ABSTRACT
OBJECTIVE: To analyse the characteristics of prostate cancers (PrCa) detected following negative multiparametric magnetic resonance imaging (mpMRI). MATERIALS AND METHODS: Eight hundred and thirty patients with elevated prostate-specific antigen (mean 11.9 µg/l) underwent mpMRI of the prostate at 1.5 Tesla with endorectal coil. The characteristics of all PrCa detected within 2 years after a negative mpMRI were analysed. Primary Gleason grade 4 or any grade 5 PrCa were considered high-grade (HG), Gleason score 3 + 4 intermediate grade (IG) and Gleason score ≤3 + 3 low-grade (LG). Tumour size was considered 'small' when <1 cm on radical prostatectomy specimen or limited to ≤2 cores on prostate biopsy. RESULTS: mpMRI was negative in 391 patients (47.1 %). In 124 patients (31.7 %) PrCa was detected within 2 years. Eighty-four (67.7 %) were LG, 22 (17.7 %) IG and 18 (14.5 %) HG. 119 (96.0 %) of the missed PrCa were organ-confined. The negative predictive value was 95.4 % (373/391) for HG PrCa. Among the 18 missed HG PrCa, 15 (83.3 %) were organ-confined and 12 (66.6 %) were small. CONCLUSION: The majority of missed tumours on mpMRI were low grade and organ-confined. In patients with elevated PSA and a negative mpMRI, consideration could be given to continued surveillance rather than immediate biopsy. KEY POINTS: ⢠The majority of missed prostate cancers were low grade and organ-confined. ⢠In patients with a negative mpMRI a biopsy may be postponed. ⢠mpMRI had a negative predictive value of 95.4 % for high-grade prostate cancer.