COLON CANCER

March is National Colorectal Awareness Month. Cancer of the colon and rectum is the third most common cause of cancer deaths in women. It is estimated that 145,000 new cases of colorectal cancer will be diagnosed in the United States this year and more than 56,000 Americans will die from the disease. It is estimated that 60% of these deaths could be prevented if everyone over the age of 50 was screened for colorectal cancer. Most colorectal cancers occur in people age 50 and older.

Some cancer screening programs do not prevent cancer but allow it to be detected at an earlier stage with a better chance of a cure; an example of this is mammography that allows cancers to be detected before they can be felt in the breast by the woman or her physician. Other cancer screening programs actually prevent cancers from developing because they can detect lesions that have the propensity to turn into a cancer. If these lesions are removed cancer cannot develop in them. Examples of this include pap smears which detect precancerous lesions of the cervix and colonoscopy which can detect precancerous lesions of the colon. Widespread use of pap smears in the United States has dramatically reduced both the incidence and mortality from cervical cancer. Widespread use of colonoscopy has the same potential to decrease both the incidence and mortality from colorectal cancer.

Symptoms of colorectal cancer include bleeding from the rectum, abdominal pain, changes in the pattern of bowel movements or a sensation of bloating. If these symptoms are present a complete diagnostic evaluation is warranted, not just a screening test. Colorectal cancer is a slow growing cancer and has clear precancerous lesions that can be detected and removed. Early stage tumors have a much better prognosis than advanced cancers. These may exist without symptoms thus the need for screening.

The three most common tests are to screen for colorectal cancers are colonoscopy, sigmoidoscopy and testing the stool for hidden blood (FOBT). Colonoscopy is the indicated screening test for people at an increased risk for colorectal cancer. This includes those people with a family or personal history of colorectal cancer or precancerous lesion (usually called adenomas or polyps) or those with a long history of ulcerative colitis. Screening should begin at the age of 40 in these individuals. For the rest of the population screening for colorectal cancer should start at the age of 50. The choice between tests becomes more difficult with issues such as cost and patient preference coming into play. A brief summary of the three screening tests follows.

After cleaning out their bowels a colonoscopy is performed under light sedation. A colonoscope is inserted into the rectum and advanced through the entire colon. The entire colon is evaluated for cancer or polyps and if found can be removed during the procedure. Colonoscopy will detect greater than 90% of significant lesion in the colon. It will pick up both cancerous and precancerous lesions. It is estimated that the reduction in death from colon cancer is 59% for people who undergo colonoscopy.

Sigmoidoscopy is generally performed without any sedation after the bowels are cleaned out with a laxative or enema. It evaluates the lower half of the colon. The procedure picks up most of the lesions within reach of the sigmoidoscope but misses 50% of cancers in the upper or right side of the colon. It is generally combined with yearly fecal occult blood testing.

Fecal occult blood testing involves placing samples of stool on a special card and testing them for blood. If blood is present a colonoscopy is typically recommended. The test should be done every year and is estimated to reduce the risk of death from colorectal cancer by 15-33%. Unfortunately, less than 50% of patients given cards to test their stool actually complete the test.

When deciding which test to use to screen for colorectal cancer it is important to remember that any testing is better than no test at all. The threat of colorectal cancer is very real. Screening for colorectal cancer, although increasing, is lower than rates for other cancers such as cervical and breast cancer perhaps because of embarrassment or concerns over perceived discomforts of the screening tests. It is important that, just like mammograms and pap smears, colorectal cancer screening is considered a component of preventative health care. In honor of Colorectal Awareness month the Jordan Hospital is hosting a seminar for the public on Thursday March 30, 2006from 6PM-8PM. Call 508-830-2490 for more information or to register for this program.