Symptom clusters in patients with head and neck cancer receiving concurrent chemoradiotherapy

Objectives: This study is to identify symptom clusters for head and neck (HNC) patients treated with concurrent chemoradiotherapy. Patients and methods: A secondary data analysis of 684 HNC patients treated on the Radiation Therapy Oncology Group (RTOG) 0129 trial comparing different RT fractionation schedules with concurrent chemotherapy was used to examine clusters. Treatment-related symptoms were measured by clinicians at three time-points during and after chemoradiotherapy using the National Cancer Institute Common Toxicity Criteria v2.0. Exploratory factor analysis was applied to identify symptom clusters, which was further verified by confirmatory factor analysis. Coefficients of congruence and alpha coefficients were employed to examine generalizability of cluster structures over different time-points and in different subgroups. Results: Two clusters were identified. The HNC specific cluster is composed of radiodermatitis, dysphagia, radiomucositis, dry mouth, pain, taste disturbance, and fatigue. The gastrointestinal (GI) cluster involves nausea, vomiting, and dehydration. With the exception of patients 65 years old or older, diagnosed with larynx cancer, or with stage III cancer, the two clusters were generalizable to different subgroups defined by age, gender, race, education, marital status, history of tobacco use, treatments, primary sites, disease stages, and tube feedings, as well as to the three symptom assessment time-points. Conclusions: The data provides preliminary support for two stable clusters in patients with HNC. These findings may serve to inform the symptom management in clinical practice. Moreover, the findings necessitate future research to examine the generalizability of identified clusters in the late symptom phase or other treatment modalities, and to understand the underlying biological mechanism.