Cancer and hypercoagulability: Which patients need treatment?
Although the pathophysiologic process is not fully understood, a link between cancer and hypercoagulability has long been recognized. In fact, malignancy—the second most common cause of acquired hypercoagulability—is associated with 10% to 20% of spontaneous DVTs.2
One possible mechanism is the interaction of tumor cells with thrombin and plasmin-generating systems, directly influencing thrombus formation.7
Cancer patients also have an elevated risk for thrombosis related to immobilization, infection, treatment with antineoplastic agents, surgery, and the insertion of central venous catheters. Approximately 30% of patients with central venous catheters develop a DVT of the arm.16
Anticoagulant therapy in cancer patients varies, depending on the severity and circumstances of the patient. According to American Society of Clinical Oncology, National Comprehensive Cancer Center Network, and ACCP guidelines, LMWH is the preferred initial treatment for thromboses in patients with cancer— that is, in the first 3 to 6 months of therapy after a thrombotic event.17,23,24 The guidelines also mention warfarin as an alternative for long-term (>6 months) anticoagulant therapy, if no contraindications exist.
Because cancer is usually a long-term illness, anticoagulant therapy should be continued indefinitely, or until the cancer has resolved.10,23,24 Prophylaxis is recommended for cancer patients who are bedridden with an acute medical illness, but should not be routinely used in patients with indwelling venous catheters or those receiving chemotherapy or hormonal therapy.13,15
CORRESPONDENCE Haley M. Phillippe, PharmD, BCPS, University of Alabama Birmingham School of Medicine-Huntsville Campus, Department of Family Medicine, 301 Governors Drive, Huntsville, AL 35801; mccrahl@auburn.edu