Digital rectal examination still plays a crucial role of predicting outcomes in the prostate cancer patients undergoing primary total prostate cryoablation

Abstract

Purpose: In the management of prostate cancer (PC), outcome prediction using clinical stages determined via magnetic resonance imaging (MRI) or digital rectal examination (DRE) is controversial. Materials and Methods: Patients with PC who received primary total prostate cryoablation (PTPC) at our institution between October 2008 and March 2021 were enrolled in this study. The primary outcome was biochemical recurrence (BCR), which was defined according to the Phoenix criteria. The concordance of clinical stages determined via DRE and MRI was measured using the weighted kappa coefficient. The Cox proportional-hazards models were used to assess the BCR risks. Results: A total of 230 patients with a median age of 70 years were included in the analysis. The consensus rate of clinical T stages between DRE and MRI was 60.9% with fair concordance (κ = 0.310). DRE upstaged 25 (10.9%) patients, whereas MRI upstaged 65 (28.3%) patients. During the median follow-up duration of 83.1 months, BCR occurred in 78 patients. The univariate analysis of BCR revealed that initial prostate-specific antigen, Gleason sum, and DRE-determined T stage (T3a–b vs. T1-2c; hazard ratio [HR] 1.88; 95% confidence interval [CI] 1.2–2.94) were statistical predictors of BCR. However, no significant association was observed between MRI-determined T stage and BCR (T3a–b vs. T1-2c; HR 1.30; 95% CI 0.83–2.02). The multivariate models consisting of DRE-determined T stage were better than those consisting of MRI-determined T stage based on the Akaike information criteria. Conclusion: In the patients who underwent PTPC, DRE was a valuable technique for evaluating preoperative tumor status and predicting outcomes.

Keywords

• biochemical recurrence
• cryoablation
• digital rectal examination
• magnetic resonance imaging
• outcome prediction
• prostate cancer