Astrocytomas in childhood: a population-based study.

A population-based study of astrocytomas occurring in children is reported. A population-based study eliminates referral bias and the bias of a series based on the experience of a given medical center or a particular surgeon. In a 42-year period, 179 such cases were diagnosed. The average age at diagnosis was 8.9 years. Over one-half of the astrocytic tumors were located in the cerebellum. A peak in the number of astrocytomas was noted between 1965 and 1970. Cumulative probability of survival of children with intracranial astrocytomas at 6 months and at 1, 2, and 5 years was 0.824, 0.752, 0.732, and 0.667; by 10 years and 20 years the cumulative probability of survival had fallen to 0.607 and 0.538. The shortest survival was observed with brainstem tumors, with an average survival of 19 months. Longer survivals were noted with tumors of the cerebral hemispheres: 0.779, 0.748, 0.678 and 0.628 at 1, 2, 5, and 10 years, respectively. The longest survivals were in those children with cerebellar astrocytomas: at 1 year they had an 0.837 probability of survival and at 20 years, 0.675.