A comparison of prostate cancer prediction models in men undergoing both magnetic resonance imaging and transperineal biopsy: Are the models still relevant?

Abstract

Objective: To externally validate and compare the performance of the European Randomized Study of Screening for Prostate Cancer risk calculator 3/4 (ERSPC-RC3/4), the Prostate Biopsy Collaborative Group risk calculator (PBCG-RC) and the van Leeuwen model to determine which prediction model would perform the best in a contemporary Australian cohort undergoing transperineal (TP) biopsy.

Materials and methods: A retrospective review identified all patients undergoing TP biopsy across two centres. Of the 797 patients identified, 373 had the data required to test all three risk calculators. The probability of high-grade prostate cancer, defined as International Society of Urological Pathology Grade Group >1, was calculated for each patient. For each prediction model discrimination was assessed using area under the receiver-operating characteristic curve (AUC), calibration using numerical and graphical summaries, and net benefit using decision curve analysis.

Results: Assessment of model discrimination for detecting high-grade prostate cancer showed AUCs of 0.79 (95% confidence interval [CI] 0.74-0.84) for the ERSPC-RC3/4, 0.81 (95% CI 0.77-0.86) for the van Leeuwen model, and 0.68 (95% CI 0.63-0.74) for the PBCG-RC, compared to 0.58 (95% CI 0.52-0.65) for prostate-specific antigen alone. The ERSPC-RC3/4 was the best calibrated in the moderate-risk range of 10-40%, whilst the van Leeuwen model was the best calibrated in the low-risk range of 0-10%. The van Leeuwen model demonstrated the greatest net benefit from 10% risk onwards, followed closely by the ERSPC-RC3/4 and then the PBCG-RC.

Conclusion: The ERPSC-RC3/4 demonstrated good performance and was comparable to the van Leeuwen model with regard to discrimination, calibration and net benefit for an Australian population undergoing TP prostate biopsy. It is one of the most accessible risk calculators with an easy-to-use online platform, therefore, we recommend that Australian urologists use the ERSPC-RC3/4 to predict risk in the clinical setting.

Keywords: biopsy; cancer; model; prediction; prostate; transperineal.