Aggregability and disaggregability of erythrocytes in women suffering from ovarian cancer: evidence for an increased disaggregation threshold.

In order to further characterize the alterations of erythrocyte aggregation described in ovarian cancer, we measured it with laser backscattering in eleven women suffering from ovarian cancer (mean age: 44.7 +/- 3.6, extreme values: 28-61 yr) compared with thirteen matched control women. Blood rheology exhibited a wide variability in cancer patients, with some unusually high values of plasma viscosity and/or RBC aggregation in individual cases. The only significant differences were found for the RBC disaggregation threshold which was higher in patients than in controls (78.06 +/- 10.14 vs 52.6 +/- 3.15 s(-1), p < 0.05), while hematocrit was lower (34.45 +/- 1.42 vs 38.23 +/- 0.75, p < 0.05). A negative correlation between hematocrit and corrected blood viscosity on the whole sample of subjects (r = 0.454, p < 0.05) indicates that hematocrit is decreased in subjects prone to high viscosity, resulting in similar values of apparent blood viscosity in controls and patients. Thus, a lower disaggregability of RBCs is evidenced in women with ovarian cancer, as well as a tendency to blood hyperviscosity compensated by a reduction of hematocrit which suggests that there may be some degree of 'viscoregulation'.