American Board of Internal Medicine (ABIM) Certification Practice Exam

Which prophylaxis is recommended for patients who have undergone cancer surgery?

1. Compression stockings

2. Low-molecular-weight heparin

3. Aspirin therapy

4. Vitamin K supplements

The correct answer is: Low-molecular-weight heparin

The recommendation for low-molecular-weight heparin (LMWH) as prophylaxis following cancer surgery is based on its effectiveness in preventing venous thromboembolism (VTE). Patients who undergo cancer surgery are at an increased risk for the development of blood clots due to several factors, including immobilization, the underlying malignancy, and surgical stress. LMWH provides anticoagulation that effectively reduces this risk in high-risk surgical patients. LMWH is preferred in this scenario because it has a favorable pharmacologic profile, including predictable anticoagulation response, ease of administration, and a lower incidence of side effects compared to unfractionated heparin. In many clinical guidelines, including those from the American College of Chest Physicians, LMWH is strongly recommended for thromboprophylaxis in patients undergoing major cancer surgery. In contrast, compression stockings can offer mechanical prophylaxis but are often not as effective alone as pharmacologic options. Aspirin therapy is not typically indicated for VTE prophylaxis in the context of surgery, despite some evidence for its role in cardiovascular disease. Vitamin K supplements are not relevant to prophylaxis in this context, as they are generally used for reversing anticoagulation rather than preventing thromboembolic events.