A new research study suggests that the use of laxatives containing polyethylene glycol (PEG) may reduce the risk of colorectal tumors by 50 percent. The study was led by Denis E. Corpet, PhD, professor, Ecole National Veterinaire in Toulouse, France, and Etienne Dorval, president of Gastroenterologists of Indre-et-Loire, France.

PEG is a nonabsorbed, nonmetabolized, water-soluble polymer that has been used to treat constipation in France since 1996, and was recently approved for use as a laxative in the U.S. and Canada. PEG is extremely potent in the chemoprevention of experimental colon carcinogenesis. PEG treatment of azoxymethane-induced tumors in rats resulted in complete inhibition of invasive colon cancers. These experimental studies showed that PEG is the most potent agent against precancerous colonic lesions, or aberrant crypt foci (ACF).

"This encouraging discovery reveals the potential prevention properties of PEG-based laxatives for colorectal cancer," said Dr. Corpet. "I am confident that if PEG were taken regularly, many colorectal cancer tumors could be regressed or prevented, as we observed in this study and in studies of rats. PEG's promising chemopreventive effect offers further insight into a potential preventive agent for this major disease. In this study population, PEG use appears to be more protective than aspirin. The striking results of preclinical trials and this epidemiological study should be confirmed in a clinical trial."

In the population-based study in France, 1,165 patients (607 women, 498 men, mean age 58.3) having a routine total colonoscopy were enrolled by gastroenterologists from October 2001 to January 2002. Patients were interviewed about taking a PEG-based laxative, their risk factors for colon cancer and diet. Of the 1,165 patients, 70% had no tumor, 28% had adenomas, and 2% had carcinomas. Of those who used a PEG-based laxative, most used Forlax, which contains the highest dose of PEG. The odds ratio of the other PEG-based laxatives were smaller than one, but none reached significance. Those who used Forlax reduced their risk of colorectal tumors by half.