Informed Patients Can Choose Method of Colon Cancer Screening

CHICAGO—Recent clinical evidence clearly indicates that primary care physicians should offer colon cancer screening to all patients over age 50. “If you are not having this discussion, if you are not making this offer, you will be viewed as providing incomplete care,” said Steven H. Woolf, MD, MPH, professor of family practice, Medical College of Virginia, Richmond.

However, Dr. Woolf advised his colleagues at the annual meeting of the American Academy of Family Physicians not to impose their own screening biases on patients. He believes primary care physicians should “give the patient the opportunity to introduce his or her own preferences into the decision-making process.” Doing so, he said, is necessary to determine the right choice for the patient. “Otherwise, they might undergo a test they would not want if properly informed,” he said.

Guidelines Vary Somewhat

During the last year, guidelines on colon cancer screening were released by the Preventive Services Task Force, American Academy of Family Physicians (AAFP), American Gastroenterological Association (AGA), American Cancer Society (ACS), and American College of Physicians. In general, these guidelines are based on a series of clinical trials in England, Denmark, and Minnesota that relate colon cancer screening with reductions in mortality of 15% to 33%.

The Preventive Services Task Force recommends screening all patients over age 50 with an annual fecal occult blood test (FOBT) or flexible sigmoidoscopy or both. The AAFP agrees with that recommendation and calls for annual screening to begin at age 40 for patients with a positive colon cancer family history.

The AGA recommends one of five options: FOBT every year, sigmoidoscopy every 5 years, FOBT and sigmoidoscopy as a combination, double contrast barium enema every 5 to 10 years, or colonoscopy every 10 years. The recommendation for all options is to start at age 50 for people at average risk. Earlier screening and different protocols are recommended for higher-risk groups.

The ACS recommends annual FOBT and sigmoidoscopy every 5 years, or double contrast barium enema every 5 to 10 years, or colonoscopy every 10 years.

Dr. Woolf pointed out that “no single test came out the clear winner, so there are a number of reasonable options we can offer patients in terms of screening.”

A study of patient preferences in the September issue of the Journal of Family Practice showed that 31% of patients preferred FOBT, 38% colonoscopy, 14% barium enema, and 13% flexible sig-moidoscopy.

“As with mammography and screening for prostate cancer, the decision about whether the patient should have this type of screening is a value judgment,” Dr. Woolf said. It is a judgment that needs to balance the apparent survival benefit against the risks of complications.

Dr. Woolf acknowledged that “some physicians may practice in a health care setting where neither you nor the patient is going to make the decision—the system of care will decide whether this type of screening will be available, and ultimately all of us may be constrained by what our payers will cover.”

However, to increase the likelihood of complying with colon cancer screening, Dr. Woolf feels that “the patient should be given the opportunity to decide whether the trade-off between the risks and benefits of screening is worthwhile.”