Colonoscopy might not be the most pleasant topic for the dinner table, but it could allow you to have a lot more of those enjoyable evening conversations. Experts estimate that if everyone were screened for colon cancer, we could save about 20,000 lives a year. So it's important to talk about how yours could be one of them.
What Is Colorectal Cancer?
Colorectal cancer is the third most common cancer and the second leading cause of cancer death in the United States.
Most colorectal cancers arise from small growths inside the colon, called polyps. Not all polyps are pre-cancerous, and most polyps that develop into cancer do so very slowly, which is why screening is so helpful -- finding polyps early, and removing them, can prevent them from ever turning into cancer. In addition, finding cancer in its early stages is much easier to treat than in its later stages.
The biggest risk factors are age -- it is quite rare below age 40 -- and family history.
How Can I Catch Polyps or Colorectal Cancer Early?
Screening is recommended for all adults 50-75 years old, and earlier for people with certain risk factors. There are a few different options for screening available, and you can talk with your doctor about what works for you. According to Dr. Lee Green, professor of family medicine at the University of Michigan, the most important thing is to be screened, not the method you use. The tests recommended by both Green and by the United States Preventive Services Task Force (USPSTF) are:
Fecal occult blood test (FOBT) yearly -- this requires colonoscopy if results are abnormal
FOBT every 3 years and sigmoidoscopy every 5 years -- this also requires colonoscopy if abnormal
Colonoscopy every 10 years
What Do These Tests Involve?
FOBT: This test is done once a year, and analyzes three stool specimens for tiny, non-visible amounts of blood. You get a kit to take home, and you send the sample in yourself. It is inexpensive, easy to do, and offers a simple way to screen.
If your stool is found to have blood, a colonoscopy is done to see if the blood is due to colon cancer, a polyp, or something else. Most people who have blood on the test do not actually have cancer.
FOBT plus sigmoidoscopy: A sigmoidoscopy uses a thin tube with a small camera on the end to look at the lower part of your colon. If a polyp is found in this area it can be removed, and then a colonoscopy is done to look at the rest of the colon. This test takes about 20 minutes and usually does not require sedation.
The problem with this test is that it can miss some cancers that are not in the part of the colon it looks at, but some recent studies show that this may not be a big issue. Some experts recommend this test over colonoscopy, because it is cheaper, easier, and may have about the same benefits. Dr. Scott Fields, professor and vice chair of family medicine at OHSU says, "Given the limited additional benefits, we are doing our country a disservice to emphasize the benefits of colonoscopy when there is an easier screening test available at about 10 percent of the cost."