Long-term follow-up of children treated for high-grade gliomas: children's oncology group L991 final study report

High-grade gliomas of the CNS are characterized by poor treatment response and prognosis for long-term survival. The Children's Oncology Group (COG) L991 study investigated the neuropsychological, behavioral, and quality of life (QoL) outcomes after treatment on the Children's Cancer Group (CCG) trial for high-grade gliomas (CCG-945).

Fifty-four patients (29 males, 25 females) with a median age of 8.8 years at diagnosis (range, 0.2 to 19.5 years) were enrolled at 25 institutions in North America, representing 81% of available survivors; median length of follow-up was 15.1 years (range, 9.5 to 19.2 years), and median age at study evaluation was 23.6 years (range, 11.3 to 36 years). Standardized tests of neuropsychological functioning and QoL were performed. Descriptive statistics summarized principal findings, and one-way analysis of variance identified potential predictors of outcomes.

With an average follow-up time of 15 years, survivors demonstrated intellectual functioning within the low-average range. Executive functioning and verbal memory were between the low-average and borderline ranges. In contrast, visual memory and psychomotor processing speed were between the borderline and impaired ranges, respectively. Approximately 75% of patient reported overall QoL within or above normal limits for both physical and psychosocial domains. Nonhemispheric tumor location (midline or cerebellum), female sex, and younger age at treatment emerged as independent risk factors.

These results serve as a benchmark for comparison with future pediatric high-grade glioma studies, in addition to identifying at-risk cohorts that warrant further research and proactive interventions to minimize late effects while striving to ensure survival.