Temozolomide Rechallenge in Patients With Recurrent High-Grade Glioma Treated With Re-Irradiation.

Abstract

PURPOSE/OBJECTIVE(S)\nTo evaluate the clinical role of temozolomide rechallenge (TMZ) in patients with recurrent high-grade glioma (HGG) treated with re-irradiation (re-RT) regardless of surgical status.\n\n\nMATERIALS/METHODS\nSingle-center retrospective review of patients with a primary diagnosis of World Health Organization (WHO) Grade III anaplastic astrocytoma or Grade IV GBM treated from 2008 to 2016 for disease recurrence with re-RT (35 Gy in 10 fractions) with and without temozolomide rechallenge. Baseline characteristics were analyzed with pairwise tests. OS/PFS were assessed with the Kaplan-Meier method and multivariable cox regression models for OS.\n\n\nRESULTS\nTwo hundred and thirty patients were treated with re-irradiation (n\u202f=\u202f67 with and n\u202f=\u202f163 without concurrent TMZ), with a median follow-up of 13.4 months. Baseline characteristics were similar between the two groups. TMZ rechallenge did not improve OS (HR 0.81 [0.51-1.3] P\u202f=\u202f0.39). Univariate regression analysis showed that higher KPS both at diagnosis and recurrence correlated with improved survival, whereas increasing histology grade of initial and recurrent disease and volume of recurrence were correlated with worse OS. Multivariate regression analysis showed primary tumor location to be a significant predictor of OS (P\u202f=\u202f0.004) with occipital lobe lesions (P < 0.001) and in-field recurrence (P < 0.001) to be most favorably correlated with OS.\n\n\nCONCLUSION\nTMZ rechallenge in patients with recurrent HGG treated with re-irradiation offered no survival benefit. Our findings suggest that patient selection may be important in TMZ rechallenge. Further studies in identifying this group of patients are warranted.\n\n\nAUTHOR DISCLOSURE\nM.M. Basree: None. A. Ali: None. S. Garg: None. J. Glass: None. L. Kim: None. C. Farrell: None. J. Evans: None. K. Judy: None. D.W. Andrews: None. W. Shi: Independent Contractor; Wenyin Shi. Research Grant; Novocure, Brainlab, Regeneron. Consultant; Varian, Brainlab, Zai lab. M. Werner-Wasik: Advisory Board; ASTRA Zeneca. Stock; Illumina. leading operations of the committee; NRG Oncology. J.D. Palmer: Research Grant; Varian Medical Systems, The Kroger Company. Consultant; Huron Consulting. Speaker s Bureau; Varian Medical Systems, Depuy Synthes. Advisory Board; Novocure. Member of panel; NCCN.