CEACAM5 and neoplasm: In addition to metformin use, our study revealed that normal presurgery serum CEA and CA19-9 levels, tumor invasion beneath the visceral peritoneum (T1–3), and negative lymph invasion (N0) were associated with positive E-cadherin expression, and high presurgery serum CEA levels, insulin injection, invasion through visceral peritoneum (T4), and positive lymph invasion (N1-2) were associated with positive vimentin expression.