Malnutrition-related symptom clusters and quality of life in nasopharyngeal carcinoma patients during radiotherapy: a network analysis

BACKGROUND: To identify symptom clusters (SCs) of nasopharyngeal carcinoma (NPC) patients during radiotherapy and examine the relative importance of specific symptoms in relation to quality of life (QoL). METHODS: This cross-sectional study recruited non-metastatic NPC patients undergoing radiotherapy at Sun Yat-sen University Cancer Center (August 23-24, 2023). Acute toxicities, malnutrition, and QoL were assessed using the patient-reported outcome version of the Common Terminology Criteria for Adverse Events (PRO-CTCAE), modified Patient-Generated Subjective Global Assessment (mPG-SGA), and European Organization for Research and Treatment of Cancer Quality of Life Questionnaire Head and Neck 35 (EORTC QLQ-H&N35), respectively. Exploratory factor analysis and network analysis were used to identify SCs and characterize central and bridge symptoms. Multivariable logistic regression was conducted to explore factors associated with QoL. RESULTS: A total of 437 eligible patients (73.46% male; median [IQR] age, 47 [38-55]) were included. Most patients reported ≥ 5 acute toxicities (88.56%) and severe malnutrition (75.06%). Three SCs (corresponding central symptoms) were identified from 18 prevalent items of PRO-CTCAE: general SC (anxiety), head-neck SC (dysphagia), and gastrointestinal SC (nausea). Malnutrition showed high bridge connectivity across SCs. The network remained relatively stable across early and late radiotherapy phases. Among multiple variables examined, the head-neck SC showed the strongest association with poorer QoL (β = 1.805, P < 0.001). CONCLUSIONS: NPC patients experience multiple co-occurring symptoms that organize into distinct clusters associated with QoL throughout radiotherapy. Dysphagia in head-neck SC and malnutrition deserve to be priorities for early management to relieve the global network burdens.