Skeletal muscle loss during anti-epidermal growth factor receptor therapy is an independent prognostic factor on non-small cell lung cancer patients survival

We aimed to assess whether skeletal muscle loss during EGFR thyrosine kinase inhibitor therapy of advance non-small cell lung cancer patients is an independent prognostic factor for progression-free survival (PFS) and overal survival (OS).A total of 45 patients who had computed tomography images were retrospectively evaluated at the diagnosis and during the treatment period before progression occurs.During treatment 19 patients (42.2%) had skeletal muscle loss. Objective response rates in muscle loss group and muscle stable group were 36.8% and 73.0%, respectively (p0.01). Median follow-up time was 18.9 months (14.8-32.1). Median PFS was 14.7 months (95% CI 12.1-17.3) in muscle stable group and 7.6 months (95% CI 6.7-8.5) in muscle loss group (p0.01). Median OS was 18.3 months (95% CI 16.5-20.2) in muscle loss group while it was 30.1 months (95% CI 22.1-38.2) in muscle stable group (p0.01). In multivariate analysis for both PFS and OS, skeletal muscle loss was an independent prognostic factor. Hazard ratios (HR) for PFS and OS were 12.2 (95% CI 4.3-34.4) and 3.51 (95% CI 1.41-8.73) respectively.On CT imaging skeletal muscle loss before progression is an independent prognostic factor for both PFS and OS in advance non-small cell lung cancer patients who received EGFR tyrosine kinase inhibitor therapy.