Epidemiology of Venous Thromboembolism After Second Cancer

Abstract

Background

Venous thromboembolism (VTE) is a serious, yet preventable, complication in cancer. Some patients are diagnosed with a second cancer; however, little is known about the epidemiology of VTE in this population.

Methods

From Danish national healthcare registries, we studied all patients diagnosed with a first breast, prostate, lung, or colorectal cancer from 1995 to 2015. We estimated incidence rates (IRs) of VTE according to the timing of the diagnosis of a second cancer. We controlled for confounder variables in Poisson regression models.

Results

In total, 309,077 patients with a first breast, prostate, lung, or colorectal cancer were included in the study. A second cancer was diagnosed in 20,090 (6.5%) of these patients. In total, 11,908 VTEs were observed in the study period, 786 of these occurred after a diagnosis of second cancer. Second cancer types such as pancreas and stomach cancer were associated with fivefold higher IRs of VTE compared with second cancer types such as breast and prostate cancer. The IR of VTE was highest within the first 6 months after the second cancer was diagnosed (IR 40.5 per 1000 person-years, 95% CI 36.3–42.2) with no differences based on how long since the first cancer it was diagnosed.

Conclusion

The epidemiology of VTE after a second cancer is similar to the epidemiology of VTE after a first cancer with higher rates within the first months after aggressive second cancer types.

Keywords:

• venous thromboembolism
• second cancer
• epidemiology
• incidence
• cancer

Author Contributions

I. L. Gade conceived the idea of the study. I. L. Gade and S. J. Riddersholm are responsible for the study design, data managing and analysis, interpretation of the results and they wrote the first draft and revised it. M. T. Severinsen, K. H. Kragholm, and S. R. Kristensen contributed to the study design, interpretation of results, reviewed and commented on the manuscript. S. R. Kristensen contributed to the study design, interpretation of results and reviewed and commented the manuscript. C. Torp-Pedersen provided access to the study data, contributed to the study design, interpretation of results and reviewed and commented on the manuscript. All authors contributed to data analysis, drafting or revising the article, gave final approval of the version to be published, and agree to be accountable for all aspects of the work.

Disclosure

Christian Torp-Pedersen reports grants from Bayer and Novo Nordisk outside the submitted work. The authors received no funding for the study and have no other disclosures to report.