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 cm2/m2 (male) and < 33.9 cm2/m2 (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.