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 samples.
SOURCE: Cancer, October 1, 2005.
Revision date: July 3, 2011
Last revised: by Jorge P. Ribeiro, MD