In this study, the investigators aim to demonstration of relationship between triceps skinfold thickness and overall survival of pancreatic cancer, cholangiocarcinoma and GB cancer.

Cachexia is frequently seen in pancreatic cancer(70-80%) and associated with reduced survival, reduced treatment tolerance and reduction in QoL. In recent studies, low-normal BMI have worse outcome (overall mortality) in cardiovascular, malignant, chronic disease (So called "obesity paradox") BMI is simple method but hard to define body composition because BMI is based on only weight and height. Skinfold thickness is strongly associated with body fatness than BMI. In this study, the ivestigators aim to demonstration of relationship between triceps skinfold thickness and overall survival of pancreatic cancer, cholangiocarcinoma and GB cancer.

Inclusion Criteria:

• Newly diagnosed pancreatic, bile duct or gallbladder cancer patients, undergoing therapeutic management (including surgery, chemotherapy or palliative care).
• Age above 18 years old

Exclusion Criteria:

• Other malignant disease
• Underlying intestinal disease that cause absorprtion disorder
• Underlying psychiatric disorder such as eating disorder (bulimia, anorexia)

Patients who visit and treated at Samsung medical center.