Taking the common cancer drug bevacizumab, also known as Avastin, with another cancer treatment may increase a patient's risk of dying from their cancer treament, a new review of studies suggests.
Cancer patients who took Avastin with chemotherapy or biological therapy were 1.5 times more likely to die from treatment-related causes than those taking the same chemotherapy or biological therapy drugs without Avastin, the review said.
Among those taking Avastin, hemorrhages caused 23.5 percent of deaths, a blood disorder called neutropenia caused of 12.2 percent of deaths and gastrointestinal tract perforation (holes in the GI tract) caused of 7.1 percent of deaths, the study showed.
Avastin is designed to work by stopping the growth of blood vessels that feed tumors.
While the study shows there are risks to taking the drug in addition to chemotherapy and biological therapy, there are cases where the benefits may outweigh the risks, said Dr. Scott Kopetz, an assistant professor of gastrointestinal medical oncology at MD Anderson Cancer Center in Houston, who was not involved with the study.
“In oncology, unfortunately, we're dealing with much more aggressive therapies, or toxic therapies, by the nature of the very aggressive disease that we're trying to treat,” Kopetz told MyHealthNewsDaily.
The review will be published Feb. 2 in the Journal of the American Medical Association.
Looking at the numbers
Researchers from Stony Brook University Medical Center in Stony Brook, N.Y., studied 16 randomized controlled trials involving Avastin published between 1966 and 2010. There were 10,217 patients in the analysis, all with a wide range of advanced tumors.
The researchers looked at how many people died from treatment-related causes when Avastin was taken with chemotherapy or biological therapy, and compared them with deaths when chemotherapy or biological therapy were taken alone.
Researchers found that 2.5 percent of all deaths in the analysis were linked with Avastin.
And patients who took drugs called taxanes or platinum agents with Avastin were 3.5 times more likely to die a treatment-related death than patients taking those drugs without Avastin, the study said.
Internal bleeding in the lungs or in the gut were the leading causes of treatment-related death, according to the study.
Weighing the risks and the benefits
Cancer treatments often bring more risks than other medications, Kopetz said. For example, physicians can prescribe blood pressure medication without much problem, but patients receiving cancer treatment must fill out consent forms to make sure they're aware of the risks involved.
The risks are sometimes accepted because patients have few treatment options, said Dr. Joanne Mortimer, director of the women's cancers program at City of Hope Cancer Center in Los Angeles, who was not involved with the study.
However, patients with some cancers may have more options than others, Mortimer said. For patients with lung and colorectal cancers, for example, the benefit of taking Avastin may outweigh the risk of treatment-related death. But for certain breast cancers, where the drug has shown little evidence of extending life, the risk may not be worth it.
In December, the Food and Drug Administration announced it was withdrawing its approval of the use of Avastin to treat breast cancer because the drug did not increase survival rates in patients with that disease. The drug is still recommended for treatment of colon, lung, kidney and brain cancers.
“Although more patients respond to chemo with bevacizumab, they don't live any longer, and they don't even stay in remission longer,” Mortimer told MyHealthNewsDaily, “and yet, there is a consistently higher risk of side effects.”
Mortimer, who is also a member of the FDA Oncology Drug Advisory Committee, said patients should talk to their doctor to discuss the risks of taking bevacizumab.
“For some diseases, bevacizumab added to chemotherapy may be helpful,” she said. “There are virtually no drugs — even aspirin — that are without side effects, and it is critical with any treatment to weigh the benefits and toxicities.”
Pass it on: Taking Avastin with chemotherapy or biological therapy to treat cancer may increase the risk of treatment-related death.
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