Factors associated with survival and recurrence for patients undergoing surgery of cerebellar metastases

Objective: Patients with cerebellar and non-cerebellar metastases are often included in the same study population, even though posterior fossa lesions typically have different presenting symptoms, clinical outcomes, and complications. This is because the outcomes for patients with cerebellar metastases are unclear. Methods: Adult patients who underwent surgery for an intracranial metastasis (single or multiple) between 2007 and 2011 were retrospectively reviewed. Stepwise multivariate proportional hazards regression analysis was used to identify an association between cerebellar location with survival and recurrence. Results: Of the 708 patients who underwent intracranial metastatic surgery, 140 (19.8%) had surgery for cerebellar metastasis. A cerebellar location was associated with poorer survival [RR (95% CI); 1.231 (1.016-1.523), P = 0.04] and increased spinal recurrence [RR (95% CI); 2.895 (1.491-5.409), P = 0.002], but not local (P = 0.61) or distal recurrence (P = 0.88). The factors independently associated with prolonged survival for patients with cerebellar metastases were: decreasing number of intracranial metastases (P = 0.0002), decreasing tumor size (P = 0.002), and radiation (P = 0.0006). The factors associated with prolonged local progression free survival were: decreasing tumor size (P = 0.0009), non small cell lung cancer (NSCLC) (P = 0.006), non-bladder cancer (P = 0.0005), and post-operative radiation therapy (P = 0.02). The factors independently associated with prolonged distal progression free survival were: age. 40 years (P = 0.02), surgical resection (P = 0.01), and whole brain radiation (WBRT) therapy (P = 0.02). Discussion: Patients with cerebellar metastases have more distinct clinical presentations and outcomes than patients with non-cerebellar lesions. The findings of this study may help risk stratify and guide treatment regimens aimed at maximizing outcomes for patients with cerebellar metastases.