Original Article Risk factors for chemotherapy-associated venous thromboembolism in a prospective observational study Alok A. Khorana, M.D. 1 *, Charles W. Francis, M.D. 1, Eva Culakova, Ph.D. 1 2, Gary H. Lyman, M.D., M.P.H. 1 2 1James P. Wilmot Cancer Center and the Department of Medicine, University of Rochester, Rochester, New York 2Department of Biostatistics and Computational Biology, University of Rochester, Rochester, New York email: Alok A. Khorana (alok_khorana@URMC.rochester.edu) *Correspondence to Alok A. Khorana, 601 Elmwood Ave, Box 704, Rochester, NY 14642 Fax: (585) 273-1042 Funded by: James P. Wilmot Cancer Research Fellowship The Awareness of Neutropenia in Cancer (ANC) Study Group Registry is funded by Amgen, Inc. Abstract BACKGROUND The incidence of venous thromboembolism (VTE) is increased in cancer, but little information is available about risk factors in cancer patients on chemotherapy. METHODS We analyzed data from a prospective, multicenter observational study to determine the frequency and risk factors for VTE in ambulatory cancer patients initiating a new chemotherapy regimen. The association of VTE with clinical variables was characterized using univariate and multivariate analysis. RESULTS Among 3003 patients treated with at least one cycle of chemotherapy, VTE occurred in 58 (1.93%) over a median follow-up of 2.4 months (0.8%/mo). The incidence varied significantly by site of cancer (P = 0.01) with highest rates in upper gastrointestinal (2.3%/mo) and lung cancer (1.2%/mo), and lymphoma (1.1%/mo). An elevated prechemotherapy platelet count was significantly associated with an increased rate of VTE (P for trend = 0.005). The incidence of VTE was 3.98% (1.66%/mo) for patients with a prechemotherapy platelet count 350,000, compared with 1.25% (0.52%/mo) for patients with platelet counts of < 200,000 (P for trend=0.0003). In multivariate analysis, a prechemotherapy platelet count of 350,000/mm3 (adjusted OR 2.81, 95% CI 1.63-4.93, P = 0.0002), site of cancer, hemoglobin < 10g/dL or use of erythropoietin, and use of white cell growth factors in high-risk sites of cancer were significantly associated with VTE. CONCLUSIONS Symptomatic VTE is a frequent complication of chemotherapy. The prechemotherapy platelet count is a unique risk factor and can help identify high-risk patients for future trials of thromboprophylaxis. Cancer 2005. Volume 104, Issue 12 , J Clin Onc, 1/06 The Oncologist, 4/04 Blood clots in Cancer Pts Remember we are NOT Doctors and have NO medical training. This site is like an Encylopedia - there are many pages, many links on many topics. Support our work with any size DONATION - see left side of any page - for how to donate. You can help raise awareness of CAM.