Association of iron with colorectal cancer.

Many studies indicate that animals and humans burdened with excess iron are at increased risk of neoplasia at various sites. This review focuses on inquiries that involve iron and colorectal cancer. Relevant studies reported in the past decade are briefly described and evaluated. The studies in animal models and in relatively large groups of humans point to a positive association of excessive iron with colorectal oncogenesis. Phytic acid, a chelator of iron and zinc, may be useful in withholding iron from the carcinogenic process. Sufficient evidence is available to justify construction of long-term prospective studies in humans in which would be monitored (i) levels of iron and phytate intake, (ii) serum transferrin iron saturation and ferritin, (iii) fecal levels of iron and hydroxyl radicals, and (iv) appearance of colorectal polyps, adenomas and carcinomas.