Venous thromboembolism and cancer

Area of Science:

• Oncology
• Hematology
• Epidemiology

Background:

• The association between cancer and venous thromboembolism (VTE) is established, but specific cancer sites and long-term risks remain unclear.
• Understanding these relationships is crucial for patient management and risk stratification.

Purpose of the Study:

• To investigate the incidence of various cancers following a VTE event.
• To analyze cancer risk during long-term follow-up after VTE.

Main Methods:

• A population-based cohort study using Swedish healthcare registers (Inpatient Register, Cancer Registry).
• Inclusion of 61,998 patients hospitalized for VTE between 1965-1983 with no prior cancer diagnosis.
• Calculation of standardized incidence ratios (SIRs) comparing cancer incidence in VTE patients to the general population.

Main Results:

• A significantly elevated cancer risk was observed at the time of VTE or within the first year (SIR 4.4), with specific high risks for polycythaemia vera (SIR 12.9) and cancers of the liver, pancreas, ovary, brain, and Hodgkin lymphoma (SIRs > 5.0).
• Cancer risk remained elevated in subsequent years (SIR 1.3), persisting even 10+ years after VTE.
• Younger patients (<65 years) exhibited higher standardized incidence ratios compared to older patients.

Conclusions:

• A substantial increase in cancer risk occurs around the time of VTE diagnosis and persists long-term.
• The findings suggest potential shared risk factors or that pre-malignant conditions may promote thrombosis.
• Further research is warranted to elucidate the underlying mechanisms connecting VTE and cancer.