Correlative analysis between external and internal lymphedema in head and neck cancer survivors.

12120 Background: More than 75% of head and neck cancer (HNC) survivors develop lymphedema following cancer treatment. Lymphedema can affect both external (e.g., soft tissue of the face and neck) and internal (e.g., pharynx and larynx) structures. Early identification and timely referral are essential for maintaining functionality and minimizing symptom burden. Understanding the relationship between external and internal lymphedema may inform assessment and treatment strategies. However, data describing the association between external and internal lymphedema remains limited. The purpose of this report is to fill this gap. Methods: A prospective, longitudinal descriptive study included 117 patients with oral cavity and oropharyngeal cancer. External lymphedema was evaluated through physical examination using the validated Head and Neck External Lymphedema and Fibrosis Assessment Criteria. Internal lymphedema was evaluated using an endoscopic examination scored with the Modified Patterson Scale. Examinations were performed at baseline and every three months for 12 months post-treatment. Somers’d correlation coefficients were calculated to test associations between external and internal lymphedema measures. Results: Both the total number of sites with external lymphedema and the total external lymphedema severity score correlated with the presence of at least one site of internal lymphedema (both d = 0.31). The total number of external sites of lymphedema moderately correlated with internal lymphedema involving the following structures: epiglottis (d = 0.31), pharyngoepiglottic folds (d = 0.35), aryepiglottic folds (d = 0.34), and anterior commissure (d = 0.32). The total external lymphedema severity score correlated with internal lymphedema involving the following structures: the epiglottis (d = 0.32), pharyngoepiglottic folds (d = 0.35), and aryepiglottic folds (d = 0.34). External submental lymphedema correlated with internal lymphedema involving the buccal mucosa (d = 0.27), epiglottis (d = 0.28), pharyngoepiglottic folds (d = 0.28), and pyriform sinus (d = 0.28). External lymphedema of the neck correlated with internal lymphedema in the pharyngoepiglottic folds (d = 0.28), arytenoids (d = 0.27), and anterior commissure (d = 0.29). External cheek lymphedema failed to correlate significantly with internal lymphedema. Conclusions: HNC survivors with external lymphedema are likely to have concurrent internal lymphedema. The presence of external lymphedema should initiate evaluation for internal lymphedema, particularly in patients with dysphagia or shortness of breath. The site of external lymphedema correlates with the sites of internal lymphedema: this may help inform assessment and management.