P14.36 Treatment patterns by O6-methylguanine DNA methyltransferase promoter (MGMT) status in newly-diagnosed glioblastoma multiforme (GBM): a multi-country chart review study

Abstract

Abstract INTRODUCTION This study explored the relationship between MGMT testing and treatment patterns of patients with newly-diagnosed GBM from France, Germany, Italy, Spain, the UK (EU5), and Canada. MATERIALS AND METHODS Medical oncologists and neuro-oncologists across EU5 and Canada completed a point in time, cross-sectional survey for the next eight GBM patients seen between May and July 2016 (GBM Disease-specific ProgrammeTM). Statistically significant differences (p<0.05) between groups are presented. RESULTS A total of 241 physicians reported on 1,747 GBM patients. 1L patients had mean age 59.7 years (SD=12.3) and 36% were female. Of 1,113 (64%) patients who had an MGMT test performed with results recorded (tested), 58% (n=651) were methylated and 42% (n=462) were unmethylated. The remaining 634 patients (36%) were MGMT untested or awaiting MGMT results at time of survey (untested). Overall, 63% of patients received surgery prior to their 1L drug therapy, 78% received radiotherapy (RT; mean 4.3 sessions) in conjunction with 1L drug therapy, 90% received corticosteroids during RT, and 89% received temozolomide (TMZ). Patients who received corticosteroids during RT received similar drug treatments to those that did not, but were less likely to receive surgery prior to 1L treatment (65% vs 83%). MGMT-tested patients were more likely to receive surgery (66% vs 57%) and RT (81% vs 71%) than untested patients. Tested patients were also more likely to receive TMZ (92% vs 83%), and less likely to receive procarbazine+/lomustine+/vincristine (PCV; 3% vs 7%) or other chemotherapies (5% vs 11%). For 1L patients that experienced side effects, the most common effects included fatigue (74%), nausea (60%), and appetite loss (59%). Untested patients were more likely to stop their 1L drug treatment due to progression/recurrence of GBM (44% vs 36%). Patients who received surgery prior to 1L treatment were more likely to receive TMZ than those who did not (93% vs 82%). Among MGMT tested patients at 1L, methylated patients were more likely to receive RT (84% vs 78%) and TMZ (95% vs 89%) than unmethylated patients, and less likely to receive PCV (2% vs 5%) or other chemotherapy (4% vs 7%). Methylated patients with reported treatment-related side effects were less likely to experience dehydration (0% vs 10%), loss of strength/unusual weakness (5% vs 25%), memory problems (16% vs 35%), and nausea (51% vs 75%). CONCLUSIONS More than one-third of GBM patients in EU5 and Canada are not tested for MGMT-methylation. Untested patients are less likely to receive standard treatments than tested patients. Generally, TMZ is used in most patients regardless of MGMT testing and status. MGMT-methylated patients are more likely to receive standard treatments and experience fewer side effects than MGMT-unmethylated patients.