Too few Americans are getting screened for colorectal cancer, government health officials say, despite the fact that screening can stop the disease before it progresses, and even prevent it from developing in the first place.

A recent report by the Centers for Disease Control and Prevention in Atlanta found that almost half of Americans who should be getting colorectal cancer screening aren’t doing so in the recommended intervals. The report was published in Morbidity and Mortality Weekly Report (Vol. 52, No. 10: 193-196).

“I think that more people need to be screened,” said Loria Pollack, MD, a CDC epidemiologist who helped prepare the report. “The screening tests are available and they are readily available.”

Pollack and her colleagues examined the results of a 2001 telephone survey of nearly 88,000 people aged 50 or older. The respondents were asked whether they had had any type of colon cancer screening procedure, and when they had had it.

About 45% of adults said they had had a fecal occult blood test, a home kit for checking a stool sample that is returned to the doctor. And 47% percent reported having lower endoscopy (either sigmoidoscopy or colonoscopy) at least once. Those numbers show slight increases over 1999 and 1997.

But Pollack said screening rates are actually lower than the figures mentioned in the report, because the survey did not distinguish between diagnostic procedures and screening procedures.

“The rates reported include some people who might have gotten the tests because of a specific problem they were having, not just for screening, which is looking for the disease before it has symptoms,” she said.

For people over age 50, the American Cancer Society recommends getting a fecal occult blood test every year, and a sigmoidoscopy every five years, preferably combined. An alternative would be a colonoscopy every 10 years or a barium enema with an x-ray of the colon every five years.

People who have a family history of colon cancer or other risk factors may need to be screened more often and begin at a younger age.

Pollack said lack of awareness about colon cancer is one reason screening rates are so low.

Many people don’t realize how common colon cancer is, or don’t know screening is available and that it can actually save their life. Colon cancer is the second leading cause of cancer deaths in the United States, according to ACS; almost 150,000 new cases will be diagnosed this year and 57,000 people will die from this disease.

Doctors also have a role to play in increasing screening, Pollack said.

“There are so many chronic disease and prevention issues to discuss,” she said, “[and] time is short, and often that just gets placed on the back burner or not mentioned at all.”

A recent report published in the Journal of the American Medical Association (Vol. 289, No. 10: 1297-1301) also said doctors need to be sure they discuss colon cancer screening with patients and encourage them to be screened regularly.

The authors, Judith Walsh, MD, and Jonathan Terdiman, MD, of the University of California, San Francisco, recommended teaching doctors about the importance of screening, and training more doctors to perform the screenings.

Pollack said the CDC is taking steps to improve physician awareness about colon cancer screening through its new education program, A Call to Action.