Methylation reprogramming associated with aggressive prostate cancer and ancestral disparities.

Simple SummaryProstate cancer (PCa) is the leading cancer in incidence and second leading cause of cancer mortality in US men. Recent data showed a 3% increase in PCa incidence rate each year from 2014 through 2019. African American (AA) men have 1.6-fold higher incidence and 2.2-fold higher PC mortality rates than European American (EA) men. Growing evidence shows that miRNAs are closely associated with aggressiveness and racial disparity in prostate cancer and might facilitate the prediction of prognosis and a treatment plan. In this study, we identified differentially expressed miRNAs, which are significantly correlated with the aggressiveness and health disparity of prostate cancer. These findings may assist personalized medicine, suggesting miRNAs as promising biomarkers for prostate cancer, especially in African American men.Prostate cancer is the leading cancer in incidence and second leading cause of cancer mortality in US men. African American men have significantly higher incidence and mortality rates from prostate cancer than European American men. Previous studies reported that the disparity in prostate cancer survival or mortality can be explained by different biological backgrounds. microRNAs (miRNAs) regulate gene expression of their cognate mRNAs in many cancers. Therefore, miRNAs may be a potentially promising diagnostic tool. The role of miRNAs in prostate cancer aggressiveness and racial disparity has not been fully established. The goal of this study is to identify miRNAs associated with aggressiveness and racial disparity in prostate cancer. Here we report miRNAs that are associated with tumor status and aggressiveness in prostate cancer using a profiling approach. Further, downregulated miRNAs in African American tissues were confirmed by qRT-PCR. These miRNAs have also been shown to negatively regulate the expression of the androgen receptor in prostate cancer cells. This report provides a novel insight into understanding tumor aggressiveness and racial disparities of prostate cancer.

The mechanistic basis of racial disparities in prostate cancer (PCa) aggressiveness between African American (AA) and Caucasian (CA) men are not yet fully understood. Further, molecular biomarkers to predict aggressive disease at its onset have been studied primarily in CAs, the relevance of these biomarkers to AAs are largely unknown. We propose a novel, paradigm-shifting hypothesis that expression of microRNA (miRNA) genes-miR-3622a and miR-383-located within frequently deleted chr8p21-22 region constitute important molecular factors contributing to racial disparities in PCa aggressiveness in AA vs CA men. Chromosome 8p deletions are a frequent alteration of PCa genome, with a common region of loss of heterozygosity at the chr8p21-22 locus. We previously showed that this region is associated with a set of tumor suppressive miRNAs (miR-3622a/b, -383, -4288) that are downregulated in PCa with important causal roles in tumor progression, recurrence and metastasis. Chr8p deletions increase significantly with tumor grade and are associated with poor prognosis. These deletions are well studied in CA men. However, there have been conflicting reports on frequency of chr8p deletions in AA men. In view of these conflicting studies and in light of our paradigm-shifting studies establishing the link between chr8p deletions and loss of miRNA genes in this region, we examined the expression of these miRNAs in AA vs CA clinical PCa tissues. We found that miR-3622a and miR-383 expression is significantly lower in AA men as compared to age, tumor stage and grade matched CAs. To examine if these miRNAs constitute causal factors contributing to PCa racial disparities, we overexpressed miR-3622a/miR-383/control miR in AA and CA PCa cell lines followed by functional assays. We found that these miRNAs exert more prominent effects on cellular proliferation and apoptosis in AA cell lines. To understand molecular mechanisms contributing to disparate functional effects of these miRNAs in AA vs CA cell lines, we examined potential miRNA target genes and found that miR-3622a regulates PCa stem cell marker, CD44 while miR-383 represses LEF1 and ZEB1 in a race-specific manner. Further, we determined the mechanistic basis of differential expression of miR-3622a in AAs vs CAs by examining copy number alterations (CNAs) and methylation at this locus using PCa clinical samples. Our analyses showed that while this locus is genomically altered at a lower frequency in AAs, significantly increased frequency of miRNA promoter hypermethylation was found in AAs as compared to CAs. In conclusion, our data suggests that miRNAs located in frequently deleted chr8p21-22 region constitute important causal factors contributing to racial disparities in PCa aggressiveness and clinical outcomes and are potential biomarkers to predict PCa aggressiveness and tumor recurrence in AA men. Citation Format: Divya Bhagirath, Nikhil Patel, Santu Ghosh, Roni Bollag, Sharanjot Saini. MicroRNAs located at chromosome 8p21-22 region as novel factors underlying racial disparities in prostate cancer aggressiveness [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 282.

African men are disproportionately impacted by aggressive prostate cancer (PCa). Key to this disparity both genetic and environmental factors, alluding to epigenetic modifications. However, African-inclusive prostate tumour DNA methylation studies are lacking. Assembling a multi-geo-ancestral prostate tissue cohort, including men with (57 African, 48 European, 23 Asian) or without (65 African) PCa, we interrogate for genome-wide differential methylation. Overall, methylation appears to be driven by ancestry over geography (152 southern Africa, 41 Australia). African tumours show substantial heterogeneity, with universal hypermethylation indicating epigenetic silencing, encompassing PCa suppressor genes and enhancer-targeted binding motifs. Conversely, African tumour-associated heterochromatic hypomethylation suggests permissive chromatin remodelling, with developmental pathway activation via enhancer targets. Taken together, we show methylation aberrations favour metastatic growth, genomic instability and disease aggressiveness in African tumours, which we hypothesise is driven by extensive plasticity of intergenic regulatory regions.

Background: African American (AA) men exhibit nearly 2-fold higher incidence and 3-fold higher mortality rates from prostate cancer (PC) compared with white men. This disparity likely results from a complex interplay between behavioral, social, neighborhood and biological factors, which all work collectively to generate increased tumor aggressiveness in AAs. Recent data from our laboratory, evaluating human PC biopsy tissue led to the identification of alternative splicing events between AA and white PC that track with increased growth and more aggressive invasion characteristics of PC in AA men. In the present study, we explored associations between genetic variants of 30 such alternatively spliced genes and PC risk, aggressiveness and survival in white and AA groups by analyzing published genome-wide association studies (GWAS) of PC. Methods: We used GWAS datasets from the Multiethnic Cohort Study of Diet and Cancer (MEC), including AA PC cases and controls, and the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial (PLCO), including white PC cases and controls, to evaluate associations of 11,073 and 10,385 single-nucleotide polymorphisms (SNPs), respectively, in 30 genes identified to be alternatively spliced between white and AA PC with PC risk, aggressiveness and survival. For risk, we evaluated 1150 cases and 1101 controls in PLCO and 670 cases and 658 controls in MEC, for aggressiveness, we evaluated 237 aggressive and 843 non-aggressive in PLCO and 234 aggressive and 436 non-aggressive in MEC, and for survival, we evaluated 1150 overall, 237 aggressive and 843 non-aggressive in PLCO. We then performed in silico bioinformatics to investigate potential functions of the SNPs. Results: Significant associations between SNPs in FN1, COL6A3 and ACACA and SNPs in SEMA3C and FASN and PC risk in white and AA populations, respectively, were identified. In addition, SNPs in ACACA and SNPs in SEMA3C, RELN, MYBPC1, NCOR2 and WDR4 were found to be significantly associated with PC aggressiveness in white and AA populations, respectively. Furthermore, significant associations between SNPs in RHOU, FN1, COL6A3, SEMA3C, RELN, CD44, LMO7 and WDR4 and PC survival in a white population were identified. All of the aforementioned SNPs were predicted to play a role in splicing regulation. Conclusions: SNPs of race-related alternatively spliced genes that are predicted to play a role in splicing regulation are significantly associated with PC risk, aggressiveness and/or survival in white and/or AA populations. Such variants have the potential to serve as novel molecular targets for development of biomarkers of increased risk of aggressive PC or therapeutics against aggressive PC. Ultimately, such biomarkers and therapeutic agents could serve as novel precision medicine interventions, reducing the mortality burden from PC among AA men. Citation Format: Jennifer Freedman, Yanru Wang, Hongliang Liu, Patricia Moorman, Terry Hyslop, Daniel George, Norman Lee, Qingyi Wei, Steven Patierno. Single-nucleotide polymorphisms of race-related alternatively spliced genes associate with prostate cancer risk, aggressiveness and/or survival. [abstract]. In: Proceedings of the Ninth AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2016 Sep 25-28; Fort Lauderdale, FL. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2017;26(2 Suppl):Abstract nr B58.

Simple SummaryProstate cancer remains one of the leading causes of death in men in the United States. The commonly utilized method of diagnosing prostate cancer is via the digital rectal examination and serum PSA assay, which is usually followed by biopsy of the prostate gland to evaluate the extent of the cancer. While serum PSA assay has been used for many years by urologists across the globe to diagnose prostate cancer, a falsely elevated level due to conditions (BPH or prostatitis) other than cancer could cause the patient to undergo prostate gland biopsy, which is invasive and poses a greater risk of complications. To overcome these issues, we evaluated whether urinary PSA, which is secreted from the prostate gland into the urine could have predictive value in differentiating aggressive prostate cancer from indolent disease. In this study, we analyzed more than 400 samples for serum and urinary PSA, and found that urinary PSA had a higher predictive power in differentiating aggressive prostate cancer, and could serve a better surrogate tumor biomarker in capitulating the tissue milieus for the purpose of detecting aggressive prostate cancer. Furthermore, combining the ratio between serum to urine PSA enhanced the performance of both biomarkers in predicting aggressive prostate diseases. These studies support the role of urinary PSA, in combination with serum, for detecting aggressive prostate cancer. Serum PSA, together with digital rectal examination and imaging of the prostate gland, have remained the gold standard in urological practices for the management of and intervention for prostate cancer. Based on these adopted practices, the limitations of serum PSA in identifying aggressive prostate cancer has led us to evaluate whether urinary PSA levels might have any clinical utility in prostate cancer diagnosis. Utilizing the Access Hybritech PSA assay, we evaluated a total of n = 437 urine specimens from post-DRE prostate cancer patients. In our initial cohort, PSA tests from a total of one hundred and forty-six (n = 146) urine specimens were obtained from patients with aggressive (Gleason Score ≥ 8, n = 76) and non-aggressive (Gleason Score = 6, n = 70) prostate cancer. A second cohort, with a larger set of n = 291 urine samples from patients with aggressive (GS ≥ 7, n = 168) and non-aggressive (GS = 6, n = 123) prostate cancer, was also utilized in our study. Our data demonstrated that patients with aggressive disease had lower levels of urinary PSA compared to the non-aggressive patients, while the serum PSA levels were higher in patients with aggressive prostate disease. The discordance between serum and urine PSA levels was further validated by immuno-histochemistry (IHC) assay in biopsied tumors and in metastatic lesions (n = 62). Our data demonstrated that aggressive prostate cancer was negatively correlated with the PSA in prostate cancer tissues, and, unlike serum PSA, urinary PSA might serve a better surrogate for capitulating tissue milieus to detect aggressive prostate cancer. We further explored the utility of urine PSA as a cancer biomarker, either alone and in combination with serum PSA, and their ratio (serum to urine PSA) to predict disease status. Comparing the AUCs for the urine and serum PSA alone, we found that urinary PSA had a higher predictive power (AUC= 0.732) in detecting aggressive disease. Furthermore, combining the ratios between serum to urine PSA with urine and serum assay enhanced the performance (AUC = 0.811) in predicting aggressive prostate disease. These studies support the role of urinary PSA in combination with serum for detecting aggressive prostate cancer.

Background: Although the overall 5-year survival rate for prostate cancer (PCa) is relatively high, there are substantial differences in survival by stage at diagnosis. In contrast to men diagnosed with localized or regional stage PCa, both of which have a 5-year survival rate of nearly 100%, only 31% of patients survive five years after being diagnosed with distant or metastatic disease. Given PCa remains the second leading cause of cancer death among U.S. men, targeted PCa screening interventions centered on early detection for men at risk for more aggressive PCa subtypes appear warranted. Under a Precision Public Health approach, the application of geospatial analysis to cancer surveillance data can help to identify and “narrow down” geographic areas where rates of aggressive PCa are higher than expected to target for intervention. Thus, the primary objective of this study was to conduct a geospatial scan to identify clusters of aggressive PCa in a State-wide analysis. Given well-known racial disparities and associations between socioeconomic status and PCa stage at diagnosis and survival, the secondary objective was to evaluate geographic variation, or changes in aggressive PCa clusters, by area-level sociodemographics and environmental exposures. Methods: The study population included 82,580 patients diagnosed with incident PCa from the Pennsylvania (PA) State Registry from 2005-2015. Patient addresses were geocoded. Patient clinical data from the registry (age, race/ethnicity, insurance status) were linked via geocodes to area-level sociodemographic measures generated from the US Census Bureau at the census tract level, and to Environmental Quality Indices (Air, water, soil) from the Environmental Protection Agency (EPA) at the county level. Aggressive PCa was evaluated using 3 separate definitions based on TNM staging and/or Gleason grade. A Bayesian geoadditive modeling approach identified census tract clusters with higher than expected rates of aggressive PCa, adjusted for individual-level factors (age, race, diagnosis year) (Baseline model). The baseline model was then compared to models that included sociodemographic and/or environmental measures by evaluating changes in model fit (DIC), cluster size, and relative risk (RR). Results: We identified 3 main clusters in PA where rates of aggressive PCa were higher than expected near Philadelphia, Altoona, and Pittsburgh. Clusters of aggressive PCa in Philadelphia were eliminated and could be fully explained after adjustment for sociodemographic characteristics (insurance, poverty, etc), but not environmental measures. In contract, clusters of aggressive PCa in Pittsburgh were only reduced after adjustment for environmental variables, particularly water quality. Conclusion: PCa screening interventions could be prioritized in high risk cluster areas. Results are novel in that they preliminarily suggest that the type of intervention and focus of future etiologic studies in aggressive PCa might vary by geographic location, even within a single State. Citation Format: Daniel Wiese, Kevin A. Henry, Carolyn Fang, Adam Reese, Mary Daly, Camille Ragin, Shannon M. Lynch. Geographic disparities in aggressive prostate cancer varies by region-specific environmental and sociodemographic characteristics: A statewide analysis [abstract]. In: Proceedings of the 15th AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2022 Sep 16-19; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2022;31(1 Suppl):Abstract nr A018.

Background: The racial disparity in the prostate cancer incidence rate is among the greatest across all cancer sites. Further, African-American men tend to have more aggressive prostate cancer than white men. Modifiable factors measured in adulthood that may explain this disparity have not been found, despite extensive study. Whether racial differences early in life, including in utero, may account for this disparity is understudied. Shorter prostate cell telomeres, repetitive sequences that protect the ends of the chromosomes, are associated with a higher risk of aggressive prostate cancer and with poor prostate cancer outcomes. Telomeres shorten with each round of cell replication, and with oxidative damage, and thus, may serve as indicators of cell proliferation and cumulative exposures to oxidants. Using telomere length in umbilical cord blood leukocytes as a surrogate for prostate cell telomere length, we investigated the association of in utero maternal and child factors with telomere length, and whether telomere length differences between African-American and white males at birth may explain some of the racial disparity in prostate cancer. Methods: In 2004–2005, venous umbilical cord blood samples were collected from 38 African-American and 38 white male neonates, along with maternal and child characteristics from the Johns Hopkins Hospital. Eligibility criteria were: full-term birth (37-42 weeks), normal range birth weight (2500-4000 g), African-American or white, no pregnancy complications, and no maternal use of hormonal medications during pregnancy. Delivery room nurses completed a standardized form on maternal age, and parity, birth and placental weights, and race. Relative telomere length was measured by quantitative PCR from extracted buffy coat DNA. Using linear regression, we estimated geometric mean telomere length and 95% confidence intervals (CI) and tested for differences by race. Results: African-American neonates had statistically significantly lower birth and placental weights (child factors) than white neonates. African-American mothers were statistically significantly younger and had higher parity (maternal factors) than white mothers. However, neither maternal nor child factors were associated with telomere length adjusting for race or when stratifying by race (all p-trend>0.4). African-American neonates (6.60 kb, 95% CI 6.02-7.23 kb) had longer cord blood leukocyte telomeres than white neonates (6.43 kb, 95% CI 5.87-7.05 kb), although this difference was not statistically significant (p=0.7). The results were unchanged after adjusting for maternal or for child factors. Conclusion: Contrary to our hypotheses, maternal and child factors were not associated with cord blood leukocyte telomere length and cord blood leukocyte telomere length was not shorter in African-American than white male neonates. FUNDING: T32 CA0093140, DOD W81XWH-06-1-0052, U54 (Hopkins CA091409) and U54 (Howard CA091431). Citation Format: Kari A. Weber, Christopher M. Heaphy, Sabine Rohrmann, Beverly Gonzalez, Jessica L. Bienstock, Tanya Agurs-Collins, Elizabeth A. Platz, Alan K. Meeker. Influence of in utero maternal and child factors on cord blood leukocyte telomere length and possible differences by race: Clues to the racial disparity in prostate cancer? [abstract]. In: Proceedings of the Twelfth Annual AACR International Conference on Frontiers in Cancer Prevention Research; 2013 Oct 27-30; National Harbor, MD. Philadelphia (PA): AACR; Can Prev Res 2013;6(11 Suppl): Abstract nr A63.

<div>AbstractBackground:<p>Studies have identified associations between neighborhood disadvantage (ND), which is more likely to affect African American (AA) individuals, and aggressive prostate cancer. Thus, ND may contribute to prostate cancer disparities. However, it is unknown what ND components drive aggressive disease and whether associations vary by race.</p>Methods:<p>We evaluated associations between aggressive prostate cancer and four ND metrics—Area Deprivation Index (ADI), validated Bayesian Neighborhood Deprivation Index (NDI), racial isolation (RI) index, and historical redlining, and whether these factors interacted with race, among men with prostate cancer treated at the University of Maryland Greenebaum Comprehensive Cancer Center (2004–2021).</p>Results:<p>We included 1,458 men (698 European American and 760 AA). AA men were more likely to experience ND. In adjusted models, the ADI, RI, and redlining were significantly associated with aggressive versus nonaggressive prostate cancer overall [ADI, OR for one SD increase = 1.14, 95% confidence interval (CI), 1.00–1.30; RI, OR = 1.27, CI, 1.07–1.51; redlining, OR = 1.77; CI, 1.23–2.56] and among AA men. The NDI was associated with aggressive prostate cancer among AA men (OR = 1.32, 95% credible interval: 1.13–1.57); percent in poverty received the largest importance weight. The ADI (<i>P</i> heterogeneity = 0.002) and NDI (exceedance probability heterogeneity = 98.1%) significantly interacted with race, such that associations were significantly stronger for AA men.</p>Conclusions:<p>We identified novel significant positive associations for racial segregation and historical redlining with aggressive prostate cancer and significant interactions between ND indices and race.</p>Impact:<p>Findings inform specific ND components that are associated with aggressive prostate cancer and suggest the ND effect is stronger for AA men, which has implications for interventions to reduce disparities.</p></div>

Studies have identified associations between neighborhood disadvantage (ND), which is more likely to affect African American (AA) individuals, and aggressive prostate cancer. Thus, ND may contribute to prostate cancer disparities. However, it is unknown what ND components drive aggressive disease and whether associations vary by race. We evaluated associations between aggressive prostate cancer and four ND metrics-Area Deprivation Index (ADI), validated Bayesian Neighborhood Deprivation Index (NDI), racial isolation (RI) index, and historical redlining, and whether these factors interacted with race, among men with prostate cancer treated at the University of Maryland Greenebaum Comprehensive Cancer Center (2004-2021). We included 1,458 men (698 European American and 760 AA). AA men were more likely to experience ND. In adjusted models, the ADI, RI, and redlining were significantly associated with aggressive versus nonaggressive prostate cancer overall [ADI, OR for one SD increase = 1.14, 95% confidence interval (CI), 1.00-1.30; RI, OR = 1.27, CI, 1.07-1.51; redlining, OR = 1.77; CI, 1.23-2.56] and among AA men. The NDI was associated with aggressive prostate cancer among AA men (OR = 1.32, 95% credible interval: 1.13-1.57); percent in poverty received the largest importance weight. The ADI (P heterogeneity = 0.002) and NDI (exceedance probability heterogeneity = 98.1%) significantly interacted with race, such that associations were significantly stronger for AA men. We identified novel significant positive associations for racial segregation and historical redlining with aggressive prostate cancer and significant interactions between ND indices and race. Findings inform specific ND components that are associated with aggressive prostate cancer and suggest the ND effect is stronger for AA men, which has implications for interventions to reduce disparities.

Obesity is an epidemic in American society with approximately one in three adults in the United States being considered obese ([1][1]). This compares to “only” one in six adults being considered obese 20 years ago ([Fig. 1][2]; ref. [1][1]). The exact reasons for this dramatic increase in

Introduction: The incidence of prostate cancer (PC) is known to vary within Appalachia, with Northern Appalachia and Southern Appalachia having higher and lower rates, respectively. However, the geographical disparity for aggressive PC has not been investigated. The objective of this study was to determine whether having more aggressive PC was associated with residing in an Appalachian/non-Appalachian county and rural/urban community. Methods: A cross-sectional study was conducted among men, aged &gt = 40 years, who had a primary, clinical PC diagnosis identified in the Pennsylvania Cancer Registry between 2004 and 2014. PC aggressiveness was defined as less aggressive (Gleason score 6 or 7 [3+4] and clinical/pathologic tumor stage T1-T2) and more aggressive (Gleason score &gt = 7 [4+3], clinical/pathologic tumor stage T3-T4, or distant metastasis) PC. Logistic regression analysis was used to examine the association between having aggressive PC (less vs more aggressive PC - dependent variable) and residing in a geographical region (Appalachian versus non-Appalachian county - independent variable), stratified by rural/urban, after adjusting for age, race, ethnicity, insurance status, marital status, serum PSA, positive lymph node status, and cancer treatment. Results: There were 94,264 PC cases, aged 40 to 105 years, included in the study. The majority of the PC cases were white (83.9%) followed by black race (10.7%). PC cases from urban Appalachian counties (35.42%) had the highest frequency of aggressive PC followed by rural non-Appalachian (34.18%), rural Appalachian (32.12%), and urban non-Appalachian counties (32.08%). In urban areas, Appalachian PC cases were more likely to be aggressive compared to non-Appalachian PC cases, after adjusting for confounders (odds ratio [O.R.] =1.16; 95% confidence interval [C.I.], 1.13-1.21). Conversely, in rural areas, Appalachian PC cases were less likely to be aggressive compared to non-Appalachian PC cases, after adjusting for confounders (O.R. =0.91; 95% C.I., 0.85-0.98). Conclusion: Differences in having more aggressive PC was observed for Appalachian populations by rural/urban status, with urban Appalachian PC cases more likely and rural Appalachian PC cases less likely to have more aggressive disease, compared to their non-Appalachian counterparts. Further investigation on the underlying mechanisms of aggressive PC in urban Appalachia in PA is warranted. Citation Format: Alicia C. McDonald, Emily Wasserman, Eugene J. Lengerich, Jay D. Raman, Nathaniel Geyer, Raymond Hohl, Ming Wang. Aggressive prostate cancer among men in Pennsylvania: Differences between Appalachian and non-Appalachian counties [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 4186.

Background: There are very few well-established risk factors for prostate cancer. Metabolomic profiling of blood represents an agnostic approach with the potential to identify biomarkers associated with risk. We previously identified several circulating lipid and energy metabolism-related compounds (e.g., alpha-ketoglutarate; AKG) that were altered in men who later developed prostate cancer. Our aim here was to determine the extent to which those findings replicated in a larger study, and whether new metabolite signals could be uncovered. Methods: We conducted a prospective prostate cancer case-control analysis nested within the Alpha-Tocopherol, Beta-Carotene Cancer Prevention (ATBC) Study cohort, and sampled 200 cases (100 aggressive and 100 non-aggressive), matching one control to each based on age and date of baseline fasting serum collection. Median time from serum collection to prostate cancer diagnosis was 10 years (range, 1-20). Sera were analyzed on a high resolution accurate mass (HRAM) platform of ultrahigh performance liquid chromatography/mass spectroscopy (LC-MS) and gas chromatography/mass spectroscopy (GC-MS) (Metabolon, Inc.) that identified 654 known metabolites. Over- and under-representation of metabolite classes among our top metabolite signals was tested using the Fisher's exact test for metabolites jointly classified as having a p-value <0.05 (Y/N) and as belonging to a specific chemical class (Y/N). For each metabolite, we used conditional logistic regression to calculate odds ratios (OR) and 95% confidence intervals (CI) of risk associated with a one standard deviation increment in metabolite concentration. Results: Of the 32 metabolites associated with aggressive prostate cancer at p<0.05, 22 were lipids, which as a metabolite class was strongly associated with aggressive but not non-aggressive prostate cancer risk (p = 3.1 × 10−4 and p = 0.10, respectively) (20 of the 22 lipids were inversely associated with aggressive disease risk). Inositol-1-phosphate and oleoyl-linoleoyl-glycerophosphoinositol-1 were the two strongest metabolite signals for aggressive prostate cancer (OR 0.55, 95% CI 0.37-0.80, p = 0.002; and, OR 0.64, 95% CI 0.47-0.87, p = 0.004, respectively). The AKG association of our earlier study was replicated in the present analysis (OR 0.65, 95% CI 0.47-0.91, p = 0.011). Some steroid and thyroid hormones were positively associated with both aggressive and non-aggressive prostate cancer. Conclusion: In this prospective study, serum lipid metabolites were inversely associated with risk of aggressive prostate cancer, including particularly inositol-1-phosphate and oleoyl-linoleoyl-glycerophosphoinositol-1, and the data confirm our previous finding that men with higher AKG were less likely to develop aggressive prostate cancer. A role for altered energy and lipid metabolism in the pathogenesis of aggressive prostate cancer is implicated. Citation Format: Alison Mondul, Steven Moore, Joshua Sampson, Stephanie Weinstein, Demetrius Albanes. Serum lipid metabolites and alpha-ketoglutarate are inversely associated with aggressive prostate cancer. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 936. doi:10.1158/1538-7445.AM2015-936

Cancer disparities represent a significant public health problem in the United States. Inequity in cancer screening, incidence, treatment, prognosis, and mortality is a hallmark of many common cancers ([1][1]). These disparities exist across groups defined by race, ethnicity, gender, age, and

Rare pathogenic variants in DNA repair genes have been found to influence risk of aggressive prostate cancer. We conducted a large case-only exome sequencing study to further understand the role of rare coding variation in aggressive prostate cancer in a study of 9,185 aggressive (prostate cancer death, metastatic disease, T4, or both T3 and Gleason≥8) and 8,361 non-aggressive cases (T1/T2 and Gleason≤6) of European ancestry from 19 international studies. Stage 1 samples (N=5,545) had whole exome-sequencing, and stage 2 samples (N=12,001) had targeted exome sequencing for 1,459 genes selected based on stage 1 results and previous evidence. Logistic regression models were used to evaluate gene-based tests and the aggregate effect of multiple genes to investigate whether carrying pathogenic/likely pathogenic/deleterious (P/LP/D) variants (18,759 identified) was associated with risk of aggressive prostate cancer, prostate cancer death (N=6,033), or metastatic disease (N=1,730) compared to non-aggressive disease. Gene-based tests were meta-analyzed across stages 1 and 2. BRCA2, ATM, and NBN had the most statistically significant gene-based results: BRCA2 P/LP/D variant carriers had 4.3-fold higher odds of aggressive disease (95% CI=3.15-5.86, P=4x10-20), 4.7-fold higher odds of prostate cancer death (95% CI=3.41-6.59, P=2x10-20), and 5.7-fold higher odds of metastatic disease (95% CI=3.71-8.76, P=2x10-15); ATM P/LP/D variant carriers had 2.2-fold higher odds of aggressive disease (95% CI=1.58-2.99, P=2x10-6), 2.2-fold higher odds of prostate cancer death (95% CI=1.52-3.05, P=2x10-5), and 3.0-fold higher odds of metastatic disease (95% CI=1.93-4.61, P=9x10-7); and NBN P/LP/D variant carriers had 5.9-fold higher odds of metastatic disease (95% CI=2.56-13.84, P=3x10-5). Among potentially novel genes with strong but not exome-wide significant statistical evidence were MMP19, involved in reproduction and metastasis, with carriers having 2.8-fold higher odds of prostate cancer death (95% CI=1.53-5.05, P=8x10-4); PKD2L2, involved in fertility, with carriers having 3.5-fold higher odds of prostate cancer death (95% CI=1.76-7.04, P=5x10-4); and SMPD1, involved in converting sphingomyelin to ceramide, with carriers having 5.3-fold higher odds of metastatic disease (95% CI=1.85-14.98, P=0.002). At least one P/LP/D variant within a subset of 24 previously curated candidate prostate cancer DNA repair genes was carried by 12.8% of aggressive cases (OR=1.48, 95% CI=1.34-1.64, P=3x10-14), 12.6% of cases who died due to prostate cancer (OR=1.47, 95% CI=1.31-1.65, P=3x10-11), and 15.1% of metastatic cases (OR=2.16, 95% CI=1.57-2.16, P=5x10-14) compared to 9.4% of non-aggressive cases. These findings support the importance of rare genetic variation in aggressive prostate cancer risk and may have important implications for prostate cancer risk stratification and screening. Citation Format: Burcu F. Darst, Ed Saunders, Tokhir Dadaev, Xin Sheng, Peggy Wan, Loreall Pooler, Lucy Y. Xia, Stephen Chanock, Sonja I. Berndt, Susan M. Gapstur, Victoria Stevens, Demetrius Albanes, Stephanie J. Weinstein, Vincent Gnanapragasam, Graham G. Giles, Tu Nguyen-Dumont, Roger L. Milne, Mark M. Pomerantz, Julie A. Schmidt, Ruth C. Travis, Timothy J. Key, Konrad H. Stopsack, Lorelei A. Mucci, William J. Catalona, Beth Marosy, Kurt N. Hetrick, Kimberly F. Doheny, Robert J. MacInnis, Melissa C. Southey, Rosalind A. Eeles, Fredrik Wiklund, Zsofia Kote-Jarai, David V. Conti, Christopher A. Haiman. Multi-stage exome sequencing study of 17,546 aggressive and non-aggressive prostate cancer cases [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 688.

Background. Significant racial disparities exist in PCa, with the incidence in African- Americans (AAs) being 50% higher than European Americans (EAs) and PCa mortality rates in AAs being more than two-fold higher. However, the disparity cannot be explained by screening, access to treatment, and genetics can only partially explain the disparity that does little to confer actionable clinical relevance. Currently, only 3 definitive risk factors for PCa have been identified: age, race, and family history of PCa. Smoking has not been an established risk factor for prostate cancer (PCa), and has not been emphasized in PCa prevention. However, recent studies have shown increasing evidence that there is a higher risk of biochemical recurrence, PCa mortality, and metastasis among current smokers, presenting an urgent need in re- evaluating the association between smoking and aggressive PCa. This study aimed to determine whether smoking increase the likelihood of developing a more aggressive prostate cancer. Methods. The study used data from the North Carolina–Louisiana Prostate Cancer Project (PCaP), which is a population-based study of incident PCa conducted between years 2004-2009 in 2 southern states where significant racial disparities in PCa are observed. Because PCa is over diagnosed and most PCa is not clinically relevant, this study will include only subjects with high (Gleason score ≥ 8; PSA > 20 ng/mL; Gleason score = 7 and stage T3–T4) or low (Gleason score < 7 and stage T1–T2 and PSA <10 ng/mL) PCa aggressiveness. 1,497 participants were included in the analysis. Chi square and t-tests were used for the variables of interest and possible confounders, and multivariable logistic regression models were used for the odds ratio estimate. Results. There were 44.9% AAs and 55.1% EAs in the study. AA participants were significantly younger (mean=61.8, SD=7.9) compared with EAs (mean=64.0, SD=7.9), with lower education levels, shorter smoking cessation period, less screening tests in the past, less cigarettes per day, and higher Gleason sum. From the analysis, more AAs (57.6%) and those who were current smokers (22.7%) were diagnosed with high aggressive PCa. Current smokers had a 2.4 times- higher risk of high aggressive PCa (unadjusted OR=2.42, adjusted OR=2.39); when stratified by race, the risk diminished for EAs (OR=1.30) but increased for AAs (OR=3.36). Conclusion. Our study shows increased risk of aggressive PCa for current smokers, especially among AAs. Previous study had shown that self-reported cigarettes per day predicts smoke intake more poorly in AAs than in EAs. Thus, there is an urgent need in validated research using biomarkers to confirm the relationship of smoking and aggressive PCa, since cigarette smoking is preventable but have not been emphasized in PCa prevention. Citation Format: Ping-Ching Hsu, Shelbie Stahr, Christopher Brazeal, Elizabeth H. Fontham, L. Joseph Su. Smoking as a risk factor for the aggressive prostate cancer for African-American men from the North Carolina–Louisiana Prostate Cancer Project (PCaP) [abstract]. In: Proceedings of the AACR Virtual Conference: Thirteenth AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2020 Oct 2-4. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2020;29(12 Suppl):Abstract nr PO-201.