Three studies presented this week at the American College of Gastroenterology's 74th Annual Scientific meeting in San Diego underscore the growing disparities in gastrointestinal disease, particularly colon cancer and Barrett's Esophagus, among certain ethnic and gender populations, including African Americans, Latinos and women. These race- and gender-specific disparities underscore the need for education and vigilance among these populations and perhaps more aggressive screening tactics than the population in general.
Using data from more than 500,000 cases of colorectal cancer contained the National Cancer Institute's Surveillance, Epidemiology and End Results Registry, Dr. Robert Wong of California Pacific Medical Center, preformed a retrospective cohort study to analyze the race and gender- specific disparities in colorectal cancer epidemiology.
Dr. Wong's analysis indicates that from 1973 through 2004, there has been a shift of newly diagnosed cancers to the proximal, or right side colon among the population in general. Females, however, have the greatest proportion of proximal cancers and female Hispanics in particular, show the greatest gender disparity versus Hispanic males (47.7 percent vs 28.2 percent).
In addition, while advanced stage colorectal cancers showed a steady decline during the study period, African Americans have the greatest proportion of advanced cancers among all racial and ethnic group. In fact, between 2001 and 2004, a full quarter (25.2 percent) of all colorectal cancers found in black males were advanced-stage cancers, the highest proportion of any ethnic group.
"The significantly higher rates of proximal cancers among women and advanced cancers in the African American population is concerning," reports Dr. Wong. "While we still must consider whether environmental and genetic factors play a role in these disparities, potential gaps in access to health care resources and education may also contribute to these differences. We should use this information to make improvements to cancer screening and prevention programs."
Proximal Cancers in African Americans
In another study of racial disparities in the prevalence and location of colon adenomas conducted at the University of Illinois at Chicago Medical Center, Dr. Amit Gajera and a team of researchers performed a retrospective analysis of 3220 patient records collected between 2005 and 2007 to determine whether the distribution and number of adenomas could be correlated to ethnic or racial group.
The study found that African American patients not only were more likely than other racial groups to have multiple polyps, but that those polyps were more often located on the proximal side of the colon as compared to other racial groups. The team also assessed whether these disparities could be the result of environmental factors such as alcohol or tobacco use, but found no correlation.
"Understanding that African American patients have a propensity for developing multiple polyps located on the all important right side of the colon is a critical factor for choosing an appropriate screening method," explains Dr. Gajera. "In these cases, we must consider whether flexible sigmoidoscopy is as effective as colonoscopy for examining the proximal colon where these polyps and adenomas are often lurking."
About Colorectal Cancer Screening in African Americans
Because of the high incidence of colorectal cancer and a greater prevalence of proximal or right-sided polyps and cancerous lesions in African Americans, in 2009, the American College of Gastroenterology updated its colorectal cancer screening guideline to include a recommendation for African Americans to begin colorectal cancer screening earlier, at age 45, rather than at age 50 as recommended to average risk patients. According to the ACG guideline, colonoscopy is the preferred strategy for colorectal cancer screening.
Largest Cohort Study to-Date Examines Barrett's Esophagus Prevalence Among Latinos
Historically, middle-aged white males with chronic gastroesophogeal reflux (GERD) have displayed the highest incidence of Barrett's Esophagus (BE). Given that Latinos are the largest and fastest-growing minority ethnic group in the United States, researchers at The University of Southern California conducted a study to determine the prevalence of BE in the Latino population compared to Non-Latino Whites, as well as identify risk factors associated with BE in Latinos.
The research team, led by Dr. Kian Keyashian and Dr. John Kim, reviewed the records of 627 patients, taken from the Los Angeles County and University of Southern California Medical Center who underwent endoscopy for primary symptoms of GERD between March 2005 and January 2009. There were no significant differences between the Latinos and non-Latino Whites in the prevalence of BE or long-segment BE and no difference in the average length of BE. In addition to established risk factors for BE, insulin resistance was also associated with BE among the Latino population.
"Previous studies to compare the prevalence of Barrett's Esophagus in Latinos and non-Latino whites have been inconclusive," explains Dr. Keyashian. "With this large cohort, we have demonstrated that Latino race may confer a higher risk for Barrett's Esophagus than previously described in the literature and, therefore, should be considered in screening Latinos for this potentially dangerous condition."
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