Lymph node ratio predicts survival in hypopharyngeal cancer with positive lymph node metastasis.

The lymph node density (LND) has been reported to be a significant prognostic factor in various types of carcinoma. This study investigated whether the LND is associated with survival in patients with hypopharyngeal squamous cell carcinoma (HPSCC) who have positive lymph nodes without distant metastasis. Forty-six patients who were pathologically diagnosed with HPSCC with positive lymph nodes and without distant metastasis were enrolled in this study. The LND was defined as the ratio of positive lymph nodes to the total number of lymph nodes. An LND of >/=0.09 was found to be significantly correlated with a shorter overall (p = 0.044) and disease-specific (p = 0.019) survival according to a log-rank test. In a multivariate survival analysis using a Cox proportional hazards model adjusted for the pathological T category (pT3-4/pT1-2), pathological N category (pN2/pN1) and positive surgical margin and/or extracapsular spread (presence/absence), both an LND of >/=0.09 and pT3-4 category were associated with significantly shorter overall survival (p < 0.01) and disease-specific survival (p < 0.01). These results suggest that the LND functions as a prognostic factor for HPSCC patients with positive lymph nodes who do not have distant metastasis.