How do you manage surveillance imaging for patients with metastatic castration-naive prostate cancer with an initial low PSA?

Low PSA progression is common at the time of radiographic progression in the mHSPC setting, particularly among men treated with potent AR inhibitors. As we recently presented in the ARCHES phase 3 study, while enzalutamide significantly improves rPFS and OS and reduces progression events, among those who experience radiographic progression, 34 and 67% of men treated with enza/ADT did NOT experience any PSA rise or PCWG2-3 defined PSA progression (nadir + 25% and at least a 2 point rise), respectively. Among men treated with ADT alone, 15 and 42% of men who experienced radiographic progression did not have a PSA rise or meet PCWG2-3 PSA progression criteria respectively.

Thus, regular imaging is indicated in men with mHSPC irrespective of P...

I fully agree with Dr. @Dr. First Last's comment that PSA alone is not a reliable indicator of progression in mHSPC. As was seen in the ARCHES trial, patients on CHAARTED trial also showed similar progression patterns. A follow-up analysis of CHAARTED patients (Bryce et al., PMID 32807727) showed >10% of patients had clinical progression below a PSA level of 2 ng/mL, and approximately 25% developed clinical progression (symptomatic or radiologic) in the absence of confirmed PSA progression. This was seen in patients with both high- and low-volume disease, and in those treated with ADT alone as well as ADT and docetaxel. The analysis in that study also revealed clinical progressions prior to PSA progression were associated with poor overall ...