"Many primary care physicians and others were telling us that they were not prepared to offer sigmoidoscopy," says Robert Smith, PhD, ACS Director of Screening and lead author of the new guidelines, which are published in the January/February 2001 issue of CA -- A Cancer Journal for Clinicians.

Smith says that this led to concern that the complexity of the double screening process was leading to inertia, and no screening at all was taking place.

"We know that fecal occult blood testing (FOBT) alone is effective," he says. "We know that flexible sigmoidoscopy alone is effective. We believe that the data show that the combined testing is more effective. But the most important thing that anyone, provider or patient, can do now is at least do something."

FOBT is an inexpensive, noninvasive test that checks a patient?s stool for blood. Blood in the stool could come from a cancer or from precancerous polyps in the colon or rectum. Providing the blood test alone would go a long way in fighting colorectal cancer, Smith says. "Our guidelines were modified to send that very strong signal: that individual providers who are not prepared to offer all the options to their patients can, at the very least, offer fecal occult blood testing and should at the very least begin to prepare to offer the others," he says.

Flexible sigmoidoscopy involves viewing the inside of the colon through a flexible, lighted tube. The sigmoidoscope is only long enough to reach about one-third of the colon. That is why it is best used in combination with the FOBT, which will often detect bleeding from a cancer or polyp beyond the reach of the sigmoidoscope.

The ACS guidelines also include two other colorectal cancer screening options. Colonoscopy is similar to sigmoidoscopy, but uses a tube long enough to view the entire colon. Double contrast barium enema is an X-ray examination that coats the lining of the colon and rectum with barium sulfate, so that irregularities of the lining can be clearly seen on the X-ray images.

Bernard Levin, MD, Vice President for Cancer Prevention at M.D. Anderson Cancer Center, says screening is critical to saving lives from colorectal cancer.

"When in it?s diagnosed in the early stages, colorectal cancer is highly curable and even if you don?t find cancer but you find adenomas, they can be removed and cancer can be prevented in that way," he says.

Levin said when deciding which test is appropriate, engaging the health care professional in a discussion is the first line of business. "People should ask for whatever test makes sense for them in their particular situation," he says. "I think it?s very important to involve the patient in the decision. All the tests have pros and cons. There is not just one answer."

For example, each of the tests differ in how often they should be repeated. Starting at age 50, the ACS recommends choosing one of the following schedules:

• FOBT annually and flexible sigmoidoscopy every five years, or
• Flexible sigmoidoscopy every five years, or
• FOBT annually, or
• Colonoscopy every 10 years, or
• Double contrast barium enema every five years.

Smith says that a critical part of the answer is convincing the family doctor that regular screening for colorectal cancer needs to be part of the patient?s check-up regimen. "That?s a big part of any cancer screening, to acquaint the primary care physicians with not only the recommended tests, but the options," he says. "There?s really no more important factor in getting a person screened for colorectal cancer than getting a recommendation from their doctor."