Risk downgrade common in GGG3 prostate cancer patients with single positive biopsy core

In Gleason grade group (GGG) 3 prostate cancer patients with a single intermediate-risk positive biopsy core, risk downgrading appears to be more likely than upgrading, reports a new study.

Drawing from the Surveillance, Epidemiology, and End Results database, researchers enrolled 1,328 patients, of whom 73 percent (n=927; median age 62 years) were GGG2 and 27 percent (n=356; median age 63 years) were GGG3 at biopsy. The rates of GGG up- and downgrading were recorded, and multivariate logistic regression models were constructed to determine related independent predictors.

Of the 927 men who were GGG2 at biopsy, 20 percent were downgraded to GGG1 by the time of radical prostatectomy (RP), while a similar proportion (17 percent) were upgraded to GGG3 (n=130), GGG4 (n=27), or GGG5 (n=8); meanwhile, majority (63 percent) remained GGG2.

In comparison, downgrading was more common than upgrading in the 356 GGG3 patients at biopsy. At RP, 36 percent were downgraded to GGG2 and 10 percent to GGG1, while only 12 percent saw an upgrade in their risk category (7 percent to GGG4 and 5 percent to GGG5). Forty-two percent remained GGG3 at RP.

Regression analysis found age to be a modest but significant predictor of downgrading in GGG2 men (odds ratio [OR], 0.94, 95 percent confidence interval [CI], 0.93–0.97; p<0.001). In GGG3 men, prostate-specific antigen 10–20 ng/mL predicted upgrading (OR, 2.89, 95 percent CI, 1.31–6.11; p=0.007) while year of diagnosis correlated with downgrading (OR, 0.78, 95 percent CI, 0.62–0.97; p=0.03).

“In the future, large scale studies are needed to confirm these findings in the context of magnetic resonance imaging-guided single intermediate-risk positive biopsy core [patients],” the researchers said.