Colon cancer is cancer of the large intestines, also known as the colon and is the second leading cancer killer in the United States. The causes of colon cancer are not clear, but researchers at the University of Maryland Medical Center (UMGCC.org) think colon cancer occurs when healthy cells in the colon become altered.The cells grow and divide in an orderly fashion in order to keep the body functioning normally.
Sometimes, however, the growth gets out of control and cells continue to divide even when new cells are not needed. This continued growth in the colon and rectum can cause precancerous cells to grow in the lining of the intestine. If this continues over a period of time, some of the areas of the abnormal cells may become cancerous.There are various ways to screen for cancerous cells in the body. Three such screening tools/tests most commonly used are rectal examination, proctoscopy and colonoscopy.A rectal examination is a simple test performed by a doctor.
The doctor sticks a gloved finger into the rectum of the patient and feels for lumps. The doctor may also check material collected from the rectum to check for traces of blood in it.The rectal examination is advantageous because it can be done with a simple blood test, and is less expensive than the other screening tools. However, there are some disadvantages of the rectal examination.While the method can easily detect colonic polyps, it has a success rate of only 85 percent, according to the Colon Cancer Resource Center (Colon Cancer Resource [CCR], 2009), which is almost 10 percent less successful than having a colonoscopy.
The risk is that some of the colon polyps have a high chance of being missed - compared to other methods – which could have disastrous effects. The search scope and results are also limited as compared to other digital forms of testing such as the colonoscopy.A sigmoidoscope is performed through an examination of the large intestine from the rectum through the last part of the colon. A sigmoidoscope is usually quick with few to no complications and is a comfortable procedure. A sigmoidoscope requires less cleansing of the colon than is required of a colonoscopy.Although the procedure is quite safe, a sigmoidoscope carries a rare possibility of the intestinal wall being torn by the instrument.
The tear could require immediate and major surgery to repair, and the removal of a polyp can sometimes lead to internal bleeding.A colonoscopy is performed with a special tool called a colonoscope which is used to look inside the rectum and the entire colon, unlike the other screening tools. This allows for the performance of a biopsy and the removal of polyps and other abnormal tissues during testing.The upside to the testing method is that the test may not be able to detect all parts of a small polyps and cancer cells and is one of the most sensitive tests currently available. Thorough cleansing of the colon is necessary before the test unlike with other screening tools and may even require sedation in some cases.
Complications during testing may also include tears of the colon lining, and bleeding.ReferencesAmerican Cancer Society (2008). Cancer Facts and Figures 2008. Atlanta, GA: AmericanCancer Society. Retrieved August 10, 2008, fromhttp://www.cancer.
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