Would Exposure to Metformin Reduce Mortality in Patients With Glioblastioma?

Speaker(s)

Shah R1, Moeller P2, Keith SW3, Alnahhas I4, Hass R2, Shi W5, Maio V2
1Jefferson College of Population Health at Thomas Jefferson University, Piscataway , NJ, USA, 2Jefferson College of Population Health at Thomas Jefferson University, Philadelphia, PA, USA, 3Sidney Kimmel Medical College at Thomas Jefferson University, Philadelphia, PA, USA, 4Division of Neuro-oncology, Department of Neurology,Thomas Jefferson University, Philadelphia, PA, USA, 5Department of Radiation Oncology, Thomas Jefferson University Hospital, Philadelphia, PA, USA

Presentation Documents

OBJECTIVES: Despite aggressive treatments, such as surgery combined with radiation and chemotherapy, median survival among glioblastoma (GBM) tumor patients remains poor, between 12 to 15 months. This study will investigate exposure to metformin and 1-year mortality in patients with GBM.

METHODS: A retrospective cohort study is ongoing, utilizing the Surveillance, Epidemiology, and End Results (SEER) national cancer registry database linked with Medicare data to identify patients 66 years and older with GBM diagnosis between 1/1/2007 and 12/31/2019. Patients were excluded if previously or subsequently diagnosed with other primary malignancies or diagnosed with GBM on autopsy or by death certificate. Mortality was captured within 1 year after GBM diagnosis. Patients were identified as exposed to metformin if they have filled at least 1 prescription of metformin between 3 months prior to and 9 months after GBM diagnosis. Descriptive statistics were computed for all variables of interest.

RESULTS: Approximately 19,500 GBM patients were identified; 47.4% were female and the mean age was 74.8±6.6 years. Of these, 1,409 (7.2%) were exposed to metformin. No major differences in patients’ age, sex, and race distributions were observed between those exposed and not exposed to metformin. 81.3% of patients exposed to metformin were coded as diabetic prior to GBM diagnosis, compared to 24.6% of patients not exposed. Patients exposed to metformin experienced higher rates of surgery and chemotherapy than those not exposed (55.1% vs 49.0% and 49.0% vs 42.9%, respectively). Exposed patients had a higher mean Charlson comorbidity index score versus not exposed (2.9 vs 2.0). Among those exposed to metformin, 69.3% died within 1 year of GBM diagnosis compared with 73.3% among those not exposed.

CONCLUSIONS: Our preliminary study results suggest that exposure to metformin may reduce mortality in GBM patients. Statistical models are under development to evaluate this association rigorously in these data.

Code

EPH48

Topic

Clinical Outcomes, Epidemiology & Public Health, Study Approaches

Topic Subcategory

Clinical Outcomes Assessment, Safety & Pharmacoepidemiology

Disease

Oncology, Rare & Orphan Diseases