title: Heparin-induced thrombocytopenia among patients of a comprehensive cancer center.
abstract: Most clinical studies of heparin-induced thrombocytopenia have not included cancer patients who have high risk of thromboembolism, frequent exposure to heparin, and many potential causes of thrombocytopenia other than heparin-induced thrombocytopenia. To estimate the incidence and prevalence of heparin-induced thrombocytopenia in cancer patients, we identified cases based on diagnostic codes, anti-heparin antibody testing, and clinical characteristics (4T score) at a comprehensive cancer center between 1 October 2008 and 31 December 2011. We estimated that the prevalence of heparin-induced thrombocytopenia to be 0.02% among all cancer patients and 0.24% among cancer patients exposed to heparin. The annual incidence of heparin-induced thrombocytopenia was 0.57 cases per 1000 cancer patients exposed to heparin. Of the 40 cancer patients with the International Classification of Diseases (Ninth Revision; ICD-9) code for heparin-induced thrombocytopenia, positive anti-heparin antibody, and 4T score ≥4, 5 (12.5%) died of related thromboembolic or hemorrhagic complications. In a multivariate logistic regression model, male gender was a significant (p = 0.035) factor, and non-hematological malignancy was a significant (p = 0.017) factor associated with anti-heparin antibody positivity. Future studies may further examine the risk factors associated with heparin-induced thrombocytopenia in larger cohorts.
authors.affiliation: Department of Emergency Medicine, The University of Texas MD Anderson Cancer Center, Houston, TX, USA; Zhongshan Hospital, Xiamen University, Xiamen, Fujian, People's Republic of China.
authors.forename: Weixin
authors.initials: W
authors.lastname: Wu
authors.affiliation: Department of Emergency Medicine, The University of Texas MD Anderson Cancer Center, Houston, TX, USA.
authors.forename: Kelly
authors.initials: K
authors.lastname: Merriman
authors.affiliation: Department of Emergency Medicine, The University of Texas MD Anderson Cancer Center, Houston, TX, USA.
authors.forename: Amr
authors.initials: A
authors.lastname: Nabaah
authors.affiliation: Department of Emergency Medicine, The University of Texas MD Anderson Cancer Center, Houston, TX, USA.
authors.forename: Nikhil
authors.initials: N
authors.lastname: Seval
authors.affiliation: Department of Benign Hematology, The University of Texas MD Anderson Cancer Center, Houston, TX, USA.
authors.forename: Vahid
authors.initials: V
authors.lastname: Afshar-Kharghan
authors.affiliation: Department of Emergency Medicine, The University of Texas MD Anderson Cancer Center, Houston, TX, USA; Department of Endocrine Neoplasia & Hormonal Disorders, The University of Texas MD Anderson Cancer Center, Houston, TX, USA.
authors.forename: Sai-Ching J
authors.initials: SC
authors.lastname: Yeung
keywords: Heparin-induced thrombocytopenia; cancer; incidence; prevalence