Dissertation
Examining how race/ethnicity, rurality, and socioeconomic status intersections are associated with colorectal cancer diagnosis, treatment, and survival
University of Iowa
Doctor of Philosophy (PhD), University of Iowa
Spring 2024
DOI: 10.25820/etd.007877
Abstract
Background: Colorectal cancer is among the leading cause of incident cancer and cancer-related death in the U.S. However, individuals in disadvantaged groups of marginalized racial identities, rural residence, and of low socioeconomic status experience an undue burden of this disease. There is little known about colorectal cancer experiences for individuals in the intersections of race/ethnicity, rurality, and socioeconomic status. The purpose of this dissertation was to assess colorectal cancer along the continuum from diagnosis through survival for individuals in the intersections of minoritized race/ethnicity, rural residence, and low socioeconomic status.
Methods: We performed three studies using the Surveillance, Epidemiology, and End Results (SEER)-17 data with specialized census-tract attributes database, the SEER Patterns of Care database, and the North American Association of Central Cancer Registries (NAACCR) Cancer in North America (CiNA) survival database. In the first study, I assessed colorectal cancer late-stage incidence rates, mortality rates, and stage at diagnosis and identified intersection groups at higher risk for late-stage incidence and mortality. In the second study, I assessed differences between intersection groups in time from colorectal cancer diagnosis to treatment as well as receipt of guideline-recommended treatment. Finally, in the third study, I examined differences in colorectal cancer overall and cause-specific survival at two- and five-years after diagnosis.
Results: In Aim 1, I identified that groups in areas of low socioeconomic status and in rural areas were more likely to be diagnosed late-stage compared to those in high socioeconomic status areas and in urban areas. In Aim 2, I observed increased risk for not receiving guideline-recommended care among non-White colon cancer patients regardless of rural/urban residence, and increased risk for late treatment initiation among non-White patients with: 1) colon cancer in rural areas, and 2) rectal cancer in urban areas. In Aim 3, Non-White patients in high poverty, rural areas experienced a greater risk for death compared to White patients. The only non-White groups with decreased hazard of death relative to White patients were those living urban areas.
Conclusions: Colorectal cancer experiences for patients in the intersections of minoritized race/ethnicity, rural residence, and low socioeconomic status are not well known, but research for these groups provide necessary context on how barriers to care can compound with increasing marginalized/underrepresented identities. This dissertation contributes to an increased understanding of mechanisms behind colorectal cancer inequities, though it is only the first step in creating equitable cancer outcomes. It is necessary moving forward to examine these inequities at the systemic and societal levels to identify opportunities for change beyond putting the emphasis on changing individual behavior.
Details
- Title: Subtitle
- Examining how race/ethnicity, rurality, and socioeconomic status intersections are associated with colorectal cancer diagnosis, treatment, and survival
- Creators
- Breanna B Greteman
- Contributors
- Mary E Charlton (Advisor)Sarah H Nash (Committee Member)Whitney E Zahnd (Committee Member)Jonathan M Platt (Committee Member)Jacob J Oleson (Committee Member)
- Resource Type
- Dissertation
- Degree Awarded
- Doctor of Philosophy (PhD), University of Iowa
- Degree in
- Epidemiology
- Date degree season
- Spring 2024
- DOI
- 10.25820/etd.007877
- Publisher
- University of Iowa
- Number of pages
- xv, 131 pages
- Copyright
- Copyright 2024 Breanna B Greteman
- Language
- English
- Date submitted
- 04/23/2024
- Description illustrations
- illustrations, tables
- Description bibliographic
- Includes bibliographical references.
- Public Abstract (ETD)
- Colorectal cancer (CRC) is among the leading causes of new cancer diagnoses and cancer-related deaths in the U.S.[1] Some groups have increased risk of being diagnosed with and dying from colorectal cancer, including marginalized racial/ethnic groups [2-6], rural residents [7-9], and those in low socioeconomic areas [10-11]. However, there is limited research on colorectal cancer for those who intersect these characteristics [12-31]. In Aim 1, we looked at patterns in colorectal cancer diagnosis and cancer-related mortality. Non-Hispanic Black patients had higher rates of stage III and IV colorectal cancer diagnosis, and non-Hispanic Black and non-Hispanic American Indian/Alaska Native patients had higher rates of cancer-related mortality compared to non-Hispanic White. We recommend future studies assess how screening impacts diagnosis and mortality for these groups. In Aim 2, we assessed time from colorectal cancer diagnosis to treatment and receipt of guideline-recommended care between intersection groups of race/ethnicity and rurality. Non- White patients in rural areas were more likely to start colon cancer treatment more than one month after diagnosis; non-White patients in urban areas were more likely to start rectal cancer treatment more than one month after diagnosis. We recommend that future studies identify unique mechanisms that impact time to treatment for these groups. In Aim 3, we examined survival for all intersection groups at two years and five years after diagnosis. Non-Hispanic Black and non-Hispanic American Indian/Alaska Native patients in rural/high poverty areas had worse survival at all time points compared to those in urban/high poverty, rural/low poverty, and urban/low poverty areas. Future studies should study how screening and treatment impact these relationships.
- Academic Unit
- Epidemiology
- Record Identifier
- 9984830729902771
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