October 30, 2008 (San Diego, California) — An effort in Maryland to perform more screening colonoscopies has resulted in an increase in the number of early-stage colorectal cancer (CRC) cases and a decrease in regional CRC disease detected in the state, according to findings presented here at the American Public Health Association 136th Annual Meeting.

The push is part of the Healthy People 2010 campaign. One of the goals of that program is to increase to 50% the proportion of Americans 50 years or older who have ever undergone a colonoscopy or sigmoidoscopy.

This is an early finding, but "it's a good indication, if it's in fact true," said lead author Jennifer Hayes, MEd, MPH, from the Maryland Cancer Registry, State of Maryland Department of Health and Mental Hygiene, in Baltimore, who presented the data in a poster session.

Using claims data maintained by the state, Ms. Hayes and colleagues determined the number of colonoscopies and sigmoidoscopies performed between 1999 and 2004. They also obtained hospital reports on CRC cases from the Maryland Cancer Registry. From these records, they found that the number of colonoscopies performed on Marylanders increased from 64,069 to 149,749 during the study period. The number of sigmoidoscopies declined from 23,553 to 3929. All in all, the percentage of people 50 years or older who had ever undergone a colonoscopy or sigmoidoscopy increased from 50% to 69%.

Despite the increase in screening, the total number of invasive CRC cases decreased only slightly and insignificantly. But the percentage of early-stage cases increased from 37% to 42% (P = .04) of cases, and regional disease decreased from 45% to 36% (P = .02). Interestingly, distant disease increased from 17% to 20%, although the change was not significant.

"Our goal is to find cancer earlier, and we are finding localized CRC at an increasing rate, although it's too early to tell if this is convincing," Ms. Hayes told Medscape Public Health & Prevention. She attributed the increase in colonoscopies to the efforts of state public-health personnel, who worked with physicians and patients to encourage people to undergo the tests. There is also more general awareness about CRC and colonoscopy among the public, she said.

The slight rise in advanced-stage disease "could be, in part, a result of case-finding: whenever a new screening test is introduced into a population, you will have a 'blip' in the trend graph because you start detecting cases that have lain dormant for years in the absence of testing," said Durado Brooks, MD, MPH, director of colorectal cancer for the American Cancer Society. "During these early years of screening, you will find larger numbers of both early- and late-stage cases.

"It is also important to keep in mind that, during the study period, there was a significant proportion of the Maryland population that had never been screened for CRC, as well as a number of people who had been screened only with sigmoidoscopy, which only views a portion of the colon," said Dr. Brooks, who was not involved in the study. "We have no idea about the screening history or the clinical history of the cancer cases documented in this study. It may be that a significant proportion of the advanced cases come from that unscreened population.

"In either case, we would expect the proportion of advanced cases to fall as the screening program matures and more individuals are up to date with screening," Dr. Brooks concluded.

The study did not receive commercial support. Neither Ms. Hayes nor Dr. Brooks disclosed any relevant financial relationships.

American Public Health Association (APHA) 136th Annual Meeting: Abstract 186296. Presented October 28, 2008.