Treatment with bevacizumab, an antiangiogenic agent, in patients with metastatic or unresectable colorectal cancer was approved less than 4 years ago in Japan. Bevacizumab improves the survival of patients with metastatic colorectal cancer; however, it may lead to complications such as bleeding, which are sometimes fatal. Bevacizumab should be administered only after careful consideration because the potential risks of therapy outweigh its benefits. Therefore, pharmaceutical companies do not recommend bevacizumab therapy for patients with brain metastases. While some reports support the cautious use of bevacizumab, others report that it is not always necessary to prohibit its use in patients with metastases to the central nervous system (CNS), including the brain. Thus, bevacizumab therapy in colorectal cancer patients with brain metastases is controversial, and it is unclear whether brain metastases are a risk factor for intracranial hemorrhage during anti-vascular endothelial growth factor (VEGF) therapy. We report a 64-year-old man and a 65-year-old man with recurrent colorectal cancer without brain metastases; these patients developed multifocal and solitary intracranial hemorrhage, respectively, after the administration of bevacizumab. Our findings suggest that intracranial hemorrhage can occur even if the patient does not have brain metastases prior to bevacizumab treatment and also suggest that brain metastases are not a risk factor for intracranial hemorrhage with bevacizumab treatment. These findings also question the necessity of excluding patients with brain metastases from clinical trials on anti-VEGF therapy.
Keywords: Anti-vascular endothelial growth factor therapy; Bevacizumab; Central nervous system; Colorectal cancer; Intracranial hemorrhage.