An abnormal mass of cells that forms in the colon defines a colon polyp. They can develop any where along the four to six-foot length of the large intestine. Shapes vary from flat to mushroom-like. Sizes range from small to large. Generally, large polyps carry a higher risk of malignancy. Small mushroom-shaped polyps are less likely to become cancerous than polyps that are flat. The orderly process of division and growth of cells is regulated by two broad groups of genes. According to the Mayo Clinic, a mutation in any one of these genes alters this process causing the formation of polyps. Over time, a benign polyp can develop into a cancerous lesion.
Colon polyps are divided into three groups. Adenomatous polyps account for 2/3 of all colon polyps. A small percentage of adenomatous polyps become cancerous. However, nearly all polyps that are confirmed as malignant, are adenomatous. Most of the remaining 1/3 are typed as hyperplastic. Frequently less than ½ centimeter in size, hyperplastic colon polyps are rarely malignant. Inflammatory colon polyps appear after an attack of ulcerative colitis or Crohn’s disease. These polyps do not present a threat, although having ulcerative colitis or Crohn’s disease increases the risk of colon cancer.
Having a family history of colon polyps increases your risk of developing them. Smokers have a 20 percent higher risk than nonsmokers. Alcohol consumption, especially beer, raises the risk. If you drink alcohol and smoke, you double your changes for developing colon polyps.
Colon polyps can become malignant. Though most people who are diagnosed with colon cancer are 50 years of age or older, the risk starts to increase at the age of 40. Early and regular screening offers the best prognosis. Detection and removal of polyps before they become cancerous is possible during a colonscopy. Additionally, lifestyle changes can reduce the possibility of colon polyps. Adding fiber and calcium to the diet, lowering fat intake, and maintaining a healthy weight are preventative measures.