BERKELEY, CA (UroToday.com) - Prostate cancer represents a wide spectrum of disease with some patients having indolent disease that may be actively monitored whereas other patients have aggressive disease that can often be fatal.
Traditionally, clinical risk factors such as Gleason score, PSA, and clinical stage have been used to stratify patients into risk groups to help guide treatment decisions. Yet, even within these risk groups, there remains a significant amount of heterogeneity. Further, in the PSA-era, the utility of clinical stage has decreased as a larger proportion of patients are now T1c.
| "MRI findings along with other molecular and imaging markers are an important area for future investigation to help better stratify patients with prostate cancer and help select appropriate treatment." |
Multiple studies have examined the utility of MRI in prostate cancer, however, a meta-analysis of earlier studies demonstrated a wide range of accuracy for MRI staging of prostate cancer. Recent work though has demonstrated that higher-powered magnets, an endo-rectal coil, and an experienced radiologist all significantly improve the accuracy of MRI staging. We sought to determine if findings from pre-treatment endo-rectal coil Magnetic Resonance Imaging (eMRI) could help predict prognosis of patients with prostate cancer.
We examined a group of 279 men uniformly treated with combination external beam radiotherapy and brachytherapy who had either intermediate or high-risk prostate cancer according to the NCCN. 60% of these men were treated with a low dose-rate implant while 40% received high-dose-rate brachytherapy. Afterwards, all men received supplemental external-beam radiotherapy to a median dose of 50.4Gy. The 5-year biochemical relapse-free survival for the entire cohort was 92%. All MRIs were reviewed by two radiologists experienced in genitourinary radiology.
On univariate analysis, multiple imaging findings correlated with biochemical outcomes, including presence of extra-capsular extension on MRI, tumor size, and MR-determined T-Stage. This is obviously expected, as clinical stage and tumor volume are often reported in surgical series to be correlated with biochemical outcomes. Interestingly, on multivariate analysis both Gleason score and presence of extra-capsular extension on MRI were independent predictors of recurrence. This suggests that after Gleason score, findings from MRI may be the next most predictive variable to determine clinical outcomes of patients treated with a dose-escalated therapy using brachytherapy and external beam radiotherapy.
These results also highlight the fact that MRI findings may help stratify patients for risk of recurrence and could possibly be considered in upfront management decisions for patients. MRI findings along with other molecular and imaging markers are an important area for future investigation to help better stratify patients with prostate cancer and help select appropriate treatment.
Written by:
Nadeem Riaz, MD, and Michael Zelefsky, MD as part of Beyond the Abstract on UroToday.com. This initiative offers a method of publishing for the professional urology community. Authors are given an opportunity to expand on the circumstances, limitations etc... of their research by referencing the published abstract.
Memorial Sloan-Kettering Cancer Center, New York, New York
More Information about Beyond the Abstract