In Metastatic Prostate Cancer, Radiographic PFS Associated with Survival

the Cancer Therapy Advisor take:

According to a new study published by the Journal of Clinical Oncology, researchers have found that radiographic progression-free survival (rPFS) was highly consistent and associated with overall survival in a randomized trial of abiraterone in patients with metastatic castration-resistant prostate cancer (mCRPC). 

Because progression-free survival in mCRPC studies has been inconsistently defined and poorly associated with overall survival, researchers sought to study a reproducible quantitative definition of rPFS to test for an association with overall survival.

Researchers defined rPFS as "≥ two new lesions on an 8-week bone scan plus two additional lesions on a confirmatory scan, ≥ two new confirmed lesions on any scan ≥ 12 weeks after random assignment, and/or progression in nodes or viscera on cross-sectional imaging, or death."

Results showed hazard ratios of 0.49 (95% CI: 0.41 - 0.60; P <0.001) and 0.53 (95% CI: 0.45 - 0.62; P < 0.001). The Spearman's correlation coefficient between rPFS and overall survival was 0.72.

The findings suggest that rPFS should be further developed as an intermediate endpoint in trials studying patients with mCRPC.