David S. Weinberg at Fox Chase Cancer Center in the USA and Michael Bretthauer, professor at the Clinical Effectiveness Research Group at the University of Oslo, discuss multicancer detection tests in an article published in The Lancet on 21 September.
The tests are designed to detect several types of cancer through a single blood test. The authors focus on the large UK Galleri trial, in which 140,000 people were randomly assigned to usual care with or without such a blood test. The study did not meet its primary endpoint of reducing the incidence of cancers diagnosed at a late stage.
“There is currently no evidence that multicancer detection tests prevent cancer, consistently detect cancer earlier, or reduce cancer mortality. The tests can also produce false-positive results, which can lead to further investigations and place a burden on people who do not actually have cancer,” says Weinberg.
Call for more rigorous testing
The authors argue that new cancer screening tests should be investigated in large, randomized trials that measure outcomes that are important to patients, including cancer incidence and mortality. They argue that new screening tests should be evaluated as rigorously as new drugs before they are introduced into use.
“Rigorous long-term studies take time and may delay the introduction of new tests, but they are nevertheless necessary to determine whether the tests actually provide more benefit than harm,” says Bretthauer.
The article “Multicancer detection tests: holy grail or cautionary tale?” is published as Correspondence in The Lancet.