Tertiary Gleason grades and consequent prognostic risk
Posted Mar 13 2011 12:00am
We have known for a while that men with a tertiary Gleason grade of 4 or 5 (as discussed below) are at heightened risk for progressive forms of prostate cancer. Indeed it has been standard practice for a while now for pathologists to report any indication of tissue showing tertiary Gleason grades in biopsy and surgical pathology reports.
A tertiary Gleason grade is defined as:
Any small amount of Gleason grade 4 or 5 tissue in a specimen from a patient who otherwise has a Gleason score of 3 + 3 = 6 or lower or
Any small amount of Gleason grade 5 tissue in a specimen from a patient who otherwise has a Gleason score of 3 + 4 = 7, 4 + 3 = 7, or 4 + 4 = 8.
Patients who have Gleason scores of 9 or 10 can not, by definition, have a clinically significant, tertiary Gleason grade.
A new article by Turker et al. reports data from a retrospective re-analysis of a total of 331 radical prostatectomy specimens from Turkish patients, and correlation of primary, secondary, and tertiary Gleason grades in these specimens to the subsequent outcomes of the patients. The researchers were able to show that:
Clinically significant tertiary Gleason patterns could be observed more frequently in specimens with higher standard Gleason scores, i.e.,
With respect to biochemical progression-free survival post-surgery
73/331 patients in the series demonstrated biochemical recurrence post-surgery.
The presence of tertiary Gleason pattern tissue in the radical prostatectomy specimen was an independent indicator of risk for biochemical recurrence (hazard ratio [HR] = 2.63).
Turker et al. conclude that patients can be categorized into three prognostic groups based on their post-surgical Gleason scores:
A good prognostic group, with a Gleason score of < 7 and no tertiary Gleason pattern tissue
An intermediate prognostic group, with a Gleason score of < 7 and the presence of tertiary Gleason pattern tissue, or with a Gleason score of 7 but no tertiary Gleason pattern tissue
A poor prognostic group, with a Gleason score of 7 and the presence of tertiary Gleason pattern tissue, or simply with a Gleason score > 7.
These findings from a large series of men in Turkey are very similar to those originally reported by Isaacs and his colleagues at Johns Hopkins and would seem to confirm the international “universality” of the importance of identifying and documenting the presence of any tertiary Gleason pattern tissue in biopsy and radical prostatectomy specimens. It is also clear that tertiary Gleason data need to be taken into account is making treatment decisions immediately following diagnosis and also immediately following surgery in men found to have tertiary Gleason pattern tissue in their surgical specimens (especially if such tissue had not been evident in the original biopsy specimens).