What is an MCED test?	It is a test looking for traces of multiple cancers simultaneously. The test is offered for people who do not have signs or symptoms of cancer. Asymptomatic people aged 50 years and older typically have an approximately 1% chance of having a cancer at the time of testing. The test does not diagnose cancer; if it is positive, further diagnostic testing is required to confirm whether there is cancer and where the cancer is located. The optimal approach to managing positive results is uncertain.
What MCED tests are available?	One blood‐based screening test that detects cell‐free DNA is commercially available as of 2024: the GRAIL Galleri test.
Who is eligible for MCED testing?	The optimal age range of when to begin and end testing average‐risk individuals has not been established. There is currently no guidance for identifying the age to initiate testing for higher risk individuals. Patients should not have MCED testing unless they are willing to undergo diagnostic evaluations for positive tests. MCED tests should not replace standard‐of‐care screenings for breast, cervical, colorectal, lung, and prostate cancers.
How much does the test cost?	The list price of the GRAIL Galleri test is $949 as of 2024. MCED testing is currently covered by only a few insurance plans—patients should confirm coverage with their individual plan. There are additional costs for follow‐up evaluations of a positive test, which could range from hundreds to thousands of dollars depending on insurance coverage. Multiple diagnostic tests may be needed to confirm whether there is cancer.
What are the potential benefits of MCED testing?	A benefit is potentially detecting cancers that currently have no recommended screening tests at an earlier stage, when they may be treated more effectively and easily. Benefits are potentially reducing the risks of cancer mortality and morbidity and increasing life expectancy.
What are the potential limitations, harms, and uncertainties of MCED testing?	We do not yet know whether MCED testing reduces cancer mortality and morbidity. False‐positive results (false alarms): the risk is lower with MCED tests than with currently recommended screening tests. Approximately half of persons with positive tests are found not to have cancer after a diagnostic evaluation. Any positive result also can cause anxiety and distress. Although a negative test indicates a very low risk for having cancer at the time of testing, patients should not ignore new symptoms and signs that could indicate a cancer. Patients should continue with recommended screening tests. The optimal strategy for evaluating positive test results is uncertain. There is a risk of harm from diagnostic procedures done to evaluate positive MCED results; the magnitude of this risk is not yet established. Overdiagnosis and overtreatment: a detected cancer may be very slow growing, or the patient diagnosed with cancer may not benefit from earlier detection and treatment because of limited life expectancy. We are not yet able to estimate the degree of overdiagnosis and overtreatment associated with MCED tests. Incidental findings (unrelated to cancer) may be found during diagnostic workups of a positive MCED test, particularly from PET‐CT scans. These findings may lead to additional testing and treatments. We are not yet able to accurately characterize the benefits and harms of incidental findings associated with MCED testing.
How often to get the test?	The optimal testing interval is unknown but regular, repeat testing will be necessary to optimize any potential benefit of MCED testing.