SUO 2017: The Role of Inguinal Lymph Node Dissection in Men with Urethral Squamous Cell Carcinoma

Washington, DC ( Urethral squamous cell carcinoma (SCC) is a rare disease with limited clinical recommendations. Dr. Werntz and colleagues presented their population-level analysis assessing the impact of inguinal lymph node dissection in men with urethral SCC. Despite the similarities to penile cancer in terms of histology and lymphatic drainage, no consensus exists on the role of inguinal lymph node dissection for men with high-risk tumors. The objective of this study was to define the rate of inguinal lymph node dissection performance and its impact on survival. 

The authors assessed the National Cancer Database (NCDB) to identify all cases of primary urethral cancer in men from 2004 to 2014. Patients with other cancer diagnoses, metastasis, non-squamous histology, and a history of radiation therapy or chemotherapy were excluded. For penile cancer comparative purposes, only male patients with urethral SCC of the anterior urethra with clinical stage ≥T1 were included for analysis. Overall survival (OS) was compared using multivariable Cox regression. There were 725 men that met inclusion criteria. The median age was 63 years (IQR 33-83) and 189 (26%) underwent lymph node dissection. Patients who underwent lymph node dissection were of significantly higher clinical T and N stage. In patients with clinical N0, the lymph node dissection rate was 21.8%, with 9% pathologically positive. In patients with clinical N1-2, the lymph node dissection rate was 76%, with 84% pathologically positive. On multivariable Cox regression, lymph node positivity was associated with worse overall survival when controlling for clinical T stage, clinical N stage, Charleston comorbidity, age, and sex (HR 1.56, 95%CI 1.3-1.9, p<0.001). On multivariable analysis, lymph node dissection was not associated with improved OS in clinically N0 patients (HR 1.4, 95%CI 0.96-2.00, p=0.07), however was associated with improved OS in patients with clinical N1 or N2 disease (HR 0.46, 95%CI 0.28-0.78, p=0.002). A limitation of the NCDB is the inability to perform analysis assessing cancer-specific survival.

The authors concluded that the lymph node positivity rate in patients with clinical T1-T4 and N0 urethral SCC is 9%, substantially lower than reported in penile cancer, arguing against routine prophylactic inguinal lymph node dissection in this population. Lymph node dissection in clinically N0 patients was not associated with improved OS, however it was for patients with clinical N1-2 disease.

Presented by: Ryan P. Werntz, MD

Co-Authors: Ryan Werntz , RIchard Fantus , Zachary Smith , Melanie Adamsky , Chris Riedinger  and Gary Steinberg

Written by: Zachary Klaassen, MD, Society of Urologic Oncology Fellow, University of Toronto, Princess Margaret Cancer Centre @zklaassen_md at the 18th Annual Meeting of the Society of Urologic Oncology, November 20-December 1, 2017 – Washington, DC