Prognostic factors in children and adolescents with low-grade oligodendrogliomas.

Few reports exist describing the progression-free and overall survival of children with low-grade (WHO grade II) oligodendrogliomas treated uniformly with aggressive surgery but without adjuvant chemotherapy or radiation therapy. Furthermore, significant prognostic features, including the MIB-1 labeling index (LI), have not been reported for children with oligodendrogliomas. The medical records of 20 consecutive patients with low-grade oligodendrogliomas were reviewed. All patients had been treated with aggressive surgical resection. Adjuvant chemotherapy and radiation therapy were reserved for radiographic or clinical progression. These patients have been followed for a median of 5.5 years (range 0.5-11.5 years) after diagnosis. To date, there have been no patient deaths. Six of the 20 patients experienced tumor progression at a median of 2.2 years (range 0.4-4.8 years) following the initial surgery. The MIB-1 LI was infrequently greater than 5. Of several prognostic factors for subsequent tumor progression that were examined, only tumors located within the parietal lobes were associated with a worse progression-free survival. Other risk factors, including presenting symptoms, age at diagnosis, MIB-1 LI and the extent of tumor resection, were not associated with an increased frequency of tumor progression.