Impact of sarcopenia and myosteatosis on survival outcomes for patients with head and neck cancer undergoing curative-intent treatment.

Malnutrition and sarcopenia are prevalent in patients with head and neck squamous cell carcinoma (HNSCC). Pre-treatment sarcopenia and adverse oncologic outcomes in this population is well described. The impact of myosteatosis and post-treatment sarcopenia is less well known. Patients with HNSCC (n=125) undergoing chemoradiotherapy, radiotherapy alone and/or surgery were assessed for sarcopenia and myosteatosis, using cross-sectional computed tomography (CT) imaging at the third lumbar (L3) vertebra, at baseline and three months post-treatment. Outcomes were overall survival (OS) at 12 months and five years post-treatment. One hundred and one participants had a CT scan evaluable at one or two timepoints, of which 67 (66%) participants were sarcopenic on at least one timepoint. Reduced muscle attenuation affected 93% (n=92) pre-treatment compared with 97% (n=90) post-treatment. Five-year OS favoured those without post-treatment sarcopenia (HR 0.37, 95% CI 0.16-0.88, p=0.06) and those without both post-treatment myosteatosis and sarcopenia (HR 0.33, 95% CI 0.13-0.83, p=0.06). Overall, rates of myosteatosis were high at both pre- and post-treatment timepoints. Post-treatment sarcopenia was associated with worse five-year overall survival, as was post-treatment sarcopenia in those who had myosteatosis. Post-treatment sarcopenia should be evaluated as an independent risk factor for decreased long-term survival post-treatment containing RT for HNSCC.