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1936 citation(s) found for "Jacob, J".

The learning curve of single‐port extraperitoneal robotic radical prostatectomy: Initial experience and outcomes from a newly graduated fellowship‐trained robotic surgeon
Hershenhouse, Jacob , Kim, S., Gevorkyan, Rafael, Hom, Brian , Eppler, Michael , Ford, Patrick, Pathak, Ram, Autorino, Riccardo, Badani, Ketan K., Crivellaro, Simone, Hemal, Sij, Autorino, Riccardo , Hershenhouse, Jacob S , Autorino, Riccardo , Badani, Ketan K , Abreu, Andre Luis , Badani, Ketan K. , Crivellaro, Simone

BJUI Compass | March 11, 2026 | Volume: 7 | Issue: 3 | Pages: No page available

10.1002/bco2.70184 | PMID 41822202 Get It

Abstract Introduction and Objective This study aims to evaluate the learning curve and perioperative outcomes of single‐port extraperitoneal robotic radical prostatectomy (SP‐EP‐RARP) performed by a single surgeon at a high‐volume academic institution. Methods A retrospective review of a prospectively maintained database was conducted for patients who underwent SP‐EP‐RARP from September 2023 to August 2025. Key metrics included operative time, estimated blood loss, conversion rate, nerve‐sparing status, pathological margin status and continence (0–1 pad for safety), and 30‐day complication rate. Descriptive statistics were used, and outcomes were analysed chronologically to assess for trends suggesting a learning curve. Results The cohort included 53 patients who underwent extraperitoneal SP‐EP‐RARP. Median operative time was 213 min (IQR: 145–281). Median estimated blood loss was 100 mL (IQR: 75–125). Nerve‐sparing was attempted in 75.5% of cases. No assist or plus one ports were utilized. Final pathology revealed pT2 disease in 64.1% (34 cases), pT3a in 32.1% (17 cases) and pT3b in 3.7% (2 cases). Overall positive margin rate was 26.4%. Thirty‐day Clavien–Dindo Grades I–II complication rates were 11.3%, and no major complications or 90‐day complications were reported. Continence rates at 6 weeks, 3 months and 6 months were 72%, 72% and 75%, respectively. Stabilization of operative times and intraoperative outcomes occurred after approximately 25–30 cases. Conclusion SP‐EP‐RARP can be safely implemented by a newly graduated fellowship‐trained robotic surgeon with acceptable oncologic and functional outcomes. Initial learning can be estimated at approximately 25–30 cases.
Navigating the arrhythmic storm in the CICU: from traditional drugs to evolving strategies
Latuscynski, Konrad , Bode, Kerstin , Dusi, V, Jentzer, J C, Dusi, Veronica , Jentzer, Jacob C. , Galluzzo, Alessandro

European Heart Journal: Acute Cardiovascular Care | March 9, 2026 | Volume: 15 | Issue: 3 | Pages: 251-253

10.1093/ehjacc/zuag033 | PMID 41802170 Get It

Guidelines for nutrition in adults with head and neck cancer: The American Society for Parenteral and Enteral Nutrition
Kiss, Nicole, Lewis, Whitney E, Mills, Jeannine B., Singh, Anurag K, Church, David D. , Mey, Jacob T. , Peterson, Sarah J. , Aguzzi, Kathleen, Bellini, Sarah Gunnell , Coelho, Maria Paula Villela, Cordwin, Laura, Duffy, Michael, Hager, Shanna J., Owen‐Michaane, Michael, Price, Kathleen C., Stanner, Heather , Storm, Bridget, Udagedara, Malika, McKeever, Liam , Church, David D , Mey, Jacob T , Peterson, Sarah , Bellini, Sarah , Coelho, Maria Paula Villela , Mundi, Manpreet S , Kiss, Nicole K. , Findlay, Merran , Frowen, Jacqui J. , Mundi, Manpreet S.

Journal of Parenteral and Enteral Nutrition | March 8, 2026 | Volume: 50 | Issue: 3 | Pages: 274-338

10.1002/jpen.70067 | PMID 41773753 Get It

Abstract Background Head and neck cancer represents the seventh most common cancer diagnosis globally. Maintaining sufficient nutrition is important for preventing malnutrition (undernutrition) and muscle wasting, which contribute to worse outcomes, although many patients are unable to maintain adequate oral intake throughout treatment. This guideline provides practice guidance on nutrition care for patients with head and neck cancer. Methods An interdisciplinary team developed key questions and scanned results from a systematic search of the PubMed, EMBASE, CINAHL, and Cochrane Central databases back to 2001. Recommendations were created for key questions concerning timing and duration of nutrition support (early vs delayed enteral nutrition [EN], postoperative feeding, and perioperative dietitian intervention), frequency of dietitian and speech pathology consultations, nutrition screening and assessment, macronutrient requirements, enteral access devices, adjunctive strategies (appetite stimulants and continuation of oral intake alongside EN), specialized nutrients (arginine, glutamine, ω‐3, and immunonutrition), and interdisciplinary care. Results Ninety‐two studies were included. Recommendations were made supporting early initiation of EN when oral intake is inadequate, nutrition within 24 h after surgery, weekly consultation with a dietitian during radiotherapy, malnutrition screening and assessment with validated tools, interdisciplinary models of care, dietitian involvement before and after surgery, and when to consider use of specialized nutrients. Recommendations are also provided for protein intake (1.2–1.5 g/kg/day) and energy intake (≥30 kcal/kg/day). Conclusion This guideline provides guidance for the nutrition care of patients with head and neck cancer, identifies research gaps, and calls for standardized outcome reporting to further the state of the evidence. This paper was approved by the ASPEN Board of Directors.
TNF-α blockade mitigates immune checkpoint–related nephritis in a humanized mouse model
Narvaez, Victor D Cuenca, Chavez, Coraima Nava, Refai, Omar Al, Gutierrez, Luis E., Zhang, Song, Li, Xiaoyan, Hirdler, Jacob B. , Romero, Michael F. , Herrmann, Joerg, Li, Xiaogang, dong, Haidong, Eirin, Alfonso, Herrmann, Sandra M., Romero, Michael F , Chavez, Coraima Claudia Nava , Jacobs, Johanna E.J., Herrmann, Joerg , Dong, Haidong , Eirin, Alfonso , Herrmann, Sandra M.

JCI Insight | March 5, 2026 | Volume: 11 | Issue: 8 | Pages: No page available

10.1172/jci.insight.199694 | PMID 41785046 Get It

Immune checkpoint inhibitors (ICIs) can cause immune-related adverse events (irAEs), with acute interstitial nephritis (ICI-AIN) being the most common irAE. While the exact mechanism remains unclear, upregulation of IFN-γ and TNF-α pathways has been implicated. This study used a humanized chimeric PD-1/PD-L1 mouse model to assess renal effects of ICIs, alone or combined with proinflammatory cytokines, and to test if selective TNF-α blockade could prevent ICI-AIN. Mice were randomly divided into 4 experimental groups: Control, ICI-Only, ICI-Cytokines (ICI-Cyt), and ICI-Block (ICI-TNF-α blockade). Renal function and cytokine profiles were assessed, while kidney tissue was analyzed using microscopy and single-cell RNA-seq. Histology revealed increased renal infiltration of CD4 + /CD8 + T cells in ICI-treated groups and decreased TNF-α expression following TNF-α blockade. Additionally, kidney tissue ELISA demonstrated reduced IFN-γ levels following TNF-α blockade. Plasma IL-6, MCP-1, and TNF-α were lower in ICI-Block mice. Single-cell RNA-seq revealed shifts in immune cell populations and genes of interest including Bcl2a1 , Icos , Il18r1 , Ccr2 , and Jaml . This humanized model replicates ICI-AIN key features, revealing a synergistic role of ICIs and proinflammatory cytokines. TNF-α blockade demonstrated protective effects, supporting its potential role in mitigating the risk of ICI-AIN.
Integrative screening identifies functional variants and VNTRs underlying GWAS signals at the 5p15.33 multi-cancer susceptibility locus
O’Brien, Aidan , Kong, Hyunkyung, Patel, Harsh , Ho, Michelle , Patel, Minal, Zhong, Jun , Xu, Mai, Papenberg, Brenen W. , Connelly, Katelyn E. , Collins, Irene , Hennessey, Rebecca C. , Thakur, Rohit , Sowards, Hayley , Funderburk, Karen, Luong, Thong Minh, Florez-Vargas, Oscar , Myers, Timothy , Jermusyk, Ashley , Gorman, Bryan, Das, Sudipto, (PanScan/PanC4), The Pancreatic Cancer Cohort and Case-Control Consortia, Lan, Qing, Rothman, Nathaniel , McKay, James , Hung, R., Iles, Mark M. , Landi, Maria Teresa , Stolzenberg-Solomon, Rachael Z, Wolpin, Brian M. , Hassan, Manal M. , Antwi, Samuel O. , Lindström, Sara , Stern, Marc-Henri, Andrésson, Þorkell , Shi, Jianxin , Choi, Jiyeon, Brown, Kevin M, Rabe, Kari G. , Patel, Minal B , Hennessey, Rebecca , Luong, Thong , Jones, Kristine , Das, Sudipto , McKay, James , Hung, Rayjean J , Amos, Christopher I , Iles, Mark M , Koutros, Stella , Landi, Maria T , Law, Matthew H , Hassan, Manal M , Klein, Alison P , Orr, Nick , Chanock, Stephen Jacob , Lindstrom, Sara , Hoskins, Jason W , Shi, Jianxin , Prokunina-Olsson, Ludmila , Choi, Jiyeon , Brown, Kevin M , Amundadottir, Laufey , Chaffee, Kari G. , Antwi, Samuel O , Zhong, Jun , Luo, Wen , Lan, Qing , Rothman, Nathaniel , Amos, Christopher I. , Koutros, Stella , Law, Matthew H. , Stolzenberg‐Solomon, Rachael Z. , Klein, Alison P. , Orr, Nick , Hoskins, Jason W. , Stern, Marc‐Henri , Choi, Jiyeon , Ámundadóttir, Laufey T.

No container title available | March 5, 2026 | Volume: No volume available | Issue: No issue available | Pages: No page available

10.64898/2026.03.03.26347427 | PMID 41867231 Get It

Abstract Chromosome 5p15.33 harbors several independent association signals which demonstrate antagonistic pleiotropy across cancer types, with causal mechanisms largely unresolved. To identify functional variants and enhancer elements at this locus, we performed statistical fine-mapping followed by massively parallel reporter assays (MPRA) and proliferation based CRISPRi screens. This approach identified eight multi-cancer functional variants (MCFVs) across three GWAS signals. Targeting rs421629 (part of the CLPTM1L signal marked by rs465498) with CRISPRi revealed opposing effects on TERT expression in pancreatic versus lung cancer cells, consistent with the antagonistic pleiotropy observed for this signal. Furthermore, CRISPRi nominated an intronic CLPTM1L variable number tandem repeat (VNTR) as a potent enhancer. Long-read sequencing established VNTR polymorphisms as potential causal variants for the rs465498 signal. We showed that Hippo-pathway transcription factors mediate VNTR enhancer activity in lung and pancreatic cancer cells. Together, these findings indicate that cancer susceptibility at 5p15.33 may be mediated by both SNPs and VNTRs and provide an integrated framework for resolving complex pleiotropic loci.
PSA Zero Radiographic Disease Progression on PSMA PET/CT
Mahmoud, Ahmed M., Day, Carter, Ahmed, E Al-Marzouk, Ahmed, M, Haloi, Rimki , Mahon, Mindie, Nikanpour, Yalda , Orme, Jacob J. , Kendi, MD Ayse Tuba, Johnson, G B, Kwon, E., Andrews, Jack R. , Ahmed, Mohamed E. , Kendi, A. Tuba , Mahmoud, Ahmed , Mahmoud, Ahmed M , Ahmed, Eman E , Ahmed, Mohamed , Childs, Daniel S , Orme, Jacob J , Kendi, A Tuba , Mahon, Mindie, Childs, Daniel S. , Johnson, Geoffrey B , Kwon, Eugene D.

Cancers | March 4, 2026 | Volume: 18 | Issue: 5 | Pages: 831

10.3390/cancers18050831 | PMID 41827764 Get It

Background and Objective: Radiographic progression in prostate cancer (PCa) can occur even when prostate-specific antigen (PSA) levels are undetectable. We aimed to determine the frequency and characteristics of radiographic disease progression (rDP) on PSMA PET/CT in patients with undetectable PSA, referred to as PSA zero rDP. Methods: We analyzed the Mayo Clinic PSMA PET Prostate Cancer Registry to identify patients with rDP on PSMA PET/CT despite undetectable PSA levels. Disease progression was confirmed via biopsy or treatment response. The cohort included patients with non-metastatic and metastatic hormone-sensitive disease, as well as those with castration-resistant prostate cancer at the time of imaging. Overall survival (OS) was estimated using the Kaplan–Meier method. Group comparisons were performed with the log-rank test. Univariate Cox regression was used to identify factors associated with poor OS. Key findings and Limitations: Among 2141 patients imaged between 2021 and 2023, 257 (12%) had PSA zero rDP. Sixty-one percent had initially localized disease; 39% had de novo metastatic disease. Median (IQR) time from diagnosis to PSA zero rDP was 51.9 (18.4–115.5) months. A total of 184 patients (72%) progressed to castration-resistant PCa. Sites of rDP included bone (57%), visceral (15%), lymph node (18%), and local recurrence (10%). During median follow-up of 8.1 (3.5–11.9) months, 5% of patients died. Only visceral metastases were significantly associated with poorer OS (p < 0.0001). Conclusions and Clinical Implications: Prostate cancer patients frequently develop metastatic disease with undetectable PSA values. Our findings suggest the use of periodic advanced imaging techniques, irrespective of PSA value, for more prompt detection and early management of disease progress.
Escherichia coli ST131 Drives Carbapenem Use for E. coli Bloodstream Infections
Mackow, Natalie , Shao, Wanying, Ge, Lizhao , Komarow, Lauren, Jiang, Jianping , Boutzoukas, Angelique , Chen, Liang , Herc, Erica, Doi, Yohei, Arias, Cesar A, Jacob, J, Satlin, Michael J. , Huskins, W Charles, Dhar, Sorabh, Shelburne, Samuel A, Hill, Carol, Sadler, Jacob M., Hill, Bravada M, Greenwood-Quaintance, Kerryl E, Schmidt-Malan, Suzannah M., Patel, Robin, Fowler, Vance G, Tamma, Pranita D, Kreiswirth, Barry N, Group, for the Antibacterial Resistance Leadership, Chambers, Chip, Evans, Scott, Hamasaki, Toshi, Cross, Heather, Harris, Anthony, Pettigrew, Melinda M. , Duin, David van, Boucher, Helen , Dixon, Dennis O., Ghazaryan, Varduhi , Zou, Lanling, Raterman, Erica, Samuel, Tamika, Moon, Kyung, Hanson, Kim, Holland, Thomas, Lodise, Tom, Shelburne, Sam, Banerjee, Ritu, Cosgrove, Sara, Paterson, David, Lautenbach, Ebbing , Mehigan, Maureen, Doernberg, Sarah, Doi, Yohei , Chen, Liang , Boutzoukas, Angelique E , Jiang, Jianping , Doi, Yohei , Albin, Owen , Saade, Elie , Miller, Loren G , Jacob, Jesse T , Satlin, Michael J , Krsak, Martin , Huskins, W Charles , Shelburne, Samuel A , Hill, Carol , Alby, Kevin , Sadler, Jacob M , Hill, Bravada M , Patel, Robin , Fowler, Vance G. , Tamma, Pranita D , van Duin, David , Pettigrew, M M , Evans, Scott R , Ge, Lizhao , Komarow, Lauren , Garcia‐Diaz, Julia , Herc, Erica , Arias, César A. , Albin, Owen , Saade, Elie , Jacob, Jesse T. , Kršák, Martin , Huskins, W. Charles , Dhar, Sorabh , Shelburne, Samuel A. , Hill, Carol , Alby, Kevin , Greenwood‐Quaintance, Kerryl E. , Patel, Robin , Tamma, Pranita D. , Kreiswirth, Barry N , Evans, Scott, Raterman, Erica L., Samuel, Tamika, Banerjee, Ritu , Cosgrove, Sara E. , Paterson, David L. , Mehigan, Maureen

Clinical Infectious Diseases | March 4, 2026 | Volume: 83 | Issue: 1 | Pages: e27-e37

10.1093/cid/ciag160 | PMID 41795867 Get It

Abstract Background Ceftriaxone-resistant Escherichia coli infections are increasingly common, partially because of the emergence of E. coli sequence type 131 (ST131), including its subclade C2/H30Rx, which produce extended-spectrum β-lactamases. Methods A prospective cohort including 14 US sites, which enrolled monomicrobial ceftriaxone-resistant and susceptible E. coli bloodstream infection (BSI) cases in a 1:1 ratio, was used to compare ST131 versus non-ST131 E. coli BSI, with specific attention to E. coli ST131 C2/H30Rx. Desirability of outcome ranking was determined at 30 days after infection onset. Results This analysis included 282 patients with E. coli BSI; 43% (121/282) were E. coli ST131 and 23% (66/282) belonged to the C2/H30Rx subclade. Resistance to ceftriaxone was present in 79% (96/121) ST131, 86% (57/66) E. coli ST131 C2/H30Rx, and 27% (43/161) E. coli non-ST131. Compared to patients with non-ST131 E. coli BSI, patients with ST131 BSI were older (median 70 years, [Q1 62, Q3 76] years vs 65 years, [51, 74]; P = .005) and more often admitted from long-term care facilities (21/121 [17%] vs 7/161 [4%], P &lt; .001). Overall and empiric carbapenem use was more frequent in the treatment of patients with ST131 BSI compared with non-ST131 BSI (overall 89/121 [74%] vs 50/161 [31%]; empiric: 58/121 [48%] vs 31/161 [19%], P &lt; .001). Desirability of outcome ranking outcomes were similar between groups. Conclusions Most ceftriaxone-resistant E. coli from US patients with E. coli BSI belong to ST131, particularly E. coli ST131 C2/H30Rx, serving as an important driver of carbapenem use.
Suppression of early pro-inflammatory senescent signature post-radiotherapy mitigates chronic bone damage
Orme, Jacob J. , Sharma, Ritika, Komel, Aqsa, Khan, Khubaib Gul, White, Thomas A. , LeBrasseur, Nathan K. , Khosla, Sundeep, Pignolo, Robert J. , Chandra, Abhishek, Khosla, Sundeep , Orme, Jacob J , LeBrasseur, Nathan K , Khosla, Sundeep , Pignolo, Robert J , Chandra, Abhishek , Achudhan, David , White, Thomas A, Park, Sean S. , Chandra, Abhishek

No container title available | March 3, 2026 | Volume: No volume available | Issue: No issue available | Pages: No page available

10.64898/2026.03.01.708630 | PMID 41867754 Get It

Abstract Cellular senescence has been implicated in the pathophysiology of radiotherapy-related bone loss. Based on our previous work, clearance of senescent cells using genetic and pharmacological tools alleviates the anomalies associated with radiation-associated bone deterioration. The pro-inflammatory senescence associated secretome referred to as senescence associated secretory phenotype (SASP), is a hallmark of cellular senescence. The modulation of SASP by senomorphic drugs, potentially can suppress the pro-inflammatory secretome of senescent cells, irrespective of the underlying senescence mechanism. In this study we tested a senomorphic drug, ruxolitinib, a Janus kinase inhibitor (JAKi), during acute and chronic radiotherapy related effects on the bone. Our clinical data indicate an early increase in several pro-inflammatory SASP proteins following radiotherapy of spinal metastasis in prostate cancer patients. Longitudinal assessment of SASP-related genes confirmed this acute elevation in several SASP markers in systemic circulation following irradiation of mouse femurs. In a proof-of-concept study, following two preclinical radiotherapy regimens of cumulative doses of 30Gy (5 x 6Gy) and 60Gy (5 x 12Gy), a senomorphic approach of JAKi treatment was more effective in alleviating radiation-related bone loss compared to the senolytic cocktail of D+Q. Early and intermittent suppression of SASP using JAK inhibitors alleviated chronic bone deterioration, diminished telomere dysfunction, lowered senescence and SASP marker expression, reduced bone-marrow adiposity, and mitigated radiation related lymphatic impairment. Overall, our study shows that early targeting of SASP proteins could be a potential therapeutic to prevent radiotherapy-related chronic bone loss and risk of fractures. Lay Summary Radiotherapy as part of cancer treatment is correlated with an acute increase in senescent cells. Here we show that the pro-inflammatory senescence associated secretory phenotype (SASP) becomes much more prominent soon after radiotherapy in both patients and mice. Suppression of the SASP using a Janus kinase inhibitor, ruxolitinib, reduced the overall senescent cell burden, improved bone architecture by promoting bone formation, reduced bone marrow adiposity, and mitigated radiation-induced lymphatic impairment. Overall, these findings suggest that early inhibition of the SASP may help mitigate several bone anomalies and prevent long-term bone loss and fractures after radiotherapy. Graphical Abstract
Circulating tumor DNA kinetics as a biomarker of response to enfortumab-pembrolizumab in advanced urothelial carcinoma.
Humayun, Muhammad Abdullah, Oberoi, Japneet Kaur , Ganadily, Naif A., Khan, Muhammad Ali , Jain, Prateek, Basu, Arnab, Zganjar, Andrew , Orme, Jacob J. , Kase, Adam M. , Tyson, Mark D. , Singh, Parminder, Yee, Claire , Jain, Prateek, Childs, Daniel S. , Zakharia, Yousef , Riaz, Irbaz Bin , Singh, Parminder Pal

Journal of Clinical Oncology | March 2, 2026 | Volume: 44 | Issue: 7_suppl | Pages: 703-703

10.1200/jco.2026.44.7_suppl.703 Get It

703 Background: The association of circulating tumor DNA (ctDNA) reduction with treatment response has been investigated across multiple malignancies. This study aims to assess the impact of ctDNA response on survival outcomes in patients receiving enfortumab-pembrolizumab (EV-P). Methods: We identified 32 patients with advanced urothelial carcinoma who received EV-P and had ≥2 ctDNA assessments with ≥1 detectable level. Deep molecular response was defined as >2-log reduction from highest ctDNA detection. Radiographic progression was determined from radiology reports documenting progression by RECIST criteria. Kaplan Meier analyses were performed to compute Hazard Ratios (HR) with 95% confidence intervals (CI) for radiographic progression free survival (rPFS), defined as time from treatment start to radiographic progression or death and overall survival (OS) defined as time from treatment start to death were computed. Log-rank tests were performed to compare PFS and OS in patients with deep molecular response to those without response. A p-value <0.05 indicated a statistically significant association with response. Results: Thirty-two patients were included (median age 71 years; range 39–90). Median follow-up was 10.6 months. At cutoff (10/1/2025), 26 patients were alive and 6 had died. Seventeen (53%) achieved a ≥2-log ctDNA reduction (responders), while 15 (47%) did not (non-responders). Progression-free survival was significantly longer in responders (log-rank P < 0.001); median PFS was 5.9 months (95% CI 2.4–NR) in non-responders and not reached in responders (HR 0.09, 95% CI 0.02–0.44; P = 0.0026). Median overall survival was 12.7 months (95% CI 10.0–NR) in non-responders versus not reached in responders (log-rank P = 0.011; HR 0.11, 95% CI 0.01–0.88; P = 0.037). At cutoff, 94% of responders and 67% of non-responders were alive. Conclusions: Achieving a >2-log decrease in ctDNA during EV + Pembrolizumab therapy was significantly associated with improved progression free and overall survival. These findings support ctDNA kinetics as a potential early biomarker of response warranting prospective validation. Clinical outcomes by >2-log ctDNA reduction status. Endpoint > 2-log drop (n = 17 ≤ 2-log drop (n = 15) Log-rank p Median (mo) ≤ 2-log > 2-log HR (95% CI) P C-index PFS 2 events (12%) 10 events (67%) 0.0002 5.9 (2.4–NA) NR 0.09 (0.02–0.44) 0.0026 0.77 OS 1 event (6%) 6 events (40%) 0.011 12.7 (10.0–NA) NR 0.11 (0.01–0.88) 0.037 0.73
Prevalence of treatment-acquired homozygous losses (homozygous deletions) of PTEN from androgen receptor pathway inhibitors (ARPI) in metastatic prostate cancer.
Bose, R., Vento, Joseph , Kase, Adam M. , Berchuck, Jacob E. , Cortez, Eliane, Ross, Jeffrey S., Graf, R., Bilušić, Marijo , Li, Gerald , Danziger, Natalie , Ross, Jeffrey S , Graf, Ryon P.

Journal of Clinical Oncology | March 2, 2026 | Volume: 44 | Issue: 7_suppl | Pages: 27-27

10.1200/jco.2026.44.7_suppl.27 Get It

27 Background: Validated homozygous loss detection is becoming increasingly important in clinical practice, with prostate NCCN guideline inclusion of BRCA1/2 loss (often portending durable PARP inhibitor benefit) and multi-tumor trials of PRMT5 and MAT2A inhibitors ongoing (biomarker: MTAP loss). Homozygous losses are challenging to detect and require intentional NGS assay design and validations. Using an FDA-approved NGS assay, we evaluated the most frequent losses identified in metastatic prostate cancer, evaluated prognostic associations on ARPI, and prevalence before and after ARPI treatments. Methods: This study used the nationwide (US-based) de-identified Flatiron Health-Foundation Medicine Prostate Cancer clinico-genomic database (FH-FMI CGDB), originating from approximately 280 US cancer clinics (~800 sites of care). Patients with metastatic prostate cancer and tissue tumor genomic testing by FoundationOne CDx were eligible for analysis. Alteration prevalence was compared between non-sequential groups of specimens obtained from patients naïve to ADT and ARPI, naïve to ARPI but not ADT, or exposed to any ARPI. Outcome analyses adjusted for: ECOG performance score, age, baseline PSA, and socioeconomic status. To limit immortal time confounding, outcome analyses were restricted to patients with specimens tested prior to initiation of ARPI. Results: 1990 specimens from 1984 unique patients met criteria for assessment. The most common losses and respective ADT & ARPI naïve vs ADT exposed & ARPI-naïve vs ARPI-exposed prevalence were PTEN (17.1% vs 24.8% vs. 33.5%, p < 0.001), FAS (2.4% vs 5.0% vs 5.8%, p = 0.003), BRCA2 (4.2% vs 3.2% vs. 2.8%, p = 0.36), RB1 (1.6% vs 3.0% vs 3.5%, p = 0.062), and TP53 (2.3% vs 2.3% vs 4.4%, p = 0.064). 227 patients had tissue specimens obtained and NGS results reported prior to initiation of ARPI. Sufficient patients with PTEN loss were present for nominal outcome associations, observing less favorable time to next treatment (HR: 1.81, 95%CI: 1.24 – 2.65, p = 0.002) and overall survival (HR: 1.65, 95%CI: 1.02 – 2.65, p = 0.040) from the initiation of ARPI. In the mHSPC (ADT and ARPI naïve) setting, 17.1% had PTEN loss, 32.8% had an HRR gene alteration, and 2.8% had both. Conclusions: Our results are consistent with homozygous losses of certain genes, notably PTEN , potentially being acquired resistance alterations to ARPI. Prostate cancer trials often do not specify timing of specimen acquisition relative to treatment initiation. For trials like IPATential-150 or CAPItello-280 that evaluate AKT inhibitors in post-ARPI setting, patients with PTEN status determined by archival tissue could be false negatives and reduce power of analysis in biomarker(+) group. Our results underscore the importance of clinical context, especially prior treatment exposures, when interpreting biomarker prevalence.