A cross-sectional analysis of muscle density and physical function in head and neck cancer patients.

e18597 Background: Head and neck cancer (HNC) is a debilitating disease that affects tens of thousands each year and both the disease and its treatment can cause long-term morbidity. HNC patients with greater physical function at baseline may better withstand both disease and treatment, therefore we hypothesized that baseline physical function is associated with baseline skeletal muscle density (SMD). Methods: A cross-sectional study of existing medical records was conducted. SMD was classified using pre-treatment PET-CT scans and interpreted using Sliceomatic software, and pre-treatment physical function assessed in three ways: hand grip strength, timed up and go, and short physical performance battery. Linear regression models were utilized to assess the association between SMD and each measure of physical function, with adjustment for muscle mass, sex and cancer stage in the hand grip strength model and adjustment for muscle mass and age in both the timed up and go, and short physical performance battery models. Results: The sample of 90 HNC patients, was mostly white, male, former smokers with an average BMI of 28 kg/m2. In adjusted models that included men only, we observed that for every Hounsfield unit increase in SMD there was a 0.08 increase in SPPB score (p=0.005), a 0.31 kg increase in hand grip strength (p=0.04), and a 0.13 second decrease in timed up and go (p=0.0007). In adjusted models that included women only, we observed that for every Hounsfield unit increase in SMD there was a 0.03 decrease in SPPB score (p=0.75), a 0.12 kg increase in hand grip strength (p=0.65), and a 0.01 second increase in timed up and go (p=0.84). Conclusions: Baseline physical function is associated with higher baseline physical SMD. Larger studies involving a more women are needed to replicate these findings and to further examine the potential role of effect modification by both sex and muscle mass.