Lymphatic spread of nodal metastases in high-risk prostate cancer: The ascending pathway from the pelvis to the retroperitoneum

BACKGROUND The aim of this study was to map the nodal metastases distribution in patients with high-risk prostate cancer (PCa) treated with extended pelvic lymph node dissection (ePLND) and retroperitoneal lymph node dissection (rLND) at the time of radical prostatectomy (RP). MATERIALS AND METHODS This prospective mapping study included 19 patients with high-risk PCa (sharing at least two out of the three following parameters: PSA >20 ng/ml, cT3, biopsy Gleason score ≤yen;8). All patients were treated with RP, ePLND (removal of the obturator, hypogastric, external iliac, presacral, and common iliac lymph nodes) and rLND (removal of para-aortal/para-caval and inter-aorto-caval lymph nodes) by a single surgeon. All patients signed an informed consent highlighting the absence of clinical data supporting the benefit of this surgical approach. RESULTS Overall, 18 out of 19 patients (94.7%) had pelvic lymph node invasion. The most commonly affected pelvic nodal landing site was obturator (88.8%), followed by external iliac (83.3%), common iliac (77%), hypogastric (44.4%), and presacral (33.3%). Moreover, 14 (77.8%) patients also had involvement of retroperitoneal lymph nodes. Only patients with positive common iliac lymph nodes having at least five positive lower pelvic lymph nodes (n = 14), also had invariably positive retroperitoneal lymph nodes. No patients with negative common iliac lymph nodes had positive retroperitoneal lymph nodes. CONCLUSIONS PCa lymphatic spread ascends from the pelvis up to the retroperitoneum invariably through common iliac lymph nodes. PCa lymphatic spread can be divided in two main levels: pelvic and common iliac plus retroperitoneal lymph nodes. Prostate 72:186-192, 2012