No Definitive Link Seen Between Vytorin and Cancer
Review results are reassuring, one cardiologist says
TUESDAY, Sept. 2, 2008 (HealthDay News) -- New research finds no definitive link between Vytorin and cancer risk, but it also suggests that the cholesterol-lowering drug cannot curb cardiovascular disease.
The results of a small study published recently suggested that Vytorin (ezetimibe) might boost the chances of developing cancer. In that study, called SEAS, researchers found that among patients taking Vytorin, 101 developed cancer, compared with 65 in the control group. Among these patients, 39 taking Vytorin died, compared with 23 in the control group.
However, a three-study analysis in the Sept. 2 issue of the New England Journal of Medicine did not find compelling evidence of such a connection. A second study in the same issue of the journal found that taking Vytorin with a statin did not benefit patients with abnormal narrowing of the aortic valve called aortic stenosis.
"Overall, the three ezetimibe trials show no credible evidence of any effect on cancer rates," the Oxford University researchers said about their review in a statement. "The SEAS result appears to have been a chance finding. When the results of all the trials are analyzed properly, no particular type of cancer is significantly increased, and there is no significant excess of death from any particular type of cancer."
"The recent, unexpected findings of the SEAS study raised concern that the use of the selective cholesterol-absorption inhibitor ezetimibe, which lowers LDL cholesterol through mechanisms different than statin medications, was associated with increased risk of cancer," said Gregg Fonarow, a professor of cardiology at the University of California, Los Angeles. "This new analysis, which included data from two larger ongoing clinical trials, is reassuring in that there has not been excess cancer risk observed in these two other trials."
"This study reduces our worry that ezetimibe might cause cancer, which was suggested by the recent SEAS study," Dr. Bryon Lee, an assistant professor of medicine at the University of California, San Francisco, said. "However, this doesn't address our lingering worry that ezetimibe simply might not work. It lowers cholesterol, but it has yet been shown to lower important endpoints like heart attack and stroke."
In the review, the Oxford group analyzed data from the ongoing SHARP and IMPROVE-IT studies. They found no increase in the risk of cancer among patients taking Vytorin. In both trials, 313 patients taking Vytorin developed cancer, compared with 326 in the control groups.
Among these patients, 97 of those taking Vytorin died from cancer, compared with 72 among patients not taking the drug, which is not considered a statistically significant difference.
"There is no evidence of a trend toward any cancer excess with more prolonged treatment," review co-author Rory Collins, from Oxford University, said in a statement. "Even among the people who had been in any of these studies for more than three years, cancer was recorded in 39 treatment versus 41 control patients. This does not provide support for there being a hazard."
Fonarow finds the results reassuring.
"Prior large-scale randomized trials and pooled analyses have clearly shown that the lowering of LDL cholesterol with statin medications substantially lowers the risk of heart attack, stroke, cardiac death and all-cause mortality without any increased risk of cancer or cancer-related deaths through five years of treatment and follow-up," Fonarow said.
Statins represent one of the most important therapeutic advances in cardiovascular medicine ever achieved, Fonarow noted.
But Vytorin may not benefit patients with abnormal narrowing of the aortic valve called aortic stenosis, the second NEJM study suggested.
In that trial, 1,873 patients with mild to moderate aortic stenosis were randomly assigned to receive Vytorin plus simvastatin or a placebo.
After 52.2 months of follow-up, 35.3 percent of the patients taking Vytorin and simvastatin suffered a major cardiac event, including death from heart disease, aortic valve replacement, heart attack, heart failure, bypass surgery, angioplasty, or a stroke, compared with 38.2 percent of the patients receiving placebo.
"Simvastatin and ezetimibe did not reduce the composite outcome of combined aortic-valve events and ischemic events in patients with aortic stenosis. Such therapy reduced the incidence of ischemic cardiovascular events, but not events related to aortic-valve stenosis," the researchers concluded.
For more about cholesterol, visit the American Heart Association.