New insights into cancer-related skeletal muscle depletion and malnutrition in patients with head and neck cancer

Malnutrition is prevalent in patients with head and neck cancer (HNC) impacting negatively on clinical, economic and patient-centred outcomes. As diagnostic assessment and phenotypic criteria of malnutrition should include evaluation of muscle mass, body composition analysis by computed tomography (CT) has become a focus of cancer research arising from its well-documented prognostic significance. Positioned within the American Academy of Nutrition and Dietetics (AND) Nutrition Care Process (NCP) Model, this thesis aimed to examine the impact of CT-defined skeletal muscle depletion on outcomes for adult patients (≥18 years) who had completed radiotherapy ± other treatment modality of curative intent for HNC. Key findings include: i) both skeletal muscle depletion and malnutrition impact negatively on outcomes and therefore hold important prognostic value for patients with HNC; ii) human body composition is complex, influencing individualised risk in an era of personalised medicine; iii) methodological consensus and reporting guidelines in CT-defined skeletal muscle research are required; and iv) the clinical utility of CT-defined skeletal muscle depletion warrants further exploration. The powerful prognostic value of nutritional status reinforces the importance of comprehensive nutrition assessment using validated tools in the oncology population, aligning with current evidence-based guidelines. This thesis substantially advances the knowledge and understanding of the impact of CT-defined skeletal muscle depletion and nutritional status on outcomes for patients with HNC. The overall findings highlight that adhering to evidence-based guidelines for optimum cancer nutrition care plays a central role in the identification of patients at high risk of poor outcomes. This research holds important implications for clinical care, education, research and policy in which dietitians are ideally placed to take a leadership role to improve outcomes for this complex patient group