The combination of chemotherapy and Avastin (bevacizumab) has been shown to increase survival in patients with metastatic colorectal and non-small-cell lung cancer, but some previous studies suggest these patients are at an increased risk for blood clots in their arteries.
Frank Scappaticci of Genentech and colleagues analyzed data from five randomized controlled trials that included 1,745 patients with metastatic colorectal, breast, or non-small-cell lung cancer.
Among patients treated with the combination therapy, 3.8% experienced blood clots in their arteries, compared with 1.7% of patients on chemotherapy alone. There was no statistically significant difference in the incidence of blood clots in veins. Risk factors for blood clots in both arteries and veins included previous blood clots and older age (65 or older.)
“The clinical benefit associated with bevacizumab therapy was maintained for all subgroups. Although death from a blood clot in the artery was uncommon, we did not capture functional disabilities from these events, and the risk factors identified in this study should be considered when making treatment decisions for individual patients,” the authors wrote.