Pelvic node dissection in prostate cancer: extended, limited, or not at all?

Pelvic lymph node dissection in patients with clinically localized prostate cancer has long been an established part of radical prostatectomy that provides prognostic information in men with locally metastatic disease. However, given downward stage migration over the last 25 years, it is no longer clear that pelvic lymphadenectomy is pertinent for most men diagnosed today. In men in whom it is pertinent, it is unclear how extensive a lymphadenectomy should be performed.

Computed tomography and magnetic resonance imaging alone are not accurate for detecting nodal metastases, but new modalities such as magnetic resonance lymphography have great apparent potential. Until these become widely available, pelvic lymph node dissection remains the modality of choice for detecting lymph node metastasis. A variety of predictive nomograms exists to predict lymph node involvement. As a pelvic lymphadenectomy has complications that generally increase with extent of dissection, lymphadenectomy should be limited to patients at an increased risk of nodal metastasis.

There is good evidence that a pelvic lymph node dissection limited to the external iliac vein nodes is unnecessary in men with low-risk prostate cancer. A standard external iliac and obturator lymph node dissection, with or without extension to hypogastric nodes, makes sense in cases of intermediate and high risk. Harvesting a greater number of lymph nodes adds prognostic and even therapeutic benefit in many cases, including in some men with no obvious nodal metastases.