Prognostic impact of weight loss during radiation therapy in patients with head and neck cancer: A systematic review

BackgroundMalnutrition and weight loss (WL) are frequent in patients with head and neck cancer (HNC) during radiotherapy (RT), affecting treatment tolerance and outcomes. Nutritional interventions aim to minimize WL and support therapy completion, yet the prognostic value of WL during RT remains unclear.Aims/ObjectivesTo systematically evaluate the prognostic impact of WL before, during and after RT in patients with HNC.Methods/MethodologyThis systematic review included studies from 2012 involving adult patients treated with definitive or postoperative RT for HNC, studies were eligible if WL/body mass index (BMI) change was analysed versus survival outcomes (overall survival (OS), disease-specific survival (DSS)/cancer-specific survival, disease-free survival (DFS)). A structured PubMed and Cochrane search was conducted and results were synthesized narratively.Results/FindingsEight studies met the inclusion criteria. Pretreatment WL > 10% consistently predicted inferior OS and disease-specific survival (DSS). WL during RT varied widely between studies: most reported no association with OS, whereas single studies reported worse DSS with critical WL, worse OS with ΔBMI >1 kg/m², or an apparent survival advantage with greater WL. Posttreatment WL ≥ 10% was associated with reduced DFS. Comparability was limited by heterogeneous WL definitions, timing and treatment techniques.ConclusionPretreatment WL is a strong negative prognostic factor in HNC, whereas evidence for WL during or after RT remains inconsistent. Standardized WL assessment and structured nutritional support should be integrated into routine RT care. Future prospective studies using harmonized definitions are needed to clarify prognostic relevance and guide evidence-based nutrition management.