Simple Blood Test to Advance Targeted Treatments for Childhood Cancer

A research team from The Institute of Cancer Research (ICR, London, UK) has been working to create a less invasive method for tracking how childhood tumors evolve and respond to treatment. Recent findings from the Stratified Medicine Pediatrics (SMPaeds1) program, published in Cancer Discovery, show that circulating tumor DNA (ctDNA) testing can provide a more comprehensive view of how a tumor progresses over time. In the study, the team examined both childhood tumor samples taken at the initial diagnosis and ctDNA—fragments of tumor DNA found in the blood—during relapse to understand how tumors adapt after treatment. In certain cases, the test even detected additional DNA mutations that were not identified in the original tumor biopsy.

Since ctDNA testing only requires a blood sample, it is far less invasive than a traditional tumor biopsy, which often requires a general anesthetic. These findings are expected to advance the understanding of why some tumors relapse or fail to respond to treatment, with the ultimate goal of developing more effective, targeted therapies. The second phase of the research program (SMPaeds2) is now underway, with plans to further refine and explore new tests building on the success of the first phase. SMPaeds2 will focus on blood cancers and solid tumors in children and young people, including those affecting the brain, muscle, and bone, which are often more difficult to diagnose and treat.

“We showed that ctDNA analysis can add valuable information and that in some patients it can detect additional DNA mutations that are in the tumor but were missed by tumor biopsy,” said study author Dr. Sally George, Group Leader of the Developmental Oncology group at ICR. “SMPaeds1 is the largest study with matched ctDNA and tissue sequencing to date and shows the value of ctDNA testing for children with cancer. We are working with colleagues across Europe to transition ctDNA analysis from being a research test to being available clinically. The project also identifies DNA mutations that become enriched at relapse. This will help us prioritize future research to understand why those mutations are enriched and if we can develop new treatments to target cancers with those mutations.”