Central Nervous System
Survivors after treatment for pediatric brain tumors are at significantly increased risk for long term health problems.
The spectrum of these toxicities includes:
- Developmental delay and decline in intellectual function, which is very likely to be associated with:
- Psychological problems with depression and behavior disorders
- Learning problems and school failure
- Recurrence of primary cancer
- Second cancers
- Hearing impairment
The treatment of almost all brain tumors includes radiation therapy (RT) which is associated with significant late effects. Chemotherapy can enhance this damage.
These impairments can have a profound impact on children and their families and can drastically alter a child’s course in life.
Survivors of pediatric brain tumors may be unable to live independently and to find employment.
Childhood Cancer Survivor Study:
Long-term outcomes among adult survivors of childhood central nervous system malignancies were assessed in the Childhood Cancer Survivor Study1:
Information was collected on treatment, mortality, chronic medical conditions, and neurocognitive functioning of adult 5-year survivors of CNS malignancies diagnosed between 1970 and 1986 within the Childhood Cancer Survivor Study (patients treated in Children's Oncology Group studies).
Using a competing risk framework, cumulative mortality was calculated according to cause of death and cumulative incidence of subsequent neoplasms according to exposure and dose of cranial radiation therapy (RT).
Neurocognitive impairment and socioeconomic outcomes were assessed with respect to dose of CNS RT to specific brain regions.
Cumulative incidence of chronic medical conditions was compared between survivors and siblings using Cox regression models. All tests of statistical significance were two-sided.
RESULTS: Among all eligible 5-year survivors (n = 2821):
- Cumulative late mortality at 30 years was increased at 25.8% (95% confidence interval [CI] = 23.4% to 28.3%)
- Primarily due to recurrence and/or progression of primary disease.
- Patients who received cranial RT of 50 Gy or more (n = 813):
- Cumulative incidence of a subsequent neoplasm within the CNS was 7.1% (95% CI = 4.5% to 9.6%) at 25 years from diagnosis compared with 1.0% (95% CI = 0% to 2.3%) for patients who did not have RT
- The risk of neurocognitive impairment was high and proportional to RT dose for specific tumor types:
- Dose-dependent association between RT to the frontal and/or temporal lobes and lower rates of employment, and marriage.
- Survivors had higher risks than their siblings of developing new endocrine, neurological, or sensory complications 5 or more years after diagnosis.
CONCLUSIONS: Survivors of childhood CNS malignancies are at high risk for late mortality and for developing subsequent neoplasms and chronic medical conditions. Care providers should be informed of these risks so they can provide risk-directed care and develop screening guidelines1.