The extent of pelvic lymph node dissection correlates with the biochemical recurrence rate in patients with intermediate- and high-risk prostate cancer

OBJECTIVE: • To assess the impact of pelvic lymph node dissection (PLND) and of the number of lymph nodes (LNs) retrieved during radical prostatectomy (RP) on biochemical relapse (BCR) in pNX/0/1 patients with prostate cancer according to the clinical risk of lymph node invasion (LNI). PATIENTS AND METHODS: • We evaluated 872 pT2-4 NX/0/1 consecutive patients submitted to RP between October 1995 and June 2009, with the following inclusion criteria: (i) a follow-up period ≥12 months; (ii) the avoidance of neoadjuvant hormonal therapy or adjuvant hormonal and/or adjuvant radiotherapy; (iii) the availability of complete follow-up data; (iv) no pathological T0 disease; (v) complete data regarding the clinical stage and Gleason score (Gs), the preoperative prostate-specific antigen (PSA) level and the pathological stage. • The patients were stratified as having low risk (cT1a-T2a and cGs ≤6 and PSA level < 10 ng/mL), intermediate risk (cT2b-T2c or cGs = 7 or PSA level = 10-19.9) or high risk of LNI (cT3 or cGs = 8-10 or PSA level ≥ 20). • The 872 patients were divided into two LN groups according to the number of LNs retrieved: group 1 had no LN or one to nine LNs removed; group 2 had 10 or more LNs. • The variables analysed were LN group, age, PSA level, clinical and pathological stage and Gs, surgical margin status, LN status and number of LN metastases; the primary endpoint was the BCR-free survival. RESULTS: • The mean follow-up was 55.8 months. • Of all the patients, 305 (35%) were pNx and 567 (65.0%) were pN0/1. • Of the 567 patients submitted to PLND, the mean number of LNs obtained was 10.9, and 49 (8.6%) were pN1. • In the 402 patients at low risk of LNI, LN group was not a significant predictor of BCR at univariate analysis, while in the 470 patients at intermediate and high risk of LNI, patients with ≥ 10 LNs removed had a significantly lower BCR-free survival at univariate and multivariate analysis. CONCLUSION: • In our study population, a more extensive PLND positively affects the BCR-free survival regardless of the nodal status in intermediate- and high-risk prostate cancer.