What is Colon Cancer?
Colon cancer is cancer cells which form in the tissue of the colon, which is the longest extension of the large intestine. Most instances of colon cancer are adenocarcinomas, which are classified as cancers which occur in cells or glands that produces and release fluid or mucus. Rectal cancer occurs in the last several inches of the colon in the area closest to the anus. It is estimated among the 108,070 colon cancers and 40,740 rectal cancers diagnosed in 2008, they will cause 49,960 deaths.
About the Disease
Most incidences of colon cancer begin as noncancerous or benign groupings of cells known as adenomatous polyps. Over time these polyps can become colon cancers. Polyps are usually small and produce few and are not associated with symptoms. These polyps can occur nearly anywhere in the colon, which is approximately 5 feet of the large intestine. Polyps will typically appear as mushroom-shaped. Precancerous growths can also appear flat or recessed into the colon. These polyps are more difficult to detect in the colon but are far less common. The three generally classified types of polyps are adenomas, hyperplastic polyps, and inflammatory polyps. Adenomas are generally considered to be the most hazardous and are typically removed if they are discovered in the colon.
Effects of the Disease
Most people with colon cancer will not experience any symptoms if the disease is in its early stages. Symptoms vary when they arrive but will often depend on the size and location of the tumor within the large intestine. Most often, indications of colon cancer will concern bowel habits. Possible signs include, diarrhea, constipation, fluctuations in stool consistency, rectal bleeding, or bloody stool. Unlocalized symptoms may include weakness, fatigue, and unexplained weight loss. Blood in the stool may be indicative of colon cancer but is also associated with many other conditions. Red stools may include blood but could also be indicative of dietary choices.
Who is Most at Risk for Colon Cancer?
Age is quite relevant in those at risk of colon cancer. About 9 out of every 10 colon cancer diagnoses occur in those older than 50. Established inflammatory conditions of the colon can also increase likelihood of the colon cancer in some people. These conditions may include ulcerative colitis and Crohn’s disease. Family history of colon cancer and genetic pre-disposition to colon inflammatory conditions also plays a significant role in colon cancer risk. Diet and alcohol consumption can lead to an increased risk of colon cancer, as well. Diets which are high in fat or low in fiber and heavy use of alcohol may increase likelihood of cancer development.
How is Colon Cancer Diagnosed?
Early detection tools for colon and rectal cancer include a stool blood or DNA test, involving the examination of fecal material. Blood tests are more common than DNA because they are more widely available. More invasive diagnostic tools include a flexible sigmoidoscopy and colonoscopy. Generally a sigmoidoscopy will examine some portion of the colon with a slender but flexible tube. If polyps are detected during this test and physician will usually recommend a colonscopy to examine the colon more thoroughly and remove polyps for examination. These tests can be uncomfortably but doctors will typically administer a minor sedative to relax the patient.
How is Colon Cancer Treated?
There are three generally recommended treatment regimens for colon cancer. Common treatments include surgery, chemotherapy, and radiation therapy. The surgical procedure involves the removal of a portion of the colon as well as some measure of tissue in the surrounding part of the organ. Surgeons will then reconnect healthy portions of the colon. Surgery to prevent cancer will typically be recommended to patients with a genetic predisposition to colon cancer. Chemotherapy and radiation therapy will attempt to use drugs or radiation to kill cancer cells and can be used in conjunction with surgery as well as in conjunction with each other depending on the effectiveness of the primary treatment regimen.
Last modified: December 28, 2010.
