Pancreatic and bile duct cancer circulating tumor cells (CTC) form immune-resistant multi-cell type clusters in the portal venous circulation.

Circulating tumor cells (CTC) enter the blood from many carcinomas and represent a likely source of metastatic dissemination. In contrast to the peripheral circulation, KRAS mutation- positive CTC thrive in the portal venous blood of patients with pancreatic ductal adenocarcinoma (PDAC). To analyze the essential interactions that contribute to carcinoma CTC growth and immune resistance, portal venous blood was collected during pancreatico-duodenectomy in 41 patients with peri-ampullary pathologies (PDAC = 11; ampullary adenocarcinoma (AA) = 15; distal cholangiocarcinoma (CC) = 6; IPMN = 7; non-malignant pancreatitis = 2).