The number of negative pelvic lymph nodes removed does not affect the risk of biochemical failure after radical prostatectomy

Abstract

To assess patients who had radical prostatectomy (RP) and pelvic lymph node dissection (PLND) for pT2-4 N0M0 prostate cancer, to determine if LN yield affects the risk of biochemical failure (BCF), as the extent of PLND at the time of RP has become increasingly uncertain with the decreasing trend in tumour stage. We reviewed the Columbia University Urologic Oncology Database for patients with pT2-4 N0M0 prostate cancer treated with RP from 1990 to 2005. Exclusion criteria included <12 months of follow-up, incomplete clinical and pathological data, and neoadjuvant androgen-deprivation therapy (ADT) or immediate adjuvant ADT or external beam radiotherapy. Unadjusted and adjusted models were used to determine the ability of clinical and pathological variables to predict BCF. The final dataset included 964 patients, with a mean age of 60.5 years and median preoperative prostate-specific antigen (PSA) level of 6.2 ng/mL. The median (range) LN yield was 7 (1-42) and the median follow-up 59 (12-190) months. In the unadjusted and adjusted models, preoperative PSA, pathological Gleason score, pathological stage, surgical margin status and year of surgery were significant predictors of BCF. The LN group was not a significant predictor of BCF in both the unadjusted and adjusted model (P = 0.759 and 0.408, respectively). When patients were stratified into high- and low-risk groups, LN yield remained an insignificant predictor of BCF. A higher LN yield at the time of RP does not increase the chance of cure for patients with pT2-4N0M0 prostate cancer. This lack of a survival advantage holds true for patients with high-risk disease.