SURG-13. Multiplicity does not affect outcomes in patients with surgically treated brain metastases

BACKGROUND: Having multiple brain lesions has been considered a negative prognostic factor in patients with brain metastases. The role of surgery in the management of these patients remains a matter of debate. METHODS: We retrospectively reviewed our patients who underwent surgical resection of brain metastases from January 2018 to December 2019, and examined outcomes including overall survival (OS), progression free survival (PFS) and rates of local failure. RESULTS: We identified 130 patients who underwent surgical resection as the primary treatment modality of brain metastases. At the time of surgery, 117 patients harbored 1–3 lesions, 13 had more than 3 lesions. Overall survival at two years for our entire cohort was 46%. The difference in OS between patients with > 3 metastases (21%) and 1–3 metastases (49%) was not statistically significant (HR=1.34, 95% CI: 0.67–2.68, p=0.41). Similarly, 27% of patients had PFS at two years, with 25% in the multiple metastases group and 28% in the comparison group (HR=1.19, 95% CI: 0.63–2.23, p=0.59). Additionally, 32% of patients overall experienced local failure at two years and there was no significant difference between patients with >3 metastases (15%) and those with fewer (33%) (HR=0.68, 95% CI: 0.21–2.19, p=0.52). A multivariate regression model examining multiple preoperative features revealed large tumor volume to be the only independent predictor of limited OS (p = 0.017) and PFS (p = 0.023), and local failure (p = 0.031). CONCLUSIONS: In carefully selected patients, surgical resection is a reasonable management option for patients with multiple brain metastases.