Reducing Disparities through Population and Cancer Control Research
UCCCC researchers are tackling the issue of cancer disparities, discovering better methods for providing cancer care to underserved populations. Much of this research benefits the people in local neighborhoods, as well as at-risk populations throughout the world. Here is a sampling of some of the discoveries made in recent years, as well as ongoing research at the UCCCC.
Colorectal Cancer in African Americans
African Americans not only have the highest incidence of colorectal cancer in the U.S., but they also have the highest mortality rate for colorectal cancer. Reasons for these differences likely involve genetic, environmental, and social factors. Sonia Kupfer, MD, assistant professor of medicine, is interested in unraveling how genetics and the environment increase risk in this population. Through a large, racially diverse collaborative study, Dr. Kupfer seeks to pinpoint genetic variants that increase the risk of colorectal cancer using genome-wide technologies. In addition, she is investigating how vitamin D regulates gene expression across different individuals and ethnic groups. These studies are motivated by the observation that African Americans have the lowest levels of vitamin D, which has been found to be protective against colorectal cancer development. The relationship between genetic response to vitamin D and differential disease risk, especially among ethnic groups, is not well understood.
Blase Polite, MD, assistant professor of medicine, and his colleagues are also looking for answers and viable solutions to this growing disparity. Based on their previous work and that of others, they suspect that spirituality holds a greater influence than once thought, or accepted by medicine; it provides meaning out of experience, informs behavior, and drives response. Armed with this knowledge, Dr. Polite’s group plans to investigate the influence of spirituality on health behavior and colorectal cancer outcomes and, hopefully, shed new light on how faith and health are interrelated.
Hormone Replacement Therapy
In 2002, many women halted their use of hormone replacement therapy in response to findings of the Women's Health Initiative trial, which demonstrated that hormone supplements increased coronary heart disease and breast cancer risk. Afterward, the incidence of invasive breast cancer among women over the age of 50 in the United States declined during 2002 and 2003. UCCCC researchers, however, found that although African Americans showed a similar decrease in the use of hormone therapy, no benefit was observed. Researchers including Dezheng Huo, PhD, assistant professor of health studies, and Olufunmilayo Olopade, MBBS, FACP, the Walter L. Palmer Distinguished Service Professor of Medicine and Human Genetics, director of the Center for Clinical Cancer Genetics and Global Health, and associate dean for global health, suspected that the observed racial disparity resulted from differences in biology. For example, nearly 80% of breast cancers in White women are estrogen receptor positive, a type of tumor that relies on estrogen for growth, compared with approximately 60% and 30% among African Americans and Nigerian women, respectively.
In addition to race/ethnicity and tumor subtype, researchers are currently examining whether the impact of hormone replacement therapy on breast cancer risk varies according to age at the time of therapy initiation, body weight, and breast density. Considering substantial heterogeneity in breast cancer risks among hormone replacement therapy users, identifying certain sub-groups with little or no excess breast cancer risk could help physicians weigh the benefits and risks of treating menopausal symptoms with short-term hormone therapy. The work underscores the need for Cancer Centers to partner with stakeholders from diverse communities and racial/ethnic backgrounds to gain a better understanding of breast cancer risk and tailor more personalized approaches for risk assessment and prevention.
Cancer Screening Behavior
Screening for colorectal cancer, the second leading cause of cancer deaths in the U.S., is not widely practiced among the Asian American population. To learn why, Karen E. Kim, MD, MS, associate professor of medicine, and her research team analyzed cancer screening behavior in a group of 113 Chinese American immigrants.
The researchers found that participants with primary care physicians were more likely to have undergone colorectal cancer screening in the past, and that the longer the participants had lived in the U.S., the more likely they were to have a primary care physician. Furthermore, nearly half of all Chinese men and women believed that they had no risk for colorectal cancer. After attending a culturally tailored educational session on colorectal cancer screening with bilingual staff, more than 70% of the participants completed a free fecal occult blood test screening.
The researchers concluded that future research and interventions that address knowledge deficits and focus on access to culturally competent healthcare have the potential to increase colorectal cancer screening among Chinese American immigrants.
Andrea King, PhD, professor of psychiatry and director of the UChicago Medicine Substance Abuse Clinic, and colleagues recognize the urgent need for prevention and treatment strategies to overcome ethnic and cultural barriers in treating substance use disorders. Their work on a community-based, culturally tailored smoking cessation program for African Americans living in Chicago’s South Side shows promise for increasing treatment retention and quit rates.
Environment and Genetics
Habibul Ahsan, MBBS, MMedSc, Louis Block Professor of Health Studies, Medicine, and Human Genetics, and UCCCC associate director for population research, studies the interrelationships between environmental and genomic (hereditary) factors in cancer and develops and evaluates disease prevention interventions in humans. For example, Dr. Ahsan is directing a genome-wide association study to identify novel genes involved in early-onset breast cancer risk and prognosis among 6,800 young women. He is also conducting several large studies on the health effects of arsenic exposure and examining why some individuals appear to be at higher risk for developing disease, including skin lesions, after exposure. To understand the molecular basis for this disease risk, Dr. Ahsan and colleagues are conducting large-scale genomic studies of individuals in Bangladesh, where about half the population was accidentally exposed to dangerous levels of arsenic through drinking water. Dr. Ahsan is also investigating the ability of vitamin E and selenium to prevent cancer and cancer-related death in populations exposed to arsenic.
Racial and Ethnic Disparities in Pediatric Neuroblastoma
Tara Henderson, MD, MPH, assistant professor of pediatrics, and Susan Cohn, MD, professor of pediatrics, evaluated the racial and ethnic differences in risk factors and survival in 3,539 pediatrics patients with neuroblastoma enrolled in the Children’s Oncology Group. Black and Native American patients had a higher prevalence of high-risk disease and significantly inferior 5-year event-free survival compared with white children with neuroblastoma. In addition, a higher prevalence of late-occurring events was seen among blacks with high-risk disease, suggesting that this population may be more resistant to chemotherapy. The researchers hypothesized that genetic variation is largely responsible for the ethnic disparities in tumor phenotype and outcome observed in neuroblastoma. They analyzed the genetic makeup of 2,709 neuroblastoma patients from ethnically diverse populations and found that African genomic ancestry was significantly associated with a high-risk neuroblastoma phenotype and lower event-free survival. These findings emphasize the key role that genomic variation plays in determining cancer outcomes in children with neuroblastoma. Efforts to understand these disparities may ultimately lead to more effective treatment strategies.
The Economics of Cancer
To achieve a richer understanding of the costs associated with cancer, The University of Chicago Medicine has established an Initiative in the Economics of Cancer. Led by Ya-Chen Tina Shih, PhD, associate professor of medicine, the first-of-its-kind program examines the diffusion of new and existing medical technologies in cancer, cancer disparities, and the associated health and economic consequences. The overarching goal of the program is to produce research that will help reduce the human and economic burdens of cancer. Dr. Shih currently serves as a principal or co-principal investigator on several research projects examining the role of underinsurance as an access barrier to receiving monoclonal antibody therapy among cancer patients; evaluating the cost-effectiveness of patient navigation programs; exploring the impact of new cancer treatment on the cost-effectiveness of mammography screening in elderly women; and developing innovative statistical and econometric methods for modeling longitudinal medical costs.
Susan Hong, MD, MPH, assistant professor of medicine, focuses her research interests on cancer survivorship, especially as it relates to other chronic health conditions. She runs the Breast Cancer Survivorship Program, and is the principal investigator for the American Cancer Society-funded Breast Cancer Survivorship Curriculum for Primary Care Providers in the community which is currently working with the Project ECHO (Extension for Community Healthcare Outcomes) Chicago team. Project ECHO is a program that uses teleconferences to connect UChicago Medicine physicians with primary care physicians providing health services to patients from underserved communities. Through this innovative pilot project, UChicago physicians are able to extend the reach of comprehensive cancer care to residents of Chicago’s South Side, where access to high-quality healthcare is a contributing factor for the large disparity in breast cancer outcomes for African American women.
These UCCCC studies represent a small sampling of the research efforts that are helping scientists and health officials understand and address cancer health disparities. This new knowledge can have profound impacts on the health of individuals in at-risk populations. The UCCCC's community outreach program is essential for bringing the full benefits of these research advances to the community.
To learn more about the UCCCC’s work in population research, see the Cancer Control and Prevention Program.