RPCRC Validation Study

External Validation of the Rotterdam Prostate Cancer Risk Calculator

Prostate multiparametric MRI (mpMRI) can detect ISUP ≥2 prostate cancer with high sensitivity. Adding biopsies targeting suspicious lesions seen on mpMRI to the classical 'systematic biopsies' (that sample the gland in a blinded way) improves the detection of ISUP ≥2 cancers. As a result, it is now recommended to perform a prostate mpMRI before biopsy and to combine targeted and systematic biopsy.

However, mpMRI suffers from a lack of specificity. In a recent meta-analysis, the pooled sensitivity and specificity of prostate mpMRI for detecting ISUP ≥2 cancers were 0.91 (95% confidence interval, 0.83-0.95) and 0.37 (95% confidence interval, 0.29-0.46) respectively. Thus, accurate triage of patients suitable for biopsy might not be possible using mpMRI findings alone.

The Rotterdam Prostate Cancer Risk Calculator (RPCRC) combines mpMRI results (Prostate Imaging-Reporting And Database System score) and basic clinical and biochemical data to predict the results of prostate biopsy. If validated, this tool could help selecting patients for prostate biopsy.

In this study, the investigators propose to retrospectively use the data of the prospective multicentric MRI-FIRST trial (NCT0285379) to perform an external validation of the RPCRC.

In addition, the PCaRisk study has two secondary objectives:

• To confirm that Prostate Specific Antigen density (i.e. PSA level divided by prostate volume) can stratify the risk of ISUP ≥2 cancer in patients with negative (PI-RADS 1-2) or inconclusive (PI-RADS 3) mpMRI, as suggested by recent literature
• To perform a preliminary evaluation of a lobe-specific risk calculator developed by our group and combining mpMRI results and clinical and biochemical data to predict the risk of ISUP ≥2 cancer at the lobe level.

Inclusion Criteria:

• Patient referred for mpMRI and prostate biopsy due to increased PSA level, abnormal DRE or family history of prostate cancer.
• Age ≤75 years
• PSA level ≤20 ng/mL
• Clinical stage ≤T2c

Exclusion Criteria:

• Contraindication for prostate mpMRI or biopsy
• History of hip prosthesis, androgen deprivation therapy, pelvic radiotherapy or prostate cancer diagnosed after trans-urethral resection of the prostate.