Screening for colon cancer: Not up for debate

Should patients be able to choose which form of colorectal cancer screening they receive? Researchers who have published a new study in the Archives of Internal Medicine suggest that they should: According to their study, providing patients with a choice between testing options increases the likelihood that they will follow through with screening.

Lead author Dr. John Inadomi from the University of Washington School of Medicine in Seattle and colleagues followed almost 1,000 adults aged 50 to 79 who used public health services in San Francisco between 2007 and 2010. The study subjects were chosen from among people with no increased risk factors for colorectal cancer; those with a history of colon polyps or inflammatory bowel disease, or a family history of colorectal cancer, were excluded. Participants were divided into three groups: In one group, doctors recommended only a colonoscopy (where a camera is inserted into the colon to visually inspect for growths); in the second group, doctors recommended only a stool test (which looks for blood in the stool); and in the third group, doctors let patients choose between these two tests.

After a year of follow-up, the researchers found that only 38 percent of the patients in the colonoscopy-only group had actually received testing. This is much lower than the number who complied with testing in the stool test group: 67 percent of these patients underwent screening. The screening participation rate was highest in the group given a choice 69 percent obtained some type of screening, although more patients selected a stool test than a colonoscopy.

The authors concluded that doctors should consider their patients preferences when making recommendations for colorectal cancer screening, since recommending only colonoscopy, as is common, may lower patients compliance with testing.

But is this the whole story? ACSH's Dr. Gilbert Ross thinks not. Although it may be true that patients given a choice for testing are more likely to follow through, if these people are choosing stool testing over colonoscopy, their likelihood of getting a protective benefit of finding a cancer early enough to prevent its spread is markedly reduced, he notes. There is certainly something to be said for giving patients a say in their care, but medical recommendations should be based on science, not solely on patients preferences.

Dr. Ross points out that stool testing is significantly less effective than colonoscopy in detecting problems. And given that, he says, it is the physician s responsibility to inform the patient that, while it s ultimately his decision, a colonoscopy is by far the more predictive choice.

Do doctors ask patients which antibiotics they would like to take for their strep throat or pneumonia? ACSH's Dr. Josh Bloom adds. Offering a choice between one highly effective test and a much less effective test makes just as little sense.