To identify biomarkers that are able to predict favorable outcomes for patients with glioblastoma treated with temozolomide (TMZ)

Glioblastoma is the most aggressive primary brain tumor. The standard of care treatment is maximum safe resection, radiation plus oral temozolomide  (TMZ) chemotherapy, followed by six months of cyclic oral TMZ.  Treatment-related side effects are common while the 5‑year overall survival is less than 10%. Previous studies have reported that TMZ-induced myelosuppression is associated with improved overall survival.

Adults with histology-confirmed glioblastoma treated at Beth Israel Deaconess Medical Center from (2017-2018) who had completed both radiation therapy and temozolomide for at least 6 months were identified. Lab values (WBC, ANC, ALC, RBC, PLT), molecular markers (IDH1 R132H, MGMT promoter methylation ), progression free survival (PFS), overall survival (OS) will be collected retrospectively. This data will be combined with published data of 86 cases [Vaios et al.].

60 new patients with glioblastoma were identified and data collected. 32 were included in this study and their data combined with previous data collected from 2012-2017 for a total of 173 patients.  Preliminary results according to Kaplan-Meier analysis with a log-rank test confirms that leukopenia is associated with increased survival (p=0.008) and progression free status (p=0.02). 

Decreased white blood cell counts may serve as a peripheral blood biomarker for OS and PFS in glioblastoma patients treated with radiation therapy and TMZ. It is possible that leukopenia reflects adequate temozolomide dosing and anti-tumor activity or reflects changes in the tumor micro-environment. Standardized approaches to peripheral blood monitoring in glioblastoma patients undergoing chemotherapy is likely to improve prognostic stratification and overall survival.