Metastatic Spread Research Articles

Common hepatic artery lymph node metastasis in pancreatic ductal adenocarcinoma: an analysis of actual survival

BackgroundThe common hepatic artery lymph node represents a second-echelon node for tumors in the head of the pancreas. Although early studies suggested survival was comparable between the common hepatic artery lymph node and remote metastasis in pancreatic ductal adenocarcinoma, whether the lymph node is associated with adverse survival remains equivocal. Here, we examined a prospective cohort of patients calculating actual survival to better understand implications of this specific lymph node metastasis. MethodsWe studied 215 patients with pancreatic head pancreatic ductal adenocarcinoma, who underwent pancreaticoduodenectomies at a single institution from 2010 to 2017 wherein the common hepatic artery lymph nodes were excised. We performed actual and actuarial overall survival and disease-free survival analyses, with subsequent univariate and multivariate analyses in node-positive patients. ResultsOf this cohort, 7.3% of patients had involvement of the common hepatic artery lymph node, and all of them had metastatic spread to first echelon nodes. Actual median survival of patients with no lymph node involvement was 49 months. In patients with any nodal involvement, the survival was no different when comparing the lymph node positive and negative (13 and 20 months, respectively). Univariate and multivariate analyses likewise attached no significance to the lymph node metastasis, while demonstrating worse survival with positive margin status and poorly differentiated histology. Our disease-free survival analyses yielded similar results. ConclusionsWe found no difference in actual survival in node-positive patients regardless of the common hepatic artery lymph node involvement and recommend against its assessment in prognosticating survival or guiding surgical treatment.

A multi-lesional analysis of diffuse idiopathic pulmonary neuroendocrine cell hyperplasia: a single-centre analysis

To conduct a multi-lesional computed tomography (CT) analysis of diffuse idiopathic pulmonary neuroendocrine cell hyperplasia (DIPNECH) patients to determine volumetric changes in lesions over 5 years. A retrospective case-note review was undertaken to identify 16 patients with histological and radiological features of DIPNECH between 2012-2021. Area and volume were calculated for 17 sets of lesions identified on high-resolution CT. Clinical data were extracted from electronic patient records, which included demographic data, outpatient clinic letters, histology reports, and imaging reports. One hundred and twenty-eight lesions were identified in 16 patients (one male, 15 female) and followed-up annually over a median 1,985 days (range 1,450-2,290). At year 1 follow-up, lesion area ranged from 1-48 mm2, and lesion volume ranged from 8-18,380 mm3; lesion area ranged from 1-45mm2 and lesion volume ranged from 11-17,800 mm3 and year 5. Half (8/16) of the patients had concomitant typical carcinoid tumours and one patient had an atypical carcinoid tumour. No statistically significant correlation (p<0.05) was found between lesion cross-sectional area or volume and duration of follow-up (years and days). No metastatic spread was observed at the time of analysis. No significant increase was observed in the size of over 100 lesions in patients with DIPNECH over a 5-year period and no metastasis occurred during the study period affirming the relatively indolent course of the disease.

Therapeutic interventions on human breast cancer xenografts promote systemic dissemination of oncogenes.

Metastatic dissemination following successful treatment of the primary tumour remains a common cause of death. There is mounting evidence that therapeutic interventions themselves may promote development of metastatic disease. We earlier reported that cell-free chromatin particles (cfChPs) released from dying cancer cells are potentially oncogenic. Based on this observation we hypothesized that therapeutic interventions may lead to the release of cfChPs from therapy induced dying cancer cells which could be carried via the blood stream to distant organs to transform healthy cells into new cancers that would masquerade as metastasis. To test this hypothesis, we generated xenografts of MDA-MB-231 human breast cancer cells in severe combined immune-deficient mice, and using immuno-fluorescence and FISH analysis looked for cfChPs in their brain cells. We detected multiple human DNA signals representing cfChPs in nuclei of brain cells of mice which co-localized with eight human onco-proteins. No intact MDA-MB-231 cells were detected. The number of co-localizing human DNA and human c-Myc signals increased dramatically following treatment with chemotherapy, localized radiotherapy or surgery, which could be prevented by concurrent treatment with three different cfChPs deactivating agents. These results suggest that therapeutic interventions lead to the release cfChPs from therapy induced dying cancer cells carrying oncogenes and are transported via the blood stream to brain cells to potentially transform them to generate new cancers that would appear as metastases. cfChPs induced metastatic spread of cancer is preventable by concurrent treatment with agents that deactivate cfChPs.

A Model for Membrane Degradation Using a Gelatin Invadopodia Assay.

One of the most crucial and lethal characteristics of solid tumors is represented by the increased ability of cancer cells to migrate and invade other organs during the so-called metastatic spread. This is allowed thanks to the production of matrix metalloproteinases (MMPs), enzymes capable of degrading a type of collagen abundant in the basal membrane separating the epithelial tissue from the connective one. In this work, we employ a synergistic experimental and mathematical modelling approach to explore the invasion process of tumor cells. A mathematical model composed of reaction-diffusion equations describing the evolution of the tumor cells density on a gelatin substrate, MMPs enzymes concentration and the degradation of the gelatin is proposed. This is completed with a calibration strategy. We perform a sensitivity analysis and explore a parameter estimation technique both on synthetic and experimental data in order to find the optimal parameters that describe the in vitro experiments. A comparison between numerical and experimental solutions ends the work.

Androgen drives melanoma invasiveness and metastatic spread by inducing tumorigenic fucosylation

Melanoma incidence and mortality rates are historically higher for men than women. Although emerging studies have highlighted tumorigenic roles for the male sex hormone androgen and its receptor (AR) in melanoma, cellular and molecular mechanisms underlying these sex-associated discrepancies are poorly defined. Here, we delineate a previously undisclosed mechanism by which androgen-activated AR transcriptionally upregulates fucosyltransferase 4 (FUT4) expression, which drives melanoma invasiveness by interfering with adherens junctions (AJs). Global phosphoproteomic and fucoproteomic profiling, coupled with in vitro and in vivo functional validation, further reveal that AR-induced FUT4 fucosylates L1 cell adhesion molecule (L1CAM), which is required for FUT4-increased metastatic capacity. Tumor microarray and gene expression analyses demonstrate that AR-FUT4-L1CAM-AJs signaling correlates with pathological staging in melanoma patients. By delineating key androgen-triggered signaling that enhances metastatic aggressiveness, our findings help explain sex-associated clinical outcome disparities and highlight AR/FUT4 and its effectors as potential prognostic biomarkers and therapeutic targets in melanoma.

Quality of Life of Oligometastatic and Polymetastatic Head and Neck Squamous Cell Carcinoma Patients.

Evidence suggests that distant metastasis in head and neck squamous cell carcinoma is a spectrum of disease. Previous studies show that oligometastasis has favorable survival compared with polymetastasis. The quality of life of patients with oligometastasis remains unknown. To further solidify the position of oligometastasis as a separate entity, we hypothesized that oligometastatic patients experience better quality of life than polymetastatic patients. Patients with distant metastasis were stratified into three groups: oligometastasis (≤3 metastatic foci in ≤2 anatomic sites), explosive metastasis (≥4 metastatic foci at one anatomic site), and explosive-disseminating metastasis (spread to ≥3 anatomic sites). Quality of life was assessed every 2 months post distant metastasis diagnosis. Between January 1, 2016, and December 31, 2021, a total of 161 patients with distant metastasis were identified, with a total of 397 measurements. In this group, 57 (35.4%) patients had oligometastasis, 35 (21.7%) patients had explosive metastasis, and 69 (42.9%) patients had explosive-disseminating metastasis. Their median post-distant metastasis survivals were 8.5 months, 3.2 months, and 3.2 months respectively (p < 0.001). A significantly better overall quality of life was observed in the oligometastasis group compared with the polymetastatic groups (+0.75 out of 7, p < 0.05). Furthermore, oligometastatic patients performed better in the subdomains of "physical functioning," "fatigue," and "pain." Results from this study underscore that subgroups exist regarding quality of life and survival within distant metastasis, with polymetastatic patients performing worse than oligometastatic patients. This highlights the significance of tailored interventions that consider the unique challenges faced by each metastatic group of patients. 3, retrospective cohort study Laryngoscope, 134:3170-3176, 2024.

B10 cells: Development, phenotype, and function in cancer.

B10 cells, a specialized subset of regulatory B cells, have been identified in both mice and humans. These cells are characterized by their regulatory impact on immune dynamics, principally through their secretion of interleukin-10 (IL-10), a cytokine known for its anti-inflammatory properties. The pivotal role of immune mediators such as B10 cells is to maintain a delicate equilibrium between antitumor immunity and tumor-promoting responses. Emerging studies have cast B10 cells as key suppressors in the antitumor immune arsenal. They operate in synergy with a spectrum of immune cells within the innate and adaptive spectrums, contributing to a milieu that favors tumor progression and metastatic spread. In this comprehensive review, we will discuss the ontogeny, phenotype and effector functions of B10 cells in murine systems. We will also review the role of B10 cells in oncological models in animal studies and extend these findings to the human clinical context, elucidating their role in facilitating tumor immune evasion. A thorough understanding of these processes is imperative for the strategic targeting and attenuation of B10 cell activity, which is anticipated to be a cornerstone in the advancement of effective cancer immunotherapy strategies.

Extra-Capsular Spread of Lymph Node Metastasis in Oral, Oropharyngeal and Hypopharyngeal Cancer: A Comparative Subsite Analysis

Background: The extra-capsular spread (ECS) of lymph node metastasis (LNM) is a hallmark of aggressive primary tumor phenotype in head and neck cancer (HNC); however, the factors influencing ECS are poorly understood. Patients and Methods: This was a retrospective study, including 190 cases of oral tongue cancer (OTC), 148 cases of oropharyngeal cancer (OPC) (118 HPV-positive and 30 HPV-negative), and 100 cases of hypopharyngeal cancer (HPC). Tumor dimension, tumor biological variables (lymphovascular/perineural invasion and histologic grade), and LNM variables (LNM number and size) were analyzed according to the presence of ECS using multivariable logistic regression and receiver operating characteristic (ROC) curve analyses. Results: LNM variables were significant factors for ECS in all subsites of HNC (p &lt; 0.05), except HPV-positive OPC. In OTC, tumor dimensional variables were significantly related to ECS (p &lt; 0.01). Meanwhile, in OPC and HPC, neither the primary tumor dimension nor the T status were significant factors for ECS occurrence. The predictability of ECS by ROC curve using multiple variables was 0.819 [95% confidence interval: 0.759–0.878] in OTC, 0.687 [0.559–0.815] in HPV-positive OPC, 0.823 [0.642–1.000] in HPV-negative OPC, and 0.907 [0.841–0.973] in HPC. Conclusion: LNM variables were correlated with ECS occurrence for most HNC subsites, and site-dependent primary tumor characteristics might contribute differentially to the ECS development of LNM in HNC.

Abstract B001: Elucidating metastatic pathways in pediatric cancers

Abstract The most common cause of death in pediatric cancer patients is a treatment resistant tumor, often further complicated by metastatic spread to multiple sites, making both surgery and radiation therapy unfeasible as curative treatment options. How metastatic spread occurs in pediatric tumors is to a large extent completely unexplored. We aimed to elucidate the evolutionary trajectories of metastatic disease in the pediatric tumors, neuroblastoma, Wilms tumor and germ cell tumors, which are the most common tumors in children besides tumors of the central nervous system and leukemias. More specifically we wanted to decipher when in the evolutionary history of the tumor, metastases appear, whether there were signs of monoclonal or polyclonal spread (one or several subclones from the primary tumor colonizing the same metastatic site), mono- or polyphyletic spread (one subclone or several subclones colonizing several metastatic sites) and intermetastatic spread (subclones from one metastatic site spreading to another). Due to the spatiotemporal genetic heterogeneity of tumors, DNA was extracted from multiple sites from the primary tumor and several metastatic sites for each patient. A total of 174 samples from 18 patients were included. All samples underwent whole genome copy number profiling and a subset also targeted deep sequencing. Phylogenetic trees were reconstructed, allowing spatiotemporal tracking of subclones for each patient. Having a median of 8 (range 4 to 22) samples available per patient we could confirm an extensive genetic heterogeneity within and between the primary tumor and metastases in each patient, stressing the importance of multiregional sampling to fully characterize the disease. In 13 of 18 patients, early metastatic spread was identified and a total of 6 of 18 patients displayed both polyphyletic and polyclonal seeding. Hence metastatic spread can occur several times during tumor evolution, several subclones possess metastatic capability and several different subclones may colonize the same site. We also found that a higher number of subclones from the primary tumor metastasize to the lymph nodes compared to distant sites, suggesting a weaker evolutionary bottleneck for locoregional lymphatic spread. Finally, intermetastatic spread could be identified in 7 out of 11 patients having metastases in at least 2 different distant sites. Our results provide further knowledge of the evolutionary dynamics of metastatic spread in pediatric cancer patients. Metastases often have a different genomic profile than the primary tumor, stressing the need to sample metastases for assessment of therapeutic targets, since metastases may completely lack targets present in the primary, resulting in progression at distant sites despite the primary tumor responding to treatment. We also found that metastatic spread can occur early and several times during tumor evolution. Strikingly, intermetastatic spread is identified as a common feature in pediatric tumors, indicating that metastases alone may act as a hub for further metastatic spread. Citation Format: Natalie Andersson, Michele Ferro, Caroline Jansson, Jenny Karlsson, Linda Holmquist Mengelbier, Subhayan Chattopadhyay, David Gisselsson. Elucidating metastatic pathways in pediatric cancers [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Translating Cancer Evolution and Data Science: The Next Frontier; 2023 Dec 3-6; Boston, Massachusetts. Philadelphia (PA): AACR; Cancer Res 2024;84(3 Suppl_2):Abstract nr B001.

Surgical Treatment and Outcome of Ovarian Cancer Patients With Liver Metastases: Experience of a Tertiary Hepatic and Peritoneal Surface Malignancy Center.

The aim of this study was to describe and evaluate the patterns, perioperative outcomes, and survival rates of patients subjected to hepatic resections for ovarian-derived liver metastasis as part of cytoreductive surgery with or without hyperthermic intraperitoneal chemotherapy (HIPEC). Furthermore, we investigated two subgroups of tumor patterns: hematogenous liver metastasis and infiltrative liver metastatic spread. A retrospective study was conducted. Patients from a University Tertiary Hepatic and Peritoneal Surface Malignancy Center with primary or recurrent ovarian cancer, who underwent liver resection as part of cytoreductive surgery between January 1992 and December 2022, were included. Data from 35 patients were analyzed. Both median overall survival (OS) and disease-specific survival (DSS) were 24.97 months. In a multivariate setting, the combined effect of age, peritoneal carcinomatosis index, body mass index, hematogenous liver metastasis vs. infiltrative spread types, and HIPEC (HR=0.2372; 95%CI=0.0719-0.7823; p=0.0181) over OS was tested. Survival analysis revealed no differences between the two metastatic spread types (OS: p=0.9720; DSS: p=0.9610). Younger age (p=0.0301), splenectomy (p=0.0320), lesser omentectomy (p=0.0178), and right upper quadrant peritonectomy (p=0.0373) were more characteristic for those patients with infiltrative liver metastatic spread. Complete cytoreductive surgery, including hepatic resection is a feasible approach with or without additional HIPEC, which may provide survival benefit for patients with advanced and/or recurrent ovarian cancer. If metastatic and infiltrative liver involvement is suspected, liver-specific imaging is recommended.

Underutilization of androgen deprivation therapy (ADT) intensification for the treatment of men with metastatic hormone-sensitive prostate cancer (mHSPC): A systematic review of real-world database studies.

66 Background: In the last decade, intensification of ADT with chemotherapy or androgen receptor pathway inhibitors (ARPi) has shown clinical benefits for men with mHSPC compared to ADT alone and has been recommended for mHSPC in clinical guidelines. The transition of these guidelines into real-world practice was investigated by several studies; however, these data have not been systematically summarized across the globe. Thus, we conducted a systematic literature review of real-world database (RWD) studies to summarize treatment patterns in mHSPC. Methods: An electronic search was performed in PubMed and Embase (covering citations until July 2023) and for relevant conferences of the past 2 years to identify RWD studies examining treatment patterns in men with mHSPC. Treatment patterns were summarized by overall study population across major geographies and factors associated with ADT intensification were described. Results: Of 2,325 retrieved citations, 29 studies met the inclusion criteria, with a total of 344,473 men with mHSPC covering study periods from 2014 to 2021. Most were cohort studies (n=26), utilizing electronic medical records (EMR)/chart reviews (n=18), and with RWDs from the United States (US) (n=21), followed by Europe (n=8), and Asia (n=6). Most studies included men with a median age of ≥70 years (n=23) and &gt;80% of men had an Eastern Cooperative Oncology Group performance status (ECOG PS) of 0/1 (n=5 of 8). In the US, most studies showed that ADT monotherapy was predominantly utilized (&gt;50%), followed by ADT/ARPi (20-40%), and ADT/chemotherapy (10-20%). Abiraterone was the most frequently used ARPi followed by enzalutamide. In Europe, most studies also reported ADT monotherapy (&gt;45%), followed by ADT/ARPi (11-25%), or ADT/chemotherapy (12-34%). In Asia, ADT monotherapy (&gt;62%) was the most common treatment in most studies, with low use of ADT/ARPIs (&lt;20%), and ADT/chemotherapy (&lt;15%). A few studies with recent EMR data (covering the 2020-21 data period) from cancer centers/registries showed high use of ADT/ARPi (&gt;40%) in both the US and Europe. Reported quantitative factors (n=13) associated with intensification beyond ADT were high disease burden (spread of metastases, high volume), young age, ECOG PS 0/1, low comorbidities, and treating physician specialty-oncologist; qualitative factors (n=2) were patient preference, unsatisfactory response to ADT treatment, ability to tolerate adverse events, and lack of cost barriers. Conclusions: This comprehensive review shows ADT monotherapy remained highly utilized across major geographies until 2021 despite new evidence and updated guideline recommendations. However, the utilization of intensified treatment with ARPi combinations is slowly increasing after the recent approvals in mHSPC.

HnRNPR-mediated UPF3B mRNA splicing drives hepatocellular carcinoma metastasis

IntroductionAbnormal alternative splicing (AS) contributes to aggressive intrahepatic invasion and metastatic spread, leading to the high lethality of hepatocellular carcinoma (HCC). ObjectivesThis study aims to investigate the functional implications of UPF3B-S (a truncated oncogenic splice variant) in HCC metastasis. MethodsBasescope assay was performed to analyze the expression of UPF3B-S mRNA in tissues and cells. RNA immunoprecipitation, and in vitro and in vivo models were used to explore the role of UPF3B-S and the underlying mechanisms. ResultsWe show that splicing factor HnRNPR binds to the pre-mRNA of UPF3B via its RRM2 domain to generate an exon 8 exclusion truncated splice variant UPF3B-S. High expression of UPF3B-S is correlated with tumor metastasis and unfavorable overall survival in patients with HCC. The knockdown of UPF3B-S markedly suppresses the invasive and migratory capacities of HCC cells in vitro and in vivo. Mechanistically, UPF3B-S protein targets the 3′-UTR of CDH1 mRNA to enhance the degradation of CDH1 mRNA, which results in the downregulation of E-cadherin and the activation of epithelial–mesenchymal transition. Overexpression of UPF3B-S enhances the dephosphorylation of LATS1 and the nuclear accumulation of YAP1 to trigger the Hippo signaling pathway. ConclusionOur findings suggest that HnRNPR-induced UPF3B-S promotes HCC invasion and metastasis by exhausting CDH1 mRNA and activating YAP1-Hippo signaling. UPF3B-S could potentially serve as a promising biomarker for the clinical management of invasive HCC.

Abstract B023: Ectopic Expression of the Obscurin PH-domain in Aggressive Breast Cancer Cells Modulates PI3K/Akt Activity and Inhibits Cellular Migration and Invasion

Abstract New therapies targeting metastatic spread are greatly needed to improve breast cancer patient survival. Recently, obscurin, an ~800kDa protein localized to the cell membrane, has risen to the spotlight as an overlooked metastasis suppressor commonly lost in breast cancer. Specifically, breast epithelial cells lacking obscurin undergo epithelial-mesenchymal transition (EMT) and demonstrate increased migration and invasion. Biochemical studies in our lab have linked breast epithelial obscurin loss to increased activation of the pro-metastatic PI3K/Akt signaling pathway. Mechanistically, the obscurin pleckstrin homology (PH)-domain directly binds the SH3-domain of the p85 regulatory subunit of PI3K. Thus far, due to obscurin’s massive size, gain of function/rescue experiments of obscurin have not been feasible. To combat this challenge, we have generated a mini-obscurin protein construct composed of an obscurin core functional unit: a myristilated obscurin PH-domain (Myr-PH). We hypothesized that expression of Myr-PH in obscurin-low breast cancer cells will reduce PI3K/Akt pathway activity and suppress metastasis. Remarkably, we report that ectopic expression of Myr-PH in the obscurin-low MDA-MB-231 (triple negative) and SKBr3 (HER2 positive) breast cancer cell lines diminishes PI3K/Akt pathway activity. Furthermore, Myr-PH sequesters p85 to the cell membrane, anchoring actin at the cell periphery. Functionally, we demonstrate that expression of Myr-PH in both cell line receptor subtypes: 1) reduces cellular migration collectively through decreased scratch assay wound closure and decreased transwell assay 8um pore migration or at the single cell level, through reduced 3um diameter microchannel migration, 2) diminishes cell seeding on multiple extracellular matrix (ECM) substrates known to populate metastatic microenvironments, and 3) decreases cell dissemination and tumorsphere invasion into a 3D collagen-1 matrix. Underlying these functional changes, we show that Myr-PH inhibits actin-dependent filopodia and invadopodia formation and decreases the expression of downstream PI3K/Akt target matrix metalloproteinases, all of which are potent drivers of metastatic dissemination. To this end, we are currently delivering the obscurin-PH domain in animals via lipid nanoparticles, aiming to examine its anti-metastatic efficacy in vivo. If successful, this work would pioneer the first gene therapy-based, targeted use of a single metastasis suppressor protein domain to block PI3K signaling and inhibit breast cancer metastasis. Citation Format: Matthew K Eason, Se-Jong Lee, Poornima Dubey, Anthony Kim, Konstantinos Konstantopoulos, Aikaterini Kontrogianni-Konstantopoulos. Ectopic Expression of the Obscurin PH-domain in Aggressive Breast Cancer Cells Modulates PI3K/Akt Activity and Inhibits Cellular Migration and Invasion [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Advances in Breast Cancer Research; 2023 Oct 19-22; San Diego, California. Philadelphia (PA): AACR; Cancer Res 2024;84(3 Suppl_1):Abstract nr B023.

Abstract PR06: Uncovering nuclear expulsion: chromatin-bound signals from dying cancer cells accelerate metastatic outgrowth through S100A4-RAGE pathway

Abstract Tumor cells are highly heterogeneous, exhibiting diverse responses when exposed to different environments. We have recently observed this heterogeneity in tumor cell apoptosis by which some tumor cell die for the benefits of the population’s survival. Majority of tumor cells undergo apoptosis in response to immune surveillance, various treatments, and a hostile microenvironment, both in circulation and at metastatic organ sites. However, the full range of apoptotic signals, or "last words," that dying cells communicate to the surviving cancer cell community remains incompletely understood. While apoptotic cell death is often perceived as a favorable therapeutic outcome, tumor cells can exploit it to enhance their metastatic capabilities, leading to poor prognoses in certain cancers. Here, we present a remarkable discovery of an altered apoptotic program in tumor cells characterized by nuclear expulsion and citrullinated chromatin, promoting metastatic outgrowth in the lungs in a Padi4-dependent manner. We further identified a calcium spike during apoptosis as the trigger for Padi4 activation, resulting in rapid chromatin de-condensation, nuclear content expulsion, followed by the generation of nuclear expulsion products (NEPs). This process was observed in various types of human cancer tissues. Profiling of proteins bound to the NEP complex unveiled an enrichment of receptor for advanced glycation end-products (RAGE) pathway proteins, such as S100a4 in mouse NEPs and high-mobility group-binding (HMGB) proteins in human NEPs. These chromatin-bound RAGE ligands activated RAGE receptors in neighboring surviving tumor cells, leading to Erk pathway activation. This, in turn, promotes proliferation through the RAGE-MAPK pathway. A nuclear expulsion signature was associated with worse prognoses in cancer patients, underscoring the clinical efficacy in the context of apoptosis-inducing treatments. As we continue our investigations, we are particularly interested in understanding how dying tumor cell-derived NEPs from chemotherapy may affect therapy outcomes. Taken together, our studies uncover a novel mechanism by which tumor cells come together as a community and that the apoptotic tumor cells help live tumor cells metastasize. This insight is likely a step forward to understand the mechanisms of metastatic spread, treatment resistance and relapse. Citation Format: Wooyong Park, Justin M Gray, Ronald J Holewinski, Thorkell Andresson, Jae Young So, Carmelo M Carmona-Rivera, Mariana J Kaplan, Steven D Cappell, Li Yang. Uncovering nuclear expulsion: chromatin-bound signals from dying cancer cells accelerate metastatic outgrowth through S100A4-RAGE pathway [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Advances in Breast Cancer Research; 2023 Oct 19-22; San Diego, California. Philadelphia (PA): AACR; Cancer Res 2024;84(3 Suppl_1):Abstract nr PR06.

Racial disparities in GU cancer metastasis: A comprehensive analysis from 2010-2018.

30 Background: Patterns of metastatic spread vary between bladder, kidney, and prostate metastasis. Of these cancers, kidney cancer often spreads to the brain, while prostate cancer is most likely to spread to bone, for example. Sites of metastasis can influence prognosis and in some instances may even direct therapy. The knowledge gap on racial disparities in metastatic patterns merits further investigation. Methods: Using the Surveillance, Epidemiology, and End Results (SEER) database, we identified bladder, kidney, and prostate cancer patients (2010-2018) in White (W) and Black (B) races. Data on metastasis to the lungs, liver, bones, and brain at diagnosis were extracted. The relative risk (RR) was calculated to compare the metastatic patterns between Black and White patients. P-value, and confidence interval were computed using SPSS 28.0. Results: 3.95% of Black and 1.65% of White patients had metastasis at diagnosis. Black patients had metastasis prevalence of 3.2% lung, 1.8% liver, 4.4% bone, and 0.3% brain. Comparatively, White patients had 1.3%, 0.8%, 3.2%, and 0.3% respectively. For bladder cancer, Black patients had a 60% higher risk for bone and lung metastasis and double the risk for liver metastasis compared to White patients. In kidney cancer, Black patients had a 90% higher brain metastasis risk but 20% lower for bone and lung than White patients. For prostate, Black patients had comparatively heightened risks of bone, lung, and liver metastases by 10%, 20%, and 30%, respectively. Conclusions: Racial disparities are evident in GU cancer metastatic patterns at time of diagnosis. Black patients especially have higher liver metastasis, often associated with poor prognosis. Further studies are vital to unravel biological, socioeconomic, and other contributing factors. [Table: see text]

Utility of PSMA PET/CT for imaging ductal carcinoma of the prostate.

49 Background: Ductal carcinoma (DC) is the second most commonly encountered histologic variant of prostate cancer. Previous studies have described its molecular features and aggressive behavior, but few have explored the performance of PSMA PET/CT in the initial staging and follow-up of DC. Methods: To address this gap, we performed a single-institution retrospective analysis using the Mayo Clinic PSMA PET database. All patients receiving a PSMA PET/CT scan in the interval of January 1, 2021, to December 31, 2022, were eligible for inclusion. Cases were filtered and categorized by histology at the time of diagnosis to select for pure DAC and mixed ductal variants. Trained research personnel annotated disease- and treatment-related variables. A board-certified radiologist performed tumor burden segmentation with calculations of SUV max, total lesion SUV mean and volume, and total lesion uptake, and ascribed a miPSMA expression score. Results: We queried 1792 patients from our PSMA PET/CT registry and identified 32 (1.8%) patients with a pathologically confirmed DC, including 8 (25%) patients with pure ductal and 25 (75%) patients with mixed histology. The indication for PSMA PET/CT was biochemical progression or restaging for 29 (91%) patients and initial staging for 3 (9%) patients. The median (IQR) time from prostate cancer diagnosis to PSMA PET scan was 41.6 (11.5-64.7) months, during this time 50% (n= 16) of patients developed CRPC. At the time of the PSMA PET/CT scan, the median age was 70 years, the median (IQR) PSA was 0.5 ng/mL (0.2-2.6). The distribution of metastatic spread and quantitative imaging parameters from PSMA PET are shown in the Table. Conclusions: Despite low PSA at the time of imaging, PSMA PET/CT frequently detected high volume osseous and/or visceral metastases in patients with DC. However, it is noteworthy that more than 50% of patients with DC had a low miPSMA score (0-1). Additional studies are needed to better understand the performance of novel imaging modalities when evaluating variant prostate cancers. [Table: see text]

THBS1 and THBS2 Enhance the In Vitro Proliferation, Adhesion, Migration and Invasion of Intrahepatic Cholangiocarcinoma Cells.

In intrahepatic cholangiocarcinoma (iCCA), thrombospondin 1 (THBS1) and 2 (THBS2) are soluble mediators released in the tumor microenvironment (TME) that contribute to the metastatic spreading of iCCA cells via a lymphatic network by the trans-differentiation of vascular endothelial cells to a lymphatic-like phenotype. To study the direct role of THBS1 and THBS2 on the iCCA cells, well-established epithelial (HuCCT-1) and mesenchymal (CCLP1) iCCA cell lines were subjected to recombinant human THBS1 and THBS2 (rhTHBS1, rhTHBS2) for cellular function assays. Cell growth, cell adhesion, migration, and invasion were all enhanced in both CCLP1 and HuCCT-1 cells by the treatment with either rhTHBS1 or rhTHBS2, although they showed some variability in their intensity of speeding up cellular processes. rhTHBS2 was more intense in inducing invasiveness and in committing the HuCCT-1 cells to a mesenchymal-like phenotype and was therefore a stronger enhancer of the malignant behavior of iCCA cells compared to rhTHBS1. Our data extend the role of THBS1 and THBS2, which are not only able to hinder the vascular network and promote tumor-associated lymphangiogenesis but also exacerbate the malignant behavior of the iCCA cells.

Cytoskeleton remodeling induced by SMYD2 methyltransferase drives breast cancer metastasis

Malignant forms of breast cancer refractory to existing therapies remain a major unmet health issue, primarily due to metastatic spread. A better understanding of the mechanisms at play will provide better insights for alternative treatments to prevent breast cancer cell dispersion. Here, we identify the lysine methyltransferase SMYD2 as a clinically actionable master regulator of breast cancer metastasis. While SMYD2 is overexpressed in aggressive breast cancers, we notice that it is not required for primary tumor growth. However, mammary-epithelium specific SMYD2 ablation increases mouse overall survival by blocking the primary tumor cell ability to metastasize. Mechanistically, we identify BCAR3 as a genuine physiological substrate of SMYD2 in breast cancer cells. BCAR3 monomethylated at lysine K334 (K334me1) is recognized by a novel methyl-binding domain present in FMNLs proteins. These actin cytoskeleton regulators are recruited at the cell edges by the SMYD2 methylation signaling and modulate lamellipodia properties. Breast cancer cells with impaired BCAR3 methylation lose migration and invasiveness capacity in vitro and are ineffective in promoting metastases in vivo. Remarkably, SMYD2 pharmacologic inhibition efficiently impairs the metastatic spread of breast cancer cells, PDX and aggressive mammary tumors from genetically engineered mice. This study provides a rationale for innovative therapeutic prevention of malignant breast cancer metastatic progression by targeting the SMYD2-BCAR3-FMNL axis.

Eosinophilic Solid and Cystic Renal Cell Carcinoma: Morphologic and Immunohistochemical Study of 18 Cases and Review of the Literature.

Eosinophilic solid and cystic renal cell carcinoma is now defined in the 5th edition of the 2022 World Health Organization classification of urogenital tumors. To perform morphologic, immunohistochemical, and preliminary genetic studies about this new entity in China for the purpose of understanding it better. The study includes 18 patients from a regional tertiary oncology center in northern China (Tianjin, China). We investigated the clinical and immunohistochemical features of these cases. The mean age of patients was 49.6 years, and the male to female ratio was 11:7. Macroscopically, 1 case had the classic cystic and solid appearance, whereas the others appeared purely solid. Microscopically, all 18 tumors shared a similar solid and focal macrocystic or microcystic growth pattern, and the cells were characterized by voluminous and eosinophilic cytoplasm, along with coarse amphophilic stippling. Immunohistochemically, most of the tumors had a predominant cytokeratin (CK) 20-positive feature, ranging from focal cytoplasmic staining to diffuse membranous accentuation. Initially, we separated these cases into different immunohistochemical phenotypes. Group 1 (7 of 18; 38.5%) was characterized by positive phospho-4EBP1 and phospho-S6, which can imply hyperactive mechanistic target of rapamycin complex 1 (mTORC1) signaling. Group 2 (4 of 18; 23%) was negative for NF2, probably implying a germline mutation of NF2. Group 3 (7 of 18; 38.5%) consisted of the remaining cases. One case had metastatic spread and exhibited an aggressive clinical course, and we detected cyclin-dependent kinase inhibitor 2A (CDKN2A) mutation in this case; other patients were alive and without disease progression. Our research proposes that eosinophilic solid and cystic renal cell carcinoma exhibits prototypical pathologic features with CK20 positivity and has aggressive potential.

Inhibition of proprotein convertases activity results in repressed stemness and invasiveness of cancer stem cells in gastric cancer.

Gastric cancer (GC), the fourth leading cause of cancer-related death worldwide, with most deaths caused by advanced and metastatic disease, has limited curative options. Here, we revealed the importance of proprotein convertases (PCs) in the malignant and metastatic potential of GC cells through the regulation of the YAP/TAZ/TEAD pathway and epithelial-to-mesenchymal transition (EMT) in cancer stem cells (CSC). The general PCs inhibitor, decanoyl-RVKR-chloromethyl-ketone (CMK), was used to repress PCs activity in CSCs of various GC cell lines. Their tumorigenic properties, drug resistance, YAP/TAZ/TEAD pathway activity, and invasive properties were then investigated in vitro, and their metastatic properties were explored in a mouse xenograft model. The prognostic value of PCs in GC patients was also explored in molecular databases of GC. Inhibition of PCs activity in CSCs in all GC cell lines reduced tumorsphere formation and growth, drug efflux, EMT phenotype, and invasive properties that are associated with repressed YAP/TAZ/TEAD pathway activity in vitro. In vivo, PCs' inhibition in GC cells reduced their metastatic spread. Molecular analysis of tumors from GC patients has highlighted the prognostic value of PCs. PCs are overexpressed in GC and associated with poor prognosis. PCs are involved in the malignant and metastatic potential of CSCs via the regulation of EMT, the YAP/TAZ/TEAD oncogenic pathway, and their stemness and invasive properties. Their repression represents a new strategy to target CSCs and impair metastatic spreading in GC.