The role of neurosurgery for brain metastases between 2012 and 2022: Results of the multicenter SUBAROMA study

Background
We analyzed the role of neurosurgery combined with postoperative treatment according to current guidelines in a real-world cohort of patients with brain metastasis (BM) over an 11-year period to (re-)evaluate predictors of local intracranial recurrence (LR) and overall survival (OS).

Methods
We conducted the SUBARoMA study (Surgery for brain metastases: a retrospective multicenter analysis) including patients undergoing surgery as initial treatment for their BM. Significant factors impacting LR and OS were analyzed by univariate (Kaplan-Meier) and multivariate (Cox regression) methods.

Results
We included 2,751 patients. Resection significantly improved patients' postoperative Karnofsky Performance Score (KPS, p < 0.001). Gross-total resection (rate 73%) increased by fluorescence guidance but excerted no effect on morbidity (rate 20.4%) (p < 0.001, respectively). The risk of LR was 23.5% at one and 40.4% at four years. Postoperative systemic- (p = 0.019), and radiotherapy (p < 0.001) had an independent impact on LR. Mean/median OS was 15.0/7.5 months. The strongest independent predictors of OS were age, number of BM, active extracranial tumor, as well as improvement of postoperative KPS, radiation-, and systemic therapy including targeted and/or immunotherapy (p < 0.001, respectively) . Over the 11-year period, application of whole-brain radiotherapy decreased in favor of focal radiation, and administration of systemic treatment, particularly targeted and/or immunotherapies, increased. By combining surgery, postoperative radiation, and systemic therapy 5-year survival rates of > 30% were achieved.

Conclusion
The SUBARoMA study confirms the crucial role of neurosurgery for patients with BM by improving their KPS to enable guideline-conform postoperative treatment and underscores meticulous patient selection for surgical management of BM.