More Americans Tested for Colon Cancer

CDC: Increase Is Encouraging but There's Still Room for Improvement

Reviewed by Louise Chang, MD on March 23, 2006
From the WebMD Archives

March 23, 2006 -- More people in the U.S. aged 50 and older are getting tested for colorectal cancer, but those tests are still too rare, the CDC says.

Data came from national surveys done by telephone in 2002 and 2004. The surveys included 111,000 adults aged 50 and older in 2002 and more than 146,700 in 2004.

Colorectal cancer screening was reported by 57.3% of the 2004 participants, compared with 54.4% of those in 2002.

"We are pleased that we were able to see an increase in just two years, and we feel that these are encouraging results but that we still have a ways to go," researcher Laura Seeff, MD, tells WebMD.

Seeff, an internist and medical officer at the CDC, worked on the study, which appears in the CDC's Morbidity and Mortality Weekly Report.

No. 2 Cause of Cancer Deaths

Colorectal cancer is the No. 2 cause of cancer deaths for U.S. adults, killing more than 56,000 people in 2002, according to the CDC.


Removing precancerous polyps (growths) and treating early cancers can make a big difference. "If you remove a polyp, you've prevented the cancer. If you treat an early cancer, a person has a much better chance of survival," Seeff says.

In recent years, data has shown a trend toward more colorectal cancer screening. "I think this is similar to what happened with mammography [in which] the rates crept up slowly and then really jumped up," she says.

"We'd clearly like them to go up higher," Seeff says. "We want to keep attention on this disease."

4 Types of Tests

Different types of colorectal cancer screening tests include:

  • Fecal occult blood test
  • Sigmoidoscopy
  • Colonoscopy
  • Double-contrast barium enema

"There are a number of factors that go into a person selecting which test is best for them," Seeff says. Test availability, cost, insurance coverage, and patient preference are among those factors, she notes.

"Our message is that everybody 50 and up should be getting screened regularly and should speak to their doctor, and through that discussion pick which test is appropriate," Seeff says.

Those with increased risk for colon cancer may start screening before 50.

Home Test

Seeff described each test, starting with the home-based fecal occult blood test.

"Fecal occult blood test is a test the patient does at home where they are essentially looking for hidden blood in a stool sample," Seeff says. "The reasoning behind that test is that most colorectal cancers begin with polyps, which is a growth in your colon that over many, many years can grow into a cancer if it's undetected."

"Those polyps can sometimes bleed and ... an early cancer certainly can bleed," Seeff continues. "The reasoning behind that fecal occult blood testing is that if you detect a sign of blood, you could find either a precancerous lesion or an early cancer. But if that test is positive, a person still needs to go on to get colonoscopy."

Checking the Colon and Rectum

In sigmoidoscopy and colonoscopy, a thin, flexible tube with a tiny camera is inserted through the rectum to look at the colon. Sigmoidoscopy goes part way up the colon; colonoscopy checks the entire colon. The recommended interval is 10 years for colonoscopy and five years for sigmoidoscopy.


"The barium enema is basically an X-ray that just shows an outline of what could be a polyp or a cancer," Seeff says. "If that's positive, it would need to be followed by a colonoscopy."

The surveys counted how many people had had a fecal occult blood test within the past year and/or lower endoscopy (sigmoidoscopy or colonoscopy) within the past decade. The data doesn't show whether participants were getting routine screening or were being tested because another test had indicated possible colorectal cancer.

Sites for Low-Income, Uninsured People

The CDC has established screening programs at five sites for people with low incomes, no insurance, or inadequate insurance for colorectal cancer screening, Seeff says.

A CDC news release lists these sites for those programs:

  • The Research Foundation of the State University of New York in Stony Brook, N.Y.
  • Nebraska's health and human services department (statewide)
  • Missouri's health and senior services department (in St. Louis)
  • Maryland's health and mental hygiene department (in Baltimore)
  • Three counties in Washington (King, Clallam, and Jefferson counties)

WebMD Health News


SOURCES: CDC, Morbidity and Mortality Weekly Report, March 24, 2006; vol 55: pp 308-311. Laura Seeff, MD, internist and medical officer, CDC. News release, CDC.
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