Introduction: Anaplastic oligodendrogliomas, which harbor the 1p19q co-deletion, currently are treated with combinatorial chemotherapy and radiation therapy following two Phase III trials. However, these trials compared combinatorial therapy with radiation alone, and it remains unknown if chemotherapy alone upfront is a viable treatment strategy.
Methods: A retrospective review of the electronic medical record was performed for patients from the University of California, San Francisco with anaplastic oligodendrogliomas from 1996-2016. Patients without the 1p19q deletion were excluded, as were patients initially diagnosed with a Grade II tumor that subsequently progressed. Survival analyses were performed with JMP software.
Results: 60 patients (median age = 43.9, 53.3% male) who underwent surgery and received a tissue diagnosis of anaplastic oligodendroglioma were included in our analyses. The median overall survival (OS) was 123.1 months and median progression free survival (PFS) was 63.1 months respectively. Patients receiving chemotherapy alone (n = 23) had shorter PFS compared to patients receiving chemotherapy plus radiotherapy or radiotherapy alone (n =35), 32.1 months vs 153.9 months respectively (p < 0.001). However, there was no difference in OS between the two groups, with some signal that patients receiving chemotherapy alone did better than those receiving combinatorial therapy (p = 0.06).
Conclusions: Patients diagnosed with anaplastic oligodendroglioma after may be managed with chemotherapy alone initially following surgical resection, with radiation reserved for patients that progress and have worsening performance status. This strategy may reduce treatment related toxicity secondary to radiation and improve patient quality of life.
Patient Care: Hopefully this work can provide the foundation for studies that elaborate on the best management strategy for patients with anaplastic oligodendrogliomas that maximizes both survival and quality of life.
Learning Objectives: - In our series, patients with anaplastic oligodendroglioma have a median OS of 123.1 months and a PFS of 63.1 months
- Chemotherapy alone as an initial treatment compared to combination radiotherapy and chemotherapy was associated with worse PFS but there was no difference in OS
- Given the relatively good prognosis for this malignant brain tumor, radiotherapy may be postponed until the time of recurrence to spare patients the damaging long term neurocognitive side effects as long as possible.