Extent of surgical resection and adjuvant temozolomide improves survival in pediatric GBM: a single center experience

Abstract

Pediatric glioblastoma (pGBM) is an uncommon entity. The importance of concurrent and adjuvant temozolomide is not known in this subset of patients. We retrospectively analyzed our database between 2000 and 2015. All patients were treated with maximally safe surgical resection. This was followed by a uniform treatment schedule of post-operative radiation with concurrent daily temozolomide at 75mg/m2. Radiation dose was 60Gy in 30 fractions planned by 3-dimensional conformal radiotherapy. Concurrent and adjuvant temozolomide was used in all patients treated after 2007. Four weeks later, adjuvant temozolomide was started at 150mg/m2, day 1 to 5 every 28days and escalated to 200mg/m2 from the second cycle onwards if well tolerated. Log-rank test was used to compare survival distribution. The data was analyzed using SPSS (version 16). Fifty-one patients were analyzed. Median age was 14years (range: 5 to 21years). Thirty-five males and 16 females were noted. Median symptom duration was 4months. Twenty-eight patients underwent a gross total resection (GTR) while 17 underwent a subtotal resection; six patients underwent decompression. Thirty-three patients received concurrent chemotherapy while 27 received adjuvant chemotherapy. Median progression-free survival (PFS) was 15.1months. One- and 3-year PFS was 54.4% and 3-year PFS was 24.6.7%. The median overall survival was 17.4months. In univariate analysis survival was better for gross total resection (17.4months vs. 11.5months; p=0.037), and significance maintained after multivariate analysis p=0.026, HR 3.069, 95% CI 1.14-8.23. In univariate analysis, survival was better for patients receiving temozolomide but did not achieve significance. However, in multivariate analysis, use of temozolomide was associated with significantly improved survival p=0.036, HR 3.315, 95% CI 1.07-10.19. GTR improves survival significantly in pGBM. Adjuvant temozolomide may improve survival in pGBM.