Risk of Second Cancer After Blood Clots in Cancer Patients

Sample size: 6285 publication Evidence: moderate

Author Information

Author(s): Sørensen H T, Pedersen L, Mellemkjær L, Johnsen S P, Skriver M V, Olsen J H, Baron J A

Primary Institution: The Department of Clinical Epidemiology, Aarhus University Hospital

Hypothesis

Is venous thromboembolism (VTE) associated with an increased risk of a second malignancy in cancer patients?

Conclusion

Cancer patients who experience venous thromboembolism have an increased risk of developing a second cancer, especially if the thrombotic event occurs more than a year after the initial cancer diagnosis.

Supporting Evidence

343 second cancers were diagnosed in the VTE cancer cohort compared to 1981 in the control cohort.
The relative risk for a second cancer diagnosis was 1.3.
Patients with VTE more than a year after their first cancer had a 40% increase in risk for a second cancer.
High risks of a second cancer were seen for patients with kidney and bladder cancer.

Takeaway

If someone with cancer has a blood clot, they might be more likely to get another type of cancer later on, especially if the blood clot happens a while after their first cancer.

Methodology

The study analyzed a cohort of cancer patients with venous thromboembolism using data from the Danish Cancer Registry and National Registry of Patients, comparing them to matched cancer controls without VTE.