EAU 2017: State of the Art Debate - Evidence for extent of lymphadenectomy in urothelial bladder cancer

London, England (UroToday.com) In this session, Professor Witjes discussed the state of the evidence for lymphadenectomy in bladder cancer. He began by quoting Dr. Skinner who believed that the patients who benefit the most from LND had low volume micrometastic disease. Clearly, survival is worse for patients who have nodal disease with estimated 3-year recurrence free survival of 66.3% for pN0 disease compared to 14.6% for pN+ disease. Thus, accurate information about nodal state is prognostically helpful. At present, CT scan lacks adequate sensitivity (~52.6%) to properly stage lymph nodes; therefore, lymphadenectomy remains the gold standard for staging purposes.

But the question of whether lymphadenectomy and its extent confers a survival benefit is more difficult to untangle. The majority of the literature considers retrospective analyses which have inherent selection biases. Moreover, the extent to which survival differences result from more accurately staging (Will-Rogers effect) remains unclear. The sole randomized trial was a German effort entitled the LEA trial. It randomized patients with cT1-cT4a bladder cancer to limited lymphadenectomy (obturator internal, and external iliac versus extended lymphadenectomy (+ deep obturator, pre-sacral, common iliac, paracaval, interaortocaval, and paraaortic nodes up to the IMA). The main exclusion criteria were neoadjuvant chemotherapy, previous pelvic radiation, presence of visceral metastasis, and lymph nodes > 1cm above the aortic bifurcation. The primary endpoint was recurrence-free survival.

The intention to treat analysis contained 190 patients who underwent limited lymphadenectomy and 183 patients who underwent extended lymphadenectomy with a median follow-up of 33.2 months (range 0-108 months). Importantly, the rate of ≤ pT2 tumors was 57.4% including 14.5% pT1 tumors. The rate of pN+ was 23.9%. Of 190 positive lymph nodes, 61% were located in the limited field and 38.9% were located in the extended field.

The recurrence-free survival in the limited node dissection group was 61.5% versus 67% in the extended dissection group (p = 0.34). Cancer-specific survival was 66.2% in the limited dissection group versus 77.6% in the extended lymph node dissection group (p=0.12). A post-hoc subgroup analysis of pT2 (n=160) patients demonstrated significant differences of 85.0% in the extended lymph node dissection group versus 62.5% in the limited lymph node dissection group (p = 0.01).

Regarding complications, there was no difference in either 30- or 90-day major complications (≥ Clavien 3). However, there were more lymphoceles that required intervention in the extended dissection group (9.3%) compared to the limited dissection group (3.7%, p = 0.03).

In conclusion, Professor Witjes stated that a meticulous lymph node dissection should include external, internal, and obturator nodes. Extended lymph node dissection more accurately determines the presence of lymph node metastases. If there is a survival benefit, it is likely to be in the organ-confined pT2 tumors.

Speaker: J.A. Witjes, Munich, DE

Written by: Benjamin T. Ristau, MD, SUO Fellow, Fox Chase Cancer Center, Philadelphia, PA.

at the #EAU17 -March 24-28, 2017- London, England

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