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<0.001), and 86%, 86%, 81%, and 71%, respectively (P<0.001). After adjustment for potential confounders, >10% WL before radiotherapy remained significantly associated with a worse OS (HR 1.7; 95% CI 1.2-2.5; P = 0.002) and DSS (HR 2.1; 95% CI 1.2-3.5; P = 0.007). The 5-year OS and DSS rates for patients with critical WL during radiotherapy were 62% and 82%, compared with 70% and 89% for patients without critical WL (P = 0.01; P = 0.001). After adjustment, critical WL during radiotherapy remained significantly associated with a worse DSS (HR 1.7; 95% CI 1.2-2.4; P = 0.004). Conclusion: Weight loss both before and during radiotherapy are important prognostic indicators for 5-year DSS in HNC patients. Randomised studies into the prognostic effect of nutritional intervention are needed.