bpMRI and Risk Based Shared Clinical Decision Making in Prostate Cancer Diagnosis

Although most of the prostate cancers (PCas) are currently being diagnosed at early stage, at present, 30% of men are diagnosed with primarily metastatic disease. The need for better diagnostic methods is, therefore, warranted. Recent studies have shown that an alternative pathway using multiparametric (mpMRI) or biparametric (bpMRI) magnetic resonance imaging as a triage test reduces unnecessary biopsies, decreases the detection of clinically non-significant PCa (non-SPCa), and improves the detection of clinically significant PCa (CSPCa). In addition, based on these trials, also EAU guideline was updated to recommend that all men should undergo pre-biopsy mpMRI. However, shortcoming of the approach is the recommendation to biopsy all men post-MRI even if there is no lesion seen in MRI, ie. risk of PCa is very low. Therefore, the primary objective of this randomised controlled trial is to compare if there is a difference between significant cancer detection rate in men undergoing prostate biopsies after MRI scan compared to men undergoing post-MRI prostate biopsies only after a shared decision-making based on prostate cancer risk estimation. The trial will enrol 600 patients from four hospital districts: Varsinais-Suomi, Satakunta, Pirkanmaa and Keski-Suomi. Key inclusion criteria are suspicion of prostate cancer based on elevated PSA and/or abnormal digital rectal examination. Men with previous PCa diagnosis and contraindications for MRI are excluded. The primary outcome measure is the comparison of the proportion of men with CSPCa (Gleason 4+3 prostate cancer or higher) between the control and intervention arms at baseline. Using PSA as strata, eligible men are randomised 1:1 in two groups. After randomisation MRI examination is performed and interpreted by one experienced uro-radiologist using Likert and PI-RADS2.1 classifications. In control arm in all men prostate biopsies are performed after MRI whereas in intervention arm prostate biopsies are performed only after a shared decision-making between urologist and the patient and the discussion is based on risk estimation. Men with negative biopsies or with no biopsies performed are all assigned for five-year follow-up with semi-annual PSA. Long-term follow-up based on health records and national registries is performed for additional 15 years for all patients.