Varying Amounts of Tumor Cells in the Bone Marrow of Patients with Nonmetastatic Colorectal Cancer

Background: The study focuses on the total amount of tumor cells in the bone marrow of nonmetastatic colorectal cancer patients (Tl-4 NO-3 MO) after radical resection of the primary tumor. Patients and Method: The bone marrow of 7 patients was examined for tumor cells by means of immunocytochemistry methods. The bone marrow cells were purified by density centrifugation, cytospin slides were developed using a monoclonal antibody against epithelial cells (cytokeratin component number 18) and alkaline phosphatase – anti-alkaline phosphatase staining. Results: Five out of 7 patients revealed a varying number of tumor cells in their bone marrow: Whereas in 3 patients only a low number was found (1, 3, 4 tumor cells/106 mononuclear cells, respectively), a high number of tumor cells was detected in 2 patients (48, 60 tumor cells/106 mononuclear cells, respectively). Conclusion: Since bone marrow puncture was performed after radical resection of the primary tumor, the amount of tumor cells in the bone marrow of these patients reflects the residual individual tumor load. Further studies should evaluate the impact of varying numbers of residual tumor cells in the bone marrow on the development of generalized metastatic disease.