Predicting early outcomes in patients with intermediate- and high-risk prostate cancer using prostate-specific membrane antigen positron emission tomography and magnetic resonance imaging

Objectives:

To identify predictors of early oncological outcomes in patients who opt for robot-assisted laparoscopic radical prostatectomy (RARP) for localized prostate cancer (PCa), including conventional prognostic variables as well as multiparametric magnetic resonance imaging (mpMRI) and prostate-specific membrane antigen (PSMA) positron emission tomography (PET). 

Patients and Methods: 

This observational study included 493 patients who underwent RARP and extended pelvic lymph node dissection (ePLND) for unfavourable intermediate- or high-risk PCa. Outcome measurement was biochemical progression of disease, defined as any postoperative prostate-specific antigen (PSA) value ≥0.2 ng/mL, or the start of additional treatment. Cox regression analysis was performed to assess predictors for biochemical progression, including initial PSA value, biopsy Grade Group (GG), T-stage on mpMRI, and lymph node status on PSMA PET imaging (miN0 vs miN1). 

Results: 

The median (interquartile range) total follow-up of all included patients without biochemical progression was 12.6 (7.5–22.7) months. When assessing biochemical progression after surgery, initial PSA value (per doubling; odds ratio [OR] 1.22, 95% confidence interval [CI] 1.07–1.40; P = 0.004), biopsy GG ≥4 vs GG 1–2 (OR 1.83, 95% CI 1.18–2.85; P = 0.007), T-stage on mpMRI (rT3a vs rT2: OR 2.13, 95% CI 1.39–3.27; P = 0.001; ≥rT3b vs rT2: OR 4.78, 95% CI 3.20–7.16; P < 0.001) and miN1 on PSMA PET imaging (OR 2.94, 95% CI 2.02–4.27; P < 0.001) were independent predictors of early biochemical progression of disease. 

Conclusion:

Initial PSA value, biopsy GG ≥4, ≥rT3 disease on mpMRI and miN1 disease on PSMA PET were predictors of early biochemical progression after RARP. Identifying these patients with an increased risk of early biochemical progression after surgery may have major implications for patient counselling in radical treatment decisions and on patient selection for modern (neo-)adjuvant and systematic treatments.