Trial of multi-cancer blood test among 142,000 NHS patients fails to meet main aim

A large-scale clinical trial involving 142,942 NHS patients tested the effectiveness of the Galleri multi-cancer early detection (MCED) blood test, designed to detect more than 50 types of cancer. Participants aged 50 to 77, all without cancer symptoms, had blood drawn annually for three years alongside standard cancer screening. Half of the participants received the Galleri test, while the other half served as a control group. The trial’s primary goal was to determine if adding the Galleri test could reduce the number of late-stage (stage three and four) cancer diagnoses. Results presented at the American Society of Clinical Oncology’s annual meeting in Chicago revealed that the Galleri test did not achieve its main objective. There was no statistically significant reduction in advanced cancer diagnoses among those tested with Galleri compared to those who underwent standard screening alone. While some encouraging trends toward earlier tumor detection were noted, the overall impact on shifting diagnoses to more treatable stages was insufficient to meet the trial’s primary endpoint. The trial represents the world’s first randomized controlled study of a multi-cancer early detection test in an asymptomatic population. Participants with positive Galleri results underwent further diagnostic evaluation, but the test’s inability to significantly reduce late-stage cancer diagnoses raises questions about its clinical utility as a screening tool. Experts at the conference, including Dr. Julie Gralow of ASCO, emphasized the importance of these findings in guiding future cancer screening strategies. Despite the disappointing outcome, the company behind Galleri, Grail, expressed cautious optimism, highlighting data suggesting potential benefits in detecting stage four cancers. The trial’s results underscore the challenges in developing effective blood-based cancer screening tests and the need for continued research to improve early cancer detection and reduce mortality.