NEW ORLEANS, LA USA (UroToday.com) - Prostate cancer is a common malignancy of men, and detection of the disease is a crucial aspect. New technologies like MR-US fusion biopsies aim to improve the toolkit urologists have in providing appropriate detection of this disease.
The investigators present a retrospective single institution long-term follow up cohort of 1 000 men in order to investigate the detection power of Gleason ≥ 3+4 cancers through MR-US fusion biopsies. The patients were roughly from equal exposures of prior biopsies (naïve, negative, and positive) and were predominantly Caucasian. Using an in-house grading system of 1-5 for the regions of interest (ROI) detected, patients were classified into differing levels of suspicion (none, low, moderate, and high). 24% of the men compromised the non-suspicious group, 39% were in low, 29% moderate and 8% in high suspicion. Cox proportional hazard analysis showed a PSA density > 0.15 as the most predictive factor for identifying Gleason ≥ 7 with a seven-fold predictive power. Another strong predictor was a PSA >10. In addition, for Gleason ≥ 6 or Gleason ≥ 7 disease, the number of ROI was found to have a step-wise increase in detection of higher suspicious disease. Of note, the investigators found that the MRI-targeted approach detected a higher number of Gleason 7, or greater disease, more so than mapping on its own. However, a combination approach of mapping and targeted shows to be the most accurate for identifying aggressive cancer.
This study represents a very well analyzed cohort of heterogeneous men, and many future studies can stem from it. One aspect that the authors could elaborate on was correlating pathological Gleason score with the MRI-US ROI, as pathological scores are of more clinical significance than biopsy Gleason scores. One aspect that the authors did not have time to elaborate on was the 15% of the patients that were not found to have any ROIs despite showing high-grade disease (Gleason ≥ 7). Perhaps, the authors can widen the scope of correlating ROIs by including the size of the lesions in addition to the number of ROIs discovered. In this matter, a negative MR-US scan will not enable the loss of men that harbor high-grade disease.
Presented by Christopher Filson at the American Urological Association (AUA) Annual Meeting - May 15 - 19, 2015 - New Orleans, LA USA
University of California, Los Angeles, CA USA
Reported by Blanca Morales (University of California-Irvine), medical writer for UroToday.com