TRLS-15 LONG-TERM ASPIRIN USE REDUCES RISK OF BRAIN METASTASIS FROM LUNG CANCER

Abstract INTRODUCTION Aspirin treatment has been linked to lower rates of cancer metastasis including to the central nervous system (CNS). Preclinical studies have implicated the role of Aspirin and Cox-1 inhibition to increased T-cell release and reduced blood brain barrier permeability, reducing the spread to and growth in the CNS. Despite these results, the effect of long-term Aspirin use on the development of brain metastasis in lung cancer patients has yet to be assessed. METHODS Using the TriNetX patient database, we retrospectively identified 499,699 patients with lung cancer, 59,787 of which have used Aspirin long-term for an associated comorbidity before and after their cancer diagnosis. We propensity score matched based on patient demographics (e.g. age, sex, race, etc.), lung cancer histology, Tumor-Nodule-Metastasis (TNM) staging, and comorbidities associated with either increased or decreased Aspirin use (e.g. cerebral infarction, ischemic heart disease, etc.), yielding a matched comparison of 55,587 patients in each cohort. Cohort 1 featured 51,342 patients with lung cancer and long-term Aspirin use while Cohort 2 featured 52,710 patients with lung cancer without long-term Aspirin use. 4,245 patients and 2,877 patients were excluded from Cohort 1 and Cohort 2 respectively because they were diagnosed with brain metastases prior to Aspirin use. RESULTS Patients with lung cancer have a reduced risk of developing brain metastasis with long term Aspirin use at 20-year follow up (HR: 0.944, CI: 0.895 to 0.999, p=0.031). Additionally, long term Aspirin use in lung cancer patients does not increase risk of intracranial bleed (HR: 1.118, CI: 0.958 to 1.303, p=0.372) or affect all cause mortality (HR: 1.035, CI: 0.880 to 1.303, p=0.761). CONCLUSION Long-term Aspirin use may represent a safe and accessible intervention to reduce the risk of brain metastasis in lung cancer patients. Further prospective studies are needed to confirm this association.