Treatment with chemotherapy and bevacizumab, an anticancer drug, is associated with a greater risk of blood clots in patients arteries compared with treatment with chemotherapy only, according to a study published online August 7 in the Journal of the National Cancer Institute.
The combination of chemotherapy and bevacizumab has been shown to increase survival in patients with metastatic colorectal and nonsmall-cell lung cancer, but some previous studies suggest these patients are at an increased risk for blood clots in their arteries.
Frank Scappaticci, M.D., Ph.D., of Genentech, Inc. in South San Francisco, Calif., and colleagues analyzed data from five randomized controlled trials that included 1,745 patients with metastatic colorectal, breast, or nonsmall-cell lung cancer.
Among patients treated with the combination therapy, 3.8 percent experienced blood clots in their arteries, compared with 1.7 percent 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 factorsidentified in this study should be considered when making treatment decisions for individual patients, the authors write.