Skeletal Muscle Depletion Predicts the Prognosis of Patients with Advanced Pancreatic Cancer Undergoing Palliative Chemotherapy, Independent of Body Mass Index

INTRODUCTION: Body composition has emerged as a prognostic factor in cancer patients. We investigated whether sarcopenia at diagnosis and loss of skeletal muscle during palliative chemotherapy were associated with survival in patients with pancreatic cancer. METHODS: We retrospectively reviewed the clinical outcomes of pancreatic cancer patients receiving palliative chemotherapy between 2003 and 2010. The cross-sectional area of skeletal muscle at L3 by computed tomography was analyzed with Rapidia 3D software. We defined sarcopenia as a skeletal muscle index (SMI)< 42.2 cm(2)/m(2) (male) and < 33.9 cm(2)/m(2) (female) using ROC curve. RESULTS: Among 484 patients, 103 (21.3%) patients were sarcopenic at diagnosis. Decrease in SMI during chemotherapy was observed in 156 (60.9%) male and 65 (40.6%) female patients. Decrease in body mass index (BMI) was observed in 149 patients (37.3%), with no gender difference. By multivariate analysis, sarcopenia (P< 0.001), decreasedBMI and SMI during chemotherapy (P = 0.002, P = 0.004, respectively) were poor prognostic factors for overall survival (OS). While the OS of male patients was affected with sarcopenia (P< 0.001) and decreased SMI (P = 0.001), the OS of female patients was influenced with overweight at diagnosis (P = 0.006), decreased BMI (P = 0.032) and decreased SMI (P = 0.014). Particularly, while the change of BMI during chemotherapy did not have impact on OS within the patients with maintained SMI (P = 0.750), decrease in SMI was associated with poor OS within the patients with maintained BMI (HR 1.502; P = 0.002). CONCLUSIONS: Sarcopenia at diagnosis and depletion of skeletal muscle, independent of BMI change, during chemotherapy were poor prognostic factors in advanced pancreatic cancer.