P17.47.a Treatment Outcomes of Patients With Low Grade Astrocytomas and Oligodendrogliomas - A Single Center Experience

Abstract BACKGROUND Gliomas are tumors of glial cell origin and are the most common primary central nervous system malignacies. Grade 2 gliomas usually affect people in their late thirties/early forties with an average survival of approximately 10-15 years. They usually slowly progress into high grade gliomas, thus choosing the right treatment can be crucial for these patients’ survival. MATERIAL AND METHODS We retrospectively collected the data of patients diagnosed with WHO grade 2 astrocytoma and oligodendroglioma. Patients with histologically confirmed gliomas were included, whose first diagnosis was made after 01 JAN 2010. Median follow up time was 75 months. 64 patients were included in the final analysis, 40 were diagnosed with astrocytoma, 24 with oligondedroglioma. The median age at the time of the diagnosis was 36.5 years for astrocytomas, 34.5 years for oligodendrogliomas. 49 patients had tumor resection and 15 patients had biopsy only. 33 patients did not recieve upfront postsurgical treatment (wait and see group) and 31 received oncotherapy. Postoperative radiotherapy combined with chemotherapy was more frequent than radiotherapy alone (21 vs 8 patients). Survival times were calculated to compare treatment outcomes. RESULTS There was no significant progression free and overall survival difference between astrocytomas and oligodendrogliomas (108 months v NR, p=0.0909). The extention of neurosurgical intervention, ie. resection or biopsy, did not affect survival outcomes either (108 months v NR, p=0.1222). Median PFS of patients with better prognostic factors in the wait and see group was 33 months. Patients in the wait and see group had a median time to next therapy (time to progression after observation and RT+PCV) of 84 months. Upfront postoperative RT+PCV chemotherapy resulted in longer PFS than radiotherapy alone (73 v 13.5 months, p=0.0044). Reoperation after progression did not result in significantly longer PFS and OS (17 v 24 months, p=0.9515 and 108 v 85 months, p=0.5179, respectively). TMZ treatment after RT+PCV chemotherapy added a median time of 15 months to the PFS. CONCLUSION Based on our results, low grade glioma patients with the right treatment can have years of overall survival. Wait and see is a relevant approach to patients with better prognostic factors. Combined therapy with RT and PCV chemotherapy is superior to radiotherapy alone and TMZ after progression has an added value to survival as well.