The Impact of Initial Cancer Stage on the Incidence of Venous Thromboembolism: The Scandinavian Thrombosis and Cancer (STAC) Cohort

BACKGROUND: Absolute measures of the impact of cancer stage on the incidence of venous thromboembolism (VTE) in distinct cancer types have not been investigated in a large population based cohort study.

OBJECTIVES: To investigate differences in incidence rates of objectively confirmed VTE according to development of cancer in a large population based cohort study. Cancer type and stage at the time of diagnosis was taken into account.

PATIENTS AND METHODS: The Scandinavian Thrombosis and Cancer cohort includes data regarding cancer types, stages and objectively confirmed VTE diagnoses among 144,952 participants followed from 1993 through 2012. We studied stage specific incidence rates of VTE and calculated incidence rate differences (IRD) for VTE according to stages in ten types of solid cancer.

RESULTS: During total follow-up 335 VTEs occurred of which 293 occurred within 5 years. The IRD of VTE in distant metastasis compared with localized disease indicated great variation dependent on the cancer types. Highest IRD was observed in pancreatic cancer (IRD 187.0*10(-3) person-years (p-y); 95% CI, -6.7 to 380.8), whereas the lowest IRD was observed in prostate cancer (IRD 3.7 *10(-3) p-y; 95% CI, -7 to 15.2). Regional spread compared with localized disease also indicated a large variance dependent of cancer type with largest IRD in uterus cancer (IRD 37.6 *10(-3) p-y; 95% CI, -23.7 to 99), whereas the IRD in breast and prostate cancer were close to zero.

CONCLUSION: More advanced cancer at time of diagnosis was associated with a higher risk of VTE, but the strength of the associations differed substantially between cancer types. This article is protected by copyright. All rights reserved.