Does increasing the nodal yield improve outcomes in contemporary patients without nodal metastasis undergoing radical prostatectomy?1

ObjectivesTo determine if the number of lymph nodes (LNs) removed is an independent predictor of biochemical recurrence (BCR) in patients without LN metastases undergoing radical prostatectomy (RP).Material and methodsRetrospective analysis of 7,310 patients treated at 7 centers with RP and pelvic LN dissection for clinically localized prostate cancer between 2000 and 2011. Patients with LN metastases (n = 398) and other reasons (stated later in the article) (n = 372) were excluded, which left 6,540 patients for the final analyses.ResultsOverall, median biopsy and RP Gleason score were both 7; median prostate specific antigen level was 6 ng/ml (interquartile range [IQR]: 5); and median number of LNs removed was 6 (IQR: 8). A total of 3,698 (57%), 2,064 (32%), and 508 (8%) patients had ≥6, ≥10, and ≥20 LNs removed, respectively. Patients with more LNs removed were older, had a higher prostate specific antigen level, had higher clinical and pathologic T stage, and had higher RP Gleason score (all P<0.002). Within a median follow-up of 21 (IQR: 16) months, more LNs removed was associated with an increased risk of BCR (continuous: P = 0.021; categorical: P = 0.014). In multivariable analyses that adjusted for the effects of standard clinicopathologic factors, none of the nodal stratifications predicted BCR.ConclusionsThe number of LNs did not have any prognostic significance in our contemporary cohort of patients with LN-negative prostate cancer. This suggests that the risk of missed clinically significant micrometastasis may be minimal in patients currently treated with RP and having a lower LN yield.