Bilateral inguinal lymph-node dissection vs. unilateral inguinal lymph-node dissection and dynamic sentinel node biopsy in clinical N1 squamous cell carcinoma of the penis

Introduction: To evaluate the role of unilateral inguinal lymph-node dissection (ILND) plus contralateral dynamic sentinel node biopsy (DSNB) vs. bilateral ILND in clinical N1 (cN1) penile squamous cell carcinoma (peSCC) patients. Material and methods: Within our institutional database (1980-2020, included), we identified 61 consecutive cT1-4 cN1 cM0 patients with histological confirmed peSCC who underwent either unilateral ILND plus DSNB (26) or bilateral ILND (35). Results: Median age was 54 years (Interquartile range [IQR]: 48-60 years). Median follow-up was 68 months (IQR 21-105 months). Most patients had pT1 (23 %) or pT2 (54.1%), as well as G2 (47.5%) or G3 (23%) tumors, while lymphovascular invasion (LVI) was present in 67.1% of cases. Considering a cN1 and a cN0 groin, overall 57 out of 61 patients (93.5%) had nodal disease in the cN1 groin. Conversely, only 14 out of 61 patients (22.9%) had nodal disease in the cN0 groin. 5-year IR-free survival was 91% (Confidence interval [CI] 80%-100%) for bilateral ILND group and 88% (CI 73%-100%) for the ipsilateral ILND plus DSNB group (P-value 0.8). Conversely, 5-year CSS was 76% (CI 62%-92%) for bilateral ILND group and 78% (CI 63%-97%) for the ipsilateral ILND plus contralateral DSNB group (P-value 0.9). Conclusions: In patients with cN1 peSCC the risk of occult contralateral nodal disease is comparable to cN0 high risk peSCC and the gold standard, namely bilateral ILND, may be replaced by unilateral ILND and contralateral DSNB without affecting positive node detection, IRRs and CSS.