Background: The prognosis of patients with anaplastic glioma tumors is relatively favorable compared with patients with glioblastoma multiforme.
Objective: To estimate survival differences between anaplastic astrocytoma (AA) and anaplastic oligodendroglioma (AO) patients and factors associated with survival prognosis.
Methods: A nationwide cohort of grade III glioma patients diagnosed between 1990 and 2008 was studied using the Surveillance, Epidemiology, and End Results registry. Multivariate Cox proportional hazard models evaluated the role of patient and clinical characteristics on overall survival.
Results: A total of 1766 patients with AA and 570 patients with AO were studied. The median overall survival was 15 and 42 months among AA and AO patients, respectively. Age increments of 10 years implicated a 50% increase in mortality hazards among AA (hazard ratio [HR], 1.49; P < .001) and AO (HR, 1.51; P < .001) patients. Among AA patients, radiation (HR, 0.62; P < .001), surgery (vs biopsy; HR, 0.73; P < .001), female sex (HR, 0.87; P = .02), and married status (HR, 0.87; P = .02) were associated with a reduction in the hazard of mortality. Longer survival if diagnosed in 2000 relative to 1990 was observed (HR, 0.84; P = .004) in AA patients. Although surgery did not significantly improve survival among AO patients, gross total resection increased the median survival from 40 to 61 months (P = .001) in this cohort.
Conclusion: First-course radiation, younger age, female sex, treatment in recent years, and surgery were associated with improved survival in AA patients. In contrast, age was the most prominent predictor of survival in AO patients. Surgery alone did not seem to benefit AO patients, and gross total resection improved survival by 21 months.