Analysis of risk factors for retropharyngeal lymph node metastasis in carcinoma of the hypopharynx.

BACKGROUND The purpose of this study was to investigate the incidence of retropharyngeal lymph node (RPLN) metastasis and to explore the associated risk factors using CT and MRI, to direct clinical radiotherapy in hypopharyngeal carcinoma (HPC). METHODS The CT and MRI images of 218 patients with pathologically confirmed HPC were analyzed retrospectively. The chi-square test and logistic regression were used for statistical analysis. RESULTS The incidence of RPLN metastasis in HPC was 17.0%, and the highest rate of 36.4% was found in pharyngeal wall carcinoma. None of the patients with N0 classification exhibited RPLN metastasis. Univariate and multivariate analyses demonstrated that primary tumor subsites, bilateral cervical lymph node metastasis, the number and size of cervical lymph nodes, and level V metastasis were significantly associated with RPLN metastasis. CONCLUSIONS Our findings demonstrated that primary carcinoma subsites and multiple metastatic cervical lymph nodes are the principal risk factors for RPLN metastasis.