Associations between severe co-morbidity and muscle measures in advanced non-small cell lung cancer patients

Introduction Several studies show that low skeletal muscle index (SMI) and low skeletal muscle density (SMD) are negative prognostic factors and associated with more toxicity from systemic therapy in cancer patients. However, muscle depletion can be caused by a range of diseases and many cancer patients have significant comorbidity, but few have investigated whether there are associations between these muscle measures and coexisting conditions in cancer patients. The aim of this study was to investigate whether there were associations between comorbidity and muscle measures in patients with advanced non-small cell lung cancer (NSCLC). Methods Patients in a phase III trial comparing two first-line chemotherapy regimens in advanced NSCLC were analysed (n=436) if information about comorbidity and baseline CT scans for assessment of muscle measures were available. Comorbidity was assessed using the Cumulative Illness Rating Scale for Geriatrics (CIRS-G) which rates comorbidity from 0 to 4 on 14 different organ scales. Severe comorbidity was defined as having any grade 3 or 4 CIRS-G score. Muscle measures were assessed from CT slides at the L3 level using the SliceOMatic software. Results Complete data were available for 263 patients (60%). Median age was 66, 57.0% were men, 78.7% had PS 0-1, 25.9% had stage IIIB, 11.4% reported appetite loss, 92.4% were current or former smokers, 17.1% were underweight (Body Mass Index