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.