Clinico-pathological Outcomes of Men with Initial Likert 2 Multiparametric Magnetic Resonance Imaging of the Prostate: Findings from a Case Series in a Non-teaching Hospital in UK

Introduction: With the recent introduction of Multiparametric MRI (MP-MRI) for suspected prostate cancer, we investigated the clinic-pathological outcome of men who were suspected to have prostate cancer but in whom initial MP-MRI was negative (Likert 2).

Methods: Demographic and clinico-pathological outcomes data were analysed in men, with minimum 2 year follow up, who had undergone investigation for suspected prostate cancer with a negative (Likert 2) initial MP-MRI. The primary outcome was subsequent identification of prostate cancer in this cohort. Secondary outcome measures included correlation of prostate volume, presence of previous prostate biopsy, age, Prostate Specific Antigen (PSA) dynamics (pre and post MP-MRI scan), Digital Rectal Examination (DRE) findings and follow-up in months with the primary outcome.

Results: With respect to the primary outcome of this study, prostate cancer was identified in 8.7% of men only (n=4). Of these, two cases were low risk and two were high risk. With regards the secondary outcome measures, there was a positive correlation between PSA dynamics, age at MP-MRI and follow-up in months with subsequent diagnosis of prostate cancer, although this was not statistically significant. There was no prostate cancer specific mortality or morbidity in this cohort.

Conclusions: In this study, despite initial negative MP-MRI scan, prostate cancer was subsequently diagnosed in 4 men (8.7%). Reassuringly, this compares very favourably to the negative predictive value (89%) from the PROMIS trial and as such, adds an important body of work to the contemporary literature on modern diagnosis of suspected prostate cancer.