To assess whether any relationship exists between the number of histologically examined lymph nodes and the detection of metastases in pelvic lymph node dissection (PLND) specimens taken from patients with radical prostatectomy (RP) for prostatic adenocarcinoma. 1690 cases of RP with PNLD were included in the study; 54 % of the patients were submitted to extended PLND (ePLND). Kaplan-Meier curves confirm the negative prognostic significance of nodal metastases on the overall patients' survival (P < 0.0001). Nodal metastases are significantly associated with older age of patients (P = 0.0466), higher pT status (P < 0.0001), higher Gleason score (P < 0.0001) and positive surgical margin (P < 0.0001). The frequency of nodal metastases is significantly increased in cases submitted to ePLND (P < 0.0001), presumably due to the significantly higher number of lymphnodes retrieved using this procedure (P < 0.0001). In addition, regardless of the extent of PLND procedure, entire histological examination of PLND specimens is significantly associated with a higher frequency of nodal metastases (P < 0.0001). When we considered only pN0 cases, 21 display adverse prognosis and died of disease during the follow-up. The number of pelvic lymphnodes examined is significantly lower in the group of patients who die of the disease compared to that of survivors (P = 0.0448). In addition, Kaplan-Meier analysis shows that patients with 10 or fewer examined lymphnodes have significantly shorter disease-specific survival (P = 0.0151). Our findings confirm the negative prognostic significance of N status in prostate cancer. We suggest the examination of a minimum number of 10 lymphnodes, together with entire PLND processing, for accurate assessment of N status.
Keywords: Lymph nodes dissection; Lymphadenectomy; Metastases; Prostatic cancer.