Variation in the Association between Antineoplastic Therapies and Venous Thromboembolism in Patients with Active Cancer.

Background:  Venous thromboembolism (VTE) is a major cause of death in cancer patients. Although patients with cancer have numerous risk factors for VTE, the relative contribution of cancer treatments is unclear.
Objective:  The objective of this study is to evaluate the association between cancer therapies and the risk of VTE.
Methods:  From UK Clinical Practice Research Datalink, data on patients with first cancer diagnosis between 2008 and 2016 were extracted along with information on hospitalization, treatments, and cause of death. Primary outcome was active cancer-associated VTE. To establish the independent effects of risk factors, adjusted subhazard ratios (adj-SHR) were calculated using Fine and Gray regression analysis accounting for death as competing risk.
Results:  Among 67,801 patients with a first cancer diagnosis, active cancer-associated VTE occurred in 1,473 (2.2%). During a median observation time of 1.2 years, chemotherapy, surgery, hormonal therapy, radiation therapy, and immunotherapy were given to 71.1, 37.2, 17.2, 17.5, and 1.4% of patients with VTE, respectively. The active cancers associated with the highest risk of VTE-as assessed by incidence rates-included pancreatic cancer, brain cancer, and metastatic cancer. Chemotherapy was associated with an increased risk of VTE (adj-SHR: 3.17, 95% confidence interval [CI]: 2.76-3.65) while immunotherapy with a not significant reduced risk (adj-SHR: 0.67, 95% CI: 0.30-1.52). There was no association between VTE and radiation therapy (adj-SHR: 0.91, 95% CI: 0.65-1.27) and hormonal therapies.
Conclusion:  VTE risk varies with cancer type. Chemotherapy was associated with an increased VTE risk, whereas with radiation and immunotherapy therapy, an association was not confirmed.
Competing Interests: A.T.C. reports receiving consulting fees and research funding from Bayer, Boehringer Ingelheim, BMS, Daiichi-Sankyo, Johnson and Johnson, Pfizer, Portola, Sanofi, and XO1. He is an advisor to the UK Government Health Select Committee, the all-party working group on thrombosis, the Department of Health and the NHS on the prevention of VTE. He is also an advisor to Lifeblood: the thrombosis charity and is the founder of the European educational charity, the Coalition to Prevent VTE. J.I.W. receives support from research grant (significant): Bayer AG, Daiichi-Sankyo, Bristol-Myers Squibb, Pfizer; Honoraria (significant): Bayer, Boehringer Ingelheim, Bristol-Myers Squibb, Daiichi-Sankyo, Ionis Pharmaceuticals, Janssen, Merck, Novartis, Portola, Pfizer. T.S.F. research supports from Bayer Canada (in-kind study medication); honoraria from Bayer Canada, Boehringer Ingelheim Canada, Pfizer-BMS, and Servier. A.K., C.M., and C.W. are employees of the Institute for Epidemiology, Statistics and Informatics GmbH. The Institute for Epidemiology, Statistics and Informatics GmbH has received grants from Bayer, Bristol-Myers Squibb, CSL Behring, and Merz Pharma outside the submitted work. M.G., A.C., S.S., and B.W. have nothing to disclose.
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