MP11-04 CONTEMPORARY INCIDENCE AND PREDICTORS OF OCCULT INGUINAL LYMPH NODE METASTASES IN MEN WITH CN0 PENILE CANCER

Abstract

INTRODUCTION AND OBJECTIVE: Clinical practice guidelines recommend inguinal lymph node dissection (ILND) for men with clinically node-negative (cN0) penile cancer at increased risk of occult lymph node (LN) metastases. However, data regarding the incidence of occult LN metastases are limited to few studies that predated the introduction of contemporary cross-sectional imaging techniques. We therefore examined the contemporary incidence and predictors of occult inguinal LN metastases. METHODS: We identified 590 adult men with cTany cN0 cM0 squamous cell carcinoma of the penis who underwent partial/radical penectomy and ILND from 2006-2016 in the National Cancer Database. Rates of pN+ disease were examined stratified by tumor features, and a multivariable regression model was constructed to examine patient and clinical features associated with pN+ disease. RESULTS: Mean age was 61 (SD 12.5) years and median tumor size was 3.5 cm (IQR 2.5-4.8). Tumors were ≤pT1 in 126 (21%), pT2 in 256 (43%), and pT3/pT4 in 143 (24%) patients. Tumor grade was 1-2 in 409 (69%) and 3-4 in 160 (27%) of patients. A median of 15 (IQR 8-22) LNs were removed at ILND. The overall pN+ rate was 24% and did not vary over the study period (Figure 1). The pN+ rate, stratified by pT stage, varied from 18-33% (Table 1). On multivariable analysis, only higher tumor grade (OR 2.16;p=0.02 for grade 2; OR 2.81;p=0.005 for grade 3-4,versus grade 1) and lymphovascular invasion (OR 3.12;p<0.001) were independently associated with pN+ disease, whereas pT stage was not. CONCLUSIONS: Contemporary rates of occult LN metastases in men with cN0 penile cancer remain high at approximately 24%. Higher tumor grade and lymphovascular invasion were independently associated with pN+ disease, whereas pT stage was not.Source of Funding: None