Purpose
Computed tomography (CT)-defined skeletal muscle (SM) depletion and malnutrition are demonstrated poor prognostic factors in patients with head and neck cancer (HNC). We aimed to examine the impact of nutritional status and SM features on overall survival (OS), treatment completion, unplanned admissions and length of stay (LOS) in patients undergoing radiotherapy (RT) or chemoradiotherapy (CRT) of curative intent for HNC.
Methodology
Retrospective, observational study with nutritional status determined by Scored Patient-Generated Subjective Global Assessment and tissue-density data derived at the third lumbar vertebra (L3). Sarcopenia and myosteatosis were defined by sex-specific threshold values stratified by body mass index (BMI) for Skeletal Muscle Index (SMI, cm2/m2) and Skeletal Muscle Radiodensity (SMR, HU).
Results
Pre-treatment data (n=277: 78% male, mean (SD) age 60 (13) years), revealed the prevalence of malnutrition (24.9%), sarcopenia (52.3%), myosteatosis (82.3%) and concurrent sarcopenia and myosteatosis (39.7%). Malnutrition was independently associated with reduced OS for moderate (HR 2.57; 95% CI 1.45-4.55, p=0.001) and severe (HR 3.19; 95% CI 1.44 – 7.07, p=0.004) malnutrition but not sarcopenia (HR 1.09; 95%CI 0.70 – 1.71, p=0.700) or myosteatosis (HR 1.28; 95% CI 0.57 – 2.84, p=0.500). Malnutrition was associated with treatment discontinuation (p<0.001), unplanned admission (p=0.021) and greater LOS (0.052). SM features were associated with unplanned admissions for: no features (32%), sarcopenia only (50%), myosteatosis only (25%) and concurrent sarcopenia and myosteatosis (50%), p < 0.001. Median (Q1, Q3) LOS was greater for: sarcopenia only (5 (3,32)), myosteatosis only (10 (5,30)), concurrent sarcopenia and myosteatosis (14 (4,33)) days versus no features (3 (2,11)) days, p<0.001.
Conclusion
Malnutrition is a more powerful prognostic indicator than CT-defined SM depletion in these patients. Nutritional status should be assessed using validated methods to move towards developing a typology of high risk criteria for this complex patient group.