October 20, 2005

Many go unscreened for colorectal cancer

By Anthony J. Brown, MD

NEW YORK (Reuters Health) - Nearly half of primary care
patients in the United States who should be screened for
colorectal cancer are not, according to a new report appearing
in the journal Cancer. Studies are now underway to understand
why the screening rate is so low.

Colorectal cancer screening with colonoscopy, flexible
sigmoidoscopy, and other measures is recommended for
asymptomatic adults starting at 50 years of age.
Population-based surveys have suggested that screening rates
are low in the U.S., but the use of screening measures in the
primary care setting had not been well studied.

To investigate, Dr. Jennifer Elston Lafata, from the Henry
Ford Health System in Detroit, and colleagues evaluated
colorectal cancer screening in a group of 21,833 patients who
were between 55 and 70 years of age and made a primary care
visit in 2003.

Just 54 percent of the patients received a recommended
screening procedure during the study period, the report
indicates. The most commonly used screening procedure was
colonoscopy, performed on 39.9 percent of screened patients,
followed by flexible sigmoidoscopy alone or in combination with
fecal occult blood testing.

Between 1999 and 2003, annual screening rates increased by
3.1 percent, the authors found.

The results also suggest that there were ample
opportunities to increase the screening rate in the study
group. Most of the subjects who did not receive recommended
screening had undergone several health maintenance examinations
(HME) and 41 percent had received at least one fecal occult
blood test.

Predictors of being screened for colorectal cancer included
more HME and other primary care visits, older age, higher
income, male gender, and African-American race.

To increase colorectal cancer screening rates, "I think
part of the challenge is to develop tests that are acceptable
to patients," Lafata told Reuters Health. "The other part is to
make sure that patients who are eligible for screening get a
recommendation from their primary care physician."

Lafata said her group is now involved in "a couple of
different studies" that should help clarify the reasons behind
the low screening rates as well as test interventions to
improve the rates.

Sigmoidoscopy and colonoscopy both involve inserting a
thin, flexible scope into the colon to look for cancer or
polyps, which are growths that can become cancerous.
Sigmoidoscopy investigates only the lower portion of the colon,
while colonoscopy inspects the entire length of the colon.
Fecal occult blood testing detects hidden blood in stool

SOURCE: Cancer, October 1, 2005.