Risk stratification in men with a negative prostate biopsy: an interim analysis of a prospective cohort study.

Abstract

To investigate whether a risk score for prostate cancer (PCa) lifetime risk can be used to optimise triaging of patients with a negative prostate biopsy, but under sustained suspicion of PCa. In this prospective clinical study, we included, and risk scored patients who had a PCa-negative transrectal ultrasonography (TRUS)-guided prostate biopsy, but elevated prostate-specific antigen (PSA), a suspicious prostate digital rectal examination and/or a positive family history (FH) of PCa. The risk score estimated individual lifetime risk of PCa, based on a polygenic risk score (33 single nucleotide polymorphisms), age, and FH of PCa. Patients were followed, under urological supervision, for up to 4years with annual controls, always including PSA measurements. Multiparametric magnetic resonance imaging (mpMRI) and/or prostate biopsy was performed at selected annual controls depending on risk score and at the urologist's/patient's discretion, which means that the follow-up differed based on the risk score. We included 429 patients. After risk scoring, 376/429 (88%) patients were allocated to a normal-risk group (<30% PCa lifetime risk) and 53/429 (12%) to a high-risk group (≥30% PCa lifetime risk). The high-risk group had significantly different follow-up, with more biopsy and mpMRI sessions compared to the normal-risk group. PCa was detected in 89/429 (21%) patients, with 67/376 (18%) patients diagnosed in the normal-risk group and 22/53 (42%) in the high-risk group. There was no statistically significant difference in the cumulative incidence of PCa between the normal-risk group and the high-risk group after 4years of follow-up. Currently, 67/429 (16%) patients are still being followed in this ongoing study. In a 4-year perspective, our PCa lifetime risk score did not demonstrate significant prognostic value for triaging patients, with a negative TRUS-guided biopsy and sustained suspicion of PCa.