To examine the incremental value of prostate MRI when used in combination with the currently available preoperative risk stratification tool the Memorial Sloan Kettering Cancer Center Pre-Radical Prostatectomy Nomogram (MSKCC).
We reviewed our institutional database of prostate MRI performed prior to radical prostatectomy between December 2014 and March 2016 (n=236). We generated a logistic regression model based on observed final pathology results and the MSKCC nomogram predictions for organ confined disease, extracapsular extension (ECE), seminal vesicle invasion (SVI), and lymph node (LN) involvement ('MSKCC Only'). We then generated a combined regression model incorporating both the MSKCC nomogram prediction with the degree of prostate MRI suspicion ('MSKCC+MRI'). Receiver operating characteristic (ROC) curves were generated, and the area under the curve (AUC) was compared.
When independently examining the MSKCC nomogram predicted risk and the degree of prostate MRI suspicion, MRI was a predictor for ECE (OR 2.8, p<0.01) and LN involvement (OR 5.6, p=0.01). When examining the 'MSKCC+MRI' and 'MSKCC Only' models, the incremental benefit in risk discrimination from the combined model ('MSKCC+MRI') was not significant for organ confined disease, ECE, SVI, or LN involvement (ΔAUC¬ +0.03, p=0.10; ΔAUC +0.03, p=0.08; ΔAUC 0.63, p=0.63; ΔAUC +0.04, p=0.42; respectively).
A combined model with prostate MRI and the MSKCC nomogram provides no additional risk discrimination over the MSKCC nomogram based model alone. Evaluation of prostate MRI as a predictive tool should be performed in combination with, not independent of, this clinical risk stratification models.
Urology. 2017 Dec 04 [Epub ahead of print]
John K Weaver, Eric H Kim, Joel M Vetter, Anup Shetty, Robert L Grubb, Seth A Strope, Gerald L Andriole
Division of Urology, Washington University School of Medicine, St. Louis, MO, USA., Mallinckrodt Institute of Radiology, Washington University School of Medicine, St. Louis, MO, USA., Urologic Oncology, Baptist MD Anderson Cancer Center, Jacksonville, FL, USA., Division of Urology, Washington University School of Medicine, St. Louis, MO, USA. Electronic address: .