These findings, the result of a data analysis of tens of thousands of cases of colorectal cancer from the three states from 1994-1998, confirm that unexplained health disparities exist for African Americans.
"Unlike previous studies that have analyzed data from largely-urban populations, this study is significant because it compared the incidence and mortality rates of colorectal cancer for African Americans and Caucasians in a large, primarily rural area," said Gene Lengerich, VMD, associate professor of health evaluation sciences, Penn State Cancer Institute, Penn State College of Medicine, and research director for the National Cancer Institute-funded Appalachian Cancer Network (ACN), which coordinated the data collection for the study. "The study also marks one of the few times that states have merged data from their own cancer registries to look at a regional health issue. Cancer registries are incredibly important for understanding cancer and its treatment."
The study was presented today (May 21, 2003) at the 2003 Digestive Diseases Week meeting in Orlando, Fla.
An earlier study led by Lengerich and the Appalachian Cancer Network revealed that residents of Appalachia – which includes most of Pennsylvania and Kentucky, all of West Virginia and parts of nine other states – are at higher risk of dying from all cancers. The Appalachian region includes 12 states that follow the spine of the Appalachian Mountains. (See map in June 21, 2002, Centers for Disease Control and Prevention (CDC) publication, http://www.cdc.gov/mmwr/preview/mmwrhtml/mm5124a3.htm).
National Cancer Institute data shows that colorectal cancer is the third most common cancer in the United States and the second leading cause of cancer deaths. African Americans are more likely to develop all cancers than persons of other racial or ethnic groups and are more frequently diagnosed after the cancer has metastasized, or spread, to regional or distant sites. In African American men and women, colorectal cancer ranks third as the leading cause of cancer deaths.
The burden from colorectal cancer in Pennsylvania is well above the average for the U.S. Among the 37 states and the District of Columbia reporting cancer occurrences during 1999, Pennsylvania had the third highest rate of colorectal cancer incidence. Among the 50 U.S. states and the District of Columbia during 2000, Pennsylvania had the ninth highest colorectal mortality rate.
For the study, the research team conducted a review of the incidence of colorectal cancer from state registries in Kentucky, Pennsylvania and West Virginia. By law, cancer is a reportable disease in each of these three states. There were 62,682 new cases of colorectal cancer among Caucasians or African Americans cases of colorectal cancer during the five-year period, or about 12,536 per year.
Of particular concern, African Americans were 18 percent more likely to have proximal, or upper, colon cancer than Causasians. (Early-stage proximal colon cancer is typically detected only through a colonoscopy.) Perhaps more alarming was data that showed that African Americans were 56 percent more likely to have proximal colon cancer diagnosed at a later stage which has only a 9 percent survivial rate. African Americans were 33 percent more likely to die from colon cancer.
"This study reveals that African Americans are more likely to have advanced-stage disease, which may be in part due to a screening disparity, leading to a delay in the detection of colon cancer, and a lower likelihood of recovery," said James Hobley, M.D., chief medical resident and instructor, who will begin a fellowship in gastroenterology and hepatology at Penn State College of Medicine, Penn State Milton S. Hershey Medical Center in July 2003.
"Colonoscopy is an especially important cancer screening technique because it is able to detect cancer high in the colon. There may be a number of reasons that this disparity exists, including differences in diet, lifestyle, education, environment, and access to cancer screenings. While we realize that these risk factors are not limited to African Americans, they are, as a whole, more likely to occur among African Americans than Causasians," Hobley said.
The research team hopes the report reinforces the importance of regular colon screenings for everyone.
"We also believe this report will heighten awareness about the potential health disparities that exist for African Americans and may lead to recommendations about improving access to colon screenings," Lengerich said.
Co-authors on the study were: Kaya M. M. Fox, MPAS, PA-C, Division of Gastroenterology, Department of Medicine, Chanty Webb, R.N., B.S.N., minority recruitment nurse specialist for the Penn State General Clinical Research Center, and Thomas McGarrity, M.D., professor of medicine, Division of Gastroenterology, Penn State College of Medicine, Penn State Milton S. Hershey Medical Center.
The Appalachian Cancer Network directs cancer research and research-based interventions toward rural areas and medically underserved people. ACN is led by the University of Kentucky through a partnership with West Virginia University and Penn State University. At Penn State both the College of Medicine in Hershey and the College of Agricultural Sciences at University Park are actively involved.