Role of magnetic resonance imaging for preoperative prediction of early biochemical failure in localized prostate cancer.

ABSTRACT

Background: The purpose of our study was to assess preoperative clinical biological and Magnetic Resonance Imaging (MRI) predictive factors of early biochemical failure (BF), defined as persistence of significant post-operative plasmatic prostate specific antigen (PSA) level after radical prostatectomy (RP) in patients with localized prostate cancer (PCa). Methods: In a retrospective cohort study we included 142 patients from our university hospital with newly diagnosed PCa, who underwent 3T multiparametric MRI prior to RP. Only the MRI target lesions [Prostate Imaging Reporting and Data System (PIRADS) ≥3] with histological correspondence were considered significant. Clinical, biological, MRI and pathological preoperative data were studied. We performed univariate and multivariate logistic regression analysis to identify significant parameters associated with early BF. Results: Early BF occurred in 14% of patients (20/142). Patients with BF had higher PSA level at diagnosis, Gleason score, number of positive biopsies, size of the largest positive biopsy and higher National Comprehensive Cancer Network (NCCN) risk score (P<0.001 for all). According to MRI, they also had higher T stage and a higher size of capsular contact (P<0.001 for all). In contrast, there was no difference concerning neither ADC value, perfusion profile and zonal location of the index lesion. In multivariate analysis, the best combination of predictive factors of early BF was the association of preoperative Gleason score ≥4+3 [odds ratio (OR) =6.8 (1.4-32.5); P=0.002] and T stage ≥3 on preoperative MRI [OR =17.4 (3.2-94.9); P<0.001] with an area under the curve (AUC) of 0.89 [99% confidence interval (CI) 0.77-1], a negative predictive value of 94% and a positive predictive value of 75%. Conclusions: Combination of simple preoperative biomarkers as Gleason score and T stage according to MRI accurately stratify the risk of early BF following RP. These results emphasize the pivotal role of preoperative MRI for the management of localized PCa.