WEDNESDAY, Dec. 1, 2004 (HealthDayNews) -- Some 42 million Americans who should be screened for colorectal cancer are not.
But an inexpensive, noninvasive test that is already being used could help close that gap in just one year, a new study finds.
Screening those who are at an average risk of developing the disease can be greatly helped with the exam, which is called fecal occult blood testing (FOBT). Those who had a positive FOBT would then follow up with a colonoscopy.
"Within a year, we wouldn't be able to offer colonoscopy to everybody," said Dr. Laura C. Seeff, lead author of the study, which appears in the December issue of Gastroenterology. "Doing FOBT with follow-up just for those that are positive is a totally appropriate way to go."
"This is the first time that we've measured the size of the unscreened population and compared that to the number of tests needed for them, so we can answer if we are ready to screen the population at large," continued Seeff, a medical officer in the Division of Cancer Prevention and Control at the U.S. Centers for Disease Control and Prevention.
The authors hope the information will help shape emerging programs.
Colorectal cancer is the third leading cancer killer in the United States. It is well accepted that people 50 years and older need to get screened, although the landscape of screening options is a confusing one.
There are currently four recommended screening tests: FOBT (to be done annually), sigmoidoscopy (to be done every five years), barium enema (also every five years) and colonoscopy (to be done every 10 years). Sometimes combinations of tests are recommended. The first three need to be followed up with a colonoscopy if there's a positive reading. "All have been shown to be effective," Seeff said. "At the moment, none rises to the top. It's really between the physician and the patient which of the four tests should be done."
For the FOBT, the patient provides a stool sample, which is then analyzed for blood that may indicate the presence of a polyp or cancer. Colorectal cancer is easily preventable by finding precancerous polyps and removing them.
Here, the study authors looked at data from the U.S. Census Bureau and the CDC's National Health Interview Survey to estimate the number of people not getting screened both nationally and regionally, as well as how many screening tests would be needed to cover this group.
They found enough FOBT to go around, but not enough flexible sigmoidoscopy and colonoscopy. It could take up to a decade to screen the unscreened population using colonoscopy, the authors stated.
The data was national, however, meaning that differences may be seen at local levels.
In an accompanying editorial, Dr. Theodore Levin said that "colonoscopy should be used judiciously." If other tests were used, then colonoscopy resources could be directed towards older patients who might benefit more.
But dealing with the "supply side" (the availability of tests and doctors to give them) is only one side of the story, pointed out Dr. David Beck, chairman of colon and rectal surgery at the Ochsner Clinic Foundation in New Orleans. "Some people just don't want it. Even when you have the capacity, patients don't always agree with it."
More information
Visit the U.S. Centers for Disease Control and Prevention for more on colorectal cancer screening.
