Characterization of Late Recurrence in Long-Term Survivors of Primary Glioblastoma

Traditionally, overall survival (OS) in primary glioblastoma (GBM) was dismal with 5% at 2 years, but recent advances have improved OS in this population. Long-term survivors (LTS), while rare, can now be identified and evaluated. In a single-center, retrospective analysis, we identified GBM LTS as defined by survival =5 years from diagnosis. To characterize late recurrence in GBM LTS, we extracted a patient subset that experienced disease/treatment free period =2 years. Demographic data was obtained along with characteristics of late recurrence: location, pathology, associated clinical symptoms, and calculation of time to death from late recurrence. 139 primary GBM patients were identified as long-term survivors from January 1, 1998 to August 31, 2011. 42 (30%) had a late recurrence. 59.5% (n=25) were male and average age was 45.6 yrs (range, 23-66yrs). 57.1% (n=24) had new neurological symptoms to indicate recurrence, but the remaining 42.9% were found to have recurrence on serial MRIs. Median OS was 6.8 yrs (95% CI 6.2, 8 years) and median time to late recurrence was 3.6 yrs (95% CI 3.3, 4.6 yrs). Once patients progressed, median time to death from recurrence was 1.3 yrs (95% CI 1, 1.7 yrs) indicating a more aggressive cancer. GBM LTS can develop late recurrences in their disease trajectory even after a protracted disease/treatment free time period. Continued close monitoring with frequent clinical evaluations and MRI imaging is warranted in this population. Establishment of survivorship programs should be considered for GBM LTS to address disease-related and psychosocial issues.