The increased risk of thrombosis seen in patients with malignancy also was recently confirmed in breast cancer patients undergoing hormonal or chemotherapeutic treatment. Besides changes within the coagulation system, alterations of hemorheologic variables have been implicated in the genesis of thrombosis. We evaluated plasma viscosity, erythrocyte aggregation, fibrinogen level, sedimentation rate, hematocrit concentration, and protein concentration in patients with breast cancer at the time of primary diagnosis and during follow-up with or without treatment. We then compared the results to a control group without malignant or infectious disease. Plasma viscosity and erythrocyte aggregation were significantly higher in patients with malignant disease, with a further increase at the time of dissemination. Plasma fibrinogen level was significantly higher only at the time of dissemination. The influence of therapy on hemorheologic variables was minor. Tumor volume was the most important factor. As individual values vary considerably and form a continuous spectrum, no cutoff line between normal and pathologic values can be defined. However, high values should induce further measures to diagnose metastatic disease. Second, these factors could explain the relative inefficiency of thrombosis prophylaxis in this patient group and suggest the addition of rheologically active drugs to the treatment regimen.
Cancer 62:350-354.1988. INCE TROUSSEAU'S' initial observation, much data S have been accumulated regarding the increased risk of venous thrombosis in patients suffering from malignant disease. Until recently, there have been few reports regarding patients with breast cancer. Goodnough' reported a 17% incidence of venous thrombosis in patients treated with multiple drug chemotherapy for advanced breast cancer. During adjuvant chemotherapy, a hypercoagulable state was demonstrated by C a n ~b b i o . ~ Venous thrombosis during hormonal therapy with tamoxifen (TAM)4 or medroxyprogesteroneacetate (MPA)' also has been reported.
Subclinical coagulopathy is seen relatively frequently in patients with malignancy,6 especially thrombocytosis, hyperfibrinogenemia, and increased fibrinogen turnover rate.' Some of the factors leading to thromboembolic complications include prolonged bed rest, surgery and the postoperative period, previous disorders of the venous system, and imbalance between coagulation factors and their inhibitors. In addition, there are theoreti-