Risk Calculator Reduces Biopsies and MRI Scans During the Diagnosis of Prostate Cancer

A recent study shows that the use of the Rotterdam Prostate Cancer Risk Calculator (RPCRC) is effective at risk stratifying the diagnostic pathway of prostate cancer (PCa), though recalibration and adaptation of the risk threshold is necessary to yield optimal results. The findings appeared in European Urology Open Science.

To effectively diagnose PCa, pathological confirmation is required, and is strongly recommended in men at high risk for clinically significant PCa (csPCa). The RPCRC quantifies the probability of detecting both PCa and csPCA at the time of biopsy by analyzing several clinical parameters, such as prostate-specific antigen (PSA), presence of abnormal digital examination (DRE), prostate volume, and any specific lesions.

The investigators of this study sought to retrospectively assess the ability of upfront risk stratification using the RPCRC and the RPCRC-MRI to reduce systematic prostate biopsies, MRI scans, and targeted prostate biopsies for biopsy-naïve men. They analyzed the following arms: a transrectal ultrasonography arm, comprising 188 men; an MRI arm, comprising 206 men (to assess any the reduction of MRI scans); and a targeted biopsy arm of 137 men (to assess reduction of targeted biopsies). The team evaluated performance via discrimination, calibration, and clinical utility.

According to the researchers, the performance of the RPCRC was good. However, they noted, “intercept adjustment was warranted.” After recalibrating, they observed a net benefit of 32% for any PCa and 10% for csPCa. After recalibration and applying a threshold of 20% for any PCa or 10% for csPCa, 28% of all biopsies could have been reduced, missing five cases of csPCa, the investigators further noted. They found that the uncalibrated RPCRC could reduce 35% of all MRI scans, with a threshold of 20% for any PCa or 4% for csPCa. In the MRI arm, the researchers deemed performance as “good” without stressing recalibration.

In conclusion, the researchers wrote, “we investigated whether we could reduce the numbers of systematic prostate biopsy procedures, MRI scans, and targeted prostate biopsies in a contemporary clinical cohort. We found that, with good performance of the RPCRC and RPCRC-MRI, recalibration and an increase in the threshold of the RPCRC were necessary to reach optimal performance.”