Can chemotherapy replace radiotherapy in low-grade gliomas? Time for randomized studies

For the last three decades surgery and radiotherapy have been the mainstay of treatment for patients with low-grade gliomas, despite a lack of support from randomized controlled trials. Recent developments in our knowledge of low-grade tumor chemosensitivity and the approval of temozolomide for treatment of gliomas have led to increased interest in chemotherapy for treating low-grade gliomas. Despite challenges, including response assessment and appropriate patient selection, several phase II studies investigating chemotherapeutic treatment of low-grade gliomas have yielded promising results. Although most of these phase II studies are of limited sample size, they have shown that chemotherapy might induce clinically relevant responses and disease stabilization in patients with low-grade gliomas. As expected, low-grade oligodendroglioma is sensitive to chemotherapy, but responses were also seen in astrocytic tumors. Randomized, controlled studies should be conducted to determine the clinical significance of responses observed in phase II studies and to assess time to progression. Two randomized, controlled studies are currently investigating chemotherapy in the treatment of low-grade gliomas. Although it will take years before the data are available, these studies will help define the role of chemotherapy in the treatment of low-grade gliomas. Perhaps then we can answer the question, can chemotherapy replace radiotherapy in low-grade gliomas?