SUPRATENTORIAL WORLD-HEALTH-ORGANIZATION GRADE-2 ASTROCYTOMAS AND OLIGOASTROCYTOMAS - A NEW PATTERN OF PROGNOSTIC FACTORS

BACKGROUND. Prognostic factors for adult patients with supratentorial World Health Organization (WHO) Grade 2 astrocytomas are poorly define d. METHODS. The prognostic importance of pretreatment patient- and tum or-related factors was analyzed retrospectively in 197 adult patients with supratentorial astrocytomas (n = 153) or oligoastrocytomas (n = 4 4) using the multivariate Cox proportional hazards model. Endpoints we re death and date of malignant transformation. All patients were treat ed similarly between 1979 and 1992 with iodine-125 implants as the pri mary treatment. RESULTS. A new prognostic pattern was detected. Unfavo rable prognostic factors with regard to survival were 1) a tumor volum e greater than or equal to 20 mt; 2) a performance status less than or equal to 80; and 3) age greater than or equal to 40 years for the fem ale subpopulation. Midline shift (another important tumor-related fact or after univariate analysis) was highly correlated with tumor volume and therefore not included in the multivariate model. Risk factors of malignant transformation were 1) a tumor volume greater than or equal to 20 mt; 2) an enhancement in the computed tomography scan; and 3) ag e greater than or equal to 40 years for the female subpopulation. Prog nostic factors created subsets of patients with 5-year survival rates ranging from as low as 5% to as high as 79%. CONCLUSIONS. Any treatmen t decision or evaluation of treatment efficacy should take into accoun t the strong influence of both patient- and tumor-related factors. Any further study design should consider the detected interaction between gender and age and the importance of tumor volume. (C) 1997 American Cancer Society.