Discussion
–10, tumor, prostatic tumors, prostate cancer
TUMOR, PROSTATE CANCER, MICROSATELLITE INSTABILITY
Our group and others have previously shown that immune checkpoint inhibitors are effective in specific prostatic tumors with microsatellite instability and high tumor mutational burden but their effect in the biology of prostate cancer is not entirely known.PSA kinetics of enrolled patients. The accelerated PSA progression after C1D1 compared with prior to C1D1 is represented by linear trend lines. PSA ratio was calculated by PSA at timepoint divided by PSA at day 0 (range, days –10 to 0).In both COU-AA-302 (abiraterone acetate) and PREVAIL (enzalutamide) which enrolled mainly Caucasian patients, the time interval between PSA progression and radiographic progression was approximately 5.3 and 5.1 months, respectively.As we expand clinical trial access and accrual to Black men, these results suggest that the interval between PSA and radiographic progression in Black men is likely to be short and thus more frequent radiographic monitoring might be necessary. Of note, this study was designed in the pre-PET scan era. Ongoing studies with PET imaging using fluciclovine or PSMA tracers (eg, NCT04158245) may offer an opportunity to improve response monitoring allowing for more effective and timely treatment decisions.