Risk assessment of late biochemical recurrence after radical prostatectomy: Usefulness of ultra-sensitive prostate-specific antigen measurement.

Objectives: This study aimed to evaluate predictors of late biochemical recurrence in patients with no recurrence at 5 years after radical prostatectomy (RP).

Methods: We retrospectively investigated patients who underwent RP for prostate cancer in our institute from 1999 to 2016, selecting those with no biochemical recurrence at 5 years post-RP. These patients did not receive neoadjuvant and adjuvant hormone therapy. Following RP, patients were regularly monitored using ultra-sensitive prostate-specific antigen (PSA) measurements, with a detection limit of 0.01 ng/mL. Biochemical recurrence was defined as PSA level ≥0.2 ng/mL, confirmed by subsequent PSA >0.2 ng/mL.

Results: Among 581 patients who underwent RP, 312 with no biochemical recurrence at 5 years post-RP were selected. The median follow-up period was 123 months. The 10-year biochemical recurrence-free survival rate for this cohort was 89.6%. Patients with a PSA value <0.02 ng/mL at 5 years post-RP had a 10-year biochemical recurrence-free survival rate of 98.5%. Multivariable regression analysis identified Grade Group ≥4 and PSA value ≥0.02 ng/mL at 5 years post-RP as independent predictors of late biochemical recurrence (hazard ratio 2.23, 95% confidence interval 1.06-4.71, p = 0.035; hazard ratio 37.5, 95% confidence interval 11.6-121.3, p < 0.001, respectively). Patients with Grade Group of 4 or more had a significantly reduced PSA doubling time at biochemical recurrence compared to those with Grade Group of 3 or less.

Conclusions: Among patients whose PSA levels remain below 0.02 ng/mL at 5 years after RP, the risk of subsequent late biochemical recurrence is very low. Utilizing ultra-sensitive PSA measurements at the 5-year mark can provide useful information regarding the need for follow-up beyond 5 years.