The Association between Patient Characteristics and Biochemical Recurrence after Radical Prostatectomy

Background: Biochemical recurrence (BCR) represents the rise of prostate-specific antigen (PSA) levels after treatment with curative radical prostatectomy (RP) or radiation for prostate cancer. The objective of the current study was to test for the association between patient characteristics, namely age, body mass index (BMI), as well as prostate volume at surgery, and BCR after RP. Material and Methods: Within a tertiary care database, patients with prostate cancer treated with RP between January 2014 and June 2023 were included. Kaplan-Meier survival analyses and Cox regression models addressed BCR after RP according to patient characteristics. Results: Of 821 patients, the median age was 66 years (interquartile range [IQR] 61-71 years), BMI was 26.2 kg/m² (IQR 24.3-28.8 kg/m²), and prostate volume was 40 cm³ (IQR 30-55 cm³). Median follow-up was 20 months. In survival analyses, the three-year BCR-free survival rates were 81 vs. 84 vs. 81% in patients aged ≤60 vs. 61-69 vs. 70 years (p = 0.1). In patients with BMI < 25.0 vs. 25.0-29.9 vs. ≥30.0 kg/m², the three-year BCR-free survival rates were 84 vs. 81 vs. 84% (p = 0.7). In patients with prostate volume ≤40 vs. >40 cm³, the three-year BCR-free survival rates were 85 vs. 80% (p = 0.004). In multivariable Cox regression models accounting for patient and pathologic tumor characteristics and adjuvant radiation therapy, a higher prostate volume independently predicted BCR as continuous (hazard ratio 1.012, 95% confidence interval 1.005-1.019; p < 0.001), as well as categorized the variable based on the median (hazard ratio 1.66, 95% confidence interval 1.17-2.36; p = 0.005). Conversely, neither age nor BMI were significantly associated with BCR after RP. Conclusions: The higher prostate volume independently predicted BCR after RP, but not age or BMI at surgery. Consequently, patients with an elevated prostate volume should be considered for closer postoperative follow-up.