Purpose: This study was designed to show, in certain patients, that colonic epithelial cells can be present in peripheral blood while absent in portal venous blood.
Methods: The circulating colorectal epithelial cells were detected by a reverse transcriptase-polymerase chain reaction assay, which involved amplifying guanylyl cyclase C transcripts. Portal venous and peripheral blood samples were obtained at intervals from 58 patients undergoing colorectal cancer surgery.
Results: Circulating colonic epithelial cells were more frequently detected in portal venous blood than in peripheral blood only before mobilization of the tumor-bearing colon segment in patients with tumors of Stage B. In five other patients, before mobilization of their tumor-bearing colon segments, and in another three patients, during the mobilization, colorectal epithelial cells were detected in peripheral blood but not in portal venous blood. These eight patients had Stage C or D tumors.
Conclusion: In 8 of 58 patients, colorectal epithelial cells were detected in peripheral but not in portal venous blood. Metastatic deposits in lymphatic vessels or liver might be the source of these cells.