SURVIVAL RATES IN PATIENTS WITH PRIMARY MALIGNANT BRAIN-TUMORS STRATIFIED BY PATIENT AGE AND TUMOR HISTOLOGICAL TYPE - AN ANALYSIS BASED ONSURVEILLANCE, EPIDEMIOLOGY, AND END RESULTS (SEER) DATA, 1973-1991

Object. The authors present population-based survival rate estimates f or patients with malignant primary brain tumors based on an analysis o f 18 years of data obtained from the Surveillance, Epidemiology, and E nd Results (SEER) program of the National Cancer Institute. Methods. E stimates of survival rates at 2 and 5 years after diagnosis for patien ts with specific histological tumor types were categorized by patient' s age at diagnosis (less than or equal to 20 years, 21-64 years, and 6 5 years or older) and by the time period in which the patients were di agnosed (1973-1980, 1981-1985, 1986-1991). When appropriate, survival estimates were adjusted for changing patterns in the mean age at diagn osis. Conclusions. The authors observed a pattern of declining surviva l rates in patients with increasing age of the patient at diagnosis fo r 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 adu lts with astrocytoma and oligodendroglioma. Improvements in survival r ates for pediatric patients with medulloblastoma have leveled off in t he most recent time period, and gender differences in survival rates f or patients with this tumor, which were present in the 1970s, have dis appeared. Clinically significant improvements in survival rates were n ot apparent in patients aged 65 years and older. Changes in diagnostic and treatment procedures since the mid-1970s have resulted in improve d survival rates for patients diagnosed as having medulloblastoma, oli godendroglioma, and astrocytoma, controlling for age at diagnosis. Gli oblastoma multiforme continues to be the most intractable brain tumor.