Harms Rarely Are Quantified in Randomized Cancer-Screening Trials

Although cancer screening is practiced widely, its potential harms (e.g., harms caused by testing itself, false-positive tests resulting in invasive procedures) often are downplayed or ignored in reports from screening trials. In this analysis, investigators determined how often randomized trials of cancer screening quantify and report harms.

Researchers identified 57 completed randomized trials (with 3.4 million participants) in which the effects of cancer screening on cancer-specific mortality, all-cause mortality, or both were assessed. The trials involved 10 different cancer-screening interventions (e.g., mammography, fecal occult blood tests, prostate-specific antigen tests, chest computed tomography). Cancer-specific incidence and canc…