Endorectal coil magnetic resonance imaging and clinicopathologic findings in T1c adenocarcinoma of the prostate

Stage T1c prostate cancer has become the most commonly diagnosed clinical stage of localized prostate cancer. Endorectal coil magnetic resonance imaging (erMRI) can be used in the staging of such patients. The purpose of this study was to correlate the preoperative erMRI findings with the pathologic characteristics of the surgical specimens. A database review of 355 radical prostatectomy specimens revealed 130 patients with T1c disease. Of these patients, 124 were clinically staged with erMRI. Standard sensitivity analysis and multivariable analysis was then applied to determine the utility of erMRI in the staging of patients with T1c prostate cancer. The mean prostate specific antigen (PSA) value was 8.3 (1.0–33.6). Most patients had Gleason score of 5 or 6 (51.6%) or 7 (33.1%), with fewer patients having Gleason scores between 2 and 4 (7.2%) or 8 and 10 (8.1%). The positive predictive value of erMRI for extracapsular disease was 38.7%, negative predictive value was 75.3%, and accuracy was 79%. Multivariable regression analysis demonstrated that erMRI and preoperative PSA were predictive for seminal vesicle involvement. However, erMRI was not predictive in multivariable or univariable analysis for extracapsular extension or margin positivity. Previous investigators demonstrated the utility and independent significance of preoperative erMRI for a select subset of patients. However, it is not a useful staging modality for patients with T1c cancer as a whole. Further stratification of the T1c patients would be necessary to identify patients within this group who may benefit from staging with erMRI.