Multiparametric Magnetic Resonance Imaging Should Be Preferred Over Digital Rectal Examination for Prostate Cancer Local Staging and Disease Risk Classification.

OBJECTIVE

To assess the impact of multiparametric magnetic resonance imaging (mp-MRI) local tumor staging on prostate cancer risk stratification and choice of treatment.

MATERIALS AND METHODS

Prostate cancer patients, newly diagnosed from 2017 to 2018 at 7 Dutch teaching hospitals were included. Risk group classification was done twice, using either digital rectal examination (DRE) or mp-MRI information. Risk group migration and rates of treatment intensification associated with mp-MRI upstaging were established. Diagnostic accuracy measures for the detection of nonorgan-confined disease (stage ≥T3a), for both DRE and mp-MRI, were assessed in patients undergoing robot-assisted radical prostatectomy.

RESULTS

A total of 1683 patients were included. Upstaging due to mp-MRI staging occurred in 493 of 1683 (29%) patients and downstaging in 43 of 1683 (3%) patients. Upstaging was associated with significant higher odds for treatment intensification (odds ratio [OR]: 3.5 95% confidence interval [CI] 1.9-6.5). Stage ≥T3a on mp-MRI was the most common reason for risk group upstaging (77%). Sensitivity for the detection of stage ≥T3a was higher for mp-MRI compared to DRE (51% vs 12%, P <.001), whereas specificity was lower (82% vs 97%, P <.001). Mp-MRI resulted in a significantly higher cumulative rate of true positive and true negative stage ≥T3a predictions compared with DRE (67% vs 58%, P <.001).

CONCLUSION

Use of mp-MRI tumor stage for prostate cancer risk classification leads to upstaging in 1 of 3 patients. Mp-MRI enables superior detection of nonorgan-confined disease compared with DRE, and should be the preferred tool for determining clinical tumor stage.