Biochemical profile and clinical characteristics of patients suspected of deep venous thrombosis and pulmonary thromboembolism treated at the Cancer Hospital

Abstract

The Barretos Cancer Hospital receives about 6,200 new patients each year. Many of these patients develop deep vein thrombosis (DVT) and pulmonary embolism (PE) during treatment. In 2007, there were 27,412 cases of DVT in Brazil. One of the problems of DVT and PE is the lack of information about the profile of patients.Often, thromboembolic events are the first manifestations of cancer, such as the paraneoplasic syndrome. Oncology patients have four times the risk of developing DVT compared with patients without cancer. If the oncology patients are submitted to chemotherapy this risk increases up to 6 times. Not only due to the risk of thrombotic events, but also by the fact that the evolution of the tumor may be more aggressive. The tumors which develop more thromboembolic events are: pancreas, lung, and stomach adenocarcinomas with unknown primary site.Recurrence of venous thromboembolism in the general population is approximately 7.8%. In cancer patients these numbers may reach 14% per year and 30% in 10 years.Statins have anti-inflammatory and immunomodulatory effect that interferes in the formation of thrombi and significantly reduce the incidence of DVT (OR 0.50, 95% CI 0.43 to 0.82) and PE (OR 0.70, 95% CI 0.53 to 0.95). In 2010 a retrospective case-control study observed the recurrence of 18% of venous thromboembolism, 21% in patients without statin and only 8% in patients on medication use (OR 0.33, 95% 0.19 to 0, 57).The D-dimer is a fibrin degradation product that presents itself as a major test in the investigation of TEP. It has a sensitivity of up to 96%, however, some situations such as surgery, acute myocardial infarction, and septicemia, may alter the baseline examination, as well as in patients with cancer. The fact that D-dimer is altered in these patients, not necessarily disables the exam because it may be necessary to set a new benchmark as a baseline.The P-selectin is an intracellular glycoprotein present in the endothelium and platelets, which induced by the tumor Necrosis Factor (TNF) and Ilterleucina 1 (IL-1), bind to the leukocytes, especially to the neutrophils with the function of facilitating the interaction (adhesion) between platelets and leukocytes with the endothelium. Besides participating actively in the process of hematogenous metastasis, P-selectin acts in thrombus formation and inflammatory processes. Elevated fibrinogen levels are associated with thromboembolic events. TNF-± is a multifunctional cytokinin which acts in the cell apoptosis, which was initially identified by its ability to induce hemorrhagic necrosis of tumors.Carcinogenesis, angiogenesis and coagulation processes are intimately involved in neoplasic diseases. As the factor Xa (FXa) actively participates in the coagulation cascade, it has an important role in the process of metastasis and thrombus formation.Interleukin-6 has an important role in the inflammatory tissue. Some evidence suggest that IL-6 has action in the clotting process. This study is divided into two stages: Retrospective, to examine the incidence and clinical profile of patients with DVT and PE diagnosed venous Doppler examinations, lung scintigraphy or chest CT performed in 2012; Prospective, using a questionnaire and conducting blood tests (blood count, creatinine, blood gas, P-selectin, factor Xa activity, D-dimer, fibrinogen, TNF-±, CRP, interleukin 6) in patients with suspected DVT or PE from June 1st, 2013 to January 31st, 2014.It is possible that the disturbances of blood vessels and coagulation are due to the activity of cancer, which damage the vessels when send metastases. We believe that both factors contribute to further debility of the patients' health.Charting the clinical profile of patients with DVT and PE may help the prevention and the early detection of such diseases, and it may also provide information for the formulation of a clinical protocol that may serve as a guideline for prevention and treatment. (AU)