BERKELEY, CA (UroToday.com) – A systematic review and meta-analysis by Dr. Harnden and associates suggests that a tertiary Gleason grade is associated with worse oncologic prostate cancer (CaP) outcomes and warrants greater prospective analysis and consideration for inclusion in the Gleason grading system. This report appears in the May 2007 issue of the Lancet Oncology.
The standard prostate pathology report includes a primary and secondary Gleason grade. On some occasions, a tertiary grade is reported. In 2005 an International Consensus Conference of uro-pathologists suggested that the Gleason system for prostatic biopsy reports should be modified to account for the presence of a poorly differentiated or undifferentiated tertiary component. The modified approach would sum the most prevalent primary grade and the highest grade. Thus, in the situation with a primary grade 3 and a secondary grade 4, cancers with a tertiary grade of 5 would be classified as high grade (3 5). This proposal has not been implemented, as the existing system is well rooted in clinical practice.
I have thought about this on several occasions. The most common situation is a patient who has a gleason score of 3+4 = 7 with a tertiary pattern of 5 after robotic prostatectomy.
My feeling is that the small amount of 5 is probably significant. Most studies have shown that the first two numbers (the most common type and second most common type) are the important ones, but it would make sense that the any gleason score of 5 (the most aggressive) would be important. I also think tumor volume is very important. One day we may list the total volume of gleason score 5 and then 4 as important factors to determine risk of recurrence of prostate cancer after surgery.