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Multi-cancer early detection: Advancing cancer screening
Provided by AAFP partner
Cancer is most treatable when found early, yet most cancer types lack routine screening. Multi-cancer early detection (MCED) testing introduces a transformative approach: a single test that screens for multiple cancers at once, including those types for which no screening exists.1
What is MCED?
The goal of MCED tests is to find cancer before symptoms develop.2 MCED tests may use different techniques — commonly analyzing cell-free DNA in blood — to identify molecular signals shed by cancers. Other approaches may use RNA, proteins or other cellular components and utilize urine, saliva or other body fluids.3
Why is MCED important?
Out of the more than 100 cancer types, only five — breast, colorectal, cervical, lung (for high-risk populations) and prostate (on an individual basis) — have recommended screening.4,5 Over 70% of cancer deaths come from cancer types with no screening.5,6 When cancer is diagnosed early, the chance of successful treatment and survival may be greater.7 A study showed that adding a blood-based MCED test to recommended screening nearly doubled the number of cancers detected, including 48% that were stage I-II and 74% that lacked standard screening.8 Modeling suggests adding MCED testing to recommended screening could reduce late-stage cancer by 78% and 5-year cancer mortality by 39%, supporting a potential 26% reduction in all cancer-related deaths.9
What are the key criteria for an MCED test?
Recent scientific reviews and consensus articles define the following criteria for responsible MCED adoption1,2:
Detect Many Cancers at Early Stages: Broad sensitivity for many cancers while prioritizing detection of lethal cancers
Low Fixed False-Positive Rate: Minimize false positives (<1%) and unnecessary diagnostic evaluations
Cancer Signal Origin: Accurately predict the affected tissue/organ to direct a more focused and efficient diagnostic evaluation
Population-Level Evidence: Validation in large, diverse studies, including intended use and asymptomatic populations
Appropriate Population Targeting: Focus on individuals with elevated risk, age 50+
Not a Replacement for Standard Screenings: MCED tests are intended to be used in addition to standard screening.
Clinical Validation: MCED tests are continually being validated as new data is collected. Clinical utility and outcomes such as mortality reduction are still areas of active research.
What are the limitations of MCED tests?1,2
Not a Diagnostic Test: MCED tests are screening tools and do not definitively diagnose cancer. Positive results require follow-up with diagnostic procedures to confirm and identify the cancer.
False Positives and Negatives: No test is perfect. MCED tests may sometimes produce false positives or false negatives.
Cancer Types Detected: While MCED tests can detect many cancer types, they cannot detect all types equally well.
Multi-cancer early detection tests are an emerging form of cancer screening designed to detect signs of several types of cancer from a single test. While these tests are still being researched and some are in the process of seeking FDA approval, they offer potential for identifying cancers at earlier stages. Learning how MCED tests function and understanding their current limitations can help you make informed choices about recommending them.
References
Klein EA, Richards D, Cohn A, et al. Clinical validation of a targeted methylation-based multi-cancer early detection test using an independent validation set. Ann Oncol. 2021;32(9):1167-77.
Hackshaw A, Clarke CA, Hartman AR. New genomic technologies for multi-cancer early detection: rethinking the scope of cancer screening. Cancer Cell. 2022;40(2):109-13.
American Cancer Society. Multi-cancer early detection (MCED) tests [Accessed 2025 Aug 14]. https://www.cancer.org/cancer/screening/multi-cancer-early-detection-tests.html
NIH, National Cancer Institute. What is cancer? [Updated 2021 Oct 11]. https://www.cancer.gov/about-cancer/understanding/what-is-cancer
US Preventive Services Task Force. A,B,C grade recommendations, cancer, screening [Cited 2025 Mar 18]. https://www.uspreventiveservicestaskforce.org/uspstf/topic_search_results
American Cancer Society. Cancer facts & figures 2025. https://www.cancer.org/research/cancer-facts-statistics/all-cancer-facts-figures/2025-cancer-facts-figures.html [GRAIL, Inc. Data on file: GA-2021-0065]
Siegel RL, Giaquinto AN, Jemal A. Cancer statistics, 2024. CA Cancer J Clin. 2024;74(1):12-49.
Schrag D, Beer TM, McDonnell CH 3rd, et al. Blood-based tests for multicancer early detection (PATHFINDER): a prospective cohort study. Lancet. 2023;402(10409):1251-60.
Hubbell E, Clarke CA, Aravanis AM, et al. Modeled reductions in late-stage cancer with a multi-cancer early detection test. Cancer Epidemiol Biomarkers Prev. 2021;30(3):460-8.
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