Impact of time since diagnosis and mortality rate on cancer-associated venous thromboembolism - the Scandinavian Thrombosis and Cancer (STAC) cohort.
J Thromb Haemost. 2018 Apr 25;:
Authors: Blix K, Gran OV, Severinsen MT, Cannegieter SC, Jensvoll H, Overvad K, Hammerstrøm J, Tjønneland A, Naess IA, Braekkan SK, Rosendaal FR, Kristensen SR, Hansen JB
BACKGROUND: Venous thromboembolism (VTE) is a common complication in cancer, and studies suggest that aggressive cancers harvest the highest risk of VTE. However, competing risk by death may result in over-estimation of VTE risk in cancers with high mortality. Therefore, we estimated the risk of VTE by cancer sites, accounting for the differential mortality between cancers.
METHODS: The Scandinavian Thrombosis and Cancer cohort included 144 952 participants followed from 1993-1997 to 2008-2012. Incidence rates, cause-specific hazard ratios (HR) and sub-distribution hazard ratios (SHR) were assessed for overall cancer and by cancer sites according to time-intervals since cancer diagnosis.
RESULTS: During follow-up, 14 272 subjects developed cancer, and 567 had cancer-related VTE. In cause-specific analyses, the risk of VTE was highest the first 6 months after cancer diagnosis (HR 17.5, 95% CI 15.1-20.3), and declined rapidly thereafter. However, when mortality was taken into account, the risk was similar in the period 6 months before (SHR 4.8, 95% CI 3.6-6.4) and 6 months after (SHR 4.6, 95% CI 3.9-5.4) cancer diagnosis. The range of the 2-year cumulative VTE incidences was substantially narrowed for all cancer sites after competing risk by death was taken into account (from 1-10% to 1-4%).
CONCLUSION: The risk of VTE by cancer sites was influenced by the mortality rate and the time since cancer diagnosis. Our findings suggest that the cancer itself is a major contributor to VTE risk and that competing risk by death should be taken into account when exploring VTE risk in cancer. This article is protected by copyright. All rights reserved.
PMID: 29691978 [PubMed - as supplied by publisher]