Prognostic Value of Neutrophil-to-Lymphocyte Ratio in Penile Squamous Cell Carcinoma Patients Undergoing Inguinal Lymph Node Dissection

Abstract

Background: Further biomarkers are warranted to improve prognostic stratification of penile squamous cell carcinoma (PSCC) patients undergoing inguinal lymph node dissection (ILND).

Objective: To assess the prognostic value of pretreatment neutrophil-to-lymphocyte ratio (NLR) in PSCC patients undergoing ILND and to investigate its role in predicting pathologic node-positive (pN+) disease.

Design, setting, and participants: In total, 84 consecutive patients undergoing ILND for PSCC at our institution between 1994 and 2014 were identified. Sixty-eight patients with a complete blood count and differential prior to surgery were included. Median follow-up was 35.5 mo.

Outcomes measurements and statistical analysis: Cut-off point analysis of NLR was performed using the Contal and O'Quigley method. Estimates of overall survival (OS), cancer-specific survival, and recurrence-free survival stratified by NLR were provided by the Kaplan-Meier method. Cox regression models were performed to determine predictors of survival and recurrence. Logistic regression models were used to identify factors associated with pathologic node-positivity.

Results and limitations: The cut-off point value was determined to be 3. Median OS was significantly shorter for patients with NLR ≥3 than those with NLR <3 (30 vs 158 mo, p<0.001). NLR ≥3 was an independent predictor of worse OS (hazard ratio=2.48; 95% confidence interval [CI]: 1.02-6.06, p=0.046). On univariable analysis, NLR ≥3 was associated with an increased risk of pN+ disease (odds ratio [OR]=3.75; 95% CI: 1.30-10.81, p=0.014). However, on multivariable analysis adjusted for primary tumor grade, lymphovascular invasion, clinical N stage, and neoadjuvant treatment receipt, the association between NLR and pN+ disease was no longer significant (OR=3.66; 95% CI: 0.82-16.42, p=0.091). The retrospective design and limited size of the study are acknowledged limitations.

Conclusions: Pretreatment NLR is an independent predictor of OS in PSCC patients undergoing ILND and highlights the association between systemic inflammation and survival. Our data suggests that a simple biomarker of inflammation can serve as a prognosticator in PSCC.

Patient summary: Penile cancer is a rare malignancy in North America and Europe. Therefore, there is a lack of prognostic parameters to help predict oncologic and survival outcomes. In this report, patients with an elevated neutrophil-to-lymphocyte ratio had an increased risk of mortality.

Keywords: Lymph node metastasis; Neutrophil-to-lymphocyte ratio; Penile squamous cell carcinoma; Recurrence; Survival.