Should You Take an At-Home Cancer Test?

While MCD tests are exciting in theory, the reality is that there may be a long way to go before anyone can expect reliable results.

MCD tests work primarily by detecting the strands of DNA that cancerous cells shed as part of their life cycle. “Some tests may also be looking for protein markers that indicate how your immune system is reacting to the presence of a possible tumor,” says Gavin Henry, MD, the medical director of the Tate Cancer Center in Glen Burnie, part of the University of Maryland Medical System.

If an MCD test detects these DNA fragments, you’ll receive a positive result; if no DNA fragments are detectable, you’ll receive a negative result.

Although MCD tests look for genetic markers, “they are not genetic tests, meaning, they don’t indicate a genetic predisposition to cancer, which is a common misconception,” says Marianne Dubard-Gault, MD, a medical oncologist with the Swedish Medical Center and the medical director of its Hereditary Cancer Clinic in Seattle.

In other cases, the tests may fail to detect cancer that’s present (a false negative).

Drawbacks aside, some experts are hopeful that MCD tests have potential. Some of the positives about the tests include these possibilities:

• They could detect cancer for which there isn’t an early screening protocol, such as pancreatic and ovarian cancers. That said, one major trial found that certain MCD tests didn’t reduce the detection rate of later-stage cancers, which suggests that the tests aren’t reliably finding cancer in the earliest, more treatable stages.

  [4]

• They may prompt a visit to a doctor. This is especially relevant for someone who’s hesitant to get regular screenings. “Sometimes patients will order these tests on their own, and it pushes us to start the screening process earlier if there’s some concern,” says Dr. Henry.

On the negative side:

• You may receive a false positive. Benign cysts or growths — such as uterine fibroids, for example — may shed DNA that triggers a false positive from a MCD test, says Dubard-Gault. Getting a positive result can trigger rounds of additional testing, which can be expensive, time-consuming, and anxiety producing.
• You may receive a false-negative. “Early-stage cancers may not even shed DNA that’s detectable,” says Dubard-Gault, and some cancers don’t shed DNA at all.
• They can be expensive. Some MCD tests cost $900 or more, and as of now, they aren’t covered by insurance. Moreover, if you have a positive result and ask your doctor for additional screenings such as a PET or CT scan those may not be covered by your insurance either.
• They are not approved by the U.S. Food and Drug Administration (FDA). These tests are marketed under a regulatory loophole that allows companies to sell them without review by the FDA.

No — and certainly not now. Right now, if you use an MCD, it should be in addition to these regular recommended cancer screenings:

• Mammogram These are recommended annually for most women starting at age 45, or younger in consultation with your doctor based on risk factors.

  [5]

• Colonoscopy The recommendation for adults at normal risk is to start screening at age 45.

  [6]

• Lung Cancer Screening People with a history of smoking should talk to their doctors about whether they should be screened with a low-dose CT scan.

  [7]

• Cervical Cancer Screening Women should get either an HPV or a PAP test starting in their early twenties.

  [8]

• PSA Test for Prostate Cancer A prostate-specific antigen (PSA) blood test is recommended for men starting at age 50, or younger if you have risk factors.

  [9]

“For now, an MCD test should be something you could do if you want, or if you’re curious or concerned, but you should think of it as something you do in combination with screenings that are vetted and reliable,” says Henry.

If you get a positive result, make an appointment with your doctor. And if you get a negative result, you should still follow recommended screening protocols, such as the ones above.

An MCD test may be a good fit for someone who is close to or just over age 50, or who has comorbidities or cancer risk factors such as a history of smoking or a strong family history of certain cancers. But even then, it’s not a decision to make lightly, says Gault-Dubard.

For instance, if you’re very worried that you might have a certain cancer, taking this test may increase your anxiety, especially if you receive a positive result. “It could take months of additional testing, including scans or biopsies, to find out if a positive result means you actually have cancer,” she says.

That can be costly and invasive, and involve a lot of time and additional worry. If you have concerns about cancer, it’s best to see your doctor and find out what tests are best for you.

“As cancer doctors, we love this as an idea,” says Henry. “Our patients always ask, ‘Can’t you just draw some blood and find out if I have cancer?’ I wish it were that easy.”

It’s possible, though, for MCD tests to improve in the future — so much so that experts might be able to recommend them to their patients. For now, though, the best way to screen for cancer is with the recommended tests, even if they aren’t all available at home.

• Multicancer detection tests are blood tests that can detect certain strands of DNA that may indicate cancer.
• Not only can MCD tests be expensive but they aren’t covered by insurance.
• It’s possible to get a false-positive result, which may prompt more follow-up tests in the future, or a false negative.
• MCD tests are improving all the time, but right now, they should not replace established screening protocols such as mammograms and colonoscopies.