Endorectal T2-weighted MRI does not differentiate between favorable and adverse pathologic features in men with prostate cancer who would qualify for active surveillance

Abstract

ObjectiveWith the increased diagnosis of low grade, low volume, potentially non-lethal disease, active surveillance (AS) has become an increasingly popular alternative for select men with low-risk prostate cancer. The absence of precise clinical staging modalities currently makes it difficult to predict which patients are most appropriate for AS. The goal of our study was to evaluate the ability of endorectal MRI (eMRI) to predict adverse pathologic features in patients who would otherwise qualify for an AS program. Materials and methodsWe retrospectively reviewed our institution's radical prostatectomy (RP) database from 1991 to 2007 and identified 172 patients who would have qualified for AS and underwent preoperative staging eMRI with T2-weighted (T2W) sequences. MRI findings were correlated to final pathology in order to assess the ability of staging eMRI to predict adverse pathologic features in patients suitable for AS. ResultsThe mean age of our cohort was 59.8 ± 6.2 years. The mean PSA at the time of diagnosis was 5.2 ± 2.2 ng/ml. In 51% of patients, no discrete tumor was visualized on eMRI and in 49% of patients a discrete tumor was detected. At the time of RP, Gleason score upgrading, extracapsular extension, and a positive surgical margin occurred in 17%, 6%, and 5% of cases, respectively. Patients with documented tumor on eMRI did not have an increased incidence of adverse pathologic findings with regard to tumor volume (P = 0.31), extra-capsular extension (P = 0.82), Gleason upgrading (P = 0.92), seminal vesicle invasion (P = 0.97), or positive surgical margin rate (P = 0.95) compared with those in whom no tumor was seen. ConclusionDiscrete tumor identification on eMRI is not predictive of adverse pathologic features in patients who would otherwise qualify for AS. eMRI likely does not provide additional information when prospectively evaluating patients for AS protocols.