NHS-Galleri Trial Finds No Significant Reduction in Stage III or IV Cancer With Multicancer Blood Screening

Clinical Summary:

• Design/Population: The randomized NHS-Galleri trial evaluated annual blood-based multicancer early-detection testing plus usual care versus usual care alone among adults in England. The primary end point was the incidence of stage III or IV cancer across prespecified cancer types after 3 screening rounds.
• Key Outcomes: Multicancer early-detection testing did not significantly reduce the incidence of stage III or IV cancer compared with usual care, and the trial therefore did not meet its primary end point. Stage IV cancer incidence numerically favored screening, although the confidence interval reached the null.
• Clinical Relevance: These findings do not establish clinical utility for adding multicancer early-detection blood testing to usual cancer screening based on reduction of late-stage disease. Continued follow-up will be important to determine whether the observed difference in stage IV cancers persists or changes over time.

Results from the randomized NHS-Galleri trial demonstrated that adding blood-based multicancer early-detection testing to usual care did not significantly reduce the incidence of stage III or IV cancers compared with usual care alone.

In this trial, 142,250 adult patients aged 50 to 77 years provided peripheral blood samples at up to 3 annual visits and were randomized 1:1 to an intervention group (n = 71,122), in which blood samples were tested, or a control group (n = 71,128) , in which samples were stored without testing.

The primary end point was the incidence of stage III or IV cancer across 12 prespecified cancer types. Stage IV cancer incidence among the same cancer types was a key secondary end point. Outcomes were assessed following 3 screening rounds and at least 12 months of follow-up after the final participant's third study visit.

The incidence of stage III or IV cancer did not differ significantly between the intervention and control groups, with an incidence rate ratio of 1.03 (95% confidence interval [CI], 0.92 to 1.14; P = .63). The study therefore did not meet its primary end point.

For the key secondary end point, the incidence rate ratio for stage IV cancer with multicancer early-detection testing versus usual care was 0.86 after 3 screening rounds.

The stage IV finding suggests a potential signal toward fewer cancers diagnosed at the most advanced stage with multicancer early-detection testing; however, the confidence interval reached 1.00, and the investigators emphasized the need for additional follow-up to determine how the between-group difference evolves over time.

Trial-related adverse events occurred in less than 1% of participants, and no serious trial-related adverse events were reported.

“In this trial, we did not observe a lower incidence rate of stage III or IV cancers across 12 prespecified cancers after three screening rounds with multicancer early-detection testing plus usual care than with usual care alone,” concluded the study investigators. “Further follow-up is warranted to assess the way in which findings for stage III or IV cancers and the between-group difference in stage IV cancers evolve over time.”

Source: 

Sasieni P, Johnson P, Round T, et al. Effect of screening with multicancer early-detection test on late-stage cancer diagnosis. N Engl J Med. Published online: September 22, 2026. doi: 10.1056/NEJMoa2505723