Public Release: 

Racial and ethnic differences in colorectal cancer emphasize importance of screening

Minorities share greater colorectal cancer risk than Caucasians

American College of Gastroenterology

Philadelphia, PA, October 15, 2007 - New research presented at the 72nd Annual Scientific Meeting of the American College of Gastroenterology emphasizes the importance of colorectal cancer (CRC) screening among racial and ethnic minorities, who have a higher incidence of colorectal cancer compared to Caucasians. Two studies found more African-Americans had advanced polyps on the right side of the colon than Caucasians, while results from colonoscopy screenings of Latin Americans revealed similarly high risk findings to African-Americans.

African-Americans have a high overall incidence of colorectal cancer and a greater prevalence of proximal or right-sided polyps and cancerous lesions. The right side of the colon includes the cecum, ascending colon and proximal transverse colon and cannot be reached by flexible sigmoidoscopy.

The reasons for higher incidence rates in African-Americans are unclear; however, dietary, nutritional factors, rates of physical inactivity, variability in screening rates, lower use of diagnostic testing, and increasing smoking rates have been most commonly implicated.

Dr. Roy D. Yen and his colleagues from the University at Buffalo and the VA Western New York analyzed the results of 587 colonoscopies (78 African-Americans, 502 Caucasians) performed at their institution in 2004. The number and location of polyps and presence of advanced lesions between the two cohorts were examined. They found significantly more African-American patients (14 percent) had advanced right-sided, or proximal, polyps compared to Caucasian patients (5.4 percent). Researchers also found more black patients had advanced polyps, proximal polyps and proximal colon cancers than whites.

Based on the results of this study, "Flexible sigmoidsocopy may be inadequate for colorectal cancer screening in this population. African Americans should undergo colonoscopy with particular attention for proximal lesions, however larger prospective studies are needed to confirm these findings," said Dr. Yen.

Colonoscopy Among Latin Americans Reveals Similar Incidence of High Risk Findings to African-Americans

In a retrospective analysis conducted at The University Hospital and the New Jersey Medical School in Newark, NJ, Dr. Stanley H. Weiss, Dr. Mark J. Sterling, and their research team reviewed screening colonoscopies performed in 2005 and 2006. They found Latin Americans had a higher than expected incidence of polyps, pathologically significant lesions, and significant right-sided lesions, similar to previously reported findings in African-American patients.

Of the 756 screening colonoscopies, 287 (38 percent) were in Latin Americans and 331 (44 percent) were in African-Americans. Forty-eight percent of Latin Americans had pathologically significant lesions, compared to forty-six percent among African-Americans. The percentage of pathologically significant right-sided polyps was similar in Latin Americans (57 percent) and African-Americans (62 percent). However, researchers found that African-Americans were significantly more likely to have a large polyp (>1 cm) than Latin Americans and were more likely to have a large right-sided polyp.

According to study leader Dr. Stanley H. Weiss, "Because right-sided lesions are detectable with colonoscopy, which examines the whole colon, but not by flexible sigmoidoscopy, these findings have important implications for appropriate screening for colon cancer in Latin Americans."

###

About Colorectal Cancer Screening

Colorectal cancer is the second leading cause of cancer deaths in the United States, second only to lung cancer. The ACG recommends that for average-risk individuals, colorectal cancer screening tests begin at age 50. The preferred approach is a screening colonosocopy every 10 years, but an alternate strategy consists of a stool test for blood every year and flexible sigmoidoscopy every 3 to 5 years. For high-risk individuals, screening colonoscopy may begin earlier and is performed more frequently.

Physician experts from the American College of Gastroenterology in 2005 issued new recommendations to healthcare providers to begin colorectal cancer screening in African- Americans at age 45 rather than 50. Colonoscopy is the preferred method of screening for colorectal cancer and data support the recommendations that African-Americans begin screening at a younger age because of the high incidence of colorectal cancer and a greater prevalence of proximal or right-sided polyps and cancerous lesions in this population. The recommendations were published in the March 2005 issue of The American Journal of Gastroenterology.

About the American College of Gastroenterology

Founded in 1932, the American College of Gastroenterology (ACG) is an organization with an international membership of more than 10,000 individuals from 80 countries. The College is committed to serving the clinically oriented digestive disease specialist through its emphasis on scholarly practice, teaching and research. The mission of the College is to serve the evolving needs of physicians in the delivery of high quality, scientifically sound, humanistic, ethical, and cost-effective health care to gastroenterology patients.

The ACG is committed to providing accurate, unbiased and up-to-date health information. Visit the ACG Web site www.acg.gi.org to access educational resources for patients and their families spanning the broad range of digestive diseases and conditions - both common and not-so-common. Organized by disease, state and organ system, these educational materials, developed by ACG physician experts, are offered for the information and benefit of patients and the public.

Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.