Earlier this week, University of Minnesota journalism professor Gary Schwitzer wrote an open memo on his blog (HealthNewsReview) to Harry Smith and CBS News regarding the network’s televised report last week of Smith’s colonoscopy:

Among the evidence cited by Schwitzer is a paper entitled “Colorectal Cancer Screening Guidelines: The Importance of Evidence and Transparency,” to be published in the journal Gastroenterology. In it, James Allison, MD, an emeritus professor of medicine at the University of California, San Francisco, writes:  “The only screening test for colon cancer shown by randomized controlled trials to decrease colon cancer mortality and incidence is fecal occult blood testing (FOBT).”

(As its name implies, FOBT involves testing a small sample of stool for the presence of hidden blood — a possible indication of colon cancer.)

Allison’s words are echoed on the National Institutes of Health’s "Factsheet" on colorectal screening, which states that “[s]tudies have shown that FOBT, when performed every 1 to 2 years in people ages 50 to 80, can help reduce the number of deaths due to colorectal cancer by 15 to 33 percent.”

And colonoscopies? “[I]t is not yet known for certain whether colonoscopy can help reduce the number of deaths from colorectal cancer.”

As Schwitzer notes in his memo to Smith and CBS, “while [colonoscopy] definitely has its merits, [it] has never been shown to be better than a much easier, cheaper test in a randomized clinical trial.”

Obstacles to overcome
Like many other aspects of health care, the United States seems to be behind Europe when it comes to fecal blood tests. According to reporting by the New York Times last year, many of the most effective fecal blood tests are not yet widely available in the United States.

That may be why Europeans get fewer colonoscopies than Americans. In Britain, for example, older people are encouraged to undergo an FOBT every two years. In the 2 percent of cases where the test comes back positive, a follow-up colonoscopy is done.

Here in the United States, using colonoscopy as a first-line screening test presents huge barriers in terms of access and cost, even among people who have health insurance (due to high co-pays and deductibles) — as was pointed out at an NIH-convened expert panel that met in February to discuss the state of current scientific knowledge about colon cancer screening

Fecal blood tests are a lot more cost-effective than colonoscopies. And that’s extremely important if we want to improve on the number of people who get screened for colon cancer, a highly curable (if caught early) disease that kills about 50,000 Americans each year. Currently only about half of Americans who should be screened for colon cancer (mostly those over the age of 50) are tested for the disease.

Are we “overselling and overpromising” the value of colonoscopies?

Yes, says Schwitzer, and he holds news media reports like Smith’s on-air colonoscopy to blame.

You can read Schwitzer's entire memo to CBS here.