Central nervous system cancers in first-degree relatives and spouses.

The increasing incidence of high-grade astrocytomas in the elderly, the associations between these malignancies and environmental factors, and case reports suggesting a familial component to these tumors prompted this study of primary brain tumors in first-degree relatives and spouses. This article describes the findings in 154 patients from 72 consecutive families accrued to the National Familial Brain Tumor Registry from 1991 to 1996. Medical records, pathological slides, and demographic data were reviewed for each identified case. Parents and children were affected in 33 families, siblings in 27, and husbands and wives in 12. The median age of the patients was 50.5 years, 55% were men, and 70% had high-grade astrocytomas. The pattern of tumor occurrence in this population is different from most familial cancers. These tumors did not involve multiple generations or occur at an unusually early age. In addition, the cases tended to cluster in time, with 47% of the familial and 50% of the husband-wife cases occurring within a 5-year span. In families with an affected parent and child, the diagnosis was made in the child before the parent in 45% of the cases. Prognostic factors for these patients appear to be similar to that reported for typical high-grade astrocytomas. This study demonstrates that primary brain tumors can occur in families without a known predisposing hereditary disease. The ages of these patients, the clustering of cases in time, the few affected generations, and the occurrence of brain tumors in spouses suggest that environmental exposures may be important in the etiology of this neoplasm. Although this hypothesis requires further study, it is plausible given the known associations in animals and humans between high-grade astrocytomas and radiation, toxic chemicals, and viruses.