Genomic Testing in Localized Prostate Cancer Can Identify Subsets of African Americans With Aggressive Disease

Racial disparity in prostate cancer: an outlook in genetic and molecular landscape

Prostate cancer (PCa) incidence, morbidity, and mortality rates are significantly impacted by racial disparities. Despite innovative therapeutic approaches and advancements in prevention, men of African American (AA) ancestry are at a higher risk of developing PCa and have a more aggressive and metastatic form of the disease at the time of initial PCa diagnosis than other races. Research on PCa has underlined the biological and molecular basis of racial disparity and emphasized the genetic aspect as the fundamental component of racial inequality. Furthermore, the lower enrollment rate, limited access to national-level cancer facilities, and deferred treatment of AA men and other minorities are hurdles in improving the outcomes of PCa patients. This review provides the most up-to-date information on various biological and molecular contributing factors, such as the single nucleotide polymorphisms (SNPs), mutational spectrum, altered chromosomal loci, differential gene expression, transcriptome analysis, epigenetic factors, tumor microenvironment (TME), and immune modulation of PCa racial disparities. This review also highlights future research avenues to explore the underlying biological factors contributing to PCa disparities, particularly in men of African ancestry.

Recent trends in the incidence of early-onset prostate cancer

Early-onset prostate cancer (EOPC) is relatively uncommon. It is unclear if the incidence of EOPC is evolving. Utilizing data from the SEER database from 2000 to 2020, the study identified prostate cancer cases in men under 55 years, focusing on trends in annual age-adjusted incidence rates (AAIR), stage at presentation, race/ethnicity, and local treatment patterns. The study encompassed 93 071 cases of EOPC, with the median age at diagnosis being 51 years. From 2000 to 2007, the AAIR of EOPC experienced a wave-like increase from 6.9 to 8.3 per 100 000 people. It then sharply declined to 5.4 by 2014, followed by 6 years of stability, and by 2020 it had dropped to its lowest point of 4.5. The trend observed across different racial groups was consistent with the overall pattern, where non-Hispanic Black patients consistently exhibited the highest incidence and the least reduction rate (annual percent change, -1.0; 95% confidence interval, -1.8 to -0.2; P < 0.05). Stage II was the most commonly diagnosed, although its AAIR declined from 4.9 to 1.2 per 100 000 people. From 2010 through 2020, the proportion of receiving prostatectomy decreased from 63.0 to 43.6%. The declining rates of EOPC across diverse racial groups emphasize the critical need for focused research and interventions. Specifically, there is an urgent call to establish a tailored screening protocol for prostate cancer targeting Black youth.

ERBB3 Overexpression is Enriched in Diverse Patient Populations with Castration-sensitive Prostate Cancer and is Associated with a Unique AR Activity Signature

PURPOSE

Despite successful clinical management of castration-sensitive prostate cancer (CSPC), the 5-year survival rate for men with castration-resistant prostate cancer is only 32%. Combination treatment strategies to prevent disease recurrence are increasing, albeit in biomarker-unselected patients. Identifying a biomarker in CSPC to stratify patients who will progress on standard-of-care therapy could guide therapeutic strategies.

EXPERIMENTAL DESIGN

Targeted deep sequencing was performed for the University of Illinois (UI) cohort (n = 30), and immunostaining was performed on a patient tissue microarray (n = 149). Bioinformatic analyses identified pathways associated with biomarker overexpression (OE) in the UI cohort, consolidated RNA sequencing samples accessed from Database of Genotypes and Phenotypes (n = 664), and GSE209954 (n = 68). Neutralizing antibody patritumab and ectopic HER3 OE were utilized for functional mechanistic experiments.

RESULTS

We identified ERBB3 OE in diverse patient populations with CSPC, where it was associated with advanced disease at diagnosis. Bioinformatic analyses showed a positive correlation between ERBB3 expression and the androgen response pathway despite low dihydrotestosterone and stable expression of androgen receptor (AR) transcript in Black/African American men. At the protein level, HER3 expression was negatively correlated with intraprostatic androgen in Black/African American men. Mechanistically, HER3 promoted enzalutamide resistance in prostate cancer cell line models and HER3-targeted therapy resensitized therapy-resistant prostate cancer cell lines to enzalutamide.

CONCLUSIONS

In diverse patient populations with CSPC, ERBB3 OE was associated with high AR signaling despite low intraprostatic androgen. Mechanistic studies demonstrated a direct link between HER3 and enzalutamide resistance. ERBB3 OE as a biomarker could thus stratify patients for intensification of therapy in castration-sensitive disease, including targeting HER3 directly to improve sensitivity to AR-targeted therapies.

Cancer statistics, 2024

Each year, the American Cancer Society estimates the numbers of new cancer cases and deaths in the United States and compiles the most recent data on population-based cancer occurrence and outcomes using incidence data collected by central cancer registries (through 2020) and mortality data collected by the National Center for Health Statistics (through 2021). In 2024, 2,001,140 new cancer cases and 611,720 cancer deaths are projected to occur in the United States. Cancer mortality continued to decline through 2021, averting over 4 million deaths since 1991 because of reductions in smoking, earlier detection for some cancers, and improved treatment options in both the adjuvant and metastatic settings. However, these gains are threatened by increasing incidence for 6 of the top 10 cancers. Incidence rates increased during 2015-2019 by 0.6%-1% annually for breast, pancreas, and uterine corpus cancers and by 2%-3% annually for prostate, liver (female), kidney, and human papillomavirus-associated oral cancers and for melanoma. Incidence rates also increased by 1%-2% annually for cervical (ages 30-44 years) and colorectal cancers (ages <55 years) in young adults. Colorectal cancer was the fourth-leading cause of cancer death in both men and women younger than 50 years in the late-1990s but is now first in men and second in women. Progress is also hampered by wide persistent cancer disparities; compared to White people, mortality rates are two-fold higher for prostate, stomach and uterine corpus cancers in Black people and for liver, stomach, and kidney cancers in Native American people. Continued national progress will require increased investment in cancer prevention and access to equitable treatment, especially among American Indian and Alaska Native and Black individuals.

Understanding and Addressing Prostate Cancer Disparities in Diagnosis, Treatment, and Outcomes Among Black Men

Despite advances in screening, diagnosis, and treatment for prostate cancer (PCa), Black men tend to be diagnosed at younger ages, have higher mortality rates, and are at increased risk of recurrence or metastasis compared to their White counterparts. PCa disparities among Black men are caused by a complex interaction of social, behavioral, and biological factors across the public policy, community, organizational, interpersonal, and individual levels. Key contributing factors include mistrust in the health care system, poor communication between patients and providers, low awareness of screening guidelines, and high medical costs. These disparities are further exacerbated by the low representation of Black men in clinical trials, which limits access to high-quality cancer care and generalizability for PCa treatments. In this narrative review of the existing literature, we examined the epidemiology and identified contributing factors, and propose multi-level strategies to address and mitigate disparities among Black men with PCa.

The prevalence and clinical significance of HER2 expression in prostate adenocarcinoma

AIMS

Abnormalities in HER2 are well-established oncogenic drivers and are approved therapeutic targets in various malignancies. Prior studies evaluating HER2 expression in prostate cancer (PCa) have yielded variable results. Most of these studies used immunohistochemistry scoring systems based on breast cancer data. The goal of this study was to determine the prevalence and clinical significance of HER2 expression using a scoring system that better reflects the HER2 staining pattern observed in PCa.

METHODS

We randomly selected similar numbers of localized low risk (AJCC stage I), locally advanced (AJCC stages II & III), and metastatic (AJCC stage IV) PCa patients treated at the DC VA Medical Center between 2000 and 2022. Among them, we included patients who had sufficient PCa tissue samples and clinical information required for this analysis. Two experienced pathologists independently scored HER2 expression (Ventana Pathway anti-HER2) according to a modified gastric cancer HER2 scoring system.

RESULTS

Out of the 231 patients included, 85 % self-identified as Black. 58.9 % of patients expressed HER2 (1+: 35.5 %; 2+: 18.2 %; 3+: 5.2 %). Validity of the results was confirmed using the HercepTest antibody. Higher HER2 expression was associated with a higher Gleason Score/Grade Group and advanced disease.

CONCLUSIONS

Our findings support the adverse prognostic impact on HER2 in PCa. We propose the use of a modified scoring system to evaluate HER2 expression in PCa. The observed high prevalence of HER2 expression supports the consideration of novel HER2-targeted therapies addressing even low levels of HER2 expression in future PCa trials.

Prostate Cancer, Race, and Health Disparity: What We Know

ABSTRACT

Prostate cancer (PCa) in African American men is one of the most common cancers with a great disparity in outcomes. The higher incidence and tendency to present with more advanced disease have prompted investigators to postulate that this is a problem of innate biology. However, unequal access to health care and poorer quality of care raise questions about the relative importance of genetics versus social/health injustice. Although race is inconsistent with global human genetic diversity, we need to understand the sociocultural reality that race and racism impact biology. Genetic studies reveal enrichment of PCa risk alleles in populations of West African descent and population-level differences in tumor immunology. Structural racism may explain some of the differences previously reported in PCa clinical outcomes; fortunately, there is high-level evidence that when care is comparable, outcomes are comparable.

Detection of Cancer-Associated Gene Mutations in Urinary Cell-Free DNA among Prostate Cancer Patients in South Africa

Prostate cancer (PCa) is the most common cause of cancer death among African men. The presence of tumor-specific variations in cell-free DNA (cfDNA), such as mutations, microsatellite instability, and DNA methylation, has been explored as a source of biomarkers for cancer diagnosis. In this study, we investigated the diagnostic role of cfDNA among South African PCa patients. We performed whole exome sequencing (WES) of urinary cfDNA. We identified a novel panel of 31 significantly deregulated somatic mutated genes between PCa and benign prostatic hyperplasia (BPH). Additionally, we performed whole-genome sequencing (WGS) on matching PCa and normal prostate tissue in an independent PCa cohort from South Africa. Our results suggest that the mutations are of germline origin as they were also found in the normal prostate tissue. In conclusion, our study contributes to the knowledge of cfDNA as a biomarker for diagnosing PCa in the South African population.

Racial disparity in the genomics of precision oncology of prostate cancer

BACKGROUND

Significant racial disparities in prostate cancer incidence and mortality have been reported between African American Men (AAM), who are at increased risk for prostate cancer, and European American Men (EAM). In most of the studies carried out on prostate cancer, this population is underrepresented. With the advancement of genome-wide association studies, several genetic predictor models of prostate cancer risk have been elaborated, as well as numerous studies that identify both germline and somatic mutations with clinical utility.

RECENT FINDINGS

Despite significant advances, the AAM population continues to be underrepresented in genomic studies, which can limit generalizability and potentially widen disparities. Here we outline racial disparities in currently available genomic applications that are used to estimate the risk of individuals developing prostate cancer and to identify personalized oncology treatment strategies. While the incidence and mortality of prostate cancer are different between AAM and EAM, samples from AAM remain to be unrepresented in different studies.

CONCLUSION

This disparity impacts the available genomic data on prostate cancer. As a result, the disparity can limit the predictive utility of the genomic applications and may lead to the widening of the existing disparities. More studies with substantially higher recruitment and engagement of African American patients are necessary to overcome this disparity.

Using Machine Learning to Predict TP53 Mutation Status and Aggressiveness of Prostate Cancer from Routine Histology Images

Despite years of progress, we still lack reliable tools to predict the aggressiveness of tumors, including in the case of prostate cancer. Biomarkers have been developed, but they often suffer from poor accuracy if used alone due to tumor heterogeneity. Nevertheless, some mutations, notably TP53 mutations, are highly correlated with progression. In their work in this issue of Cancer Research, Pizurica and colleagues implemented a machine learning-based model applied to routine histology and trained with prior information on TP53 mutation status. Their model output provides a quantitative prediction of TP53 mutation status while having a strong correlation with aggressiveness, showing promise as a prognostic in silico biomarker. See related article by Pizurica et al., p. 2970.

Transcriptomic Signatures Associated With Outcomes in Recurrent Prostate Cancer Treated With Salvage Radiation, Androgen-Deprivation Therapy, and Enzalutamide: Correlative Analysis of the STREAM Trial

PURPOSE

Men with rising prostate-specific antigen (PSA) after radical prostatectomy (RP) may progress despite radiation and androgen-deprivation therapy (ADT). Tissue-based transcriptomic signatures can identify who may benefit from a more aggressive systemic approach.

METHODS

We performed a retrospective analysis of a prospective phase II multicenter trial of enzalutamide, ADT, and salvage radiotherapy in men with rising PSA after RP. Tumor tissue was analyzed using the Decipher platform for gene expression, including a novel prostate subtyping classifier, PTEN loss, homologous recombination deficiency (HRD), and ADT response. Cox models were used to associate signature scores with progression-free survival (PFS).

RESULTS

Of the 38 men enrolled, 31 had tissue with sufficient-quality RNA for genomic analysis. Luminal differentiated (LD) subtype tumors had the longest 3-year PFS at 89% compared with 19% in the luminal proliferating subtype. Men with signatures of PTEN loss (hazard ratio [HR], 1.32; 95% CI, 1.07 to 1.64; P = .01) or HRD (HR, 1.21; 95% CI, 1.05 to 1.39; P = .009) had worse PFS, while those with higher ADT response signature scores (HR, 0.75; 95% CI, 0.61 to 0.94; P = .01) were associated with improved PFS. Analysis of these signatures in a large cohort (n = 5,330) of RP samples from patients with biochemical recurrence found that these signatures provide complementary information related to outcomes with salvage radiation.

CONCLUSION

Despite aggressive systemic therapy with salvage radiation, nearly 50% of high-risk men relapse within 3 years. We show that LD and higher ADT sensitivity tumors had favorable outcomes. Those with a luminal proliferating subtype, PTEN loss, and/or HRD signatures had poor outcomes despite ADT/radiation and enzalutamide and may benefit from alternative approaches.

Current Status and Future Direction to Address Disparities in Diversity, Equity, and Inclusion in Prostate Cancer Care

PURPOSE OF REVIEW

Disparities in prostate cancer care and outcomes have been well recognized for decades. The purpose of this review is to methodically highlight known racial disparities in the care of prostate cancer patients, and in doing so, recognize potential strategies for overcoming these disparities moving forward.

RECENT FINDINGS

Over the past few years, there has been a growing recognition and push towards addressing disparities in cancer care. This has led to improvements in care delivery trends and a narrowing of racial outcome disparities, but as we highlight in the following review, there is more to be addressed before we can fully close the gap in prostate cancer care delivery. While disparities in prostate cancer care are well recognized in the literature, they are not insurmountable, and progress has been made in identifying areas for improvement and potential strategies for closing the care gap.

Review of Cardiovascular Risk of Androgen Deprivation Therapy and the Influence of Race in Men with Prostate Cancer

Androgen deprivation therapy is the cornerstone of prostate cancer therapy. Recent studies have revealed an association between androgen deprivation therapy and cardiovascular adverse effects such as myocardial infarction and stroke. This review summarizes the available research on the cardiovascular risk of men using androgen deprivation therapy. We also discuss racial disparities surrounding both prostate cancer and cardiovascular disease, emphasizing the importance of biological/molecular and socioeconomic factors in assessing baseline risk in patients beginning androgen ablation. Based on the literature, we provide recommendations for monitoring patients who are at high risk for a cardiovascular adverse event while being treated on androgen deprivation therapy. This review aims to present the current research on androgen deprivation therapy and cardiovascular toxicity with an emphasis on racial disparities and provides a framework for clinicians to decrease the cardiovascular morbidity in men that are being treated with hormone therapy.

Cancer statistics, 2023

Each year, the American Cancer Society estimates the numbers of new cancer cases and deaths in the United States and compiles the most recent data on population-based cancer occurrence and outcomes using incidence data collected by central cancer registries and mortality data collected by the National Center for Health Statistics. In 2023, 1,958,310 new cancer cases and 609,820 cancer deaths are projected to occur in the United States. Cancer incidence increased for prostate cancer by 3% annually from 2014 through 2019 after two decades of decline, translating to an additional 99,000 new cases; otherwise, however, incidence trends were more favorable in men compared to women. For example, lung cancer in women decreased at one half the pace of men (1.1% vs. 2.6% annually) from 2015 through 2019, and breast and uterine corpus cancers continued to increase, as did liver cancer and melanoma, both of which stabilized in men aged 50 years and older and declined in younger men. However, a 65% drop in cervical cancer incidence during 2012 through 2019 among women in their early 20s, the first cohort to receive the human papillomavirus vaccine, foreshadows steep reductions in the burden of human papillomavirus-associated cancers, the majority of which occur in women. Despite the pandemic, and in contrast with other leading causes of death, the cancer death rate continued to decline from 2019 to 2020 (by 1.5%), contributing to a 33% overall reduction since 1991 and an estimated 3.8 million deaths averted. This progress increasingly reflects advances in treatment, which are particularly evident in the rapid declines in mortality (approximately 2% annually during 2016 through 2020) for leukemia, melanoma, and kidney cancer, despite stable/increasing incidence, and accelerated declines for lung cancer. In summary, although cancer mortality rates continue to decline, future progress may be attenuated by rising incidence for breast, prostate, and uterine corpus cancers, which also happen to have the largest racial disparities in mortality.