Critical weight loss is a major prognostic indicator for disease-specific survival in patients with head and neck cancer receiving radiotherapy

Background: Pre-treatment weight loss (WL) is a prognostic indicator for overall survival (OS) in head and neck cancer (HNC) patients. This study investigates the association between WL before or during radiotherapy and disease-specific survival (DSS) in HNC patients. Methods: In 1340 newly diagnosed HNC patients, weight change was collected before and during (adjuvant) radiotherapy with curative intent. Critical WL during radiotherapy was defined as >5% WL during radiotherapy or >7.5% WL until week 12. Differences in 5-year OS and DSS between WL groups were analysed by Cox’s regression with adjustments for important socio-demographic and tumour-related confounders. Results: Before radiotherapy, 70% of patients had no WL, 16% had ⩽5% WL, 9% had >5–10% WL, and 5% had >10% WL. Five-year OS and DSS rates for these groups were 71%, 59%, 47%, and 42% ( P