Colon Polyps and Cancer

Overview

Polyps are growths that form on the inside lining of the colon. They are usually shaped like mushrooms or dome-like buttons, and vary in size from a tiny pea to larger than a plum.

While colon polyps start out as benign tumors, certain types of polyps may turn into cancer. The risk is greater as the polyp gets larger.

There are several types of colon polyps, including:

  • Adenomatous - A majority of polyps are adenomatous, and only a small percentage of these become cancerous. However, if a polyp does become malignant, it will most likely be adenomatous.
  • Serrated - These types of polyps may become cancerous, especially those that are larger and in the upper colon as they are difficult to detect due to their flat appearance.
  • Inflammatory - Following a bout of ulcerative colitis or Crohn's disease, these polyps may appear.

 

 

Causes

The complete cause of polyp formation and colon cancer is unknown, but it is known that heredity plays a key role.

Genes

A person whose parents, brothers or sisters have colon cancer or polyps is at significantly greater risk of developing it. There is also risk, but to a lesser degree, if uncles, aunts or grandparents have had the disease. Therefore, people with a family history of polyps and colon cancer should be evaluated by their physician and examined regularly.

Ethnicity

African Americans are naturally at high risk of colon cancer and polyps and should consult with their doctor about when to start screening.

Other Factors

Additionally, people who smoke, are not physically active or have unmanaged Type 2 diabetes are at high risk.

Symptoms

The most common symptoms of colon cancer are no symptoms at all, which is why following recommended screening guidelines is optimal in preventing colon cancer and polyps.

Some people may have symptoms though, including:

  • Rectal bleeding
  • Blood in your stool
  • Change in stool color
  • Change in bowel habits lasting longer than a week
  • Nausea or vomiting
  • Iron deficiency anemia

If you experience any of these symptoms, consult your doctor immediately.

Treatments

Screening is a key component to finding polyps before they turn cancerous, which is why the recommended screening guidelines suggest colonoscopy screening to begin at age 50. However, if you have a family history of the disease, screening should start earlier. Talk to your doctor about what screening age and methods are best for you.

Screening methods include: 

During the procedure, the doctor will be able to remove most polyps with a small wire snare. Polyps that are too big in size or cannot safely be reached may be removed in a separate minimally invasive surgery. In very rare cases, the colon and rectum may have to be entirely removed.

Prevention

Genetics are one of the most important factors in determining your risk of developing colon polyps and cancer, but there are some measures you can take to further reduce your risk:

  • Dietary Changes
    • Vegetables and fruits - The red, yellow, orange and green colored fruits and vegetables are particularly rich in a complex mixture of substances called antioxidants. The cruciferous vegetables have very high levels of natural cancer-fighting chemicals. There is increasing medical data that people who eat these foods plus generous amounts of unprocessed grains have less colon cancer. There is no medical evidence that taking antioxidant supplements such as vitamin C and E and beta carotene is helpful.
    • Folic acid - Data was published in 1999 which studied a large group of nurses over a 14 year period. Folic acid or folate seemed to be very protective for these females, especially those who received over 400 micrograms a day from food and/or a multivitamin.
    • Meats and saturated fats - Meat contains saturated fat, as do many prepared products. Always read the food labels to see how much saturated fat a food contains. These fats are broken down by the body's digestive juices and bile, and some of these byproducts are known to cause cancer in laboratory animals. There is some evidence that meat-rich diets may increase the risk of breast cancer and possibly colon cancer. The risk may depend on how the meat is prepared. 
    • Calcium - Calcium is one of the most common minerals in the body. Animal studies have found that a lack of calcium leads to excessive cell growth in the colon. It is not clear if calcium has a cancer preventive benefit for humans. All adults should have 1000 mg per day. After menopause, females have a greater risk of osteoporosis and should have 1500 mg of calcium a day.
  • Aspirin - Some, but not all, medical studies show that the incidence of cancer of the colon may be less in those people who take aspirin regularly. It is known that prostaglandin (a hormone-like substance produced by the body) may promote excessive or abnormal cell growth in the intestine. Aspirin appears to interfere with prostaglandin which may account for a possible role in preventing colon cancer. Aspirin can cause stomach ulcers, serious bleeding or hemorrhagic strokes, so it should only be taken with the approval of a physician.
  • Lifestyle - Keep an active lifestyle - exercise regularly. 
  • Cigarettes - Do not smoke cigarettes. Long term smokers are more likely to develop colon cancer than non-smokers.