We always thought aggressive childhood cancers were there from birth, but it turns out they don't even start growing until after infancy.
bioRxiv · March 13, 2026 · 10.64898/2025.11.28.691194
Why it matters
This discovery explains why massive public health screening programs for infants failed to lower cancer deaths—they were looking for tumors before the most dangerous ones even existed. It suggests we have been timing our early-detection efforts for childhood cancer completely wrong.
From the abstract
In neuroblastoma, population screening during infancy failed to lower mortality because it primarily detected biologically indolent tumors rather than aggressive, life-threatening disease. The failure may reflect limited screening sensitivity, or disease onset after infancy among aggressive tumors. Here, we used an epigenetic mitotic clock based on fluctuating CpG DNA methylation to estimate patient-specific tumor mitotic ages and calendar ages in a cohort of unscreened children diagnosed with n