Shift in prostate cancer Gleason grades from 1989 to 2001

Download PDF Copy

Jun 26 2006

Since the clinical introduction of PSA testing, there is reason to hypothesize that prostate cancer (CaP) Gleason grades may have shifted due to a variety of factors.

Dr. Sengupta and associates at the Mayo Clinic report this to be the case in the epub version of Cancer.

Between 1989 and 2001, 8750 patients who underwent radical prostatectomy at the Mayo clinic met the study criteria. Gleason grades over the 13 year period were reviewed and biochemical recurrence (defined as a PSA >0.4ng/ml) was recorded. Biochemical recurrence-free survival (BRFS) was estimated using Kaplan Meier methodology.

The percentage of RP specimens assigned a Gleason grade of 3 as either the primary or secondary grade increased from 86% vs. 49% for primary and 71% vs. 47% for secondary pattern for 1999-2001 vs. 1989-1999, respectively. During the same time periods, the prevalence of Gleason grade 2 tumors decreased from 0.4% vs. 38% for primary and 1.3% vs. 28% for secondary Gleason grade patterns. As a result, less Gleason score 4-5 tumors and more Gleason score 6-7 tumors were identified.

The BRFS for patients with Gleason score 6 and 7 tumors improved over the time periods. For Gleason score 6 the 5-year BRFS improved form 47% to 87% over the two time periods. For Gleason score 7 the 5-year BRFS improved form 51% to 66% over the two time periods. There were no significant changes noted over the same time periods for Gleason scores 2-4 or 8-10. In multivariate analysis, improved BRFS remained for Gleason score 6, but not for patients with Gleason score 7 tumors.

The noted Gleason grade shifts may be a result of true stage migration secondary to PSA screening or changes in pathologic interpretation over the time period studied.

By Christopher P. Evans, MD

Reference: