AUA 2022: Bilateral Inguinal Lymph Node Dissection Versus Inguinal Lymph Node Dissection and Dynamic Sentinel Node Biopsy in Clinical N1 Squamous Cell Carcinoma of the Penis

( In a podium presentation at the 2022 American Urologic Association Annual Meeting held in New Orleans and virtually, Dr. Nazzani presented on the role of bilateral inguinal lymph node dissection (ILND) versus unilateral inguinal lymph node dissection with contralateral dynamic sentinel node biopsy (DSNB) in patients with clinical N1 (cN1) penile squamous cell carcinoma (peSCC) patients.

To do so, the authors used their institutional database to identify 61 consecutive patients with cT1-4 cN1 cM0, histological confirmed peSCC who underwent either ipsilateral ILND plus contralateral DSNB or bilateral ILND between 1980–2020 inclusive. The authors then stratified patients according to treatment (ipsilateral ILND plus contralateral DSNB or bilateral ILND). The authors then considered each groin independently, dividing them into 61 clinical positive (cN1) and 61 clinical negative (cN0) groin regions according to clinical nodal disease to separately analyze the risk of pathological disease according to clinical status. The authors then divided these patients according to presence or absence of disease in the cN0 groin to better understand potential differences between patients with unilateral vs bilateral disease. Finally, the authors used the Kaplan-Meier technique to examine illustrated inguinal relapse (IR) rates and cancer-specific survival (CSS) rates according to ipsilateral ILND plus contralateral DSNB or bilateral ILND.

Among the 61 included men, the median age was 54 years [Interquartile range (IQR): 48-60 years). Most patients had pT1 (23 %) or pT2 (54.1%) tumors. Grade 2 (47.5%) and Grade 3 (23%) tumors, while lymphovascular (LVI) invasion was present in 67.1% of cases. Median clinical nodal volume was 20 mm (interquartile range [IQR] 18, 30 mm). Patients undergoing ipsilateral ILND plus contralateral DSNB were older than those treated with bilateral ILND (63 vs 54 years old, p-value 0.039) and they more frequently had organ sparing surgery (26.9 vs 2.9%, p-value 0.023).

Considering a cN1 and a cN0 groin, 57 out of 61 patients (93.5%) had pathological evidence of nodal disease in the cN1 groin. Conversely, only 14 out of 61 patients (22.9%) had nodal disease in the cN0 groin. After stratification according to presence or absence of pathological disease in the cN0 groin (cN0pN+ vs cN0pN0), cN0pN+ patients had tumor stage higher than pT1 in 92.8% of cases vs 57.4% of cN0pN0 patients though this difference did not reach statistical significance (p-value 0.1). Similarly, LVI was present in 92.9% vs 70% of cN0pNplus vs cN0pN0 patients, though again this did not reach statistical significance (p-value 0.08).

Over a median follow-up of 68 months (IQR 21-105 months), 5-year inguinal relapse-free survival was 91% [Confidence interval (CI) 80-100%] among patients treated with bilateral ILND and 88% (CI 73%-100%) for those who underwent ipsilateral ILND plus DSNB, a non-significant difference (p-value 0.8). Similarly, 5-year cancer specific survival was 76% (CI 62-92%) for those undergoing bilateral ILND and 78% (CI 63%-97%) for those who received ipsilateral ILND plus contralateral DSNB (p-value 0.9).

Thus, the authors conclude that, in patients with cN1 peSCC, the risk of occult contralateral nodal disease is comparable to cN0 high-risk peSCC. Thus, unilateral ILND and contralateral DSNB may be used in place of the gold standard bilateral ILND, without affecting positive node detection, inguinal relapse rates, or cancer specific survival.

Presented by: Sebastiano Nazzani, MD, Università degli Studi di Milano

Written by: Christopher J.D. Wallis, University of Toronto, Twitter: @WallisCJD during the 2022 American Urological Association (AUA) Annual Meeting, New Orleans, LA, Fri, May 13 – Mon, May 16, 2022.