The International Society of Urologic Pathology (ISUP) has endorsed modifications to the Gleason grading system for prostate cancer . Five Grade Groups have been defined with tumors of Grade Group 1 being the least aggressive and having the lowest likelihood of progression, whereas those of Grade Group 5 have the highest likelihood of early systemic spread. This new system provides clearer guidance for pathologists to classify cancers on the basis of gland morphology, and it aligns better with contemporary management including active surveillance.
The editors of the major uro-oncology journals believe this is a helpful change for clinicians, researchers, and patients alike and are eager to help this system establish itself in the reporting of pathologic grade. To that end we are now asking investigators to use the new system in the reporting of prostate cancers in their publications. As the Grade Groups correspond to current Gleason scores 6, 3+4, 4+3, 8, 9 and 10, the translation should be relatively simple. Over the next one to two years, side-by-side reporting of old and new histology may temporarily be necessary. We do recognize that some institutional and national databases are not set up to make the translation and exceptions will be granted in these cases.