Patterns of Care in Recurrent Glioblastoma in the Era of Molecular Diagnosis (P6.129)

Objective: N/A Background: Recurrent glioblastoma has poor prognosis with limited therapeutic options. We evaluated patterns of care and survival in patients with recurrent glioblastoma treated at the Cleveland Clinic. Design/Methods: We analyzed 258 patients diagnosed with recurrent glioblastoma between 2012 and 2017. Overall survival (OS) was calculated from the date of first recurrence to the date of death or last follow up, and progression free survival (PFS) was calculated from date of first to second recurrence, assuming treatment occurred near first recurrence, with death counting as an event for PFS. Results: At the time of analysis, median age was 62 years, 177 patients (69%) had died, and 11 (4.3%) were lost to follow up. 249 patients (97%) had reported molecular testing for MGMT, EGFR, or IDH. Of patients with available data, 66 (37%) had MGMT methylation, 93 (44%) with EGFR amplification, and 13 (6.9%) with IDH mutation. Median durations from initial diagnosis to first recurrence, and from first to second recurrence (PFS) were 6.9 and 4.6 months, respectively. After first recurrence, 62 patients had surgery, 26 received re-irradiation, 32 received Lomustine, 82 received Bevacizumab, 21 received both, 73 received other chemotherapy, and 79 enrolled in clinical trials. Median OS was 11.7 months. MGMT-methylated patients had longer median time to first recurrence (10 vs 5.7 months, P Conclusions: Surgical re-resection can still offer an OS advantage for patients with recurrent glioblastoma. Compared to Lomustine, Bevcizumab improved PFS in MGMT-methylated but not MGMT-unmethylated glioblastomas. Disclosure: Dr. Migdady has nothing to disclose. Dr. Dai has nothing to disclose. Dr. Thapa has nothing to disclose. Dr. Bellamkonda has nothing to disclose. Dr. Ahluwalia has nothing to disclose.