"This is the best thing that's come along for
colon cancer prevention in 20 years," he tells WebMD.
The combination treatment worked so well that the study was halted
"We're all pretty excited," says Roy Herbst, MD. "The data is
The study was presented here at the annual meeting of the American
Association for Cancer Research. Herbst, a cancer specialist at the University
of Texas M.D. Anderson Cancer in Houston, moderated the session.
Colorectal cancer will strike about 150,000 Americans in 2008. It will kill
about 50,000 men and women, according to the American Cancer Society.
Reduction in Risk of Multiple Colon Growths
Meyskens and colleagues studied 375 people who had at least three colorectal
polyps, also known as adenomas, removed.
They were randomly assigned to treatment with either a combination of DFMO
and sulindac, or placebo.
After three years, colonoscopy exams showed that 12.3% of patients given the
drug combination had developed a new polyp, compared with 41.1% of patients
given a placebo. This translates to a 70% reduction in risk.
"Even more remarkable was that there was a 92% reduction in the risk of
advanced adenomas that are more likely to go on to cancer," Meyskens says.
A total of 0.7% of patients in the treatment group had advanced adenomas --
such as those that are 1 centimeter in size or larger or have signs of abnormal
cell growth under the microscope (dysplasia) -- vs. 8.5% in the placebo
"The real home run: A 95% reduction in multiple adenomas," Meyskens
says. A total of 0.7% of patients in the treatment group developed more than
one adenoma, versus 13.2% in the placebo group.
There was no significant difference in the rate of serious side effects,
including heart attacks and strokes, between the two groups.
Use Foreseen in People at High Risk of Colon Cancer
Meyskens says that DFMO, which is short for difluoromethylornithine, was
developed as a cancer medication, but is now
used to treat African sleeping sickness. It's also used to remove unwanted
hair. Sulindac, a non-steroidal anti-inflammatory drug (NSAID), is also sold as
Meyskens says that further study is needed to confirm both the safety and
effectiveness of the combo treatment. But he thinks it will eventually be used
to help prevent colon cancer in "people at highest risk, such as people
with advanced adenoma on colonoscopy."
It may also prove useful for "people with early colon cancer who have
been cured. Without treatment, about one-third will go on to have another colon
cancer," he says.