COMPUTER TOMOGRAPHY-ASSESSED MUSCLE MASS AS AN INDICATOR OF LONGEVITY IN PATIENTS WITH SPINAL METASTASIS

Background Loss of muscle mass (sarcopenia) and function in ageing are associated with reduced functional ability, quality of life and reduced life expectancy. In cancer patients, age related muscle loss may be exacerbated by cachexia and poor nutritional intake. Individuals with widespread disseminated disease are most prone to increasing functional decline, increased morbidity and accelerated death. However subjective assessments of physical performance have been shown to be poor indicators of life expectancy in these patients. Aims To develop an objective measure to aid calculation of life expectancy in cancer by investigating the association between objectively measured lean muscle mass and longevity, in 41 patients with known spinal metastases from all cause primaries. Methods Lean muscle mass was calculated as total psoas area (TPA)/height (m)2. Two blinded doctors independently calculated TPA from CT images at the L3 level, performed routinely within 7 days of diagnosis of spinal metastases. Time to death was recorded from retrospective analysis of hospital notes. Results Of patients within the highest tertile for muscle mass 85% were alive at one year, compared with 50% in the lowest tertile. Conclusion Death within one year in individuals with spinal metastases is significantly higher in patients with low lean muscle mass at presentation.