Factors associated with regional recurrence after lymph node dissection for penile squamous cell carcinoma.

Abstract

To identify factors associated with regional recurrence after lymph node dissection (LND) for squamous cell carcinoma (SCC) to determine which patients might benefit from adjuvant therapy. Men who underwent LND for penile SCC from 1977 to 2014 were identified from an institutional database. Kaplan-Meier curves estimated recurrence-free survival (RFS) calculated from the date of LND. Cox regression models evaluated the association between RFS and patient and tumour characteristics. In all, 182 men who underwent LND for penile SCC were identified. The median patient age was 62 years and the median follow-up was 4.2 years. After LND 34 men had regional recurrence, of which 24 developed isolated regional recurrences without distant metastasis. The median RFS was 5.7 months, and the 3-year RFS rate was 70%. On univariate analysis, lymphovascular invasion, clinical and pathological nodal stage, pathological inguinal laterality, pelvic nodal involvement, lymph node density ≥5.2%, ≥3 pathologically involved lymph nodes, and extranodal extension (ENE) were associated with worse RFS (all P < 0.05). On multivariate analysis, clinical N3 disease [adjusted hazard ratio (AHR)] 3.53, 95% confidence interval (CI) 1.68-7.45; P = 0.001), ≥3 pathologically involved lymph nodes (AHR 3.78, 95% CI 2.12-6.65; P < 0.001), and ENE (AHR 3.32, 95% CI 1.93-5.76; P < 0.001) were associated with worse RFS. The 3-year RFS for patients with cN0, cN1, cN2, and cN3 disease was 91.7%, 64.5%, 54.7%, and 38.3%, respectively. For men with ≥3 involved nodes, the 3-year RFS was 17% vs 82.4% in men with <3 involved nodes. The 3-year RFS was 29.7% in men with ENE and 85.7% in men without ENE. The presence of clinical N3 disease, ≥3 pathologically involved lymph nodes, and ENE was associated with worse RFS. As regional recurrence portends a dismal prognosis with few salvage options, adjuvant therapies should be developed for men with the aforementioned adverse factors.