The U.S. Preventive Services Task Force currently recommends average-risk screening for four cancer types, including colorectal, cervical, breast, and lung cancer (for those with a sufficient smoking history). Despite this, approximately 70% of cancer-related deaths in the United States are due to malignancies for which there is no screening test. The advent of blood-based multicancer detection (MCD) tests offers a potentially transformative approach to finding cancer at an early stage with just a simple blood draw before individuals experience any clinical signs or symptoms of disease.

However, a systematic review of these tests to assess their benefits, accuracy, and harms in asymptomatic adults has found that no completed controlled studies report benefits of screening with these tests. In addition, the review found that there is insufficient evidence to evaluate the harms and accuracy of MCD tests, and that accuracy varies by test and study design. The review by Kahwati et al is published in Annals of Internal Medicine.

Study Methodology

The researchers searched MEDLINE, the Cochrane Library, two clinical trial registries, and relevant government and commercial websites between 2013 and 2024 for controlled studies of MCD tests in asymptomatic populations reporting cancer detection, mortality, quality of life, and harms, such as psychosocial, adverse events, and decreases in standard-of-care screening. They also reviewed studies for harms of diagnostic evaluation and test accuracy for detecting cancer. They conducted surveillance of the literature through March 31, 2025.

Results

The researchers found no controlled studies evaluated the benefits of screening. Twenty studies (n = 109,177) reported accuracy for 19 MCD tests. Seven studies (five with high risk of bias [ROB], two with unclear ROB) reported the accuracy of future cancer detection in asymptomatic individuals followed for 1 year (prediagnostic performance); the rest estimated accuracy from high ROB case-control studies in clinically confirmed cancer cases and healthy, cancer-free, control participants (diagnostic performance).

Across the tests, the researchers found sensitivity ranged from 0.095 to 0.998, specificity ranged from 0.657 to 1.0, and area under the curve (AUC) ranged from 0.52 to 1.0. Sensitivity and AUC were higher in diagnostic performance compared with prediagnostic performance studies. No other patterns in accuracy were discernible. Although one cohort study reported harms, these data were limited.

“No controlled studies are completed that report benefits of screening with MCD tests. Evidence was judged insufficient to evaluate harms and accuracy. Accuracy varies by test and study design,” concluded the study authors.

Leila C. Kahwati, MD, MPH, of RTI International, is the corresponding author of this study.

Disclosure: Funding for this study was provided by the United States Department of Health and Human Services. The study authors’ conflicts of interest disclosures may be found at acpjournals.org.