Is the Duration of Temozolomide Predictive for Sequential Bevacizumab Treatment Responses in the Glioblastoma Multiforme Cancer Setting

OBJECTIVE To evaluate the predictive significance of the duration of temozolomide (TMZ) in patients with glioblastoma multiforme (GBM) who were treated with bevacizumab (Beva) as second-line setting. STUDY DESIGN Descriptive study. PLACE AND DURATION OF STUDY Bezmialem Vakif University School of Medicine Hospital, Istanbul, Turkey, from January 2014 to September 2020. METHODOLOGY A total of 109 patients, 47 (43.1%) females and 62 (56.9%) males, were retrospectively included in the study. All patients received TMZ as first-line and Beva as second-line treatment. Kaplan-Meier method and Cox regression model were performed for survival and univariate/multivariate analyses, respectively. RESULTS Patients treated with first-line TMZ were divided into two groups according to the PFS. Group 1 is <9 months and group 2 is ≥9 months. Overall survival (OS) of group 1 and group 2 patients was evaluated  after the initiation of second-line bevacizumab treatment. The OS in group 1 was 7.8 months (6.9-8.6, 95% CI), and group 2 was eight months (6.4-9.5, 95% CI), but it was statistically non-significant (p = 0.837). CONCLUSION Duration of first-line TMZ treatment was not a predictor for OS of the GBM patients, who were treated with Beva as second-line setting. Key Words: Bevacizumab, Duration of treatment, Glioblastoma multiforme, Predictive score, Temozolomide.