Radiographic Progression With and Without Prostate-Specific Antigen Rise in Patients With Advanced Prostate Cancer Treated With Enzalutamide
An important post-hoc analysis from ARCHES and PROSPER that quantifies something we've suspected clinically, roughly 1 in 4 enzalutamide-treated patients who progress radiographically have no prostate-specific antigen (PSA) rise, and the majority won't meet PCWG2/3 PSA progression criteria. Liver metastases were 5-fold more common at radiographic progression on enzalutamide versus control, suggesting lineage plasticity and AR-independent clones are the culprit. Bottom line for practice: don't wait for PSA to rise before imaging your metastatic hormone-sensitive prostate cancer (mHSPC) and nonmetastatic castration-resistant prostate cancer (nmCRPC) patients on ARPIs, periodic cross-sectional imaging, especially in the first two years, is warranted regardless of PSA trend.