Risk stratification for disease progression in pT3 prostate cancer after robot-assisted radical prostatectomy

The aim of this study is to identify optimal patients for adjuvant radiation therapy (ART) in pT3 prostate cancer. The role of ART for patients with adverse pathologic features after radical prostatectomy (RP) has been demonstrated, but over- or under-treatment remains a significant concern. Two-hundred and five patients with pT3N0M0 who underwent robot-assisted RP without ART were analyzed. Multivariate Cox proportional regression analyses were used to identify predictors of biochemical recurrence (BCR) and clinical progression (CP). The estimated 5-year BCR-free survival (BCRFS) and CP-free survival (CPFS) were 52.8% and 85.6%, respectively. Preoperative prostate-specifc antigen (PSA) ≥10 ng ml-1 (hazard ratio [HR]: 3.288-6.027; P = 0.003), pathologic Gleason score (pGS) ≥8 (HR: 4.146; P = 0.014), and lymphovascular invasion (LVI) (HR: 2.167; P = 0.026) were associated with BCR. Based on these factors, a risk stratification tool was developed. Patients with no risk factors (PSA <10 ng ml-1 , pGS 6, and absent LVI) showed excellent BCRFS and CPFS at 5 years (91.9% and 100.0%, respectively), but those with two or more risk factors (PSA ≥10 ng ml-1 , pGS ≥8, or present LVI) had poor BCRFS and CPFS (12.1% and 54.6%, respectively). In addition, the multivariate analysis revealed that pathologic stage pT3b (HR: 5.393; P = 0.025) was the only predictor of CP. Our study demonstrated the heterogeneity of oncologic outcomes in patients with pT3 prostate cancer. The proposed risk stratification can be used to identify patients who are at risk for disease progression and may aid in identifying the best patients for ART.