Background: To determine prognostic factors associated with progression to castration-resistant prostate cancer following biochemical recurrence which is lethal prostate cancer and establish a risk stratification model of progression to castration-resistant prostate cancer.
Methods: We retrospectively reviewed the data of 550 patients who experienced biochemical recurrence after radical prostatectomy. The endpoint of the present study was progression to castration-resistant prostate cancer. The actuarial probabilities of progression to castration-resistant prostate cancer-free survival were determined using Kaplan-Meier analysis. Univariate and multivariate Cox proportional hazards regression analyses were used to identify independent predictors of biochemical recurrence.
Results: Fifty-two patients experienced progression to castration-resistant prostate cancer during the follow-up period. The progression to castration-resistant prostate cancer-free survival rate after biochemical recurrence at 10 years was 76.8%. In multivariate analysis, pathological Gleason score ≥ 9, lymphovascular invasion, and prostate-specific antigen velocity ≥ 0.4 ng/mL/year were independent predictive factors for progression to castration-resistant prostate cancer. The patients were stratified into three groups using a risk stratification model incorporating these variables. The 10-year progression to castration-resistant prostate cancer-free survival rates were 96.7% in the low-risk group, 84.7% in the intermediate-risk group, and 24.5% in the high-risk group.
Conclusions: The present results suggest that the pathological Gleason score, lymphovascular invasion, and prostate-specific antigen velocity were independent predictive factors for progression to castration-resistant prostate cancer. The risk stratification model established in the present study could be useful for patient counseling and in identifying patients with a poor prognosis.
Keywords: Biochemical recurrence; Castration-resistant prostate cancer; Radical prostatectomy; Risk stratification model.