RMTD-02 Practice Variation and Impact of Pre-Operative and Post-Operative Dexamethasone on Patient Outcome in the Resected Brain Metastasis – Insights From the Clindexmet Multicenter Registry

BACKGROUND Patients with brain metastases that undergo brain metastasis resection regularly receive perioperative dexamethasone. We sought to evaluate variation in pre- and post-operative dexamethasone dosing and whether perioperative dexamethasone in brain metastases is linked to patient outcome. METHODS This was a multicenter retrospective study collecting data on daily pre- and post-operative dexamethasone dosage over a period of 27 days in patients undergoing brain metastasis resection. Non arbitrary cutpoint selection was performed using maximally selected rank statistics to dichotomize patients. Propensity score matching served to reduce bias and adjust for potential confounders including tumor and edema volume, localization of the dominant brain metastasis, disease-specifc GPA score, presence of other non-oncological diseases. RESULTS 988 patients were included. Median follow-up time was 55,2 months [95% CI: 50.7 – 61.5]. After propensity score matching patients below the determined cutpoint of 122 mg cumulative dexamethasone showed an overall survival of 16.0 months [95% CI: 13.3 – 21] vs. patients with more than 122 mg cumulative dexamethasone with a OS of 10.6 months [9.0 – 12.7], p=0.0022. No effect on extracranial or intracranial disease progression was observed. In a multivariable model for the matched data the cumulative peri-operative dexamethasone above the cutpoint remained independently associated with overall survival (HR: 1.3 [95% CI: 1.12 – 1.6], p=0.001). CONCLUSION Cumulative perioperative dexamethasone is associated with decreased survival in the context of brain metastasis resection. Strict dosage, down taper or methods reducing corticosteroid dependency should be regularly evaluated in clinical practice in patients with brain metastases.