The association of VTE with underlying malignancy was first reported by Armand Trousseau in 1865.
VTE includes both deep venous thrombosis (DVT) and pulmonary embolism (PE).
DVT is divided into 4 categories---
1--Upper extremity; 2--Distal lower extremity (e.g., calf);
3--Central/proximal major veins 4--Central Venous Catheter patients with VTE.
FACTS ABOUT VTE------
• Cancer accounts for 20%, patients receiving chemotherapy accounting for as much as 13 of total VTE cases...2,3(The reported rates of VTE in patients with cancer are believed to be underestimated, given that autopsy rates of VTE can be as high as 50% compared with clinical rates of 4% to 20%.4,5
• Venous thromboembolism (VTE) is a major complication of cancer, occurring in 4% to 20% of patients, and is one of the leading causes of death in patients with cancer.1
• Hospitalized patients with cancer and those receiving active therapy seem to be at the greatest risk for development of VTE.
• VTE A RISING TREND IN CANCER PATIENTS. In a recent analysis of more than 66,000 patients with cancer hospitalized at 120 US academic medical centres, 5.4% developed VTE per hospitalization, increasing by 36% from 1995 to 2002 (P < .0001 for trend).1
• Vascular toxicity, particularly thromboembolism, is a specific toxicity of antiangiogenic drugs. Newer cancer regimens that include thalidomide, lenalidomide, or bevacizumab have reported very high rates of VTE.6,7
• Hospitalized patients with VTE have a greater in-hospital mortality rate (odds ratio, 2.01; 95% CI 1.83 to 2.22; P < .0001), and this is true of patients both with and without metastatic disease.8
• The risk of fatal PE in patients with cancer undergoing surgery is three-fold greater than in patients without cancer undergoing similar surgery.9
• VTE recurs three-fold more frequently in cancer patients than in patients who do not have cancer, and requires long-term anticoagulation with a two-fold greater risk of bleeding complications than in patients who do not have cancer.10 VTE in patients with cancer also consumes health care resources.



Available Anticoagulants--------------
1-----Unfractionated Heparin 2---Vitamin K antagonists--Warferin
3----Low molecular weight heparin--- Dalteparin, Enoxaparin, Fondaparinux
4----Parenteral Direct Thrombin Inhibitors: Lepirudin (recombinant Hirudin), Argatroban
Bivalirudin .
Recommendation for thromboprophylaxis ------
1--- Hospitalized patients with cancer should be considered candidates for VTE prophylaxis with anticoagulants in the absence of bleeding or other contraindications to anticoagulation.
2---Routine prophylaxis with an antithrombotic agent is not recommended in ambulatory patients with cancer during systemic chemotherapy.
3--Patients receiving thalidomide or lenalidomide with chemotherapy or dexamethasone are at high risk for thrombosis and warrant prophylaxis.
4---All patients undergoing major surgical intervention for malignant disease should be considered for thromboprophylaxis.
5---Patients undergoing laparotomy, laparoscopy, or thoracotomy lasting greater than 30 minutes should receive pharmacologic thromboprophylaxis with either low-dose UFH or LMWH unless contraindicated because of a high risk of bleeding or active bleeding.
6---Prophylaxis should be commenced preoperatively, or as early as possible in the postoperative period.
7--- A combined regimen of pharmacologic and mechanical prophylaxis may improve efficacy, especially in the highest-risk patients.
8---Prophylaxis should be continued for at least 7 to 10 days postoperatively. Prolonged prophylaxis for up to 4 weeks may be considered in patients undergoing major abdominal or pelvic surgery for cancer with high-risk features such as residual malignant disease after operation, obese patients, and those with a previous history of VTE. 11






TREATMENT FOR PATIENTS WITH CANCER WITH ESTABLISHED VTE TO PREVENT RECURRENT VTE

1. 1--- LMWH is the preferred approach for the initial 5 to 10 days of anticoagulant treatment of the cancer patient with established VTE.
2. 2---LMWH given for at least 6 months is also the preferred approach for long-term anticoagulant therapy. Vitamin K antagonists with a targeted INR of 2 to 3 are acceptable for long-term therapy when LMWH is not available.
3. 3---After 6 months, indefinite anticoagulant therapy should be considered for selected patients with active cancer, such as those with metastatic disease and those receiving chemotherapy. This recommendation is based on Panel consensus in the absence of clinical trials data.
4. 4---The insertion of a vena cava filter is only indicated for patients with contraindications to anticoagulant therapy and in those with recurrent VTE despite adequate long-term therapy with LMWH.
5. 5---For patients with CNS malignancies, anticoagulation is recommended for established VTE as described for other patients with cancer. Careful monitoring is necessary to limit the risk of hemorrhagic complications. Anticoagulation should be avoided in the presence of active intracranial bleeding, recent surgery, pre-existing bleeding diathesis such as thrombocytopenia (platelet count < 50,000/µL) or coagulopathy.
6. 6---For elderly patients, anticoagulation is recommended for established VTE as described for other patients with cancer. Careful monitoring and dose adjustment is necessary to avoid excessive anticoagulation and further increase in the risk of bleeding.









References---
1. Khorana AA, et al: Thromboembolism is a leading cause of death in cancer patients receiving outpatient chemotherapy. J Thromb Haemost 5:632-634, 2007.
2. Caine GJ, et al: The hypercoagulable state of malignancy: Pathogenesis and current debate. Neoplasia 4:465-473, 2002.
3. Heit JA, et al: Relative impact of risk factors for deep vein thrombosis and pulmonary embolism: A population-based study. Arch Intern Med 162:1245-1248, 2002.
4. Gomes MP, et al: Diagnosis of venous thromboembolic disease in cancer patients. Oncology (Huntingt) 17:126-135, 2003; discussion 139-144.
5. Ottinger H, et al: Deep venous thrombosis and pulmonary artery embolism in high-grade non Hodgkin's lymphoma: Incidence, causes and prognostic relevance. Eur J Haematol 54:186-194, 1995.
6. Cavo M, et al: Deep-vein thrombosis in patients with multiple myeloma receiving first-line thalidomide-dexamethasone therapy. Blood 100:2272-2273, 2002.
7. Shah MA, et al: Thromboembolic events in gastric cancer: High incidence in patients receiving irinotecan- and bevacizumab-based therapy. J Clin Oncol 23:2574-2576, 2005.
8. Khorana AA, et al: Thromboembolism in hospitalized neutropenic cancer patients. J Clin Oncol 24:484-490, 2006.
9. Gallus AS et al : Prevention of post-operative deep leg vein thrombosis in patients with cancer. Thromb Haemost 78:126-132, 1997.
10. Prandoni P, et al: Recurrent venous thromboembolism and bleeding complications during anticoagulant treatment in patients with cancer and venous thrombosis. Blood 100:3484-3488, 2002.
11. Gary H. L, et al : American Society of Clinical Oncology Guideline: Recommendations for Venous Thromboembolism Prophylaxis and Treatment in Patients With Cancer. Journal of Clinical Oncology, Vol 25, No 34 (December 1), 2007: pp. 5490-5505.