Aminsharifi et al present their study on the predictive accuracy of PSAD for prostate cancer grade group 2 or greater. The study cohort consisted of 2,162 men with PSA in the diagnostic gray zone of 4 to 10 ng/ml, of whom 1,210 (56%) were African American. Interestingly the predictive accuracy of PSAD was independent of race and BMI. Stratification using a PSAD cutoff of 0.08 ng/ml/cc could have avoided 273 of 2,162 biopsies (13%), missing 48 of 622 grade group 1 cancers (8%) and 10 of 499 grade group 2 or greater cancers (2%).
This study confirms what we have known for a while. PSAD is the strongest predictor of prostate cancer and it can be used to avoid unnecessary biopsies. The strength of PSAD is confirmed in the latest prediction models, including omics. Recently it was shown that prostate volume was the strongest predictor in the Stockholm-3 model, including PSA and its subforms (reference 1 in article). Nevertheless, parameters such as DRE, previous biopsy status, patient age and family history add to the predictive accuracy of all PSAD based models like the PCPT 2.0 (reference 12 in article) and ERSPC (reference 16 in article) risk calculators.
In the current study it is important to realize the fact of calibration in the comparison between PSAD and the PCPT 2.0 risk calculator (reference 12 in article). The performance of PSAD was directly derived from the institutional cohort while risk calculators were developed in different study cohorts. Without doubt the performance of these risk calculators would be better after a simple calibration step. Therefore, we acknowledge the strength of PSAD to predict the biopsy outcome but think that ignoring other relevant information is not the way to go.