Bevacizumab-induced Aortic Arterial Thrombosis

Area of Science:

• Oncology
• Vascular Medicine
• Radiology

Background:

• Bevacizumab is a targeted therapy used in chemotherapy regimens for advanced non-small, non-squamous lung cancer.
• Thromboembolic events are a known potential adverse effect of bevacizumab therapy.
• Atherosclerosis is a common condition that predisposes individuals to thrombotic events.

Observation:

• A 65-year-old patient with advanced non-small, non-squamous lung cancer developed near-complete occlusion of the abdominal aortic artery by a thrombus after two cycles of chemotherapy including bevacizumab.
• The patient was asymptomatic despite the significant arterial thrombus.
• A computed tomography scan prior to treatment revealed pre-existing calcification and a small organized clot in the abdominal artery, indicative of atherosclerosis.

Findings:

• Treatment with anticoagulants (heparin and warfarin) successfully reduced the size of the arterial thrombus.
• Subsequent chemotherapy cycles administered without bevacizumab did not result in further thrombotic events.
• The case suggests a potential link between bevacizumab administration and the acute exacerbation or formation of arterial thrombi in patients with underlying atherosclerosis.

Implications:

• Pre-treatment evaluation for atherosclerosis, including imaging assessment of the aorta, is crucial before initiating bevacizumab therapy.
• Identifying patients with pre-existing vascular disease may help in risk-stratifying individuals for bevacizumab treatment.
• This finding underscores the importance of considering vascular health in cancer patients undergoing treatment with angiogenesis inhibitors like bevacizumab.