Stopsack, Konrad H.

Abstract Introduction: Most people who die from prostate cancer are older than 75 years. However, prostate cancer diagnosed at younger ages is often more aggressive. While epidemiologic studies have examined the association between age and survival in patients with prostate cancer overall, the clinical drivers of this relationship in patients with advanced disease remain unclear. We leveraged the International Registry of Men with Advanced Prostate Cancer (IRONMAN, NCT03151629) to (1) quantify the association between age and overall survival and (2) explore whether this association is explained by treatments. Methods: We included 3, 734 patients enrolled from 15 countries with new diagnoses of metastatic hormone sensitive (mHSPC, N=2, 642) or castration resistant prostate cancer (CRPC, N=1, 092). Age at enrollment was categorized as <55, 55-59, 60-64 (reference), 65-69, 70-74, 75-79, 80-84, 85+ years. We computed age-specific death rates (95% confidence intervals [CIs]) by disease state (mHSPC, CRPC) at enrollment. To explore whether this relationship was explained by treatment, we fitted disease state-stratified Cox models and sequentially adjusted for (1) de novo metastatic status and country, and (2) baseline treatment (androgen deprivation therapy [ADT] alone, ADT + androgen receptor pathway inhibitors [ARPI], ADT + chemotherapy, ADT + ARPI + chemotherapy, other). Results: Over 5.5 years of follow-up (median: 3.2 years, IQR: 1.7, 4.8), 995 patients died from any cause. Younger patients were more likely to have de novo metastatic disease. Among those with mHSPC at enrollment, the age-specific death rates per 1, 000 person-years followed a J-shaped pattern: 80 (95% CI: 54, 117) in patients under 55 years, 58 (46, 74) in patients aged 60-64, 102 (78, 133) in patients aged 80-84, and 172 (125, 236) in patients aged 85 and older. The death rates among those with CRPC followed a similar pattern, albeit rates were higher in magnitude: 212 (95% CI: 140, 323) in patients under 55 years, 153 (115, 202) in patients aged 60-64, 200 (155, 258) in patients aged 80-84, and 204 (142, 291) in patients aged 85 and older. After adjusting for disease state, country, and the timing of diagnosis of metastases, death rates were substantially higher for ages 75-79 (HR 1.4; 95% CI 1.1, 1.7), 80-84 years (HR 1.6; 95% CI 1.2, 2.1), and 85 years and older (HR 2.0; 95% CI: 1.5, 2.7) compared to ages 60-64 years. Patients aged under 55 years had 1.4-fold higher death rates (95% CI: 1.0, 1.9) compared to those 60-64 years. After additionally adjusting for baseline treatment, overall survival remained worse for the older patients and the youngest age group with hazard ratios remaining meaningfully unchanged. Conclusion: Age at enrollment is associated with overall survival in people with advanced prostate cancer enrolled in IRONMAN in a J-shaped pattern. This relationship is not explained by differences in baseline treatment. Citation Format: Hannah E. Guard, Michelle O. Sodipo, Colleen B. McGrath, Anna Siefkas, Lauren E. Howard, Konrad H. Stopsack, Christopher M. Sauer, Robert Dreicer, Emilio Esteban, Hassan M. Dogo, Ademola Popoola, Charles Waihenya, Anders Bjartell, Kim N. Chi, Sebastien Hotte, Richard Cathomas, Deborah Enting, Scott Tagawa, Michael Ong, Michael Kolinsky, Vincent Khoo, Joaquin Mateo, Chidiebere N. Ogo, Rana R. McKay, Stefanie Fischer, Heather H. Cheng, Russell Szmulewitz, Young E. Whang, Anand Sharma, Frédéric Pouliot, Simon Crabb, Monica S. Chatwal, Miguel A. Climent, Raymond McDermott, Ian D. Davis, Camille Ragin, Folakemi T. Odedina, Simon Anderson, Simone Badal, Natalie Greaves, Karen A. Autio, Laurel Cannon, Alyssa Chan-Cuzydlo, Marie Grant, Travis Gerke, Hannah D. McManus, Philip W. Kantoff, Daniel J. George, Lorelei A. Mucci, IRONMAN investigator team. Disentangling the association between age and overall survival in an international cohort of patients with advanced prostate cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2025; Part 1 (Regular Abstracts); 2025 Apr 25-30; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2025;85(8_Suppl_1):Abstract nr 4935.

Abstract Introduction: The standard of care for metastatic hormone-sensitive prostate cancer (mHSPC) has evolved with the expanded approval of androgen receptor pathway inhibitors (ARPIs) alongside androgen deprivation therapy (ADT). ADT alone has been shown to affect cognitive function. However, the cognitive impact of distinct treatment combinations remains unclear. We investigated the association between first-line systemic treatments and the trajectory of subjective cognitive function among mHSPC survivors in the International Registry for Men with Advanced Prostate Cancer (IRONMAN). Methods: This analysis included 2435 newly diagnosed mHSPC patients enrolled across 15 countries between July 2017 and August 2024. Treatments were reported by site personnel and physicians. For this analysis, we focused on first-line systemic treatment and classified treatment groups at enrollment as ADT monotherapy (referent), ADT + ARPIs, or ADT + chemotherapy. Subjective cognitive function was assessed via the EORTC QLQ-C30 Cognitive Function subscale, with patient-reported scores (range 0-100) collected at enrollment and every 3 months for up to 5 years; higher scores reflect better cognitive function. Associations were estimated using linear mixed effects models with clustering by study site and country to examine differences at enrollment and across trajectories of subjective cognitive function by first-line treatment, adjusting for demographic and clinical factors. Results: Median age at enrollment was 70 years, with a median follow-up of 1.7 years. 724 (30%) participants were treated with ADT monotherapy, 1317 (54%) with ADT + ARPIs, and 394 (16%) with ADT + chemotherapy. Mean cognitive function scores at enrollment were 85.4 (Standard Deviation [SD] 19.5) for participants treated with ADT monotherapy, 86.7 (SD 17.3) for ADT + ARPIs, and 86.7 (SD 18.0) for ADT + chemotherapy. Cognitive function scores decreased by -0.60 points (95% Confidence Interval [CI] -0.72, -0.48) per year among those treated with ADT monotherapy, with similar rates observed for those treated with ADT + chemotherapy. Participants treated with ADT + ARPIs had a slower decline in cognitive function, with scores decreasing by -0.36 points (95% CI -0.60, -0.08) per year. Conclusion: In this international cohort of mHSPC survivors, subjective cognitive function scores were generally high at enrollment but declined over time. There was no evidence of worse cognitive function in those treated with ADT + ARPIs nor ADT + chemotherapy over time compared to ADT monotherapy. Cognitive functioning is a key component of survivorship, and defining cognitive trajectories associated with first-line treatment can inform supportive interventions, patient treatment decision-making, and clinical guidelines. Citation Format: Michelle O. Sodipo, Alicia K. Morgans, Erica T. Warner, Emily M. Rencsok, Lauren E. Howard, Colleen B. McGrath, Anna Siefkas, Konrad H. Stopsack, Christopher Sauer, Robert Drecier, Emilio Esteban, Hassan M. Dogo, Ademola Popoola, Charles Waihenya, Anders Bjartell, Kim Chi, Sebastien Hotte, Richard Cathomas, Deborah Enting, Scott Tagawa, Michael Ong, David Lorente, Elisabeth Heath, Rana McKay, Stefanie Fischer, Heather H. Cheng, Young E. Whang, Frederic Pouliot, Simon Crabb, Monica Chatwal, Miguel A. Climent, Raymond McDermott, Ian D. Davis, Camille Ragin, Folakemi Odedina, Natalie Greaves, Simone Badal, Simon Anderson, Sharon Harrison, Karen Autio, Laurel Cannon, Marie Grant, Alyssa Chan-Cuzydlo, Travis Gerke, Hannah D. McManus, Philip W. Kantoff, Daniel George, Sebastien Haneuse, Lorelei A. Mucci, on behalf of the IRONMAN Registry. First-line therapies and subjective cognitive function trajectories among international metastatic hormone-sensitive prostate cancer survivors [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2025; Part 1 (Regular Abstracts); 2025 Apr 25-30; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2025;85(8_Suppl_1):Abstract nr 3630.

Importance Germline gene panel testing is recommended for men with advanced prostate cancer (PCa) or a family history of cancer. While evidence is limited for some genes currently included in panel testing, gene panels are also likely to be incomplete and missing genes that influence PCa risk and aggressive disease. Objective To identify genes associated with aggressive PCa. Design, Setting, and Participants A 2-stage exome sequencing case-only genetic association study was conducted including men of European ancestry from 18 international studies. Data analysis was performed from January 2021 to March 2023. Participants were 9185 men with aggressive PCa (including 6033 who died of PCa and 2397 with confirmed metastasis) and 8361 men with nonaggressive PCa. Exposure Sequencing data were evaluated exome-wide and in a focused investigation of 29 DNA repair pathway and cancer susceptibility genes, many of which are included on gene panels. Main Outcomes and Measures The primary study outcomes were aggressive (category T4 or both T3 and Gleason score ≥8 tumors, metastatic PCa, or PCa death) vs nonaggressive PCa (category T1 or T2 and Gleason score ≤6 tumors without known recurrence), and metastatic vs nonaggressive PCa. Results A total of 17 546 men of European ancestry were included in the analyses; mean (SD) age at diagnosis was 65.1 (9.2) years in patients with aggressive PCa and 63.7 (8.0) years in those with nonaggressive disease. The strongest evidence of association with aggressive or metastatic PCa was noted for rare deleterious variants in known PCa risk genes BRCA2 and ATM ( P ≤ 1.9 × 10 −6 ), followed by NBN ( P = 1.7 × 10 −4 ). This study found nominal evidence ( P < .05) of association with rare deleterious variants in MSH2 , XRCC2 , and MRE11A . Five other genes had evidence of greater risk (OR≥2) but carrier frequency differences between aggressive and nonaggressive PCa were not statistically significant: TP53 , RAD51D , BARD1 , GEN1 , and SLX4 . Deleterious variants in these 11 candidate genes were carried by 2.3% of patients with nonaggressive, 5.6% with aggressive, and 7.0% with metastatic PCa. Conclusions and Relevance The findings of this study provide further support for DNA repair and cancer susceptibility genes to better inform disease management in men with PCa and for extending testing to men with nonaggressive disease, as men carrying deleterious alleles in these genes are likely to develop more advanced disease.

AbstractObjectiveThe purpose of this study was to assess differences in reported information about treatment, integration into care, and respect by self‐identified Black and White individuals with advanced prostate cancer in the United States.Patients and MethodsThis is a prospective cohort study of 701 participants (20% identifying as Black) enrolled in the International Registry for Men with Advanced Prostate Cancer at 37 US sites from 2017 to 2022. Participants were asked six questions from the Cancer Australia National Cancer Control Indicators about their experience with care at study enrollment. Prevalence differences by self‐reported race were estimated using marginal standardization of logistic‐normal mixed effects models (adjusted for age at enrollment and disease state at enrollment), and 95% CIs were estimated using parametric bootstrapping.ResultsMost participants reported a high quality of care for each question. Black participants generally reported higher care quality compared with White participants. Black participants reported more frequently that they were offered a written assessment and care plan (71%) compared with White participants (58%; adjusted difference, 13 percentage points; 95% CI, 4–23). Black participants also reported more frequently being given the name of nonphysician personnel who would support them (64%) than White participants (52%; adjusted difference, 10; 95% CI, 1–20). Prevalence differences did not differ by disease state at enrollment.ConclusionsBlack participants generally reported a higher quality of care compared with White participants. This study calls attention to the need to study potential mediating factors and interpersonal aspects of care in this population to improve survivorship.

PURPOSE To describe a newly established international registry recruiting diverse patients with advanced prostate cancer across academic and community practices to address unmet needs in this population. PATIENTS AND METHODS Initiated in 2017, IRONMAN (International Registry for Men with Advanced Prostate Cancer) is a prospective cohort of patients with advanced prostate cancer. The study will enroll 5,000 patients with metastatic hormone-sensitive prostate cancer (mHSPC) or castration-resistant prostate cancer (CRPC), recruited from Australia, the Bahamas, Barbados, Brazil, Canada, Ireland, Jamaica, Kenya, Nigeria, Norway, South Africa, Spain, Sweden, Switzerland, the United Kingdom, and the United States. The study is collecting datatypes to study variation in care and treatment of advanced prostate cancer across countries and across academic, community-based, and government practices with a focus on clinical outcomes, patient-reported outcomes, epidemiologic data, biologic subtypes, and clinician questionnaires. RESULTS Through July 2022, 2,682 eligible patients were enrolled in 11 of 12 active countries. Sixty-six percent of patients have mHSPC, and 34% have CRPC. On the basis of self-report, 11% of patients are Black and 9% are Hispanic. Five Veterans Affairs Medical Centers are enrolling patients. Globally, 23% of patients report being veterans of military service. CONCLUSION To our knowledge, this is the first international cohort of people newly diagnosed with advanced prostate cancer designed to describe variations in patient management, experiences, and outcomes. IRONMAN aims to identify optimal treatment sequences to improve survival, understand patient-reported outcomes, and explore novel biomarkers to understand treatment resistance mechanisms. Insights from IRONMAN will inform and guide future clinical management of people with mHSPC and CRPC. This cohort study will provide real-world evidence to facilitate a better understanding of the survivorship of people with advanced prostate cancer.

Abstract Background Safety is a central consideration when choosing between multiple medications with similar efficacy. We aimed to evaluate whether adverse event (AE) profiles of 3 such drugs in advanced prostate cancer could be distinguished based on published literature. Methods We assessed consistency in AE reporting, AE risk in placebo arms, and methodology used for risk estimates and quantification of statistical uncertainty in randomized placebo-controlled phase III trials of apalutamide, enzalutamide, and darolutamide in advanced prostate cancer. Results Seven included clinical trials enrolled a total of 9215 participants (range = 1051-1715 per trial) across 3 prostate cancer disease states. Within disease states, baseline patient characteristics appeared similar between trials. Of 54 distinct AE types in total, only 3 (fatigue, hypertension, and seizure) were reported by all 7 trials. Absolute risks of AEs in the placebo arms differed systematically and more than twofold between trials, which was associated with visit frequency and resulted in different degrees of uncertainty in AE profiles between trials. No trial used inferential methodology to quantify statistical uncertainty in AE risks, but 6 of 7 trials drew overall conclusions. Two trials concluded that there was no elevated AE risk because of the intervention, including the trial of darolutamide, which had the greatest statistical uncertainty. Conclusions Rigorous comparison of drug safety was precluded by heterogeneity in AE reporting, variation in AE risks in the placebo arms, and lack of inferential statistical methodology, underscoring considerable opportunities to improve how AE data are collected, analyzed, and interpreted in oncology trials.

65 Background: DNA repair genes including BRCA1 are commonly altered in metastatic prostate tumors. However, mutations and copy number aberrations in these genes are rare in primary tumors. Instead, preliminary studies suggest that higher tumor expression of the BRCA1 protein may be associated with worse prognosis. Methods: We undertook a prospective study of tumor BRCA1 protein expression and lethal prostate cancer among men with clinically localized prostate cancer in the Health Professionals Follow-up Study. We performed immunohistochemical staining for BRCA1 on tumor tissue microarrays using a validated antibody and scored expression as positive or negative. We also assessed tumor proliferation by immunostaining for Ki67, angiogenesis by immunostaining for CD34, and apoptosis using a TUNEL assay. Proportional hazards regression was used to evaluate the association between BRCA1 protein expression and development of lethal prostate cancer (metastasis or cancer-specific death). Results: Ten percent of tumors (60 of 589) stained positive for the BRCA1 protein. BRCA1-positive tumors were characterized by higher Gleason scores, a higher proliferative index, and a higher apoptotic index. During a median follow-up of 14.3 years, 18 men (34%) in the BRCA1-positive group and 74 men (14%) in the BRCA1-negative group developed lethal prostate cancer. There was a strong positive association between BRCA1 protein expression and lethal prostate cancer in both unadjusted analyses (HR 2.71, 95% CI 1.73–4.26) and after adjusting for clinical factors (HR 2.00, 95% CI 1.26–3.18). The positive association with BRCA1 protein expression was also independent of proliferation index. Conclusions: Primary prostate tumors expressing the BRCA1 protein have a highly proliferative phenotype and are more likely to progress to lethal disease, independent of its higher proliferative index. Assessing tumor protein expression of BRCA1 may help elucidate the Janus-faced role of DNA repair pathways in prostate cancer progression.[Table: see text]

39 Background: The excess risk of high-grade prostate cancer in the Prostate Cancer Prevention Trial (PCPT) among men randomized to finasteride raised concerns that a chemoprevention benefit would be offset by increased mortality. Two 2019 publications had contrasting results whether 5-ARIs increased prostate cancer mortality. In PCPT, there was no excess prostate cancer mortality. In a VA study, 5-ARI use was associated with later stage at diagnosis and 39% higher prostate cancer mortality risk. We studied men with regular access to health care and screening to address this conflicting evidence. Methods: We performed two parallel analyses in the Health Professionals Follow-up Study. 5-ARI use was reported on biennial questionnaires starting in 1996. In line with PCPT, we studied 38,047 men for cancer incidence and mortality through 2016. In line with the VA study, we undertook a case-only study of 4,225 patients with localized/locally advanced cancers followed similarly. We estimated hazard ratios (HR) and 95% confidence intervals accounting for screening patterns, lifestyle factors, and concomitant medications. Results: 5-ARI ever-users (n = 4,101; 10.7%) were more likely to have had regular PSA screening (74% vs. 57% nonusers) and a negative prostate biopsy before diagnosis. Neither ever 5-ARI use (HR 1.08, 0.73-1.60, 445 events) nor long-term use ( > 4 years, HR 1.03, 1.03-2.02) were associated with lethal prostate cancer. There was no difference in stage. Diagnostic PSA levels were lower in 5-ARIs users (10.0 vs. 16.0 ng/ml in never-users). Among nonmetastatic cases, 278 men died of prostate cancer; there was no association between 5-ARIs and prostate cancer survival (HR 0.85, 0.51-1.43). Conclusions: Our results align with PCPT and show no excess risk of lethal prostate cancer, no higher stage at diagnosis, and no excess mortality after diagnosis associated with 5-ARI. Men on 5-ARIs had more interactions with health care, which may have led to higher quality care. This contrasts with the VA study where men on 5-ARIs were diagnosed later due to suppressed PSA and had worse survival. These results show the importance of real-world data in framing the benefits and risks associated with 5-ARIs.

318 Background: Apalutamide, enzalutamide, and darolutamide were approved for non-metastatic castration-resistant prostate cancer (nmCRPC) based on three randomized placebo-controlled trials that showed similar efficacy. Adverse event (AE) profiles have been invoked to differentiate the drugs but have only been informally compared. Methods: We accounted for baseline characteristics, AE collection and reporting, and statistical uncertainty when comparing AE risks in the drug and placebo arms of SPARTAN (NCT01946204), PROSPER (NCT02003924), and ARAMIS (NCT02200614). Results: Patients in SPARTAN, PROSPER, and ARAMIS had a similar median age (74 years in all studies), median PSA doubling time (3.7-4.7 months) and ECOG performance status (68-80% with ECOG 0). AEs were gathered consistently using CTCAE 4.0 or 4.03. However, PROSPER and ARAMIS reported AEs occurring in ≥5% of patients; SPARTAN reported AEs occurring in ≥15%. Trials also reported 5 to 14 ‘AEs of interest.’ Of 34 AE types reported overall, only 10 were reported in all three trials. Absolute risks of adverse events in the placebo arms differed considerably. Compared to the placebo arm of SPARTAN, AEs were on average 44% less common in the placebo arm of PROSPER (95% CI, 28-56%) and 54% less common in the placebo arm of ARAMIS (95% CI, 41-64%), a difference not explained by length of follow-up. With lower event numbers, relative risk estimates were less precise with wider confidence intervals. For example, comparing treatment vs. placebo arms, the relative risk for fatigue, the most common AE, was 1.45 (95% CI, 1.16-1.80) in SPARTAN, 2.37 (95% CI, 1.86-3.04) in PROSPER, and 1.39 (95% CI, 1.01-1.91) in ARAMIS. Across all AE types, compared to SPARTAN, relative risks from PROSPER were 23% less precise and relative risks from ARAMIS were 30% less precise. Conclusions: While conducted in similar patient populations, these trials had remarkable differences in AE reporting and in absolute AE risks between placebo arms. Rather than indicating better safety, low absolute adverse event numbers decrease confidence in AE profiles. Published data are insufficient to differentiate the AE profiles of these agents in nmCRPC.

149 Background: Patients with metastatic hormone-sensitive prostate cancer (mHSPC) have a variable response to ADT and some benefit from the addition of docetaxel or an androgen signaling pathway inhibitor. We found that loss of the epigenetic regulator KDM5D is associated with more aggressive prostate cancer (PC). We sought to determine whether MYBL2 which is regulated by KDM5D mediates this effect. MYBL2 is a transcription factor which controls key genes (e.g. FOXM1) and increases cell cycle progression and survival. Methods: AR expressing hormone-sensitive cell lines, LNCaP and LAPC4 were used. Motif analysis and CHiPseq of LNCaP with and without siKDM5D was performed and impact of modulation of KDM5D and MYBL2 in both cells on cell survival was assessed. Gene expression profiling (GEP) data assessed MYBL2’s association with KDM5D levels in localized disease (publicly available data) and mHSPC (Decipher whole Affymetrix platform on CHAARTED samples). Results: Silencing KDM5D increased H3K4me3 and increased MYBL2 expression. GEP showed a strong negative correlation between KDM5D and MYBL2 in patients with localized PC (-0.66; TCGA) but not from primary prostate cancer tissue with mHSPC (-0.03; CHAARTED). Cells with low KDM5D and high MYBL2 were androgen independent and more resistant to docetaxel. In TCGA, patients with high MYBL2 had a higher rate of relapse from localized disease. In patients with metastatic disease (CHAARTED) low MYBL2 was associated with a better overall survival (OS) on multivariable analysis when treated with ADT or ADT + docetaxel. Conclusions: Low MYBL2 is associated with a longer OS with ADT alone and ADT and docetaxel independent of clinical variables. Patients with high MYBL2 expression had better OS with ADT plus docetaxel compared with patients with high MYBL2 treated with ADT alone.[Table: see text]