Biochemical Relapse in Low-risk Prostate Cancer Treated with Radical Prostatectomy and Bilateral Pelvic Lymphadenectomy

Introduction For low-risk prostate cancer (PCa), curative treatment with radical prostatectomy (RP) can be performed, reporting a biochemical relapse-free survival rate (bRFS) at 5 and 7 years of 90.1% and 88.3%, respectively. Prostatic specific antigen (PSA), pathological stage (pT), and positive margins (R1) are significant predictors of biochemical relapse (BR). Even though pelvic lymphadenectomy is not recommended during RP, in the literature, it is performed in 34% of these patients, finding 0.37% of positive lymph nodes (N1). In this study, we aim to evaluate the 10-year bRFS in patients with low-risk PCa who underwent RP and extended pelvic lymph node dissection (ePLND).

Methodology All low-risk patients who underwent RP plus bilateral ePLND at the National Cancer Institute of Colombia between 2006 and 2019 were reviewed. Biochemical relapse was defined as 2 consecutive increasing levels of PSA > 0.2 ng/mL. A descriptive analysis was performed using the STATA 15 software (Stata Corp., College Station, TX, USA), and the Kaplan-Meier curves and uni and multivariate Cox proportional hazard models were used for the survival outcome analysis. The related regression coefficients were used for the hazard ratio (HR), and, for all comparisons, a two-sided p-value ˂ 0.05 was used to define statistical significance.

Results Two hundred and two patients met the study criteria. The 10-year bRFS for the general population was 82.5%, statistically related to stage pT3 (p = 0.047), higher Gleason grade group (GG) (p ≤ 0.001), and R1 (p ≤ 0.001), but not with N1. A total of 3.9% of the patients had N1; of these, 75% had R1, 25% GG2, and 37% GG3. Among the N0 (non-lymph node metástasis in prostate cáncer) patients, 31% of the patients had R1, 41% GG2, and 13% GG3.

Conclusions Our bRFS was 82.5% in low-risk patients who underwent RP and ePLND. With higher pT, GG, and presence of R1, the probability of BR increased. Those with pN1 (pathologicaly confirmed positive lymph nodes) were not associated with bRFS, with a pN1 detection rate of 3.9%.

Details: In low-risk PCa, curative treatment with RP can be performed, reporting a bRFS rate at 5 and 7 years of 90.1% and 88.3%, respectively. Despite the fact that pelvic lymphadenectomy is not recommended during RP in clinical guidelines, in the literature, it is performed in 34% of these patients, finding 0.37% of N1. In this study, we report the 10-year bRFS in patients with low-risk PCa who underwent surgery.