Prognostic capacity of the lymph node ratio in squamous cell carcinomas of the head and neck.

INTRODUCTION AND OBJECTIVES Lymph node density or lymph node ratio (LNR), defined as the quotient between the total number of positive lymph nodes and the total number of dissected lymph nodes, has demonstrated a prognostic capacity in several tumour models, including patients with head and neck squamous cell carcinomas (HNSCC). The aim of the present study is to analyse the prognostic value of LNR in a wide cohort of patients with HNSCC. METHODS We carried out a retrospective study of a cohort of 1,311 patients with HNSCC treated with unilateral or bilateral neck dissections. Of the patients included in the study, 55.0% had lymph node metastases (pN+). We proceeded to calculate the value of the LNR, and its categorization through a recursive partition analysis considering specific survival as the dependent variable. RESULTS Three categories were defined according to the value of the LNR with a cut-off point at the values < of .025 and .118. The 5-year specific survival for patients with an LNR less than .025 (n=654, 49.8%) was 87.2%, for patients with a LNR .025-.118 (n=394, 30.1%) it was 51.6%, and for patients with a LNR greater than .188 (n=263, 20.1%) it was 27.3% (P=.0001). According to the results of a multivariate analysis, the LNR significantly related to specific survival. CONCLUSION The LNR can be a prognostic variable to be considered in the pathological staging of the lymph nodes.