A recent study highlights a mismatch between PSA blood tests and PSMA-PET scans in tracking prostate cancer. While patients taking enzalutamide saw PSA levels drop dramatically—sometimes to 0 ng/mL—their PSMA scans often showed remaining tumor or even slight increases in tumor volume. This suggests that the two measures do not always align.
Experts warn that relying solely on PSMA scans to guide treatment decisions could be misleading. A persistent spot on imaging might appear concerning even when the patient’s PSA is undetectable and the disease is under control. The study underscores that changes in PSMA tumor volume do not always predict clinical response or the duration of PSA suppression.
The trial is ongoing and will eventually test whether combining enzalutamide with the immunocytokine PDS01ADC can further prolong PSA suppression. Meanwhile, researchers advise using PSMA imaging cautiously when evaluating treatment benefit.