Performance of a multi-cancer early detection test in the randomized controlled NHS-Galleri trial.

The multi-cancer early detection test demonstrated a positive predictive value of up to 58% and detected primary cancers in 0.60% to 0.41% of participants across three screening rounds in NHS screening.

• Why it matters: Early detection of cancer can improve outcomes, but effective, accurate screening tools are needed for population-wide implementation. This study addresses the performance of a novel MCED test in real-world NHS screening, filling a gap in evidence for its clinical utility.
• What they did: The trial involved 142,250 participants aged 50-77, randomized equally to intervention and control groups, with the intervention group receiving the MCED test across three annual rounds. Positive results prompted diagnostic referrals based on predicted cancer origin, and test performance metrics were analyzed descriptively.
• The result: The MCED test showed high specificity (99.50–99.60%) and negative predictive value (~99%), with moderate sensitivity (26.7–37.2%) overall, and higher sensitivity (47.6–63.4%) for key cancer types, supporting its potential role in population screening.