The trial data presented in Chicago, Illinois, this year at the 2016 meeting of the American Society of Clinical Oncology (ASCO) are going to change daily clinical practice for the treatment of patients with gliomas. The first of 3 practice-changing reports was from the European Organisation for Research and Treatment of Cancer (EORTC) randomized phase III CATNON (Trial 26054)1 for adult patients with newly diagnosed anaplastic gliomas without codeletion of 1p/19q in the tumor tissue. This trial investigated the effects of adjuvant or maintenance therapy (12 cycles) and/or concurrent chemotherapy with temozolomide in addition to or after the standard radiotherapy of the involved part of the brain. In a short period of less than 8 years, 748 patients with this very rare disease were randomized through August 2015. An interim analysis based on 221 events with a median follow-up of 27 months revealed a hazard ratio (HR) reduction for overall survival (OS) of 0.645 (95% CI, 0.450-0.926; P = .001) with the use of adjuvant temozolomide. For progression-free survival (PFS), the risk-adjusted HR of adjuvant temozolomide was 0.586 (95% CI, 0.472-0.727; P < .001). The OS at 5 years in the arms without adjuvant temozolomide was 44.1% and 55.9% in the arms with adjuvant temozolomide. Median PFS increased from 19.0 months to 42.8 months with adjuvant temozolomide.1