Between Pathological Prostate Cancer Lymph Nodes and Sentinel Nodes: Which Information Is the Leader?

ABSTRACT

PURPOSE: On the basis of the concept of sentinel lymph node biopsy (SLNB), SLNs should contain decisive information for clinical outcomes. In localized prostate cancer patients, this study assessed retrospectively clinical outcome after radical laparoscopic prostatectomy associated with SLNB and extensive pelvic lymph node dissection. METHODS: A total of 231 consecutive patients of intermediate to high risk were analyzed. Recurrence-free survival (RFS) was assessed with Kaplan-Meier curves. Various pathological parameters were analyzed using univariable and multivariable analyses through Cox regression analysis. The study was approved and registered under 2007-R41. RESULTS: The median follow-up was 7.1 years (95% confidence interval, 6.6-7.5). In total, 38/231 (16.5%) patients were pN1. Of these 38 patients, 27 had only SLN involvement (SLNI), 10 patients had both SLN and non-SLNI, and 1 patient had isolated non-SLNI, indicating a false-negative (FN). If the updated Briganti nomogram threshold set at >7% for recommending extensive pelvic lymph node dissection had been applied to these patients, we would have missed 44% (12/27) of patients with SLNI and 50% (5/10) of patients with SLNI and non-SLNI, as well as the FN patient. At the time of final follow-up, 84/231 (36.5%) patients had recurrence. In multivariable analysis, and regarding node status, the most significant prognostic factor was SLN with macrometastases and/or micrometastases, respectively, P = 10-3 and P < 10-3. No more information was obtained with non-SLN status. Probabilities of RFS between negative and positive SLN patients presented a major significant difference (P < 10-15) with a risk of event 8.75 times more frequent if SLN was involved than if it was metastasis-free. CONCLUSIONS: SLNB seems to contain decisive information for the clinical outcome of patients with localized intermediate- and high-risk prostate cancer patients. The question raised is thus whether immediate additional postoperative treatment should be offered to patients with metastatic SLN.