Can preoperative neutrophil:lymphocyte and platelet:lymphocyte ratios be used as predictive markers for lymph node metastasis in squamous cell carcinoma of the vulva?

Abstract

Objective: To determine whether the neutrophil:lymphocyte ratio (NLR) and platelet:lymphocyte ratio (PLR) before complete surgical staging provide information on lymph node metastasis in vulvar squamous cell carcinoma (SCC).

Study design: All patients with vulvar SCC who underwent complete surgical staging at two institutions between 1 January 2005 and 31 December 2011 were identified retrospectively from patient databases. Receiver operating characteristic (ROC) curve analysis was used to evaluate cut-off, sensitivity, and specificity values for preoperative NLR and PLR to predict lymph node metastasis.

Results: Data from 64 women with adequate information were analyzed. Lymph node involvement was detected in 19 (29.7%) patients. NLR and PLR were higher in the lymph node--positive group than in the--negative group (p < 0.001). The best cut-off values for predicting lymph node metastasis were 2.81 for the NLR, with 84.5% sensitivity and 89.5% specificity, and 139.5 for the PLR, with 68.9% sensitivity and 89.5% specificity. Forty of the 64 (62.5%) patients had NLRs ≤ 2.81 and 24 (37.5%) had NLRs >2.81. Lymph node involvement was more common in the NLR >2.81 group [60.7% vs. 5.6%; relative risk RR = 10.9, 95% confidence interval CI = 2.7-43.4; p < 0.001]. Mean tumor sizes were 4.2 ± 2.3 cm in the NLR >2.81 group and 2.1 ± 1.2 cm in the NLR ≤ 2.81 group (p = 0.001). The rate of lymph node involvement was higher in the PLR >139.5 group than in the PLR ≤ 139.5 group (54.8% vs. 6.1%; RR = 9.0, 95% CI = 2.2-35.9; p<0.001).

Conclusion: Preoperative NLR and PLR are directly associated with nodal involvement status of vulvar SCC. These markers are simple, readily obtained and calculated, and easy to integrate into the surgical work-up of patients with vulvar SCC, at no extra cost.

Keywords: Lymph node metastasis; Neutrophil:lymphocyte ratio; Platelet:lymphocyte ratio; Preoperative; Vulvar squamous cell carcinoma.