Date Posted, by Goli Samimi, Ph.D., M.P.H. & Liz Freedman, M.S.W., M.P.H.
Questions and Answers about MCD Tests
Learn how MCD tests work, risks involved with these tests, and potential benefits.
More than half of cancer deaths involve cancers that have no recommended screening tests, including highly deadly cancers like ovarian and pancreatic cancer.1 Multi-cancer detection (MCD) tests are a new type of blood test designed to detect multiple cancers. Despite limited evidence on their benefit, some MCD tests are currently available to the public as cancer screening tools and many more are in development.
Research is underway to try to address the many unanswered questions about cancer screening with MCD tests. To learn more about the uncertainties related to public and clinician perceptions of MCD tests, program officials at the National Cancer Institute (NCI), led by Goli Samimi, Ph.D., M.P.H., Program Director in the Breast and Gynecologic Cancer Research Group in the Division of Cancer Prevention (DCP), decided to ask them directly. NCI facilitated focus groups with practicing primary care physicians (PCPs) and laypersons to learn about their awareness and knowledge of MCD tests and their thoughts on the benefits, harms, uncertainties, and acceptability of using this emerging technology.
“More rigorous data on MCD tests is needed to inform the development of national guidelines for use as cancer screening tools,” said Lori Minasian, M.D., FACP, Deputy Director, DCP, NCI. “We need to know more about people in the community who will be consumers of MCD tests and the professionals responsible for administering tests, interpreting results, and determining next steps.”
Focus group results from this exploratory study were published in Cancer Medicine.2
Primary care physician focus group results
Demographics
In early 2023, NCI conducted six focus groups with 45 practicing PCPs. The PCPs spoke English, were board-certified physicians (M.D. or D.O.) with a focus on internal or family medicine or both, provided care to patients, and regularly ordered cancer screenings for patients. They ranged in age from 35-75 (average age about 55). Twenty-seven (60%) were women and 18 (40%) were men. The majority of PCPs were non-Hispanic white (78%) and Asian (20%).
Awareness of and concerns with MCD tests
The majority of PCPs (80%) were familiar with MCD tests. Based on open-ended questions and discussion during the focus groups, they identified the following potential benefits of MCD tests:
- ease of use.
- potential ability to detect cancers earlier than conventional screening tests.
- potential to screen for certain cancers that do not have conventional screening tests.
Their main concerns included:
- skepticism about the accuracy and value of MCD tests for saving lives from cancer.
- lack of practice guidelines for diagnostic follow-up tests.
- cost and potential harms of physically or mentally painful diagnostic follow-ups.
- patient privacy and insurance issues.
- fear and anxiety over confirmation of MCD test results.
- malpractice liability related to false negative test results.
- major need to systematically evaluate MCD technology before it is used for cancer screening.
PCP focus group quotes by select themes
(For a complete listing of quotes, see the Cancer Medicine paper.)
| Theme | Quote |
|---|---|
| PCP perceptions of the acceptability of MCD tests | “Numbers should be available, number needed to treat, to save one life or to detect one cancer. All that information should be available to the physicians.” - Female Family Medicine PCP with 21+ years’ experience |
| PCP perceptions of the harms of MCD tests | “I've had a few patients inquire, … and I'm basically saying it's not ready for prime time yet and stay tuned.” - Male Internal Medicine PCP with 21+ years’ experience |
Layperson focus group results
Demographics
In late 2022, NCI conducted 12 focus groups with 80 laypersons between ages 50-75 (average age about 63). Two of the focus groups included Spanish speaking participants only. Participants were identified through a consumer research firm which used a screening survey to determine eligibility.
Laypersons selected had no cancer diagnosis in the past five years, never had an MCD test, and spoke either English or Spanish. More than half were White (64%), 19% were Hispanic, and 15% were Black/African American. Forty-five (56%) were women and 34 (43%) were men.
Awareness of and concerns with MCD tests
Unlike the PCPs, most participants from the laypersons group were unfamiliar with MCD tests (a finding consistent with data from NCI’s Cancer Information Service, which responds to requests from the public); and some confused MCD tests with genetic testing or blood-test companies in the news such as Theranos.
They identified two potential benefits of MCD tests: ease of use and the potential ability to detect cancers early. Their concerns focused on costs, insurance coverage, privacy, and anxiety over a positive test result.
Layperson focus group quotes by select themes
(For a complete listing of quotes, see the Cancer Medicine paper.)
| Theme | Quote |
|---|---|
| Preference for established cancer screening versus MCD tests | “I would repeat the test with a conventional test. Specifically, for the type of cancer…I think I would go back to conventional to be more specific.” - Woman, 50, Hispanic or Latino, (Spanish-Language) |
| Factors affecting layperson focus group participants willingness to take MCD tests | “I would want false positives to be extremely low because I don't want to go through all the worry, the second tests, my family is on edge, just to find out that there was nothing there.” - Man, 67, White
|
Next steps
NCI has established the Cancer Screening Research Network (CSRN) to conduct a pilot Vanguard study in 2025. This Vanguard study will assess the feasibility of studying MCD tests in randomized controlled trials (RCTs).
“Randomized controlled trials (RCTs), the gold standard for evaluating the effectiveness of a new test, will help us to better understand the benefits and harms of widespread use of MCD tests in people with no symptoms of cancer,” said Minasian.
“MCD tests are promising and hold hope, but before they go full steam ahead, clinical trials are needed to provide the evidence that using these tests will save lives,” said Minasian. “Because MCD tests potentially detect multiple different cancers, designing a clinical trial is complicated. It is critical to work out the kinks and test drive our assumptions first in the Vanguard study before NCI launches a larger RCT with ten times the number of participants.”
More Information
References
- Siegel RL, Miller KD, Wagle NS, Jemal A. Cancer statistics, 2023. CA Cancer J Clin. 2023; 73(1): 17-48. doi:10.3322/caac.21763
- Goli, S, LeeVan, E, Rubinstein, W., Minasian, L. Cancer Medicine, 2024 Nov 13(21); doi: 10.1002/cam4.70281
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