Chemotherapy for low-grade gliomas

Low-grade gliomas (LGG) in adults include oligodendrogliomas, oligoastrocytomas, and astrocytomas.1 These tumors are classified by the World Health Organization (WHO) as grade II tumors and usually present with seizures in the fourth and fifth decades of life. Although LGGs grow slowly, they generally recur and result in significant morbidity and mortality. Treatment for these tumors consists primarily of radiation therapy and surgery. However, there is increasing evidence that chemotherapy may be effective. In the late 1980s Cairncross and Macdonald2 reported that anaplastic oligodendrogliomas (WHO grade III) were unusually chemosensitive. Since then, there have been many reports confirming this finding and demonstrating that deletions of chromosome 1p and 19q are associated with increased responsiveness of anaplastic oligodendrogliomas to radiation therapy and chemotherapy.1,3–5 Efficacy of chemotherapy for low-grade oligodendrogliomas and astrocytomas has been more controversial; however, there are accumulating data from retrospective and small phase II studies demonstrating activity of chemotherapy in LGGs including the combination of procarbazine, lomustine (CCNU) and vincristine (PCV),6 and single agent temozolomide.7–9 Temozolomide yields response rates of 10 …