Smaller prostate gland size and older age predict Gleason score upgrading

Gleason score is important for prostate cancer (CaP) risk stratification and prognostication but has a significant rate of upgrading. We examined the effect of prostate size and age on upgrading of Gleason 6 CaP.

A retrospective review was performed of patients with Gleason 6 CaP who underwent radical prostatectomy from 2001 through 2010. Preoperative clinical and pathologic variables were assessed to determine association with risk of upgrading at prostatectomy.

A total of 1,836 patients were identified with Gleason 6 on prostate biopsy. Upgrading was observed in 543 (29.6%) patients with a final Gleason score of 3+4 in 463 (25.2%), 4+3 in 49 (2.7%), and 8-10 in 31 (1.7%). On univariate logistic regression, age, prostate weight, and PSA were significant predictors of Gleason score upgrading and remained significant on multiple logistic regression. Prostate weight was inversely related to risk of upgrading. To further explore this effect, we performed multiple logistic regression to examine risk of Gleason 6, 7, or 8-10 disease in 2,493 patients with Gleason 6-10 at prostatectomy. After controlling for age and PSA, there was a progressively increased risk of Gleason 6, 7, and 8-10 disease with decreasing prostate weight.

Older age, higher PSA, and smaller prostate gland size are associated with increased risk of Gleason score upgrading. The inverse relationship of prostate weight to risk of Gleason upgrading may be related to increased high-grade disease in smaller glands.