Impact of Gleason Pattern 5 on outcomes of patients with prostate cancer and iodine-125 prostate brachytherapy.

BACKGROUND: The Gleason grading system is a powerful predictor of prostate cancer (PCa) prognosis. Gleason scores (GS) of 8-10 are considered as a single high-risk grade category, and Gleason Pattern 5 (GP5) predicts biochemical recurrence. We report the clinical outcomes of patients treated with (125)I prostate brachytherapy for clinically localized PCa and prognosis in the presence or absence of GP5.

METHODS: We enrolled 316 patients with T1c-T2N0M0 PCa and undergoing prostate brachytherapy treatment. All patients were followed up for ≥ 1 year. The primary endpoint was biochemical recurrence-free survival. Biochemical recurrence was defined by the Phoenix criteria. Survival curves were calculated by the Kaplan-Meier method, and the prognostic impact of biochemical recurrence was analyzed using a Cox proportional hazards model.

RESULTS: The 5-year biochemical recurrence-free survival rate for all patients was 95.2%, and according to the D'Amico risk classification criteria, the rates were 98.7% for patients in low-risk, 96.9% in intermediate-risk, and 81.1% in high-risk groups (P < 0.0001). The 5-year biochemical recurrence-free survival rates for patients with GS8 or GS9-10 were 87.7% and 61.5%, respectively (P = 0.0057). Multivariate analysis found that GS and clinical T stage were independent predictors of biochemical recurrence.

CONCLUSIONS: The presence of GP5 in GS9-10 prostate cancer has a worse prognosis than GS8 prostate cancer in the absence of GP5 for patients undergoing prostate brachytherapy.