WEDNESDAY, June 2, 2004 (HealthDayNews) -- Two new drugs improve the outlook for patients with very different cases of colorectal cancer, researchers in the United States and Europe report.
One drug buys some precious extra months of life when the cancer has spread throughout the body. The other provides a significant increase in the rate of disease-free survival when the cancer is detected early enough to be removed surgically.
The one thing both treatments have in common is that each drug is added to the standard regimen for cancer of the colon and rectum -- a combination of fluorouracil and leucovorin, say separate reports in the June 3 issue of the New England Journal of Medicine.
The American trial probably will get most public attention, since the drug it used, bevacizumab, has been widely acclaimed as the first example of a unique attack against cancer proposed years ago by Dr. Judah Folkman of Harvard University. That process is called antiangiogenesis, which tries to stop the growth of new blood vessels that a cancer needs to flourish.
The study covered just one use of the drug, for patients whose cancers have spread so much that surgery is not possible. Their survival time usually is measured in months.
"Our study demonstrated several things," said study author Dr. Herbert I. Hurwitz, an associate professor of medicine at Duke University. "The first is that the addition of bevacizumab to first-line therapy conferred a significant benefit in terms of survival, tumor control and tumor shrinkage."
The study also appears to provide "the first blue-chip data set to validate the antiangiogenesis hypothesis," Hurwitz said. But he leaves open the possibility that the drug might act in a different way.
The 402 patients who were given bevacizumab in addition to other cancer drugs survived for an average of 20.3 months, compared to 15.6 months for those who got the standard regimen.
"We hope that the validation of the drug's value with one target can be expanded to provide better benefits against other targets," Hurwitz said.
A number of studies using the drug, whose brand name is Avastin, have already begun, he said.
In the European study, the rate of disease-free survival for patients who got a different new agent, oxaliplatin, in addition to standard therapy after surgery was 78.2 percent after three years, compared to 72.9 percent for those who got only the standard regimen, said a report by a group led by Dr. Aimery de Gramont of the Hospital San Antoine in Paris.
The improvement is statistically significant, said Dr. Robert J. Mayer, director of the center for gastrointestinal oncology at the Dana-Farber Cancer Institute in Boston. He grumbled somewhat about the failure of the European researchers to provide data on survival for more than the three years covered in the report, but said he stood by the title of an editorial he wrote in the same issue: "Two Steps Forward in the Treatment of Colorectal Cancer."
Mayer urged caution about Avastin, noting there has been "a great deal of publicity about this molecule."
"Many patients come to me with the understanding that it is a cure," he said. "We need to be clear in exactly what settings it should be used."
Given the need for carefully controlled trials, progress is inevitably slow, Hurwitz said, but it is being made.
"In 2004, we have seen approval of three drugs for colorectal cancer," he said. "If this pace of progress continues, then we will be doing very well."
More information
What you need to know about colorectal cancer is available from the American Cancer Society.
