The American Cancer Society estimates that over 100,000 men and women living in the United States will be diagnosed with colon cancer in 2013. Statistically, cancers of the colon and rectum are often combined and referred to as colorectal cancer. This addition brings the total to over 140,000 affected individuals with over 50,000 of these diagnoses resulting in death (American cancer society, 2013). Globally, the impact of this disease reached over one million people in 2008 with over 600,000 deaths attributed to colorectal cancer (Dusek, Maluskova, & Musik, 2013).
Colon cancer is preventable with a healthy diet, exercise, and curable with regular bowel exams. However, signs and symptoms of colon cancer usually do not present until the cancer is advanced which results in a less favorable prognosis. Routine colon screens may lead to a diagnosis at an early stage in the progression and can reduce the number of deaths from this disease even when the individual is genetically predisposed to colon cancer (Colon cancer, 2013).
The colon is an integral part of the digestive system. It consists of the last five or six feet of the intestines. There are four layers of tissue that make up the colon. The mucosa, submucosa, muscular layer and the serosa. Matter moves through the lumen small intestine rather quickly and the majority of nutrients are absorbed. Then, the waste travels slowly through the lumen of the colon where water is absorbed and fiber is broken down by bacteria. This process forms the fecal matter that is then stored in the colon until peristaltic waves of smooth muscle continue the motility toward the rectum and anus for defecation (Butler, Lewis, & Shier, 2013)
Certain factors increase an individuals risk of the epithelial cells of the mucosa layer to undergo an irreversible change in DNA. The presence or history of benign polyps is associated with the early development of colon cancer. These precancerous growths are known as adenomatous polyps which is an abnormal accumulation of tissue that extends from mucus producing glands into the lumen of the colon before becoming cancerous. When these cells become neoplastic they begin to grow into the layers of the colon and beyond as well. This event facilitates contact with capillaries and lymph vessels and cancer cells can then break off and migrate through the entire body (McCartney & Oberleitner, 2011).
The risk of cancer increases with age, and colon cancer is included in this factor with 62 being the most common age at diagnosis (McCartney & Oberleitner, 2011). Repeated exposure to carcinogens over time can cause mutations in DNA, especially in highly mitotic epithelial cells, resulting in cancerous growths. An immune response in a young and healthy body would destroy the early formation of cancer cells. Unfortunately, individuals of advanced age suffer a decrease in the capabilities of the immune system. This puts them at a higher risk of dysplastic cells multiplying in the colon.