Peri-operative filtration of disseminated cytokeratin positive cells in patients with colorectal liver metastasis.

Background: Liver resection is the only potential cure for patients with colorectal liver metastasis. However, more than 30% of patients will develop tumour recurrence, probably caused by tumour cells disseminated before or during surgery. As prevention of cell dissemination is barely obtainable, alternative concepts have to be discussed.

Methods: The potential of leukocyte adhesion filters for the removal of cytokeratin positive cells (CK+) from blood was studied in 18 patients undergoing liver resection for colorectal liver metastasis. Blood sampling was done via a liver venous catheter during hepatic mobilisation. Filtration was done with an in-line WBF2 filter system. To define the relation between surgery and cell release we compared patients' pre-operative and intra-operative blood and bone marrow (BM) samples with their CK expression using immunochemical staining.

Results: CK+ cells were detected in BM samples of nine of 14 patients before surgery, indicating early dissemination. In ten of 18 patients CK+ cells were detected in blood samples during hepatic mobilisation; all ten patients underwent major liver surgery (R0 resection). In those patients recurrent disease was observed more often (P < or = 0.05). In 17 of 18 patients CK+ cells were not detectable after filtration procedure, which indicated cell adhesion to the filter medium.

Conclusion: Liver resection due to metastasis leads to frequent intra-operative tumour cell shedding. As the detection of CK+ cells is correlated with disease recurrence, modification of surgical techniques to prevent cell dissemination, and additional therapeutic concepts such as advanced filtration technology, have to be discussed.