The study, conducted by a team of neurosurgeons and epidemiologists from the University Hospital of Basel, the University Children’s Hospital of Basel, and the Childhood Cancer Registry at the University of Bern, relied on the Swiss Childhood Cancer Registry, a nationwide database founded in the 1970s to which all pediatric oncology centers in the country report directly. The registry is estimated to capture more than 90 percent of all cancer cases diagnosed in children younger than 16 years of age, with a completeness of up to 95 percent achieved since 1995, and a lost-to-follow-up rate of less than 2 percent. After accounting for potentially incomplete registration among 16- and 17-year-olds, who are sometimes treated in adult cancer centers, the researchers estimated a total of 641 cases of pediatric low-grade glioma across the 30-year study window.

The headline incidence figure is 1.4 cases per 100,000 children per year. That rate was remarkably consistent across most childhood ages, hovering between 1.4 and 1.5 for children aged 2 through 17, but dropping to just 0.9 among infants younger than 2. Pilocytic astrocytoma, the most benign and most common histological subtype, carried the highest incidence at 0.8 per 100,000, while other glioma subtypes registered as low as 0.1. Perhaps more intriguing was the temporal trend: over the three decades examined, incidence rates climbed in both the infant group and the 12-to-15-year-old group, rising from 0.85 to 1.01 and from 1.09 to 1.54, respectively. The authors attribute this rise not to a growing burden of disease but to improved detection, driven by more frequent use of neuroimaging, higher surgical rates, and expanded criteria for deeming children eligible for surgical intervention.

Demographically, the 591 observed cases split almost evenly between sexes, with 53.3 percent diagnosed in boys and 46.7 percent in girls. Nearly 60 percent of all diagnoses occurred in children aged 2 to 11, the prime window of early and middle childhood. Anatomically, the tumors divided cleanly: roughly half arose above the tentorium cerebelli in the supratentorial compartment, and just under half occurred below it in the infratentorial region, with only a small fraction, 4.6 percent, located in the spinal cord. Histologically, more than four in five tumors were World Health Organization grade 1, and pilocytic astrocytoma accounted for 58.2 percent of the cohort, followed by other specified and unspecified intracranial and intraspinal neoplasms at 19.6 percent and non-pilocytic astrocytomas at 17.4 percent.

Treatment patterns revealed the enduring centrality of surgery. Nearly 85 percent of children underwent a surgical procedure in their first year after diagnosis, and among those, more than half received a gross total resection, defined as removal of greater than 90 percent of the tumor mass. Fully three-quarters of the entire cohort, 74.6 percent, were treated with surgery alone, a figure that aligns with international benchmarks from the Children’s Oncology Group and European pediatric neuro-oncology trials. Adjuvant therapies played a comparatively minor role in this period: only 3.2 percent of children received upfront chemotherapy without surgery, 0.8 percent received radiotherapy alone, and 1.7 percent received both without any prior resection. Neurofibromatosis type 1, a genetic syndrome strongly predisposing to low-grade gliomas, was documented in just 3.7 percent of patients, a figure the authors suspect may reflect underdiagnosis or underreporting rather than a true rarity, particularly in the era before widespread molecular testing.

The survival statistics are the study’s most striking contribution. At the end of follow-up, 91 percent of children were alive. Among those treated with surgery alone, five-year observed survival reached 99.0 percent and ten-year survival 97.2 percent. Survival improved steadily across calendar periods, with five-year overall survival rising from 95.2 percent in 1995 through 2004 to 97.1 percent in 2015 through 2019, and ten-year survival climbing from 91.6 percent to 95.2 percent over the same interval. This trajectory signals real, measurable improvement in the standard of pediatric neuro-oncological care in Switzerland over the past three decades.

Yet the picture darkens for certain subgroups. Children whose initial treatment involved surgery followed by radiotherapy and/or chemotherapy faced dramatically lower survival, with five-year survival of just 40 percent and ten-year survival of 20 percent, a finding the authors caution is likely confounded by tumor biology rather than caused by the treatments themselves, since children requiring multimodal therapy tend to harbor more aggressive or less surgically accessible tumors. Non-pilocytic astrocytomas carried significantly lower five-year, ten-year, and overall survival, 98.8, 85.8, and 82.1 percent respectively, compared with other histological subtypes. Spinal tumors fared worst of all by anatomical location, with ten-year survival of 72.8 percent versus 93 percent or higher for supratentorial and infratentorial tumors, and spinal location independently doubled the hazard of progression, recurrence, metastasis, or death compared with infratentorial tumors.

One counterintuitive finding deserves particular attention. While overall survival improved over time, event-free survival, the time to progression, recurrence, metastasis, or death, actually declined across calendar periods, falling from 81.2 percent at five years in 1995 through 2004 to 70.9 percent in 2015 through 2019. The researchers interpret this paradox not as a therapeutic failure but as a reflection of evolving practice philosophy: surgeons increasingly accept intentional subtotal resections in eloquent brain regions to spare children neurological deficits, relying instead on chemotherapy to manage subsequent radiological progression. More sensitive follow-up imaging also detects smaller recurrences earlier. Children diagnosed in infancy bore the highest event hazard, with adjusted hazard ratios of 0.51 for ages 2 to 11 and 0.27 for ages 12 to 15 relative to infants, and adolescents aged 16 to 17 showed the lowest overall survival, possibly because late-teenage gliomas more closely resemble adult tumors with less favorable molecular profiles.

The study’s limitations are candidly acknowledged. The data span 1990 to 2019 and therefore predate both the WHO 2021 molecular reclassification of gliomas and the clinical introduction of MEK and BRAF inhibitors, targeted therapies that have since transformed frontline treatment for BRAF V600E-mutated tumors following a landmark randomized trial demonstrating response rates of 47 percent versus 11 percent for conventional chemotherapy. No molecular diagnostics were captured, no information on quality-of-life or cognitive outcomes exists in the registry, and causes of death were not distinguished. Still, as the first nationwide epidemiological portrait of pediatric low-grade glioma in Switzerland, the study affirms that children in high-income healthcare systems now face these tumors with survival odds exceeding 90 percent, a stark contrast to the 60 to 90 percent range observed in low- and middle-income countries, where the World Health Organization’s Global Initiative for Childhood Cancer aims to lift survival by 2030. Future studies incorporating molecular diagnostics, the authors conclude, are essential to complete the epidemiological picture and further refine treatment stratification for every child diagnosed with these tumors.

Subject of Research: National epidemiology of pediatric low-grade glioma incidence and survival in Switzerland

Article Title: Incidence and survival of pediatric low-grade gliomas in Switzerland

Article References: Greuter, L., Michalopoulou, E., Redmond, S., der Weid, N. V., Licci, M., Wyss, J., Guzman, R., & Soleman, J. (2026). Incidence and survival of pediatric low-grade gliomas in Switzerland. World Journal of Pediatrics. https://doi.org/10.1007/s12519-026-01085-8

Image Credits: AI Generated

DOI: 10.1007/s12519-026-01085-8

Keywords: pediatric low-grade glioma, pilocytic astrocytoma, brain tumor, Switzerland, childhood cancer registry, incidence, survival, neurosurgery, radiotherapy, chemotherapy, NF-1, epidemiology