Lymphovascular and perineural invasion are risk factors for inguinal lymph node metastases in men with T1G2 penile cancer

PURPOSE: To analyse the risk of inguinal lymph node (ILN) metastases in T1G2 penile cancer stratified by lymphovascular invasion (LVI), perineural invasion (PNI) and tumour size. METHODS: Retrospective study of men with localised T1G2 penile cancer with non-palpable lymph nodes and no local recurrence during follow-up at six European institutional high-volume centres was performed. ILN involvement was defined as cancer detected during ultrasound-guided fine-needle aspiration cytology, core needle biopsy, dynamic sentinel lymph node biopsy, ILN dissection or inguinal recurrence during follow-up. Uni- and multivariable logistic regression analyses were performed. RESULTS: In the cohort of 554 men with T1G2 penile cancer, from 6 European institutions, ILN metastases were observed in 46/554 men (8%, 95% confidence interval (CI) 6-11%). Men with both, LVI- and PNI- primary cancers had the lowest risk of ILN involvement (6%) whereas men with LVI + or PNI + showed ILN metastases in 22% and 30%. In multivariable regression, men with LVI + or PNI + had higher odds for ILN metastases compared to men with LVI- and PNI- (OR 3.9, 95% CI 1.6-9.0, p value