Emerging genomic biomarkers for improving kidney, prostate, and bladder cancer health disparities outcomes

Racial disparities in stage at bladder cancer diagnosis in the US Veterans Affairs healthcare system

OBJECTIVE

To describe patient characteristics and pathological stage at bladder cancer (BCa) diagnosis in a diverse population within a national, equal-access healthcare system.

METHODS

This retrospective cohort study identified 15 966 men diagnosed with BCa in the Veterans Affairs (VA) healthcare system from 2000 to 2020. The primary outcome was pathological stage at diagnosis, determined by index transurethral resection of bladder tumour. Logistic regression was used to assess the relationship between race and stage. Competing risk models tested the association between race and BCa-specific mortality with cumulative incidence estimates.

RESULTS

Of 15 966 BCa patients, 12 868 (81%), 1726 (11%), 493 (3%) and 879 (6%) were White, Black, Hispanic and Other race, respectively. Black patients had significantly higher muscle-invasive bladder cancer (MIBC) rates than White patients (35% vs 32%; P = 0.009). In multivariable analysis, the odds of presenting with MIBC did not differ significantly between Black and White patients (odds ratio [OR] 1.10, 95% confidence interval [CI] 0.98-1.22) or between Hispanic patients (OR 0.82, 95% CI 0.67-1.01) and White patients. Compared to White patients, Black patients had a similar risk of BCa-specific mortality (hazard ratio [HR] 0.89, 95% CI 0.75-1.06), whereas Hispanic patients had a lower risk (HR 0.56, 95% CI 0.38-0.82).

CONCLUSIONS

Black patients presented with the highest rates of de novo MIBC. However, in a large, equal-access healthcare system, this did not result in a difference in BCa-specific mortality. In contrast, Hispanic patients had lower risks of MIBC and BCa-specific mortality.

A Large Genetic Causal Analysis of the Gut Microbiota and Urological Cancers: A Bidirectional Mendelian Randomization Study

BACKGROUND

Several observational studies and clinical trials have shown that the gut microbiota is associated with urological cancers. However, the causal relationship between gut microbiota and urological cancers remains to be elucidated due to many confounding factors.

METHODS

In this study, we used two thresholds to identify gut microbiota GWAS from the MiBioGen consortium and obtained data for five urological cancers from the UK biobank and Finngen consortium, respectively. We then performed a two-sample Mendelian randomization (MR) analysis with Wald ratio or inverse variance weighted as the main method. We also performed comprehensive sensitivity analyses to verify the robustness of the results. In addition, we performed a reverse MR analysis to examine the direction of causality.

RESULTS

Our study found that family Rikenellaceae, genus Allisonella, genus Lachnospiraceae UCG001, genus Oscillibacter, genus Eubacterium coprostanoligenes group, genus Eubacterium ruminantium group, genus Ruminococcaceae UCG013, and genus Senegalimassilia were related to bladder cancer; genus Ruminococcus torques group, genus Oscillibacter, genus Barnesiella, genus Butyricicoccus, and genus Ruminococcaceae UCG005 were related to prostate cancer; class Alphaproteobacteria, class Bacilli, family Family XI, genus Coprococcus2, genus Intestinimonas, genus Lachnoclostridium, genus Lactococcus, genus Ruminococcus torques group, and genus Eubacterium brachy group were related to renal cell cancer; family Clostridiaceae 1, family Christensenellaceae, genus Eubacterium coprostanoligenes group, genus Clostridium sensu stricto 1, and genus Eubacterium eligens group were related to renal pelvis cancer; family Peptostreptococcaceae, genus Romboutsia, and genus Subdoligranulum were related to testicular cancer. Comprehensive sensitivity analyses proved that our results were reliable.

CONCLUSIONS

Our study confirms the role of specific gut microbial taxa on urological cancers, explores the mechanism of gut microbiota on urological cancers from a macroscopic level, provides potential targets for the screening and treatment of urological cancers, and is dedicated to providing new ideas for clinical research.

Race reporting and disparities regarding clinical trials in bladder cancer: a systematic review

PURPOSE

To systematically review the literature to investigate racial disparities among bladder cancer clinical trial enrollees.

METHODS

A systematic review was conducted using Ovid, MEDLINE® to identify clinical trials between 1970 and 2020. Articles were reviewed and were included if they assessed race in their outcomes reporting among bladder cancer patients enrolled in clinical trials. The review was conducted in accordance with the PRISMA statement.

RESULTS

We identified 544 clinical trials meeting our initial search criteria, with only 24 (4.4%) studies reporting racial demographic data. Enrollees were largely Caucasian (81-98%), with a strikingly small proportion of enrolled patients consisting of African-Americans (2-8%) and Hispanics (2-5%). Only one of the studies reported results on the efficacy and safety/tolerability of the tested treatment separately for racial groups and performed analyses stratified by race.

CONCLUSION

Race is poorly studied in bladder cancer clinical trials. Trial cohorts may not reflect multicultural populations. The potential association between race and efficacy, safety or tolerability of the tested interventions is unknown. Given the up to twofold increase in bladder cancer-specific death among African-Americans, further research is needed to address the impact of race in clinical trials, while encompassing socioeconomic factors and disease risk factor exposures.

Repair-Assisted Damage Detection Reveals Biological Disparities in Prostate Cancer between African Americans and European Americans

Simple Summary

Prostate cancer is the most diagnosed cancer among men in the United States. African American men are diagnosed with and succumb to prostate cancer at higher rates than other demographic groups. Previously published works described the biological differences in prostate tumors that may contribute to poorer outcomes in African American men compared to European American men. This study was designed to explore the DNA lesion profiles found in prostate tissues. Using tissue microarrays, we found that prostate tumors from African American patients have more uracil and pyrimidine damage, elevated UNG levels, and reduced XRCC1 levels than European American tumors, which may indicate defects in the base excision repair pathway. In addition, these men had higher UMP and lower expression of folate cycle metabolites, suggesting that metabolic rewiring may also contribute to the dysregulation of base excision repair.

Abstract

African Americans (AA) are two times more likely to be diagnosed with and succumb to prostate cancer (PCa) compared to European Americans (EA). There is mounting evidence that biological differences in these tumors contribute to disparities in patient outcomes. Our goal was to examine the differences in DNA damage in AA and EA prostate tissues. Tissue microarrays with matched tumor-benign adjacent pairs from 77 AA and EA PCa patients were analyzed for abasic sites, oxidative lesions, crosslinks, and uracil content using the Repair Assisted Damage Detection (RADD) assay. Our analysis revealed that AA PCa, overall, have more DNA damage than EA PCa. Increased uracil and pyrimidine lesions occurred in AA tumors, while EA tumors had more oxidative lesions. AA PCa have higher levels of UMP and folate cycle metabolites than their EA counterparts. AA PCa showed higher levels of UNG, the uracil-specific glycosylase, than EA, despite uracil lesions being retained within the genome. AA patients also had lower levels of the base excision repair protein XRCC1. These results indicate dysfunction in the base excision repair pathway in AA tumors. Further, these findings reveal how metabolic rewiring in AA PCa drives biological disparities and identifies a targetable axis for cancer therapeutics.

LncRNA ZNF503-AS1 acts as a tumor suppressor in bladder cancer by up-regulating Ca2+ concentration via transcription factor GATA6

PURPOSE

Ca2+ homeostasis plays a pivotal role in regulating proliferation and apoptosis during cancer development. This study intended to examine the potential tumor-suppressing role of ZNF503 antisense RNA 1 (ZNF503-AS1) in bladder cancer, which may be implicated in the regulation of Ca2+ homeostasis.

METHODS

Differentially expressed long non-coding RNAs (lncRNAs) related to bladder cancer were identified using microarray analysis, followed by the verification of transcription factors to which they bind. The relationship between ZNF503-AS1, GATA6 and SLC8A1 was assessed using dual luciferase reporter, RIP and ChIP assays. The expression levels of ZNF503-AS1, GATA6 and SLC8A1 were modulated to examine their effects on the tumorigenic potential, intracellular Ca2+ concentration and Ca2+-ATPase activity in bladder cancer cells. The in vivo tumorigenic ability was validated in nude mice.

RESULTS

Microarray-based expression profile analysis of the GEO GSE61615 dataset revealed that the expression of ZNF503-AS1 was decreased in bladder cancer. Subsequently, we found that ZNF503-AS1 can bind to the transcription factor GATA6 to up-regulate the expression of SLC8A1. ZNF503-AS1 and SLC8A1 were found to be down-regulated in both primary bladder cancer tissues and cells. Exogenous overexpression of ZNF503-AS1 or SLC8A1 attenuated bladder cancer cell proliferation, invasion and migration, but promoted their apoptosis, accompanied by decreased Ca2+-ATPase activities and increased intracellular Ca2+ concentrations. Additional in vivo experiments validated the inhibitory effect of ZNF503-AS1 overexpression on the tumorigenic capacity of bladder cancer cells in nude mice.

CONCLUSION

ZNF503-AS1 can recruit transcription factor GATA6 to up-regulate SLC8A1 expression, thereby increasing the intracellular Ca2+ concentration and repressing the proliferation, invasion and migration, and enhancing the apoptosis of bladder cancer cells.