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Updated: Dec 23, 2025
Microarray-based Identification of Individual HERV Loci Expression: Application to Biomarker Discovery in Prostate Cancer
Published on: November 2, 2013
SEER and Gene Expression Data Analysis Deciphers Racial Disparity Patterns in Prostate Cancer Mortality and the
Wensheng Zhang1, Yan Dong2, Oliver Sartor3
1Bioinformatics Core of Xavier NIH RCMI Center of Cancer Research; Department of Computer Science, Xavier University of Louisiana, New Orleans, 70125, LA, USA.
Insights
Racial disparities in prostate cancer (PCa) mortality are linked to higher rates of high-grade cancers in African Americans (AA). However, survival rates are similar between AA and European American (EA) patients with the same cancer grade, suggesting "equal grade, equal outcomes" is achievable.
Area of Science:
- Oncology
- Epidemiology
- Genetics
Background:
- African American (AA) patients exhibit higher prostate cancer (PCa) mortality rates compared to European American (EA) patients.
- This disparity may be influenced by differences in cancer grading and tumor aggressiveness.
- Understanding the root causes is crucial for developing targeted interventions.
Purpose of the Study:
- To investigate the racial disparity in PCa mortality between AA and EA patients.
- To analyze the relationship between high-grade PCa and mortality rates across racial groups.
- To explore the role of gene expression in PCa racial disparities.
Main Methods:
- Utilized SEER 2009-2011 data, stratifying patients by race and cancer grade.
- Performed statistical analyses, including linear regression, to assess mortality rates.
- Analyzed gene expression data to identify molecular differences between racial groups.
Main Results:
- A significant association between high-grade PCa and mortality was observed in EAs, but not in AAs.
- Racial disparities in high-grade PCa prevalence varied by age and patient outcomes.
- Survival rates were similar between AA and EA patients within the same cancer grade category.
- Few genes showed differential expression between AA and EA tumors of the same grade.
Conclusions:
- The perception of more lethal prostate tumors in AAs is partly explained by a higher prevalence of high-grade cancers.
- However, when cancer grade is controlled, racial differences in survival diminish, challenging the notion of inherent tumor aggressiveness disparity.
- "Equal grade, equal outcomes" is a verifiable hypothesis and an achievable public health goal for reducing PCa racial disparities.
Abstract:
A major racial disparity in prostate cancer (PCa) is that African American (AA) patients have a higher mortality rate than European American (EA) patients. We filtered the SEER 2009-2011 records and divided them into four groups regarding patient races and cancer grades. On such a partition, we performed a series of statistical analyses to further clarify the aforementioned disparity. Molecular evidence for a primary result of the epidemiological analysis was obtained from gene expression data. The results include: (1) Based on the registry-specific measures, a significant linear regression of total mortality rate (as well as PCa specific mortality rate) on the percentage of (Gleason pattern-based) high-grade cancers (PHG) is demonstrated in EAs (p < 0.01) but not in AAs; (2) PHG and its racial disparity are differentiated across ages and the groups defined by patient outcomes; (3) For patients with cancers in the same grade category, i.e. the high or low grade, the survival stratification between races is not significant in most geographical areas; and (4) The genes differentially expressed between AAs' and EAs' tumors of the same grade category are relatively rare. The perception that prostate tumors are more lethal in AAs than in EAs is reasonable regarding AAs' higher PHG, while high grade alone could not imply aggressiveness. However, this perception is questionable when the comparison is focused on cases within the same grade category. Supporting observations for this conclusion hold a remarkable implication for erasing racial disparity in PCa. That is, "Equal grade, equal outcomes" is not only a verifiable hypothesis but also an achievable public health goal.
