cancerfree— fast!
​Early detection helped Joyce Ares become cancer-free — fast!
Leah Nash

Ares’ early cancer was discovered with the Galleri Multi-Cancer Early Detection (MCED) blood test from the health care company Grail. “Her cancer had no symptoms,” says her husband, Richard Ares, 77, whose own cancer blood test was negative. “Her doctors said it would never have been found at such an early stage without the blood test.”​

spinner image Image Alt Attribute

AARP Membership— $12 for your first year when you sign up for Automatic Renewal

Get instant access to members-only products and hundreds of discounts, a free second membership, and a subscription to AARP the Magazine.

Join Now

Galleri screens for more than 50 different cancers by searching a blood sample for tiny scraps of DNA cast off by cancer cells. Though it hasn’t been approved by the Food and Drug Administration, it can be ordered by your health care provider under an FDA provision called laboratory-developed tests. The Galleri test costs $949, and unfortunately, it is not covered by most insurance. A second type of MCED test, called OneTest, sells for about $189 and looks for 20 or more cancer types. Other MCEDs are in development as cancer researchers and biotech entrepreneurs race to close a lethal gap: There are currently no reliable screening tests for more than 50 percent of deadly cancers.​​“

The earlier the stage, the more confined the cancer is, the better the outcomes with chemotherapy, surgery and radiation,” says radiation oncologist Nima Nabavizadeh, M.D., an associate professor at Oregon Health & Science University (OHSU) and principal investigator of a second stage of the prospective study Joyce and Richard Ares participated in. “Essentially, detecting cancer as early as possible is one of the most important ways to reduce cancer deaths. It’s the rationale for mammography and other screenings.” Despite that, we have good screening tests for only a few types of cancers.

​​The promise of early detection through MCEDs has stirred big hopes, but major questions remain. There were 19 confirmed cancers found in 6,516 older adults age 50-plus in the Pathfinder I prospective study conducted at major U.S. medical centers, including the OHSU Knight Cancer Institute, the Mayo Clinic, the Cleveland Clinic and the Dana-Farber Cancer Institute, and presented in preliminary fashion at the American Society of Clinical Oncology meeting in 2021.


AARP® Vision Plans from VSP™

Exclusive vision insurance plans designed for members and their families

See more Insurance offers >

But there were also 11 false positive test results and 10 more where, so far, the location of the suspected cancer has not been pinpointed. False positives, which can also happen with mammograms and other cancer screening tests, can lead to expensive and invasive procedures such as biopsies; so can test results that uncover nonthreatening, slow-growing cancers that probably need no treatment, wrote Philip Castle, director of the National Cancer Institute’s Division of Cancer Prevention, on an NCI blog in April 2022. ​​

Nabavizadeh notes that a follow-up prospective multicenter study of 20,000 midlife and older adults he is leading at OHSU will look at an array of issues, such as false positives. “Are we picking up cancers even earlier than PET scans or MRIs can find them — or are they truly false positives? It’s still an active area of investigation.” OHSU is considering opening a high-risk clinic, he says, to follow these specific patients with these puzzling results. ​​A bigger question: Do early detection tests save more lives? That has yet to be answered, Castle noted. The NCI set a goal to launch a study comparing MCED tests within two years. ​​

In the meantime, Joyce and Richard Ares have no doubts about the test’s value for them. After her experience, the couple urged friends and family to sign up for the study, and dozens have been tested, with negative results. “Hodgkin’s lymphoma is not a fun thing to go through,” Joyce says. “Finding it early was such a wonderful gift.”

​​Other Cancer Advancements​​

Rectal cancer drug​​

spinner image The FDA-cleared PrecisionPoint Transperineal Access System
The PrecisionPoint Transperineal Access System
Courtesy Perineologic

In a small Memorial Sloan Kettering Cancer Center clinical trial whose results have been hailed as unprecedented, tumors seem to have disappeared in 14 people with rectal cancer who received the experimental immunotherapy drug dostarlimab — without the need for surgery, radiation or chemotherapy. Researchers say the drug worked because it was carefully matched to people who had early stage tumors with a specific genetic signature found in approximately 5 to 10 percent of rectal cancers. The same genetic marker, which can be detected with available tests, is found in some endometrial, gastrointestinal, pancreatic and prostate cancers. ​​

Easier prostate biopsies

​​The FDA-cleared PrecisionPoint Transperineal Access System, which takes prostate samples for cancer testing through the skin under local anesthesia in the doctor’s office, reduces the need for more invasive biopsies. In studies, the procedure had an infection rate significantly lower than with rectal biopsies that had a similar rate of cancer detection.​​

Sponge on a string for esophageal diseases ​​

Getting tested for cancers and precancers of the esophagus involves an endoscopy — having a lighted tube with a camera inserted into the esophagus (the tube that carries food to the stomach), often under sedation. Medtronic’s FDA-cleared Cytosponge can help your doctor tell if you really need one. Patients essentially swallow this sponge on a string, and it takes samples along the esophagus, looking for potentially abnormal cells in people at risk due to esophageal diseases. In a recent U.K. study, researchers suggested the sponge, combined with other medical information, could help doctors decide who really needs an endoscopy and who doesn’t. The most common side effect: a sore throat.

Discover AARP Members Only Access

Join AARP to Continue

Already a Member?

spinner image membership-card-w-shadow-192x134

LIMITED TIME OFFER. Join AARP for just $9 per year when you sign up for a 5-year term. Join now and get a FREE GIFT!