Impact of rheological variables in cancer

Rheological alterations are commonly found in malignant disease and are most pronounced in advanced-stage cancer. Although most of these changes are caused by cancer-unspecific mechanisms, it has been shown that the extent of these changes in some cancer types is related with the stage of cancer, prognosis of disease, and the patient's risk for thrombosis. Monitoring of rheological variables during follow-up of patients has been useful in gynecologic cancer; a significant increase in the main determinants of blood viscosity was found when metastasis became clinically apparent. The most frequent constellation in newly diagnosed cancer is an increase in plasma viscosity (PV) and red blood cell (RBC) aggregation that produces hyperviscosity and is compensated for by anemia. Unconditional elevation of the hematocrit in cancer can deteriorate microcirculatory flow properties and may plunge the patient into an undesirable hemorheological condition that limits effectiveness of cytoreductive treatment and favors dissemination of cancer cells and the development of thrombosis. Modification of hyperviscosity, most likely at the plasma level, may represent a concept for cancer treatment and prevention of thrombosis. Anticoagulants and anti-inflammatory substances seem most suitable at this point, because high fibrinogen turnover is an important determinant of hyperviscosity in malignancy.