Dr. Charnita Zeigler-Johnson studies prostate cancer disparities and risk factors that influence prostate cancer occurrence, progression and treatment outcomes. These risk factors include genetic polymorphisms, inflammation biomarkers, race/ethnicity, obesity, baldness, socioeconomic status and neighborhood characteristics. Her research goals are to identify possible modes for cancer prevention in high-risk populations and to provide new understanding about how contextual factors influence disease outcomes.
Neighborhood-Based Prostate Cancer Intervention
Although prostate cancer (PCa) survival has improved over the years due to early detection and improved treatment options, socioeconomic (SES) and racial disparities persist. Research shows that men who reside in low SES neighborhoods are less likely to be screened for prostate cancer and more likely to have aggressive forms of PCa than men who live in higher income neighborhoods. Given these facts, it can be surmised that men who live in economically deprived neighborhoods are at high risk of poor PCa outcomes due to delayed timing of detection and the nature of the disease.
The goal of the current research is to provide PCa education for men who live in neighborhoods with high rates of advanced prostate cancer. We aim is to increase PCa awareness in high-risk communities and prompt informed decision making about screening. The study utilizes a mixed-methods approach involving quantitative analyses of state cancer registry data, population level survey data, and Philadelphia vital health statistics; qualitative analyses of focus group results; and the test of a targeted educational intervention with a pre/post survey design.
Obesity and Prostate Cancer Outcomes
PCa is a common, complex disease with strong ethnic disparities and only a few confirmed and non-modifiable risk factors. African-Americans are at highest risk for developing PCa and often present with advanced disease. Obesity, a potentially modifiable risk factor, has been shown to increase the risk of advanced disease at diagnosis and treatment (biochemical) failure. Obesity is also most prevalent in African-American populations. However, there has been controversy regarding obesity’s role in PCa progression, as all studies have not shown associations. Inconsistencies may be caused by differences in factors that may alter observed associations of obesity with outcomes. Although linked to obesity and advanced cancer, patient- and neighborhood-level factors have not been studied as modifiers of obesity effects in PCa patients. Multi-level models are required to examine the effects of these variables on the relationship between obesity and PCa outcomes.
The goal of this project is to examine disparities in the relationship between obesity and PCa outcomes. We will also build multi-level models of obesity and prostate cancer outcomes by adjusting for patient- and neighborhood- level variables. This is a secondary analysis study conducted in collaboration with co-investigators at the University of Pennsylvania. We will use a case-case study design to examine the relationship between patient- and neighborhood-level characteristics and disparities in prostate cancer severity.
To date, few studies have been able to examine multilevel factors for prostate cancer disparities. Determining significant modification by patient and neighborhood variables may suggest novel pathways for prostate cancer progression, identify groups of patients at highest risk for poor outcomes, and provide strategies for effective intervention to decrease disparities.
Tumor Microenvironment Inflammation
In recent years, there has been a growing interest in the tumor microenvironment as a potential area for investigating the underlying biology of carcinogenesis and metastasis. Inflammation is a key characteristic of cancer that has been associated with disease severity. Under chronic inflammation, common immune cells, including T lymphocytes and macrophages in the tumor microenvironment secrete various factors that may increase cell proliferation and inhibit cell death. The presence of these immune cells may be indicative of aggressive tumors that are likely to metastasize.
Quantification of changes in the tumor microenvironment under various conditions may provide tumor signatures that improve diagnostics of PCa. The goal of this pathology-based research is to examine PCa specimens to characterize differences in tumor infiltrating lymphocytes and macrophages within the tumor microenvironment by obesity status and cancer severity.