A study conducted by the University of California, Irvine,  also found that the drug combination was much less toxic than  chemotherapy. “I think we are on track to develop a medical means to  prevent colon cancer,” in people at high risk of developing the  disease, said Dr. Frank Meyskens, director of the university’s  cancer center. He said earlier efforts to develop a preventive  treatment were thwarted by the fact that available therapies  caused too much toxicity. Meyskens lead a study in which 375 patients with at least  one previous colorectal polyp, also known as adenomas, were  treated with either a combination of one-time cancer drug DFMO  (difluoromethylornithine) and sulindac, a non-steroidal  anti-inflammatory drug (NSAID), or placebo. The results, presented at a meeting of the American  Association for Cancer Research in San Diego, were so  encouraging that the study was stopped early. After three years, the overall risk of recurrent adenoma  was 12.3 percent in treated patients, compared with 41.1  percent for patients in the placebo group, or a 70 percent risk  reduction. For patients with more than one previous polyp, 0.7 percent  of treated patients had a recurrence, compared with 13.2  percent of placebo patients — a 95 percent reduction. The researchers said an analysis of side effects and  toxicity found no difference between the treatment and placebo  groups. There also was no difference in side effects requiring  overnight hospitalization, gastrointestinal side effects or  cardiovascular side effects between the two groups. DFMO is the basis of the drug eflornithine, which was  initially developed as a cancer medication, but is now used to  treat African sleeping sickness. A cream formulation of  eflornithine is marketed as a hair removal agent under the  brand name Vaniqa. Sulindac is sold by Merck & Co Ltd under the brand name  Clinoril as a treatment for arthritis and other inflammatory  conditions. Meyskens said larger trials will be needed to assess the  risk of cardiovascular and other adverse side effects, as well  as to determine whether the incidence of actual colorectal  cancer can be reduced in either patients with low stage prior  colorectal cancers or in very high risk individuals. Chronic use of other NSAIDs, such as Merck’s Vioxx, has  been linked to an increased risk of heart attack and stroke. Sulindac is associated with liver toxicity. A separate large study presented at the conference showed  that Pfizer Inc’s Cox-2 inhibitor Celebrex, or celecoxib,  significantly reduced the risk of colon polyps during a trial  that was cut short after too many patients developed  cardiovascular problems. “For patients without major cardiovascular risk factors,  celecoxib at low doses protects against high-risk lesions that  can lead to colon cancer,” said Dr. Monica Bertagnolli,  associate professor of surgery at the Brigham and Women’s  Hospital, and the lead researcher on the Celebrex study. Meyskens said the combination therapy was likely to  eventually be used in people at high risk of colon cancer,  including those discovered to have advanced adenomas, as well  as patients diagnosed with low-stage colon cancer who have had  their disease cured. “About 30 to 35 percent of those patients will develop  another colon cancer,” he said. According to the American Cancer Society, colon cancer will  kill 52,000 people this year in the United States alone.
Drug combination reduces colon cancer risk.