Prostate Cancer Central Nervous System Metastasis in a Contemporary Cohort

Introduction: Central nervous system (CNS) metastasis from prostate cancer (PCA) is a rare event, but one with significant prognostic impact for those affected. There are limited data on its impact in contemporary cohorts treated with modern agents.

Patients and methods: A retrospective institutional review was performed to characterize the occurrence/outcome of PCA CNS metastasis on all cases of PCA from 2011 to 2017. A manual chart review was performed to confirm PCA CNS metastases in all cases identified through a diagnostic code screening of the health data.

Results: A total of 6596 cases of PCA were identified, with 29 (20 dural and 9 intraparenchymal) confirmed cases of CNS metastases from PCA. The median survival from the time of diagnosis of CNS metastasis was 2.6 months (95% confidence interval, 2.04-10.78 months) and 5.41 months (95% confidence interval, 3.03 months to not reached) for dural and parenchymal metastases, respectively. Among those who developed CNS metastases, approximately 79% of patients had prior exposure to abiraterone and/or enzalutamide, of whom 50% had ≥ 6 months of exposure. Four (0.07%) of the 5841 patients developed CNS metastases prior to the initiation of therapy or on androgen deprivation therapy alone. In contrast, 24 (8.6%) of the 279 patients with 2 or more lines of medical therapy developed CNS metastases.

Conclusions: Our analysis highlights the continued poor prognosis of parenchymal and dural CNS metastases from PCA. CNS metastases in PCA remain a rare event with a 0.4% incidence in this series, but this incidence is considerably increased in patients who receive medical therapy beyond first-line androgen deprivation therapy.