GPT and obstructive jaundice: High level of GAR was significantly associated with pancreatic head cancer (P < 0.001), large tumor size (P < 0.001), presence of vascular invasion (P = 0.003), presence of obstructive jaundice (P < 0.001), preoperative biliary drainage (P < 0.001), high level of ALP (P < 0.001), high level of ALT (P < 0.001), high level of AST (P < 0.001), high level of GGT (P < 0.001), and low level of ALB (P < 0.001).