Improved Blood Tests for Diagnosis and Monitoring in Children with High-Risk Cancer

In a liquid biopsy, tiny DNA fragments—which tumors release into the bloodstream, among other places—are analyzed. Compared to a tissue biopsy, this procedure is significantly less invasive for patients and can be performed multiple times during treatment. While liquid biopsies are already being used more and more frequently in adults, their application in childhood cancers has so far been much more difficult. Reasons for this include the small blood volume and the rarity of many tumor types.

As part of the INFORM precision oncology program, researchers analyzed blood samples from 130 children and adolescents with various high-risk tumors. To do so, they developed new laboratory and bioinformatics methods specifically tailored to the needs of pediatric oncology. A newly developed analysis algorithm significantly improved the sensitivity and accuracy of tumor detection from blood samples compared to previous analysis methods.

The study also demonstrates the potential of liquid biopsy for monitoring treatment. In one child’s case, the liquid biopsy showed signs of renewed tumor growth approximately two months before routine imaging. “Such early indications could help adjust treatments in a timely manner in the future,” says Kendra Maaß of the Hopp Children’s Cancer Center Heidelberg (KiTZ), the Heidelberg Medical Faculty (MFHD) at Heidelberg University, Heidelberg University Hospital (UKHD), the German Cancer Research Center (DKFZ), and the National Center for Tumor Diseases (NCT). The researcher led the study together with Kristian Pajtler and Benedikt Brors from the NCT, DKFZ, the German Consortium for Translational Cancer Research (DKTK), and the MFHD.

The accuracy of tumor detection was approximately 95 percent, making it significantly more precise than previous standard liquid biopsy analyses. Furthermore, the blood analysis was able to reveal genetic differences between various tumor sites that cannot be detected in a single tissue sample. As a result, the liquid biopsy provides additional information about a tumor’s development and its changes over the course of the disease.

The researchers view their work as an important methodological advance for liquid biopsy in pediatric oncology. The analysis pipeline they developed is already being used as an additional molecular test in the INFORM program. However, the authors emphasize that further studies are needed before the method can become part of routine diagnostics.

Original publication:
Maass, K.K., Puranachot, P., Volz, S. et al. Circulating tumor DNA precision oncology enables effective and sensitive molecular diagnostics and actionable target detection in pediatric solid tumors - the INFORM experience. In: Genome Med 18, 112 (online publication July 27, 2026).). https://doi.org/10.1186/s13073-026-01737-4