Single Institutional Clinical And Genetic Analysis Of Metastatic Prostate Cancer With And Without Brain Metastases

Abstract BACKGROUND Brain metastases (BMs) from metastatic prostate cancer (mPCa) are rare so little is known about clinical, genetic, and anatomic risk factors (RFs) for developing BMs. This single-center review of mPCa patients evaluates RFs for BM development. METHODS We reviewed records of mPCa patients at Tulane from 1991 – 2020 to evaluate disease, treatment, cell free DNA, and germline mutations between men with mPCa without confirmed BMs (smPCa) and men with mPCa and confirmed BMs (mPCaBMs). RESULTS We reviewed 580 patients with mPCa, of whom 11 had BMs (1.9%). Median age of stage 4 disease was 60.9 and 67.6 for men with mPCaBMs and smPCa respectively. Most mPCaBMs patients had Gleason 8 disease (81.8%) and higher median initial PSA (32 ng/mL) compared to 52.5% and 22.5 ng/mL for patients with smPCa. The development of castrate resistant disease (p=0.30) and overall survival (p=0.53) did not differ between the two populations. There were no differences in frequency of pathogenic mutations for the 68.9% (mPCaBMs) and 72.7% (smPCa) of patients with available genetic testing. Among the 11 mPCaBMs patients, 81.8% had supratentorial and 45.5% had infratentorial involvement (36.4% both). Forty-five percent had adjacent bony metastasis. Median time from SMs to BMs was 65 months (5.28 – 163.63 months), and median survival after diagnosis of BMs was 6.23 (0.49 – 70.82) months after treatment with WBRT, SRS, or GK. CONCLUSIONS The higher incidence of BMs likely reflects Tulane’s aggressive mPCa population. Interestingly 45% of BMs occurred from direct bony extension. Although 45% had infratentorial disease reflecting posterior fossa predilection, 82% of patients with BMs had supratentorial metastases. Our data suggest that men with mPCaBMs have aggressive disease and younger age at diagnosis. Due to sample size, no clinical or genetic statistically significant RFs for BMs were identified.