Haemorheology of cancer metastases: An example of malignant melanoma. Survival times and abnormality of blood viscosity factors 1

Abstract

Rheological study was initiated in 1971 on blood samples obtained from patients treated by Melanoma Clinic (Head: Professor Gerald Milton) of Sydney Hospital. These studies, covering 120 patients, included investigations of blood viscosity, plasma viscosity, rigidity of red cells, aggregation of red cells, protein levels and ratios, and formation of artificial thrombi in vitro. Patients were followed in order to observe effect of metastases and in order to correlate time intervals between tests and death with blood viscosity factors. Only half of the patients survived till end of 1980. Both the survivors and the deceased showed significant abnormalities of blood viscosity factors when compared to normal values. Presence of high degree of aggregation of red cells and of high plasma viscosity appears to be linked with the onset of metastases, and appears to be a diagnostic and predictive test even when the usual clinical tests for metastases are negative. Plasma viscosity in patients with metastases was elevated 2.7 to 4.5 standard deviations above the normal mean value; aggregation of red cells was elevated by 2.8 to 3.4 standard deviations above the normal mean value. Abnormalities increase as the death from metastases nears by. For instance, correlation between plasma viscosity and survival time shows correlation coefficient r = −0.437 and significance P < 0.02. The predictive value of rheological assessment of survival time improves when two main parameters, plasma viscosity and aggregation of red cells, are used simultaneously as a sum of standard deviations from the normal values: y (surv time)= = −3.99x + 36.1 ± 8.7; r = −0.803, P<0.001. Hypothesis has been proposed that metastases are enhanced by increased aggregation of red cells and hyperviscosity (which also inhibits immunological defence).