Prediction of biochemical failure using prostate-specific antigen half-life in patients with adverse pathologic features after radical prostatectomy

Purpose: Prostate-specific antigen nadir and time to prostate-specific antigen nadir are predictors of disease progression in patients who undergo radical prostatectomy. However, a mutually conflicting relationship exists between them. Thus, we compared postoperative prostate-specific antigen levels at the first follow-up with the expected levels while considering the half-life of prostate-specific antigen to improve the prediction of biochemical failure after radical prostatectomy in patients with adverse pathologic features. Methods: Patients treated with robot-assisted laparoscopic prostatectomy were enrolled. Patients with a follow-up duration of < 12 months or positive lymphadenectomy results were excluded. “Adverse prostate-specific antigen” was defined as a prostate-specific antigen level higher than the expected level at 6 weeks. Results: Among 450 patients, adverse pathologic features and adverse prostate-specific antigen were found in 260 (57.8%) and 245 (54.5%) patients, respectively. Analysis of patients with and without abnormal prostate-specific antigen level revealed significantly different biochemical failure-free survival outcomes. Patients with one adverse pathologic feature but without adverse prostate-specific antigen showed similar biochemical failure-free survival to those without adverse pathologic features. Adverse prostate-specific antigen was identified as an independent predictor for biochemical failure within 1 year after radical prostatectomy. The area under the curve when adding adverse prostate-specific antigen to the conventional factors was significantly higher than that for the conventional factors alone. Conclusion: The difference between postoperative prostate-specific antigen levels at the first follow-up visit after radical prostatectomy and the expected level while considering the half-life of prostate-specific antigen is a predictive factor for treatment efficacy following radical prostatectomy.