HEMOSTATIC ABNORMALITIES ASSOCIATED WITH CANCER AND ITS THERAPY

Hemostatic abnormalities associated with malignancy have been describe d since the middle of the 19th century. Abnormalities associated with hypercoagulability and hemorrhage are reported in various percentages of patients depending upon the underlying neoplasm and the type of the rapy. Changes in the quantitative and qualitative aspects of protein c oagulation factors, anticoagulant proteins, circulating anticoagulants , platelets, and vascular responses have been noted. Clinical or subcl inical disseminated intravascular coagulopathy (DIG) and associated pa radoxical bleeding are common. Hemorrhage may be associated with a dec rease of particular coagulation factors or alterations of vascular int egrity and platelet numbers or function in various combinations. Evalu ation of hemostatic abnormalities associated with cancer (HAAC) includ es a careful history and physical examination, assessment of the proth rombin and activated partial thromboplastin times, platelet count, a t est for fibrin or fibrinogen degradation products, and assay of fibrin ogen levels. Specific findings may suggest the need for tests for natu rally occurring protein anticoagulants (e.g., protein S, protein C, an d antithrombin III), coagulation inhibitors, abnormalities of the fibr inolytic system, or other esoteric tests. Testing for F1 + 2 and fibri nopeptide A may be useful in determining early activation of prothromb in and thrombin, respectively, and a clue to incipient onset of DIG. B esides the disease, therapies for cancer can alter hemostatic activity . Chemotherapy has been reported. to be associated with venous and art erial thromboses, cerebrovascular events, and coagulopathies. Radiatio n therapy decreases platelet production, particularly if the active bo ne marrow has been included in the field. Laboratory evaluation of HAA C requires consideration of the type of malignant disorder, the histor y and physical condition of the patient and any therapy.