Colorectal cancer screening: Make the recommendation

AMA Leader Commentary. By J. Edward Hill, MD, and John R. Seffrin, PhD, April 17, 2006.

AMA LEADER COMMENTARY

A few words about current events in medical practice

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A message to all physicians from the president of the American Medical Association, J. Edward Hill, MD; and the chief executive officer of the American Cancer Society, John R. Seffrin, PhD.

Words are powerful medicine when it comes to saving lives from colorectal cancer. A physician recommendation might be the most important factor in whether a patient is screened.

In a recent survey of women ages 50 and older, 72% indicated they would be screened for colorectal cancer if their doctor recommended it. Patients are clearly ready to take action, and we should be, too.

There is enormous opportunity to save lives, because this is one cancer that can be prevented.

Screening can detect and remove precancerous polyps and, therefore, prevent or detect cancer at the earliest, most treatable stage. Yet only 39% of colorectal cancers are detected early.

The alternative is tragic: Once a cancer metastasizes, the five-year survival rate is less than 10%, compared with a 90% survival rate if tumors are found early.

So what keeps doctors from talking to patients about the critical need for colorectal cancer testing? Obstacles abound. But, discussions with physicians who have overcome them turned up these ideas:

Educational materials and checklists can engage and motivate patients despite limited time with them. Some practitioners have developed a checklist of screening exams that both the patient and the doctor sign and initial. The agreement is placed in the patient's file and reviewed during subsequent checkups. The American Cancer Society's Great American Health Check, available online (www.cancer.org/healthcheck), asks patients a few quick questions and gives action plans that explain which cancer screenings are right for them based on age and family history.
Insurance fears are often unfounded. Many insurers and Medicare cover routine screenings, including colonoscopies.
Engaging in an ongoing dialogue can allay fears about discomfort caused by screening. The greater the patient education, the less the fear factor. More than one conversation might be needed to allay patient fear, but the time is well spent.

Test and test again

Stool occult blood, flexible sigmoidoscopy, colonoscopy and barium enema have unique requirements and performance characteristics. Patient preferences vary. Providers and patients must work together to make an informed choice. When considering these options, the only "wrong" choice is choosing to not screen.

Two articles in the January 2005 Annals of Internal Medicine studied usage and reliability of fecal occult blood tests in screening for colorectal cancer.

They uncovered convincing evidence of the total lack of value of in-office fecal occult blood testing performed at the time of a digital rectal exam. In the first article, researchers found:

Low sensitivity (only 4.9%) for the in-office FOBT done at the time of rectal exam.
Markedly greater sensitivity for pre-cancers and cancers combined (24% detection rate) and an even higher sensitivity for cancers (44%) with FOBTs performed correctly (i.e., the three-card, take-home method recommended by the American Cancer Society and other major medical organizations).

A different study looked at the use (and misuse) of FOBT in primary care practices. The study found one-third of primary care physicians use in-office FOBT as their primary method of screening. Despite unequivocal and unanimous recommendations for colonoscopy follow-up of a positive FOBT, one-third of patients report receiving another FOBT or having no diagnostic work-up for this finding.

Getting the best results from any colon cancer test requires that the test be used as directed. Based on the findings of these studies, there is clearly significant room for improvement in FOBT use.

Emerging technologies

Work is under way to examine the possible role of exciting technologies as colorectal cancer screening tests:

Computed tomographic colonography (or virtual colonoscopy) holds tremendous potential but is not yet proven as a screening tool. Digitized thinly sliced CT images are merged into two- and three-dimensional images by specialized computer software. Published research on CT colonography in colorectal cancer screening has shown inconsistency in test performance characteristics when compared with traditional screening approaches. This variation is thought to be due to a number of issues, including variation in the manner in which the test is performed and interpreted and the level of expertise of radiologists reading the study. An ongoing study, sponsored by the National Cancer Institute, is designed to address these questions and concerns. Results are expected in late 2006.
Fecal DNA analysis has been evaluated by both the American Cancer Society and the U.S. Multisociety Task Force on Colorectal Cancer. Both groups viewed the technology as promising but decided the available evidence was not yet sufficient to support its inclusion in their guidelines.

Stool screening by DNA analysis is based on the fact that a number of DNA mutations associated with the process of colonic carcinogenesis have been recognized, and methods have been developed to detect the presence of these mutations in excreted cells. A number of issues must be addressed before this approach can be advocated as a screening measure for the general population. There are technical issues, including a lack of consensus on the optimal combination of markers and continuing refinement of testing methods. Also, there are no studies or data that allow an evidence-based assessment of the frequency with which the test should be performed.

The American Cancer Society continually monitors ongoing research related to CT colonography and fecal DNA testing and will evaluate those findings along with new data for other screening tests when its guidelines are updated.

Finally, new drugs show extraordinary promise. But prevention and early detection still have the greatest potential to save lives at the lowest cost and with the least suffering.

We urge you to continue to inform and motivate your patients. Both the American Medical Association and the American Cancer Society can help by offering tools that save you time, open dialogue with your patients and effectively communicate the critical messages of colorectal cancer risk and prevention.

Materials to help break down patient barriers to lifesaving colorectal cancer screening are available on the ACS Web site (www.cancer.org/colonmd) or by phone at 800-227-2345.

Dr Seffrin, PhD, the chief executive officer of the American Cancer Society, co-wrote this column.

Dr. Hill, a board-certified family physician in Tupelo, Miss., was AMA board chair during 2002-03 and served as president during 2005-06.