Predictors of Unfavorable Disease after Radical Prostatectomy in Patients at Low Risk by D'Amico Criteria: Role of Multiparametric Magnetic Resonance Imaging

PurposeWe identified risk factors predicting unfavorable pathological outcomes after radical prostatectomy in patients with low risk prostate cancer. We also evaluated the role of magnetic resonance imaging.Materials and MethodsWe retrospectively reviewed the medical records of 1,262 patients who underwent 12-core biopsy, preoperative magnetic resonance imaging and radical prostatectomy at a single center between September 2007 and June 2012. A total of 382 men with low risk prostate cancer by the D'Amico criteria were included in study. Multivariate logistic regression analysis was used to identify factors predicting unfavorable pathological outcomes.ResultsMedian patient age was 65 years and median preoperative prostate specific antigen was 4.6 ng/ml. Gleason sum was upgraded in 212 patients (55.5%). In 249 patients (65.1%) prostate cancer was identified on 3 Tesla T2-weighted and diffusion-weighted magnetic resonance imaging without dynamic contrast imaging. The lesion was in the anterior and posterior of the prostate in 42.9% and 57.0% of cases, respectively. Unfavorable pathological results were found postoperatively in 29.6% of patients. Multivariate analysis revealed that older age (OR 1.072, p <0.001), number of positive cores (OR 1.373, p <0.001) and an anterior index tumor site on magnetic resonance imaging (OR 2.121, p = 0.017) were significant predictors of unfavorable final pathological results (pT3 or greater, or tumor upgrading to Gleason 3 + 4 plus tumor volume 15% or greater, or upgrading to Gleason 4 + 3 or greater).ConclusionsAn anterior site of cancer on magnetic resonance imaging was useful for predicting Gleason sum upgrading or an unfavorable pathological outcome after radical prostatectomy in patients with low risk prostate cancer.