Is it possible to block the cancer cells in circulating blood by extracorporeal circulation? Implications of the immune system and other factors (review)

The presence of cancer cells in circulating blood and the possibility of colonization in the tissues of the body worsen in a determinant way the prognosis of the disease. Nevertheless, there are factors in the body that can lead to a prognostic improvement, even in such conditions. In addition to the immune system, other favorable factors can act at the level of the microenvironment of the tumor so much that cases of spontaneous total regression, not only of primary tumors but also metastases, have been reported in the literature. Since it was recently reported that patients with renal tumors and in permanent hemodialysis present at post mortem examination, a metastatic spread much less extensive than observed in patients deceased for renal tumors but not on hemodialysis. The authors maintain it likely that the dialytic membrane concurs to block at least in part the cancer cells circulating in the blood. The possibility to block cancer cells can be extended in addition to the dialytic membrane also to other types of filters inserted in the extracorporeal circulation. The block of the cancer cells thus is obtained and that occurs in regional lymph nodes and in the microenvironment of the tumor causing a relative increase in the elements of the immune system compared to the number of cancer cells, which could determine clearly positive therapeutic results also in cases with advanced metastatic spread.