Pediatric cancers are relatively rare, making up just 1 to 2% of all cancers in developed countries. In France, about 2,300 children are diagnosed annually, which is roughly 0.6% of all cancer cases across all age groups, according to the National Cancer Institute (Inca). The most common types of cancer in children under 17 are leukemias (blood cancers), central nervous system tumors (brain and spinal cord cancers), and lymphomas (cancers of the lymphatic system). Unlike adult cancers, these pediatric cancers often have different characteristics, symptoms, and treatment responses. Dr. Anne-Sophie Defachelles, a pediatric oncologist at the Oscar Lambret Center in Lille, explains that while many parents initially suspect genetic factors, most of these cancers are not inherited. The role of environmental factors, such as pesticide exposure, remains unclear, with current evidence inconclusive. Over the past 16 years, the five-year survival rate for children under 15 in France has improved from 81% to 85%, a trend seen in many high-income countries, especially for leukemias and brain tumors. However, certain types of pediatric cancers still have poor prognoses, such as central nervous system tumors in infants and gliomas in older children. Cancer remains the leading cause of death from disease in children over one year old. In low- and middle-income countries, survival rates are often below 30%, prompting the World Health Organization to launch a program in 2025 to provide free access to essential cancer drugs. Significant progress in treatment has improved outcomes, with four out of every five children in France being cured, depending on the cancer type and stage at diagnosis. This success is due to more effective chemotherapy, multidisciplinary care, and standardized treatment protocols at both national and international levels. Dr. Defachelles leads the Interregional Pediatric Oncology Network in the Northwest of France, which collaborates with institutions like the University Hospitals of Lille, Rouen, and Amiens. She also participates in the European consortium ITCC, which ensures access to the latest, most effective therapies based on international research. Initiatives like "September in Gold," launched in 2012 in the U.S. and 2016 in France, engage the public in funding research and improving long-term care for survivors. At the Gustave Roussy Institute, scientists are investigating gene mutations and proteins that influence survival in pediatric gliomas, while also exploring AI-driven therapies. Researchers at the Curie Institute are developing immunotherapy for Ewing’s sarcoma, a rare bone cancer affecting around 80 to 100 children yearly. Cell therapies like CAR-T cells, which are genetically modified to target cancer cells, show promise in blood cancers but face challenges when applied to solid tumors. Adapting adult-developed drugs for children also presents difficulties, such as dosing and ease of administration. Thanks to these advancements, more children with cancer are surviving and growing into adulthood. However, these survivors often face long-term health and psychological effects, requiring specialized follow-up care. The Gustave Roussy Institute has created a personalized prevention program called "Interception" to address these needs. Dr. Defachelles emphasizes that many of these adults experience lasting effects that require care beyond what traditional physicians are accustomed to providing. As treatment continues to evolve, the focus is shifting toward not only curing childhood cancers but also ensuring the long-term well-being of survivors.