Association of Imaging-Defined Deep Invasion and Tumor Volume With Clinical Cervical Lymph Node Metastasis in Hypopharyngeal Carcinoma

OBJECTIVE: Deep tumor invasion is a recognized pathologic risk factor for cervical lymph node metastasis in patients with hypopharyngeal carcinoma, but the relationship between imaging findings of the primary tumor and clinical lymph node metastasis has not been fully defined. In this study, we assessed whether imaging-defined deep invasion and tumor volume are associated with clinical lymph node metastasis. METHODS: This retrospective study included 142 consecutive patients with newly diagnosed hypopharyngeal squamous cell carcinoma who underwent contrast-enhanced CT and MRI before treatment. Deep anterior wall (paraglottic space) invasion was graded according to tumor contact with the superior laryngeal neurovascular bundle. Deep posterior wall invasion was evaluated on MRI. Tumor diameter and volume were measured, and associations with lymph node status were assessed. Multivariable logistic regression was used to identify independent factors of clinical lymph node metastasis. RESULTS: Clinical cervical lymph node metastasis was present in 78/142 patients (54.9%). The median tumor volume was greater in node-positive than in node-negative tumors (3.92 vs. 0.22 cm3, P<0.001). Deep anterior wall invasion was detected in 82 patients, and was more common in node-positive cases (73.1% vs. 39.1%, P<0.001). In multivariable analysis, deep anterior wall invasion (OR=2.42; 95% CI: 1.02-5.78; P=0.04) and tumor volume (OR=1.32 per cm3; 95% CI: 1.08-1.73; P=0.025) were independently associated with clinical cervical lymph node metastasis. CONCLUSION: Deep anterior wall invasion and larger tumor volume were associated with clinical cervical lymph node metastasis in hypopharyngeal carcinoma.