Is negative multiparametric magnetic resonance imaging really able to exclude significant prostate cancer? The real-life experience

Objectives: To evaluate the histopathological results after radical prostatectomy (RP) in patients that had normal preoperative multiparametric magnetic resonance imaging (mpMRI), in order to determine whether they had significant or insignificant disease. Moreover, we evaluated the influence of the expertise of the radiologist on the results.

Patients and methods: We retrospectively included patients who underwent RP in our centre and who had a preoperative negative mpMRI. The MRIs were considered negative when no suspicious lesion was seen or when the Prostate Imaging Reporting and Data System version 1 score was <7. We used Pathological tumour-node-metastasis staging and Gleason score on pathology reports, and whole-mount sections to calculate tumour volume.

Results: We identified 101 patients from 2009 to 2015. Final pathology showed that 16.9% had extraprostatic extension, 13.8% had primary Gleason pattern 4 (4 + 3 and above), 47.5% had secondary Gleason pattern 4 or 5, and 55.9% and 20.6% had a main tumour volume of ≥0.5 and ≥2 mL, respectively. When limiting the analysis to expert reading only, the numbers improved: only one patient (3.4%) had extraprostatic extension (P < 0.05), one patient (3.4%) had primary Gleason pattern 4 (P = 0.05), and 64.7% and 5.9% had a main tumour volume of ≥0.5 and ≥2 mL, respectively (P = 0.01).

Conclusion: A negative MRI does not guarantee the absence of significant prostate cancer.