A collaborative effort between the Arizona Cancer Center and the National Cancer Institute (NCI) to understand the influence of diet on recurrence of colorectal adenomas (polyps) a precursor to cancer indicates that a high-fiber diet may be more important for men than women. Although the reason for a sex difference is unknown, researchers suggest that it may be related to hormonal effects or the difference between the sexes in location of polyp formation.
It has been well established that colorectal adenomas are a precursor to colon cancer. Prevention of these adenomas through dietary supplementation is a research focus at both the Arizona Cancer Center and the NCI. Large clinical trials performed at both centers failed to show protection from recurrent adenomas with dietary intervention. In fact, an association between dietary fiber and colorectal adenomas has never been firmly established due to equivocal results.
In collaboration with researchers from the NCI, Arizona Cancer Center members Elizabeth Jacobs, Ph.D.; Patricia Thompson, Ph.D.; Mar?a Elena Martinez, Ph.D.; and Arizona Cancer Center Director David S. Alberts, M.D. pooled the study populations from the two clinical intervention trials. With a new study population of more than 3,200 participants, Dr. Jacobs and her team detected a positive effect on dietary intervention for men, but not for women.
Detection of a sex difference may explain the discrepancy in results from previous studies. Further, identifying a real and significant relationship between dietary intervention and reduced risk of colorectal adenoma recurrence provides a possible preventative treatment option for men who have had colorectal adenomas.
More and more, we are understanding colorectal cancer as a disease that has different pathways, explains Dr. Jacobs. It is possible that these pathways to cancer vary to some degree depending on the sex of the patient. Therefore, while the mechanism by which fiber may act is not understood, it is plausible that it has different effects in men as opposed to women.
Results of this study were published earlier this year in the February 2006 issue of the American Journal of Clinical Nutrition.
The Arizona Cancer Center, the state s premier National Cancer Institute-designated comprehensive cancer center, is celebrating its 30th anniversary this year. With primary locations at the University of Arizona in Tucson and the Virginia G. Piper Cancer Center in Scottsdale, the Center has more than a dozen research and education offices distributed throughout the state and 250 physician and scientist members working to prevent and cure cancer. For more information, go to www.azcc.arizona.edu.