Succinate Dehydrogenase Deficient Renal Cell Carcinoma With Sarcomatoid and Rhabdoid Features-A Diagnostic Dilemma.

Succinate dehydrogenase (SDH)-deficient renal cell carcinoma (RCC) is a rare epithelial tumor with a biallelic mutation involving any subunit of the SDH complex. Mostly, it has low-grade morphology and a favorable prognosis. We present a case of a 36-year-old woman with weight loss, night sweats, and symptomatic anemia. Her imaging showed a hypo-enhancing heterogeneous right renal mass with invasion of the renal vein and inferior vena cava. Microscopically, the tumor had focal low-grade areas (5%) and extensive areas with high-grade features, including rhabdoid (85%) and sarcomatoid (10%) dedifferentiation. Cytoplasmic inclusions, foci of extracellular mucin, coagulative necrosis, and inflammatory infiltrate were present. The tumor cells, including rhabdoid differentiated, were focally positive for AE1/AE3. Tumor cells showed loss of SDHB immunostaining, consistent with diagnosis. Genetics testing was recommended, but the patient expired due to metastatic carcinoma. Prior studies suggest that sarcomatoid transformation and coagulative necrosis increase the risk of metastasis by up to 70% in SDH-deficient RCC. Follow-up with surveillance for other SDH-deficient neoplasms is recommended in cases of germline mutation. Here, we report the first case of SDH-deficient RCC with concomitant rhabdoid and sarcomatoid features and a detailed review of diagnostic difficulties associated with high-grade tumors.

Primary adrenal angiosarcoma: A case report and review of the literature.

Primary adrenal angiosarcoma is an extremely rare malignant tumor with challenging diagnosis. A 66-year-old woman had a 4.3 cm right adrenal mass suspicious for adrenal cortical carcinoma. Pathological examination demonstrated a hemorrhagic adrenal cyst with numerous irregularly shaped anastomosing vascular channels lined by atypical endothelial cells that had frequent atypical mitotic figures (12/10 HPF, Ki67 10%). The tumor cells were positive for CD31, ERG, and FLI-1, but negative for adrenal and other tumor lineage markers by immunohistochemistry. NGS fusion gene testing ruled out epithelioid hemangioendothelioma. Accurate diagnosis and differential inclusion are important for appropriate treatment of this rare tumor.

Enhancing bladder cancer care through the multidisciplinary clinic approach.

INTRODUCTION: To report the impact of our 25-year multidisciplinary care delivery model experience on patients with muscle invasive bladder cancer treated at our National Cancer Institute (NCI)-designated Sidney Kimmel Cancer Center at Jefferson University. To our knowledge, our multidisciplinary genitourinary cancer clinic (MDC) is the longest continuously operating center of its kind at an NCI Cancer Center in the United States. MATERIALS AND METHODS: We selected a recent group of patients with cT2-4 N0-1 M0 bladder cancer seen in the Sidney Kimmel Cancer Center Genitourinary Oncology MDC from January 2016 to September 2019. These patients were identified retrospectively. SEER-18 (Surveillance, Epidemiology, and End Results) database, November 2019 submission was queried to obtain patients with similarly staged disease diagnosed between 2015 and 2017. Completion rates of radical cystectomy, use of neoadjuvant therapies, and survival outcomes were compared between the two cohorts. RESULTS: Ninety-one patients from the MDC form this time period were identified; 65.9% underwent radical cystectomy and 71.8% received neoadjuvant therapy in the form of chemotherapy, immune checkpoint inhibition or a combination of the two - higher than reported national trends for neoadjuvant therapies. Progression of disease was seen in 24.2% of patients. A total of 8675 patients met inclusion criteria in the SEER database. Rates of radical cystectomy were significantly higher in MCD patients when compared to SEER derived data (65.9% vs. 37.7%, p =< 0.001). MCD patients had significantly better cancer-specific survival (mean 20.4 vs. 18.3 months p = 0.028, median survival not reached). CONCLUSION: Our long term experience caring for patients with genitourinary malignancies such as bladder cancer in a uniform multidisciplinary team results in a high utilization of neoadjuvant therapies. When compared to a contemporary SEER-derived cohort, multidisciplinary patients were more likely to undergo radical cystectomy and had longer cancer-specific survival.

A rare metastatic mesenteric malignant PEComa with TSC2 mutation treated with palliative surgical resection and nab-sirolimus: a case report.

BACKGROUND: Malignant perivascular epithelioid cell tumors (PEComas) are exceedingly rare malignant mesenchymal neoplasms with characteristic morphological and immunohistochemical (IHC) patterns. However, some malignant PEComas are poorly differentiated with atypical histopathological features, making a definitive diagnosis difficult. PEComas are most commonly found in females and often show either TSC1 or TSC2 alterations, which result in the activation of the mTOR pathway, or TFE3 fusions. Given these molecular characteristics, mTOR inhibitors have recently been approved by the FDA in the treatment of malignant PEComas, particularly in those with TSC1/2 alterations. Therefore, molecular analyses may be helpful for both the diagnostic workup of and predicting response to mTOR inhibitors in cases of malignant PEComas. CASE PRESENTATION: Here, we report a case of an aggressive, 23 cm mesenteric malignant PEComa with multiple peritoneal metastases in a young male patient. Pathological examination of the initial biopsy showed a malignant epithelioid neoplasm with high-grade morphology and atypical immunoprofile, which precluded a definitive diagnosis. Because of the patient's excessive transfusion requirements due to intra-tumoral hemorrhage, a palliative R2 resection was performed. Histopathological examination of the tumor revealed focal immunoreactivity for Melan-A, HMB-45, desmin, and CD117. Although a diagnosis of malignant PEComa was favored, other entities such as epithelioid gastrointestinal stromal tumor (GIST) or melanoma could not be definitively ruled out. Given the favored diagnosis, the patient was started on sirolimus, an mTOR inhibitor, rather than chemotherapy. Molecular analyses were performed and the tumor was found to harbor mutations in TP53 and TSC2, supporting a definitive diagnosis of malignant PEComa. The patient was then switched to nab-sirolimus, with initial stabilization of the disease. CONCLUSIONS: This report details a multidisciplinary approach for the diagnosis and management of a highly aggressive, metastatic malignant PEComa in a young male patient. The basis for the treatment of malignant PEComas with the recently FDA-approved mTOR inhibitor, nab-sirolimus, is also reviewed. In summary, this case highlights the importance of molecular analysis, particularly TSC1/2 alterations, for both the definitive diagnosis of malignant PEComas and predicting their response to nab-sirolimus.

The DACH1 gene is frequently deleted in prostate cancer, restrains prostatic intraepithelial neoplasia, decreases DNA damage repair, and predicts therapy responses.

Prostate cancer (PCa), the second leading cause of death in American men, includes distinct genetic subtypes with distinct therapeutic vulnerabilities. The DACH1 gene encodes a winged helix/Forkhead DNA-binding protein that competes for binding to FOXM1 sites. Herein, DACH1 gene deletion within the 13q21.31-q21.33 region occurs in up to 18% of human PCa and was associated with increased AR activity and poor prognosis. In prostate OncoMice, prostate-specific deletion of the Dach1 gene enhanced prostatic intraepithelial neoplasia (PIN), and was associated with increased TGFß activity and DNA damage. Reduced Dach1 increased DNA damage in response to genotoxic stresses. DACH1 was recruited to sites of DNA damage, augmenting recruitment of Ku70/Ku80. Reduced Dach1 expression was associated with increased homology directed repair and resistance to PARP inhibitors and TGFß kinase inhibitors. Reduced Dach1 expression may define a subclass of PCa that warrants specific therapies.

The DACH1 gene is frequently deleted in prostate cancer, restrains prostatic intraepithelial neoplasia, decreases DNA damage repair, and predicts therapy responses.

Prostate cancer (PCa), the second leading cause of death in American men, includes distinct genetic subtypes with distinct therapeutic vulnerabilities. The DACH1 gene encodes a winged helix/Forkhead DNA-binding protein that competes for binding to FOXM1 sites. Herein, DACH1 gene deletion within the 13q21.31-q21.33 region occurs in up to 18% of human PCa and was associated with increased AR activity and poor prognosis. In prostate OncoMice, prostate-specific deletion of the Dach1 gene enhanced prostatic intraepithelial neoplasia (PIN), and was associated with increased TGFb activity and DNA damage. Reduced Dach1 increased DNA damage in response to genotoxic stresses. DACH1 was recruited to sites of DNA damage, augmenting recruitment of Ku70/Ku80. Reduced Dach1 expression was associated with increased homology directed repair and resistance to PARP inhibitors and TGFb kinase inhibitors. Reduced Dach1 expression may define a subclass of PCa that warrants specific therapies.

Sarcomatoid renal cell tumor harboring a novel BYSL::TFEB fusion with concurrent TFEB amplification.

Transcription factor EB (TFEB)-rearranged renal cell carcinoma (RCC) exhibits diverse gene fusion patterns and heterogeneous clinicopathologic features. Rare TFEB-amplified RCCs have been described recently and are associated with a more aggressive clinical course. Herein, we report a case of an 86-year-old man with a solid 9.2-cm kidney tumor that showed a diffuse high-grade sarcomatoid morphology. The tumor demonstrated a novel BYSL::TFEB fusion containing exons 1-2 of the BYSL gene fused to exons 3-10 of TFEB via next-generation sequencing by using NextSeq sequencer. Fluorescence in situ hybridization (FISH) studies displayed concurrent high-copy number TFEB amplification in two distinct patterns, a balanced increase of 5' and 3' copies, and solely increased 5' copies, and mouse double minute 2 (MDM2) gene amplification by using TFEB (6p21.1) dual-color break-apart probe and MDM2 FISH probe. Notably, the tumor showed a distinctive immunoprofile with overexpressions of TFEB, epithelial membrane antigen, Cathepsin K, and PDL-1 (SP263). FISH test for transcription factor binding to IGHM enhancer 3 (TFE3) was negative for rearrangement and corresponding immunonegativity of TFE3. These findings not only expand the repertoire of known TFEB fusion partners implicated in tumorigenesis, but also may provide novel information for target therapy.

The NOGO receptor NgR2, a novel αVß3 integrin effector, induces neuroendocrine differentiation in prostate cancer.

Androgen deprivation therapies aimed to target prostate cancer (PrCa) are only partially successful given the occurrence of neuroendocrine PrCa (NEPrCa), a highly aggressive and highly metastatic form of PrCa, for which there is no effective therapeutic approach. Our group has demonstrated that while absent in prostate adenocarcinoma, the αVß3 integrin expression is increased during PrCa progression toward NEPrCa. Here, we show a novel pathway activated by αVß3 that promotes NE differentiation (NED). This novel pathway requires the expression of a GPI-linked surface molecule, NgR2, also known as Nogo-66 receptor homolog 1. We show here that NgR2 is upregulated by αVß3, to which it associates; we also show that it promotes NED and anchorage-independent growth, as well as a motile phenotype of PrCa cells. Given our observations that high levels of αVß3 and, as shown here, of NgR2 are detected in human and mouse NEPrCa, our findings appear to be highly relevant to this aggressive and metastatic subtype of PrCa. This study is novel because NgR2 role has only minimally been investigated in cancer and has instead predominantly been analyzed in neurons. These data thus pave new avenues toward a comprehensive mechanistic understanding of integrin-directed signaling during PrCa progression toward a NE phenotype.

A Novel Role for DNA-PK in Metabolism by Regulating Glycolysis in Castration-Resistant Prostate Cancer.

PURPOSE: DNA-dependent protein kinase catalytic subunit (DNA-PKcs, herein referred as DNA-PK) is a multifunctional kinase of high cancer relevance. DNA-PK is deregulated in multiple tumor types, including prostate cancer, and is associated with poor outcomes. DNA-PK was previously nominated as a therapeutic target and DNA-PK inhibitors are currently undergoing clinical investigation. Although DNA-PK is well studied in DNA repair and transcriptional regulation, much remains to be understood about the way by which DNA-PK drives aggressive disease phenotypes. EXPERIMENTAL DESIGN: Here, unbiased proteomic and metabolomic approaches in clinically relevant tumor models uncovered a novel role of DNA-PK in metabolic regulation of cancer progression. DNA-PK regulation of metabolism was interrogated using pharmacologic and genetic perturbation using in vitro cell models, in vivo xenografts, and ex vivo in patient-derived explants (PDE). RESULTS: Key findings reveal: (i) the first-in-field DNA-PK protein interactome; (ii) numerous DNA-PK novel partners involved in glycolysis; (iii) DNA-PK interacts with, phosphorylates (in vitro), and increases the enzymatic activity of glycolytic enzymes ALDOA and PKM2; (iv) DNA-PK drives synthesis of glucose-derived pyruvate and lactate; (v) DNA-PK regulates glycolysis in vitro, in vivo, and ex vivo; and (vi) combination of DNA-PK inhibitor with glycolytic inhibitor 2-deoxyglucose leads to additive anti-proliferative effects in aggressive disease. CONCLUSIONS: Findings herein unveil novel DNA-PK partners, substrates, and function in prostate cancer. DNA-PK impacts glycolysis through direct interaction with glycolytic enzymes and modulation of enzymatic activity. These events support energy production that may contribute to generation and/or maintenance of DNA-PK-mediated aggressive disease phenotypes.

Imaging urothelial bladder cancer: A VPAC PET targeted approach.

INTRODUCTION Accurate staging of urothelial bladder cancer (UBC) with imaging, which guides effective bladder cancer treatment, remains challenging. This investigation is to validate a hypothesis that targeting Vasoactive intestinal and pituitary adenylate cyclase activating peptide (VPAC) receptors using 64Cu-TP3805 can PET image UBC efficiently. MATERIALS AND METHODS: Nineteen patients (44-84 years of age) scheduled for radical cystectomy, underwent VPAC positron emission tomography (PET) imaging prior to surgery. Sixteen had completed neoadjuvant chemotherapy prior to imaging. All 19 received 64Cu-TP3805 (148 % ± 10% MBq) intravenously, and were imaged 60 to 90 minutes later. Standard uptake value (SUV)max for malignant lesions and SUVmean for normal tissues were determined and mean +/-SEM recorded. Following radical cystoprostatectomy, pelvic lymphadenectomy and urinary diversion imaging, results were compared with final surgical pathology. RESULTS: 64Cu-TP3805 had no adverse events, negligible urinary excretion and rapid blood clearance. UBC PET images for residual disease were true positive in 11 patients and true negative in four. Of remaining 4, one had false positive and 3 had false negative scans, equating to 79% sensitivity (95%, CI 49%-95%), 80% specificity (95%, CI 28%-100%), 92% positive predictive value (95%, CI 62%-100%) and 57% negative predictive value (95%, CI 18%-90%). CONCLUSIONS: These first in man results, in a group, heavily pretreated with neoadjuvant chemotherapy, indicate that VPAC PET imaging can identify UBC effeiciently and suggest, that VPAC PET can diagnose UBC in a treatment naïve cohort for accurate staging, guide biopsy and treatment in patients with suspected metastasis and determine response to therapy. Further investigation of this molecular imaging approach is warranted.

RB/E2F1 as a Master Regulator of Cancer Cell Metabolism in Advanced Disease.

Loss of the retinoblastoma (RB) tumor suppressor protein is a critical step in reprogramming biological networks that drive cancer progression, although mechanistic insight has been largely limited to the impact of RB loss on cell-cycle regulation. Here, isogenic modeling of RB loss identified disease stage-specific rewiring of E2F1 function, providing the first-in-field mapping of the E2F1 cistrome and transcriptome after RB loss across disease progression. Biochemical and functional assessment using both in vitro and in vivo models identified an unexpected, prominent role for E2F1 in regulation of redox metabolism after RB loss, driving an increase in the synthesis of the antioxidant glutathione, specific to advanced disease. These E2F1-dependent events resulted in protection from reactive oxygen species in response to therapeutic intervention. On balance, these findings reveal novel pathways through which RB loss promotes cancer progression and highlight potentially new nodes of intervention for treating RB-deficient cancers. SIGNIFICANCE: This study identifies stage-specific consequences of RB loss across cancer progression that have a direct impact on tumor response to clinically utilized therapeutics. The study herein is the first to investigate the effect of RB loss on global metabolic regulation and link RB/E2F1 to redox control in multiple advanced diseases.This article is highlighted in the In This Issue feature, p. 2113.

Differential expression of αVß3 and αVß6 integrins in prostate cancer progression.

Neuroendocrine prostate cancer (NEPrCa) arises de novo or after accumulation of genomic alterations in pre-existing adenocarcinoma tumors in response to androgen deprivation therapies. We have provided evidence that small extracellular vesicles released by PrCa cells and containing the αVß3 integrin promote neuroendocrine differentiation of PrCa in vivo and in vitro. Here, we examined αVß3 integrin expression in three murine models carrying a deletion of PTEN (SKO), PTEN and RB1 (DKO), or PTEN, RB1 and TRP53 (TKO) genes in the prostatic epithelium; of these three models, the DKO and TKO tumors develop NEPrCa with a gene signature comparable to those of human NEPrCa. Immunostaining analysis of SKO, DKO and TKO tumors shows that αVß3 integrin expression is increased in DKO and TKO primary tumors and metastatic lesions, but absent in SKO primary tumors. On the other hand, SKO tumors show higher levels of a different αV integrin, αVß6, as compared to DKO and TKO tumors. These results are confirmed by RNA-sequencing analysis. Moreover, TRAMP mice, which carry NEPrCa and adenocarcinoma of the prostate, also have increased levels of αVß3 in their NEPrCa primary tumors. In contrast, the αVß6 integrin is only detectable in the adenocarcinoma areas. Finally, analysis of 42 LuCaP patient-derived xenografts and primary adenocarcinoma samples shows a positive correlation between αVß3, but not αVß6, and the neuronal marker synaptophysin; it also demonstrates that αVß3 is absent in prostatic adenocarcinomas. In summary, we demonstrate that αVß3 integrin is upregulated in NEPrCa primary and metastatic lesions; in contrast, the αVß6 integrin is confined to adenocarcinoma of the prostate. Our findings suggest that the αVß3 integrin, but not αVß6, may promote a shift in lineage plasticity towards a NE phenotype and might serve as an informative biomarker for the early detection of NE differentiation in prostate cancer.

Small extracellular vesicles modulated by αVß3 integrin induce neuroendocrine differentiation in recipient cancer cells.

The ability of small extracellular vesicles (sEVs) to reprogram cancer cells is well established. However, the specific sEV components able to mediate aberrant effects in cancer cells have not been characterized. Integrins are major players in mediating sEV functions. We have previously reported that the αVß3 integrin is detected in sEVs of prostate cancer (PrCa) cells and transferred into recipient cells. Here, we investigate whether sEVs from αVß3-expressing cells affect tumour growth differently than sEVs from control cells that do not express αVß3. We compared the ability of sEVs to stimulate tumour growth, using sEVs isolated from PrCa C4-2B cells by iodixanol density gradient and characterized with immunoblotting, nanoparticle tracking analysis, immunocapturing and single vesicle analysis. We incubated PrCa cells with sEVs and injected them subcutaneously into nude mice to measure in vivo tumour growth or analysed in vitro their anchorage-independent growth. Our results demonstrate that a single treatment with sEVs shed from C4-2B cells that express αVß3, but not from control cells, stimulates tumour growth and induces differentiation of PrCa cells towards a neuroendocrine phenotype, as quantified by increased levels of neuroendocrine markers. In conclusion, the expression of αVß3 integrin generates sEVs capable of reprogramming cells towards an aggressive phenotype.

The membrane-associated form of cyclin D1 enhances cellular invasion.

The essential G1-cyclin, CCND1, is a collaborative nuclear oncogene that is frequently overexpressed in cancer. D-type cyclins bind and activate CDK4 and CDK6 thereby contributing to G1-S cell-cycle progression. In addition to the nucleus, herein cyclin D1 was also located in the cytoplasmic membrane. In contrast with the nuclear-localized form of cyclin D1 (cyclin D1NL), the cytoplasmic membrane-localized form of cyclin D1 (cyclin D1MEM) induced transwell migration and the velocity of cellular migration. The cyclin D1MEM was sufficient to induce G1-S cell-cycle progression, cellular proliferation, and colony formation. The cyclin D1MEM was sufficient to induce phosphorylation of the serine threonine kinase Akt (Ser473) and augmented extranuclear localized 17ß-estradiol dendrimer conjugate (EDC)-mediated phosphorylation of Akt (Ser473). These studies suggest distinct subcellular compartments of cell cycle proteins may convey distinct functions.

The αvß6 integrin in cancer cell-derived small extracellular vesicles enhances angiogenesis.

Prostate cancer (PrCa) cells crosstalk with the tumour microenvironment by releasing small extracellular vesicles (sEVs). sEVs, as well as large extracellular vesicles (LEVs), isolated via iodixanol density gradients from PrCa cell culture media, express the epithelial-specific αvß6 integrin, which is known to be induced in cancer. In this study, we show sEV-mediated protein transfer of αvß6 integrin to microvascular endothelial cells (human microvascular endothelial cells 1 - HMEC1) and demonstrate that de novo αvß6 integrin expression is not caused by increased mRNA levels. Incubation of HMEC1 with sEVs isolated from PrCa PC3 cells that express the αvß6 integrin results in a highly significant increase in the number of nodes, junctions and tubules. In contrast, incubation of HMEC1 with sEVs isolated from ß6 negative PC3 cells, generated by shRNA against ß6, results in a reduction in the number of nodes, junctions and tubules, a decrease in survivin levels and an increase in a negative regulator of angiogenesis, pSTAT1. Furthermore, treatment of HMEC1 with sEVs generated by CRISPR/Cas9-mediated down-regulation of ß6, causes up-regulation of pSTAT1. Overall, our findings suggest that αvß6 integrin in cancer sEVs regulates angiogenesis during PrCa progression.

FOXD3 Regulates VISTA Expression in Melanoma.

Immune checkpoint inhibitors have improved patient survival in melanoma, but the innate resistance of many patients necessitates the investigation of alternative immune targets. Many immune checkpoint proteins lack proper characterization, including V-domain Ig suppressor of T cell activation (VISTA). VISTA expression on immune cells can suppress T cell activity; however, few studies have investigated its expression and regulation in cancer cells. In this study, we observe that VISTA is expressed in melanoma patient samples and cell lines. Tumor cell-specific expression of VISTA promotes tumor onset in vivo, associated with increased intratumoral T regulatory cells, and enhanced PDL-1 expression on tumor-infiltrating macrophages. VISTA transcript levels are regulated by the stemness factor Forkhead box D3 (FOXD3). BRAF inhibition upregulates FOXD3 and reduces VISTA expression. Overall, this study demonstrates melanoma cell expression of VISTA and its regulation by FOXD3, contributing to the rationale for therapeutic strategies that combine targeted inhibitors with immune checkpoint blockade.

Decipher identifies men with otherwise clinically favorable-intermediate risk disease who may not be good candidates for active surveillance.

BACKGROUND: We aimed to validate Decipher to predict adverse pathology (AP) at radical prostatectomy (RP) in men with National Comprehensive Cancer Network (NCCN) favorable-intermediate risk (F-IR) prostate cancer (PCa), and to better select F-IR candidates for active surveillance (AS). METHODS: In all, 647 patients diagnosed with NCCN very low/low risk (VL/LR) or F-IR prostate cancer were identified from a multi-institutional PCa biopsy database; all underwent RP with complete postoperative clinicopathological information and Decipher genomic risk scores. The performance of all risk assessment tools was evaluated using logistic regression model for the endpoint of AP, defined as grade group 3-5, pT3b or higher, or lymph node invasion. RESULTS: The median age was 61 years (interquartile range 56-66) for 220 patients with NCCN F-IR disease, 53% classified as low-risk by Cancer of the Prostate Risk Assessment (CAPRA 0-2) and 47% as intermediate-risk (CAPRA 3-5). Decipher classified 79%, 13% and 8% of men as low-, intermediate- and high-risk with 13%, 10%, and 41% rate of AP, respectively. Decipher was an independent predictor of AP with an odds ratio of 1.34 per 0.1 unit increased (p value = 0.002) and remained significant when adjusting by CAPRA. Notably, F-IR with Decipher low or intermediate score did not associate with significantly higher odds of AP compared to VL/LR. CONCLUSIONS: NCCN risk groups, including F-IR, are highly heterogeneous and should be replaced with multivariable risk-stratification. In particular, incorporating Decipher may be useful for safely expanding the use of AS in this patient population.

Targeting VPAC1 Receptors for Imaging Glioblastoma.

PURPOSE: Scintigraphic imaging of malignant glioblastoma (MG) continues to be challenging. We hypothesized that VPAC1 cell surface receptors can be targeted for positron emission tomography (PET) imaging of orthotopically implanted MG in a mouse model, using a VPAC1-specific peptide [64Cu]TP3805. PROCEDURES: The expression of VPAC1 in mouse GL261 and human U87 glioma cell lines was determined by western blot. The ability of [64Cu]TP3805 to bind to GL261 and U87 cells was studied by cell-binding. Receptor-blocking studies were performed to validate receptor specificity. GL261 tumors were implanted orthotopically in syngeneic T-bet knockout C57BL/6 mouse brain (N = 15) and allowed to grow for 2-3 weeks. Mice were injected i.v., first with ~ 150 µCi of 2-deoxy-2-[18F]fluoro-D-glucose ([18F]FDG) then 24 h later with ~ 200 µCi of [64Cu]TP3805. In another set of tumor-bearing mice, (N = 5), ionic [64Cu]Cl2 was injected as a control. Mice were imaged at a 2-h post-injection using an Inveon micro-PET/CT, sacrificed and % ID/g of [64Cu]TP3805 and [64Cu]Cl2 were calculated in a tumor, normal brain, and other tissues. For histologic tissue examination, 3-µm thick sections of the tumors and normal brain were prepared, digital autoradiography (DAR) was performed, and then the sections were H&E stained for histologic examination. RESULTS: Western blots showed a strong signal for VPAC1 on both cell lines. [64Cu]TP3805 cell-binding was 87 ± 1.5 %. Receptor-blocking reduced cell-binding to 24.3 ± 1.5 % (P < 0.01). PET imaging revealed remarkable accumulation of [64Cu]TP3805 in GL261 MG with a negligible background in the normal brain, as compared to [18F]FDG. Micro-PET/CT image analyses and tissue distribution showed that the brain tumor uptake for [64Cu]TP3805 was 8.2 ± 1.7 % ID/g and for [64Cu]Cl2 2.1 ± 0.5 % ID/g as compared to 1.0 ± 0.3 % ID/g and 1.4 ± 0.3 % ID/g for normal mouse brains, respectively. The high tumor/normal brain ratio for [64Cu]TP3805 (8.1 ± 1.1) allowed tumors to be visualized unequivocally. Histology and [64Cu]TP3805 DAR differentiated malignant tumors from healthy brain and confirmed PET findings. CONCLUSION: Targeting VPAC1 receptors using [64Cu]TP3805 for PET imaging of MG is a promising novel approach and calls for further investigation.

Prospective study to define the clinical utility and benefit of Decipher testing in men following prostatectomy.

BACKGROUND: Genomic classifiers (GC) have been shown to improve risk stratification post prostatectomy. However, their clinical benefit has not been prospectively demonstrated. We sought to determine the impact of GC testing on postoperative management in men with prostate cancer post prostatectomy. METHODS: Two prospective registries of prostate cancer patients treated between 2014 and 2019 were included. All men underwent Decipher tumor testing for adverse features post prostatectomy (Decipher Biosciences, San Diego, CA). The clinical utility cohort, which measured the change in treatment decision-making, captured pre- and postgenomic treatment recommendations from urologists across diverse practice settings (n = 3455). The clinical benefit cohort, which examined the difference in outcome, was from a single academic institution whose tumor board predefined "best practices" based on GC results (n = 135). RESULTS: In the clinical utility cohort, providers' recommendations pregenomic testing were primarily observation (69%). GC testing changed recommendations for 39% of patients, translating to a number needed to test of 3 to change one treatment decision. In the clinical benefit cohort, 61% of patients had genomic high-risk tumors; those who received the recommended adjuvant radiation therapy (ART) had 2-year PSA recurrence of 3 vs. 25% for those who did not (HR 0.1 [95% CI 0.0-0.6], p = 0.013). For the genomic low/intermediate-risk patients, 93% followed recommendations for observation, with similar 2-year PSA recurrence rates compared with those who received ART (p = 0.93). CONCLUSIONS: The use of GC substantially altered treatment decision-making, with a number needed to test of only 3. Implementing best practices to routinely recommend ART for genomic-high patients led to larger than expected improvements in early biochemical endpoints, without jeopardizing outcomes for genomic-low/intermediate-risk patients.

Acute Gastrointestinal Hemorrhage due to Epstein-Barr Virus Colitis.

Epstein-Barr virus (EBV) is a member of the herpesvirus family that is associated with various disease manifestations, including EBV-associated colitis. There are few case reports describing hemorrhage associated with EBV colitis. We report a 61-year-old woman with acute gastrointestinal bleeding due to EBV colitis after initiation of methylprednisolone and enoxaparin for spinal cord infarction. To our knowledge, there are only a few case reports of hemorrhagic EBV colitis. Perhaps we need to have a higher suspicion for EBV in cases of colitis associated with hemorrhage even in relatively immunocompetent patients.