By S. Todd Stolp MD
©July 2008
Disease prevention is a familiar battle cry of public health. It is better to diminish the risk of disease before an assault begins than to wait for the first skirmishes to occur. But there are several criteria that must be met for a particular test to effectively identify risk of illness, and thereby allow an opportunity to prevent disease. Colon and rectal (“colorectal”) cancer prevention provides an excellent opportunity to explore the characteristics of screening tests that can make a difference.
The tests recommended for colorectal cancer prevention fall into two categories. The “fecal tests” involve testing the bowel movements each year by collecting small smears of stool on a card or in a container. There are several “fecal occult blood tests” (FOBT) available for this which test for the presence of otherwise invisible amounts of blood in the stool. Each should be done carefully and in accordance with recommendations provided with the test. There are also new fecal tests available that detect certain cancer markers in the stool, but these are more expensive.
The second category of testing includes examinations of the structure of the lower bowel (the colon) and rectum, most often with a scope called a colonoscope or sigmoidoscope. Fourteen million annual colonoscopies are performed in this country.
Each person’s health care provider will recommend the test that is most appropriate for the individual based upon factors like family history, age and overall health. In general and in accordance with American Cancer Society recommendations, colorectal cancer screening should begin at age 50 years.
For a preventive test to be effective, the disease you wish to prevent must be worthy of attention. It makes little sense to mount a campaign to identify people at risk of developing hiccups. Colorectal cancer is the second leading cause of cancer death and the third most common cancer in the United States, more than justifying the effort to screen for the disease.
Even though no test is perfect, a test that is used to screen the population for risk of disease must be acceptably accurate, without over-measurement or under-measurement. In the case of colorectal cancer, the target being measured may be blood in the bowel movement, DNA in the bowel movement or physical abnormalities in the lining of the colon or rectum, called “polyps” (small lumps attached to the lining) or “ulcers” (shallow sores).
Even if the test is accurate, it must be capable of detecting disease risk at a time when steps can be taken to cure the patient. In some cases, a colorectal cancer test may detect polyps or growths before they are cancerous, and in other cases they may detect growths that have already turned cancerous. To be effective, a colorectal cancer test must detect cancers or pre-cancers at a time when surgical treatment of the condition, either via a scope or by traditional surgery, is curative.
The test must be affordable. In an era when “affordable health care” sounds ever more like an oxymoron, there is little need to explain why affordability is a vital part of any health care recommendation. Screening tests for colorectal cancer may be completely free, such as Fecal Occult Blood Testing at the annual Tuolumne County Health Fair, or screening may run up to as much as $6000 for a colonoscopy and biopsy. An affordable method of screening should be available for every person, and ultimately saves in health care costs to the community.
Finally, people must be willing to undertake the test. It is difficult to motivate the public to perform tests on three separate bowel movements when they prefer to deny any personal relationship to sewage whatsoever. However, people become increasingly compliant with annual stool tests, colonoscopy or other screening modalities as they learn the value of colorectal cancer screening and hear of friends or relatives who have benefited from early detection.
Screening rates for risk of colorectal cancer by low income households in our area steadily decreased between 2001 and 2005, while colorectal cancer screening for the general population increased by almost 10%. These kinds of trends contribute to the disparity in health between different economic segments of our community. At least in regards to colorectal cancer prevention, screening tests are available that are effective and affordable. Please spread the word that this simple test is worth your time: fecal occult blood tests will be available at the Tuolumne County Health Fair in October.