MRI Screening for Spinal Cord Compression in Metastatic Castration-Resistant Prostate Cancer

Spinal cord compression (SCC) remains a true oncologic emergency, as loss of neurologic function has devastating effects on a patient's quality of life. Given the bone tropism of metastatic prostate cancer, it is not surprising that studies report an SCC incidence ranging from 7% to 24%. To explore the utility of early intervention based on spinal magnetic resonance imaging (MRI) findings, investigators in the U.K. conducted an open-label, randomized, controlled, phase 3 study.

Patients with progressive metastatic castration-resistant prostate cancer (mCRPC) with bone metastases, asymptomatic spinal metastases, or both, and with ECOG performance status of 0-2 were randomized to either no MRI or whole-spine screening MRI within one month. Radiologists used a 7-point epidural SCC (ESCC) scoring system and deemed patients as having radiographic SCC (rSCC) if they were asymptomatic with evidence of epidural disease and as having clinical SCC (cSCC) if they were symptomatic. Patients with rSCC were offered preemptive treatment with radiotherapy or surgery per standard of care guidelines. All patients were followed up every 3 months for the first 2 years and then at 30 and 36 months or as clinically indicated. The primary outcome measure was the incidence of and time to development of clinically confirmed SCC.

Of 420 men randomized over a 4-year period, median age was 74 and median prostate-specific antigen concentration was 48 ng/mL. Screening MRI identified rSCC in 31% of patients in the screening group. At a median follow up of 22 months, time to cSCC was not significantly improved in the screening group (hazard ratio, 0.64; P=0.12). At 1 year, incidence of cSCC was 4.3% in the screening group and 6.7% in controls. Median time to cSCC was not reached in either group.