From the Guidelines
Metastatic cancer significantly increases the risk of both venous thromboembolism (VTE) and bleeding compared to non-metastatic cancer, with patients having approximately a 4-13 fold higher risk of developing VTE, as reported in the 2011 ESMO clinical practice guidelines 1. The elevated risk is due to several factors, including the release of procoagulant factors and inflammatory cytokines by metastatic tumors, which activate the coagulation cascade. Additionally, patients with metastatic disease often undergo more extensive treatments, including surgeries, chemotherapy, and radiation, and typically have reduced mobility, which may lead to compression of blood vessels by tumor masses. Regarding bleeding risk, metastatic cancer patients also face higher rates of hemorrhagic complications, particularly when metastases involve organs like the brain, liver, or gastrointestinal tract. Some key points to consider in the management of these patients include:
- The use of anticoagulation therapy, which can be burdensome and have a negative impact on patient quality of life, as noted in the 2013 study on treatment of cancer-associated thrombosis 1.
- The importance of VTE risk assessment in patients with cancer, as emphasized in the 2014 guidelines for treatment and prevention of VTE among patients with cancer 1.
- The need for careful balancing of thromboprophylaxis with bleeding risk assessment, and consideration of using lower doses of anticoagulants in patients with high bleeding risk.
- Regular reassessment of the risk-benefit ratio of anticoagulation therapy as the patient's clinical status changes.
From the Research
Metastases and Risk of VTE and Bleeding
- Metastases increase the risk of venous thromboembolism (VTE) and bleeding in patients with cancer, as shown in a study published in 2024 2.
- The presence of metastatic disease is an independent predictor of both recurrent VTE and major bleeding, with a hazard ratio (HR) of 2.57 for recurrent VTE and an HR of 2.80 for major bleeding 2.
- Another study published in 2009 found that the incidence of VTE is highest in patients with metastatic cancer, particularly those with cancers associated with a high one-year mortality rate, such as pancreatic cancer 3.
Comparison to Non-Metastatic Cancer
- Patients with metastatic cancer have a higher risk of VTE and bleeding compared to those with non-metastatic cancer, as the presence of metastatic disease is a significant predictor of these outcomes 2.
- The risk of VTE is also influenced by other factors, such as cancer type, stage, and grade, as well as patient characteristics, including age, ethnicity, and comorbid conditions 4, 5.
- A study published in 2016 found that the incidence of VTE is highest in the first few months after the diagnosis of cancer, and it decreases over time thereafter, regardless of whether the cancer is metastatic or non-metastatic 3.
Management and Treatment
- Anticoagulation therapy is recommended for patients with cancer and VTE, with low-molecular-weight heparin (LMWH) being the preferred treatment option 4, 6, 5.
- Direct oral anticoagulants (DOACs) may also be used, but their efficacy and safety in patients with cancer are still being studied, and they may be associated with an increased risk of major bleeding in certain patient populations 6.
- The management of recurrent VTE includes identifying the cause of the recurrence and addressing potential precipitants, as well as continuing anticoagulation therapy for at least 6 months or indefinitely if the cancer is active or under treatment 2, 4, 6.