Primary prevention of colorectal cancer: myth or reality?

Colorectal cancer incidence has been rising strongly in parallel with economic development. In the past few decades, much has been learned about the lifestyle, dietary and medication risk factors for this malignancy. With respect to lifestyle, compelling evidence indicates that prevention of weight gain and maintenance of a reasonable level of physical activity can positively influence in lowering the risk. Although there is controversy about the role of specific nutritional factors, consideration of dietary pattern as a whole appears useful for formulating recommendations. Though quite often recommended, the role for many supplements, including omega-3, vitamin D, folate, and vitamin B6, remains unsettled. Only calcium and vitamin D supplementation appear to add a modest benefit, particularly in those with a low daily intake. With regard to chemoprevention, medications such as aspirin and nonsteroidal anti-inflammatory drugs, and postmenopausal hormonal replacement for women might be associated with substantial reductions in colorectal cancer risk, though their utility is affected by their side effect profile. However, the role of agents such as statins, bisphosphonates and antioxidants have yet to be determined. Ultimately, primary prevention strategies focusing on modifying environmental, lifestyle risk factors, and chemopreventive drugs are options that have already been tested, and may impact on colon cancer incidence.