Chemo with bevacizumab ups blood clot risk

SOUTH SAN FRANCISCO, Calif., Aug. 9 (UPI) -- A U.S. study suggests chemotherapy used with the anti-cancer drug bevacizumab produces a greater risk of blood clots than with chemotherapy alone.

The combination of chemotherapy and bevacizumab has been shown to increase survival in patients with metastatic colorectal and non-small-cell lung cancer. But some previous studies suggested such patients were at an increased risk for arterial blood clots.

In the new research, Dr. Frank Scappaticci 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 non-small-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.

"The clinical benefit associated with bevacizumab therapy was maintained for all subgroups," the researchers said. "Although death (from an arterial blood clot) 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 research appears online in the Journal of the National Cancer Institute.