Introduction: While an elevated PSA significantly increases the risk of men harboring prostate cancer, many men with a persistently elevated PSA have negative prostate biopsies. More recently, multiparametric MRI (mpMRI) has had promising implications for the diagnosis of prostate cancer. We aim to investigate the diagnostic role of mpMRI in predicting the future diagnosis of prostate cancer in patients with an initial negative biopsy.
Methods: This study included all men with negative biopsies, elevated PSA and mpMRI. All patients had their age, PSA, and PSAd recorded. mpMRI lesions were classified using the PI-RADS 2 scoring system.
Results: mpMRI imaging was performed in 336 men with an initial negative biopsy, of whom 108, 111, 76 and 41 men underwent single, two, three and four biopsies, respectively. Of the 228 men with more than one biopsy, 115 patients were diagnosed with prostate cancer on further biopsies. Older patients and men with higher PSA, PSAd and PIRADS score had a significant risk to progress to cancer but only higher PSAd and higher PI-RADS score were significantly associated with clinically significant cancers. For clinically significant cancer; sensitivity and specificity of PI-RADS scoring was 86 and 45%, respectively, and a NPV of 87.6%. When combined with PSAd, NPV was 93%.
Conclusion: Men with benign prostatic biopsy and both PSAd < 0.15 and low PI-RADS score may avoid second biopsy. PI-RADS scoring system has a high sensitivity to diagnose clinically significant prostate cancer and repeat biopsy should be recommended in men with benign biopsy and high score.
Keywords: Multiparametric MRI; Negative biopsy; PI-RADS; PSA density; Prostate cancer.