#AUA14 - Characterizing the dominant/index lesion in prostate cancer: Implications for grading and staging - Session Highlights

ORLANDO, FL USA (UroToday.com) - Several factors are considered in the estimating a prognosis after radical prostatectomy. Some evidence has suggested that the index lesion will have both the highest tumor volume as well as the greatest Gleason score (GS), and will serve as the stage-defining tumor. Dr. Kazuhiro Matsumoto and colleagues, feeling that not enough had been evaluated in this regard, undertook a study to further evaluate these factors. Thus, they presented work on determining how well the tumor volume, highest GS, and stage are associated with the index/dominant lesion in the prostate.

auaThey performed a study of "266 whole-mounted and entirely submitted RP specimens," and for each case, calculated the tumor volume, GS, and pathologic stage for each tumor. Their aim was to calculate the number of cases in which the index tumor was indeed the largest with greatest GS and stage (congruous) and to compare that with the number of cases in which the index tumor was not found to have the highest volume and greatest GS and stage (incongruous).

Ultimately, they found that in 82% of cases, the index tumor was indeed the largest, exhibited the highest GS, and defined the pathologic staging of the cancer. That said, they elaborated on the incongruous cases, with one-third exhibiting a maximum GS in non-index nodule that was > 1 GS higher than the index nodule. Similarly, they found that "the stage-determining nodule may not have the largest TV" or highest GS. This study implies that some changes to analysis and reporting of pathology results may need to be made in order to improve the diagnostic accuracy of studies meant to inform prognosis. It will be interesting to see this work expanded to include patients for whom follow-up data has or is being collected, and to begin to test the utility of these data in performing more sensible analyses of prostate specimens.

Presented by Kazuhiro Matsumoto at the American Urological Association (AUA) Annual Meeting - May 16 - 21, 2014 - Orlando, Florida USA

New York, NY USA

Written by Martin Hofmann, MD, University of California (Irvine), and medical writer for UroToday.com