![]() | Only 14 pages are availabe for public view |
Abstract Venous thromboembolism (VTE), includes both deep vein thrombosis (DVT) and pulmonary embolism (PE), is the second-leading causes of death in hospitalized and ambulatory cancer patients. The risk of VTE in cancer patients is increased three- to five fold for those who are undergoing surgery and 5-6 folds for those who are receiving chemotherapy. In the 19th century, the association between thrombosis and malignancy was described in 1823 by Bouillaud and then in 1865 by Armand Trousseau and is now often referred to as Trousseau syndrome. A few years later, in 1878, histological evidence for tumor cells within a thrombus was founded by Theodor Billroth. This rate of venous thromboembolism (VTE) in patients with cancer is greater than that in patients without cancer and chemotherapy increases the risk to a greater fold. The mechanism of the so-called ―Trousseau‘s syndrome‖ probably includes all aspects of Virchow’s triad: stasis of blood, trauma or pathology of the endothelium and hypercoagulability of the blood itself. The pathogenesis of VTE in cancer patients is complex and involves the interplay of multiple factors – related to the tumor itself, patient and anticancer therapies. Several biomarkers were identified as potential predictors of VTE events. These include elevated platelet and leukocyte counts, decreased hemoglobin, elevated Ddimer, elevated prothrombin activation products, elevated soluble P-selectin, peak thrombin generation and elevated levels of TF bearing microparticles. Risk assessment includes 5 parameters known as ―Khorana-Score‖ include: 1. Site of cancer (Very high risk (stomach, pancreas) - High risk (lung, lymphoma, gynecologic, bladder, testicular)), 2. Platelet count (≥350,000/μL), 3. Hemoglobin (<10 g/dL) and/or use of erythropoiesisstimulating agents, 4. Leukocyte count (>11,000/μL), and 5. Body mass index (BMI) (35 kg/m² or more) to predict chemotherapy-associated thrombosis in cancer patients.This risk scoring model expanded by inclusion of two further biomarkers, sP-selectin (>53.1 ng/mL) and D-dimer (>1.44ug/ml). The diagnosis of VTE is done through: 1- Clinical presentation (including sign, symptoms & differential diagnosis), 2- Clinical likelihood assessment (through well’s score & revised Geneva score), 3- Laboratory testing (including Plasma D-dimer, imaging duplex ultrasound, chest CT, Magnetic Resonance angiography). The typical symptoms of DVT include pain, heaviness, cramps in the lower extremity, particularly in the calf, which may progress slowly or may suddenly accelerate more rapidly leading to swelling and blue-red or cyanotic discoloration. Signs of DVT include Low grade pyrexia, increase in heart rate, tenderness of the veins in the popliteal region, calf or over the distribution of the deep veins, because soreness and pain is the most common. Typical presentations of PE comprise acute dyspnea, chest pain, or coughing with or without hemoptysis. It is important to consider syncope as a characteristic, albeit infrequent presentation of PE. Characteristic signs of pulmonary embolism include tachycardia and tachypnea. On auscultation, there is typical pleural leather rub and crackles. Pain is often caused by pleural inflammation due to peripheral emboli causing pulmonary infarction, alveolar hemorrhage, hemoptysis. ECG changes are describes and arterial blood gas analysis typically shows hypoxia, hypocapnia and respiratory alkalosis, but sometimes show normal values. VTE may result in the debilitating long-term complications of post-thrombotic syndrome of the legs and chronic thromboembolic pulmonary hypertension which can be fatal where there is sudden cardiac death during exertion. Treatment and prophylaxis of venous thromboembolism is maintained through: 1. Pharmacological agents including include: Parenteral anticoagulants (Unfractionated heparin, low molecular weight heparin, Fondaparinux), Oral antithrombotics: (Warfarin (VKA), New oral anticoagulants including (dabigatran, rivaroxaban), Oral antiplatelet drug (aspirin). 2. Mechanical methods include elastic stockings and intermittent pneumatic compression. 3. Vena Cava filter are the main ways of preventing thrombosis and the central venous catheter thrombosis. |