Survival rates in patients with primary malignant brain tumors stratified by patient age and tumor histological type: an analysis based on Surveillance, Epidemiology, and End Results (SEER) data, 1973-1991

Object. The authors present population-based survival rate estimates for patients with malignant primary brain tumors based on an analysis of 18 years of data obtained from the Surveillance, Epidemiology, and End Results (SEER) program of the National Cancer Institute. Methods. Estimates of survival rates at 2 and 5 years after diagnosis for patients with specific histological tumor types were categorized by patient's age at diagnosis (less than or equal to 20 years, 21-64 years, and 65 years or older) and by the time period in which the patients were diagnosed (1973-1980, 1981-1985, 1986-1991). When appropriate, survival estimates were adjusted for changing patterns in the mean age at diagnosis. Conclusions. The authors observed a pattern of declining survival rates in patients with increasing age of the patient at diagnosis for most histological groups and overall improvements in survival rates of patients across these time periods adjusting for age at diagnosis. There were improvements in 2- and 5-year survival rates over the three time periods for children and adults with medulloblastoma and for adults with astrocytoma and oligodendroglioma. Improvements in survival rates for pediatric patients with medulloblastoma have leveled off in the most recent time period, and gender differences in survival rates for patients with this tumor, which were present in the 1970s, have disappeared. Clinically significant improvements in survival rates were not apparent in patients aged 65 years and older. Changes in diagnostic and treatment procedures since the mid-1970s have resulted in improved survival rates for patients diagnosed as having medulloblastoma, oligodendroglioma, and astrocytoma, controlling for age at diagnosis. Glioblastoma multiforme continues to be the most intractable brain tumor.