Oligodendroglial Component in Anaplastic Astrocytomas: A Prognostic Factor for Survival

Perhaps contrary to expectations, the presence of an oligodendroglialcomponent in patients with anaplastic astrocytomas was associated witha significantly longer survival than were pure anaplastic tumors. Thisfinding emerged from a randomized phase I-II trial from the Radiation TherapyOncology Group (RTOG).

In this study, Dr. Bernadine Donahue of New York University, and colleaguesreviewed the data on 133 adults who met the criteria defined for an anaplasticastrocytoma: the absence of tumor necrosis with the presence of two ormore of the following features: nucleopleomorphism, increased cell density,mitotic figures, or vascular prominence. Of these patients, 24 were consideredto have oligodendroglial elements.

There was a marginally significant difference in age, with patientswho had oligodendroglial elements being slightly older than patients withpure anaplastic astrocytomas. Patients with oligodendroglial elements werealso more likely to have had resection than biopsy. Although there wasno difference in the performance status or neurologic function status betweenthe patients with pure anaplastic astrocytomas and the patients who hadanaplastic astrocytomas with oligodendroglial components, there was a significantdifference in survival: the median survival of patients with pure anaplasticastrocytomas was 3 years vs 7.3 years for patients who had anaplastic astrocytomaswith oligodendroglial elements.