Lymph node ratio as a prognostic factor in head and neck cancer patients

BACKGROUND: Lymph node status is one prognostic factor in head and neck cancer. The purpose of this study is to investigate the prognostic value of lymph node ratio (LNR) in head and neck cancer patients who received surgery plus postoperative chemoradiotherapy. METHODS: From May 1991 to December 2012, a total of 117 head and neck cancer patients who received surgery plus postoperative chemoradiotherapy were analyzed. The primary sites were oral cavity (93), oropharynx (13), hypopharynx (6), and larynx (5). All patients had pathologically confirmed squamous cell carcinoma and 63 patients had neck lymph nodes metastasis. LNR was calculated for each patient. The endpoints were overall survival (OS), local failure-free survival (LFFS), and distant metastasis-free survival (DMFS). RESULTS: The median follow up time was 36 months, with a range from 3.4 to 222 months. The 3-year rates of OS, LFFS, and DMFS were 59.7, 70.3, and 81.8 %, respectively. The median value of LNR for lymph nodes positive patients was 0.1. In univariate analysis, patients with an LNR value less than 0.1 had better 3-year OS (67.0 % vs.41.0 %, p = 0.004), 3-year LFFS (76.1 % vs. 54.9 %, p = 0.015) and 3-year DMFS (87.2 % vs. 66.4 %, p = 0.06). Multivariate analysis revealed that LNR was an independent prognostic factor for OS (hazard ratio [HR] = 2.92; 95 % confidence interval [CI] = 1.367–6.242; p = 0.006) and LFFS (HR = 4.12; 95 % CI = 1.604–10.59; p = 0.003). CONCLUSION: LNR is an important prognosis factor for OS and LFFS in head and neck cancer patients. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s13014-015-0490-9) contains supplementary material, which is available to authorized users.