Endorectal magnetic resonance imaging (MRI) added to the initial clinical evaluation of patients with clinically low-risk prostate cancer (PCa) helps predict findings on confirmatory biopsy and evaluate eligibility for active surveillance, researchers concluded.
Hebert Alberto Vargas, MD, and colleagues at Memorial Sloan-Kettering Cancer Center in New York studied 388 consecutive PCa patients who had a PSA level below 10 ng/mL, a clinical stage T2a or less, and a Gleason score of 6 or less. All underwent endorectal MRI prior to confirmatory biopsy. Three radiologists independently scored tumor visibility on endorectal MRI using a five-point scale, where 1 referred the definite absence of a tumor and 5 referred to the definite presence of a tumor.
Gleason score was upgraded in 79 patients (20%) on confirmatory biopsy. MRI scores of 2 or less had a high negative predictive value and specificity for upgrading on confirmatory biopsy, the researchers reported in the Journal of Urology (2012;188:1732-1738). In addition, an MRI score of 5 was highly sensitive for upgrading. On multivariate analysis, men with higher MRI scores were twofold to fourfold more likely to have disease upgraded on confirmatory biopsy compared with men who had lower scores.