Unique study aims at why blacks get, die from cancer more often
NASHVILLE, Tenn. – The National Cancer Institute has awarded a multi-million-dollar grant for a potentially landmark study to determine why African Americans are more likely than other groups to develop cancer and to die from the disease.
The grant will provide an anticipated $22 million over five years to fund the "Southern Community Cohort Study," which will enroll and follow 105,000 people – two-thirds of them African-Americans – in six southeastern states. The group, or cohort, will be tracked to identify genetic, environmental and lifestyle factors that contribute to cancer development.
It will be the first study of its kind in the southern United States and the largest population-based health study of African-Americans ever conducted.
The initiative is a collaborative effort of the Vanderbilt Ingram Cancer Center, Meharry Medical College, both located in Nashville, and the International Epidemiology Institute, based in Rockville, Md.
The research team will include epidemiologists (scientists expert in the study of large populations over time) who are members of the Vanderbilt-Ingram Cancer Center, Vanderbilt’s Center for Health Services Research, the Meharry faculty and IEI.
"By determining why African-Americans have higher rates of most forms of cancer, we hope to be able to develop prevention strategies to lower the rates of cancer not only among blacks but among all racial groups," said William Blot, Ph.D., principal investigator. Blot is a member of Vanderbilt-Ingram, a professor of Medicine in Vanderbilt’s Division of General Internal Medicine, and a director of IEI. The Southern Community Cohort Study is being launched to collect information to help prevent cancer and improve its treatment. However, co-principal investigator Margaret Hargreaves, Ph.D., noted that its implications are much broader. "This study will allow us to learn more about the association of lifestyle factors to key chronic diseases, such as cancer , cardiovascular disease and diabetes, in residents of the southeastern United States," said Hargreaves, associate professor in Meharry’s Department of Internal Medicine.
The study is also expected to yield important health information about low-income and rural populations, regardless of race.
"What excites me about the study is that we will finally get at the ‘why’ questions implicit in health disparities," said John E. Maupin Jr., D.D.S., president of Meharry Medical College. "What we haven’t known – and what this study will give us – are the reasons why people behave the way they do about their health. Once we have a handle on that, the scientific community will be in a position to develop culturally sensitive interventions to impact health behavior and to have a demonstrable effect on health status and outcomes."
Cohort studies typically enroll large numbers of people and track them over many years for subsequent development of cancer or other diseases. Such studies have yielded much of what is known about the cause and prevention of disease. Some of the better-known cohort studies include the Framingham Heart Study, the Harvard Nurses and Physicians studies, and the American Cancer Society cohort study.
However, these existing cohorts have tended not to include sizeable proportions of African-Americans. Black people comprise only 1-2 percent of the Harvard and ACS studies, for example. In addition, these studies do not include large groups of low-income participants, and except for one study of women in Iowa, have not targeted rural populations.
"Racial, ethnic and socioeconomic disparities in the health of our citizens is a major obstacle in ensuring quality of life for all Americans," said U.S. Sen. Bill Frist (R-Tenn.) "These discrepancies will not be solved without the rigorous science to understand each of the variables that contribute to them. I congratulate Meharry Medical College, Vanderbilt-Ingram Cancer Center and the International Epidemiology Insitute for coming together on this pioneering initiative."
As a group, African-Americans face a disproportionate burden from cancer compared to other racial or ethnic groups. According to the American Cancer Society:
Black women suffer the highest incidence rates of colorectal and lung cancers than other ethnic groups.
Of any group, black men have the highest incidence rates of prostate, colorectal and lung cancer.
African-Americans are 33 percent more likely to die of cancer than whites, and twice as likely to die of cancer as Asian/Pacific Islanders, American Indians and Hispanics.
Black women are more likely to die of breast cancer and colorectal cancer than any other ethnic group (though white women have the highest incidence of breast cancer).
Black men are more than twice as likely to die of prostate cancer than men of other ethnic groups.
Blacks also have higher rates of incidence and mortality from other cancers, including those of the mouth, throat, esophagus, stomach, pancreas and larynx, as well as multiple myeloma.
In addition, the Southeast has some of the highest rates of cancer, among both blacks and whites, in the United States – for largely unknown reasons, Blot said.
The Southern Community Cohort Study will explore several specific factors that may play a role in the disparities. These variables include the higher-fat "southern diet" and potential differences in activity levels, body mass index, use of over-the-counter medication use (including aspirin and non-steroidal anti-inflammatory drugs), use of folk and herbal supplements, tobacco use, metabolism of carcinogens and genetic factors.
The study will involve a survey of lifestyle and health history information, follow-up contact every other year, and the optional collection of blood and saliva samples. These samples will be invaluable sources for DNA testing as new genes and proteins are identified and new technologies are developed to identify "markers" of disease risk.
"Laboratory studies using these specimens could make far-reaching contributions to research in cancer, heart disease and other diseases for decades to come," Blot said. "Thanks to what we learn from the life experiences of 40-to-79-year-olds today, the children and grandchildren of this generation may be able to reduce their risks for these diseases in the future."
Information will also be gathered from the federal government’s National Death Index and state cancer registries to determine whether individuals in the study have died or been diagnosed with cancer.
The Institutional Review Board at Vanderbilt, which oversees all research at the center involving human subjects, has reviewed and approved the study. The Meharry IRB has also provided initial approval.
Enrollment in the study is expected to begin in early spring at 22 large community health centers in Mississippi, Georgia, Tennessee, South Carolina, Alabama and Florida. In 2004, random telephone sampling will begin in these six states. Hargreaves will be a liaison between the community health centers and the research teams at Meharry and Vanderbilt.
Participants must be 40-79 years of age, not currently diagnosed with or under treatment for a terminal illness, and willing to be contacted (and keep in contact with the study coordinators) in the future.
The SCCS collaboration is an outgrowth of the innovative Meharry-Vanderbilt Alliance established in 1999 to promote interaction between the neighboring academic health centers to enhance educational, research and clinical programs at and between both institutions. The multi-year, multi-investigator cohort study will be the largest research endeavor at the Vanderbilt-Ingram Cancer Center. It represents the kind of "population-based" science that was critical in the center’s designation earlier this year by the National Cancer Institute as the only Comprehensive Cancer Center in Tennessee.
"This study will provide the in-depth information about causes of cancer that will be critical in the quest to defeat this disease," said Dr. Harold Moses, director of the Vanderbilt-Ingram Cancer Center.
The Vanderbilt-Ingram Cancer Center is the only Comprehensive Cancer Center designated by the National Cancer Institute in Tennessee, and one of only 41 nationwide. This designation, the highest ranking awarded to cancer centers by the world’s foremost authority on cancer, recognizes research excellence in cancer causes, development, treatment and prevention, as well as a demonstrated commitment to community education, information and outreach. To learn more: www.vicc.org.
Meharry Medical College is a leading source for educating and training African-American physicians, dentists, and biomedical scientists. Founded in 1876, the College is noted for emphasizing the special primary health care needs of minorities, the poor and the disadvantaged of America, and its graduates are respected nationwide for their commitment to those populations. To learn more: www.mmc.edu. The International Epidemiology Institute is a biomedical research organization founded in 1994 by senior scientists from the National Institutes of Health. The Institute provides state-of-the-science expertise for addressing the complex biomedical issues that confront the public and private sectors, universities, and other institutions in today's rapidly changing world. To learn more: www.iei.ws.