Multicancer blood tests not ready for widespread screening use, review finds

Researchers analyzed 20 studies involving over 100,000 participants and 19 different blood tests

RESEARCH TRIANGLE PARK, N.C. — A new systematic review led by experts at the RTI International–University of North Carolina Evidence-based Practice Center and The Ohio State University College of Medicine has found insufficient evidence to support the use of blood-based multicancer detection (MCD) tests for routine cancer screening in asymptomatic adults.

Published today in Annals of Internal Medicine and commissioned by the Agency for Healthcare Research and Quality (AHRQ), the review analyzed 20 studies involving over 100,000 participants and 19 different MCD tests cumulatively. Researchers assessed the benefits, harms, and accuracy of blood tests that aim to detect more than one kind of cancer in adults who do not have symptoms. Despite growing interest in the tests, which promise to detect multiple cancers from a single blood sample, the review found no completed controlled studies that show if these tests help asymptomatic people live longer or feel better or if they reduce the number of advanced cancers.

“We found that while some tests show promise in detecting cancer signals, the evidence is not yet strong enough to support their use for population-wide screening,” said Leila C. Kahwati, M.D., M.P.H., a senior research scientist and Fellow at RTI. “Accuracy varied widely across tests and study designs, and most studies had significant limitations. Importantly, no studies have yet shown that using these tests leads to better health outcomes.”

The review found that most studies used designs that were prone to bias, such as case-control studies comparing known cancer patients to healthy controls. Only seven studies followed asymptomatic individuals over time to assess whether MCD tests could detect cancer before symptoms appeared, and in those studies, the tests correctly identified people with cancer at rates ranging from 7.0% to 71%.

The review also revealed that false positives, which occurred frequently, could lead to unnecessary diagnostic procedures and radiation exposure.

“There is a lot of excitement about using multicancer blood tests for population-wide screening, but testing large numbers of asymptomatic people can result in many false positive results, unnecessary testing, costs and harms,” said Daniel E. Jonas, M.D., M.P.H., Director of General Internal Medicine and Endowed Professor of Health Services Research at The Ohio State University College of Medicine. “It’s important that we have better evidence from large, randomized studies to ascertain the balance of benefits and harms associated with these tests.”

While some MCD tests are already available in the U.S. as laboratory-developed tests, none have received U.S. Food and Drug Administration approval for multicancer screening.

The RTI–University of North Carolina Evidence-based Practice Center is led by RTI, an independent scientific research institute, in collaboration with the Cecil G. Sheps Center for Health Services Research at the University of North Carolina at Chapel Hill and The Ohio State University College of Medicine. The center has reviewed and analyzed scientific evidence to inform the decisions of health care practitioners since 1997.

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