There is a 3-in-10 chance a whole-body MRI finds something that generates uncertainty rather than answers, according to a JAMA Viewpoint by Matthew S. Davenport and Scott B. Reeder. They report that whole-body MRI screening in the general population currently lacks evidence supporting net clinical benefit.

The Argument

The authors contend that the appeal of these scans rests on assumptions that early detection consistently improves outcomes despite limited supporting evidence. No major medical society currently recommends whole-body MRI for the general population because the likelihood of identifying disease that is both clinically important and meaningfully treatable remains low, according to the authors. As a historical parallel, they point to South Korean thyroid cancer screening — a 15-fold rise in diagnoses, hundreds of thousands of surgeries, tens of thousands of complications, and no measurable reduction in mortality. Whole-body MRI identifies cancer in roughly 1 to 2 out of 100 people screened, but the authors argue many detected cancers may be low risk or already advanced, and there is no evidence screening improves quality of life or survival.

“Although cancer will be identified in 1 or 2 out of 100 people, finding cancer with this test is unlikely to help you because most types will be low risk or already advanced. There are no studies showing that undergoing this test will improve the quality or length of your life.”

The Open Question

The authors argued that commercial expansion of whole-body MRI screening has occurred before evidence demonstrating improved clinical outcomes. The recently reported NHS-Galleri trial — involving 142,000 patients and a blood-based multicancer detection test — was cited by the authors as another example of how difficult it can be for screening interventions to demonstrate reductions in advanced-stage cancer.

Clinical Implications

The authors recommended discussing pretest probability, potential downstream harms, and limitations of current evidence with patients considering commercial whole-body MRI screening. They emphasized that this test does not replace proven, evidence-based screening — mammography, colonoscopy, and other established programs — that remain underutilized in the populations most likely to benefit.

Disclosures can be found in the published Viewpoint.

Source: JAMA