Adenocarcinoma Research Articles

A real-world study: third-line treatment options for metastatic colorectal cancer

BackgroundNumerous third-line treatment options exist for colorectal cancer. This study aims to assess the efficacy and safety of third-line therapies, including TKIs (fruquintinib, regorafenib) combined with PD-1 inhibitors, and trifluridine/tipiracil combined with bevacizumab, in patients with refractory microsatellite stable metastatic colorectal cancer who have progressed or are intolerant following standard first- and second-line treatments.Materials and methodsThis retrospective analysis collected data from patients with microsatellite stable advanced colorectal adenocarcinoma, diagnosed through histopathology and treated at Henan Provincial Cancer Hospital from May 2019 to April 2023. We compared the efficacy and safety of fruquintinib combined with PD-1 inhibitors, regorafenib combined with PD-1 inhibitors, and trifluridine/tipiracil combined with bevacizumab.ResultsAmong 60 eligible patients with refractory microsatellite stable metastatic colorectal adenocarcinoma, 29 (48.3%) received fruquintinib combined with PD-1 inhibitors, 15 (25%) received regorafenib combined with PD-1 inhibitors, and 16 (26.7%) received trifluridine/tipiracil combined with bevacizumab. The average follow-up period was 12.6 months (ranging from 2.3 to 37.6 months). After third-line treatment, the overall objective response rate (ORR) was 8.6%, and the disease control rate (DCR) was 78.6%. The median overall survival (OS) for the regorafenib, fruquintinib, and trifluridine/tipiracil groups was 19.2 months, 14.0 months, and 16.2 months, respectively, with no statistically significant differences observed. However, there were statistically significant differences in progression-free survival (PFS); the median PFS for the regorafenib group was 6.3 months, for the fruquintinib group was 4.2 months, and for the trifluridine/tipiracil group was 5.4 months. Pairwise comparisons indicated that the PFS for the regorafenib group was similar to that for the trifluridine/tipiracil group, both of which were superior to the fruquintinib group. Cox univariate regression analysis revealed that the presence of liver and peritoneal metastases was associated with PFS in third-line treatment.ConclusionIn the third-line treatment of colorectal cancer, regorafenib combined with PD-1 inhibitors and trifluridine/tipiracil combined with bevacizumab showed superiority over fruquintinib combined with PD-1 inhibitors in terms of PFS, but no statistically significant difference in OS was noted among the three groups.

Computer Assisted Nodule Analysis and Risk Yield is Associated with Occult Lymph Node Status in Clinical Stage I-IIA Lung Adenocarcinoma Undergoing Resection

BackgroundCurrent staging work-up does not capture all occult lymph node (OLN) disease. We sought to determine if Computer Assisted Nodule Analysis and Risk Yield (CANARY) analysis could help distinguish OLN status in early-stage lung adenocarcinoma. MethodsRetrospective review of resected lung cancer patients from 2016-2021 was performed. Patients with surgically resected clinical stage I-IIA lung adenocarcinoma were included. Preoperative imaging was entered into the CANARY software, and each lesion was categorized into good, intermediate, and poor risk. OLN status was determined per pathology results. Pearson's Chi-square correlation, univariate and multivariate logistic regression models were used to assess OLN metastases as a function of CANARY risk profile, with statistical significance at α=0.05. ResultsIn total, the study cohort included 228 patients with median age of 70. By clinical stage, 195 (85.5%), 24 (10.5%), and 9 (3.9%) patients were determined to be in IA, IB, and IIA, respectively. 28 (12.3%) patients were found to have OLN metastases. Among them, 1 (3.6%), 3 (10.7%), and 24 (85.7%) patients had a good, intermediate, and poor CANARY risk profile, respectively. CANARY risk profile was significantly associated with OLN metastases (χ2=9.9, p=0.007). Relative to the good/intermediate group, patients with poor risk had a more-than 3-fold increase in likelihood of having OLN metastases (odd ratio [OR]=3.3, 95% confidence interval [CI]:1.6-9.2, p=0.007). ConclusionCANARY analysis was able to risk-stratify the likelihood of OLN metastases in early-stage lung adenocarcinoma. CANARY can provide an adjunctive non-invasive tool to aid in determining an appropriate individualized treatment plan. Micro-abstractWe were able to identify potential prognostic capability of the Computer Assisted Nodule Analysis and Risk Yield (CANARY) program in the determination of occult lymph node metastasis in clinical stage I-IIA lung adenocarcinoma. In a single-institution cohort of 228 patients, those with poor risk determined by Score Indicative of Lung Cancer Aggression (SILA) has a 3-fold increase in likelihood of having occult lymph node metastasis (odds ratios = 3.3 [1.6-9.2]).

HOXA11-As Promotes Lymph Node Metastasis Through Regulation of IFNL and HMGB Family Genes in Pancreatic Cancer

Recent studies have shown that long noncoding RNAs (lncRNAs) play pivotal roles in the development and progression of cancer. In the present study, we aimed to identify lncRNAs associated with lymph node metastasis in pancreatic ductal adenocarcinoma (PDAC). We analyzed data from The Cancer Genome Atlas (TCGA) database to screen for genes overexpressed in primary PDAC tumors with lymph node metastasis. Our screen revealed 740 genes potentially associated with lymph node metastasis, among which were multiple lncRNA genes located in the HOXA locus, including HOXA11-AS. Elevated expression of HOXA11-AS was associated with more advanced tumor stages and shorter overall survival in PDAC patients. HOXA11-AS knockdown suppressed proliferation and migration of PDAC cells. RNA-sequencing analysis revealed that HOXA11-AS knockdown upregulated interferon lambda (IFNL) family genes and downregulated high-mobility group box (HMGB) family genes in PDAC cells. Moreover, HMGB3 knockdown suppressed proliferation and migration by PDAC cells. These results suggest that HOXA11-AS contributes to PDAC progression, at least in part, through regulation of IFNL and HMGB family genes and that HOXA11 AS is a potential therapeutic target in PDAC.

Survival scenarios of patients with localized and metastatic pancreatic adenocarcinoma: A population-based study.

Pancreatic adenocarcinoma (PAC) is notorious for its poor survival. The provision of survival scenarios-that is, best-case, typical and worst-case scenarios-could prove valuable to patients and clinicians. This study investigated survival scenarios and how these have changed over a period of 16 years for patients with PAC. Data from the Netherlands Cancer Registry were used to identify patients with localized and metastatic PAC (2005-2021). Survival scenarios, including best-case, upper-typical, typical (median), lower-typical, and worst-case, were estimated based on survival curve percentiles (p10, p25, p50, p75, and p90). Annual differences were assessed for significance using weighted linear regression analyses. Factors associated with these scenarios were identified through univariable tests. Overall, 14,622 patients with localized and 20,199 with metastatic PAC were included. For patients with localized PAC, the best, upper-typical and typical survival scenarios improved statistically significant with average annual improvement of 1.54 (95%CI: 1.2-1.88), 0.67 (0.56-0.78), and 0.24 (0.19-0.29) months, respectively. For patients with metastatic PAC the best and upper-typical survival scenarios increased statically significantly with annual improvement of 0.28 (0.21-0.34) and 0.06 (0.02-0.09) months, respectively. The best-case and upper-typical scenarios were associated with younger patients, more aggressive disease-focused treatments, fewer comorbidities, and better overall performance status. Over the past 16 years, survival improvements in patients with PAC have been most notable in these scenarios. Although the absolute gains were modest, these results offer encouraging potential for advancements in life-prolonging care for this type of cancer.

ASO Visual Abstract: Negative Impact of Systemic Therapy on Survival in Patients Undergoing Cytoreductive Surgery and Hyperthermic Intraperitoneal Chemotherapy for Low-Grade Metastatic Appendiceal Adenocarcinoma.

ASO Visual Abstract: Negative Impact of Systemic Therapy on Survival in Patients Undergoing Cytoreductive Surgery and Hyperthermic Intraperitoneal Chemotherapy for Low-Grade Metastatic Appendiceal Adenocarcinoma.

Exploring the multifaceted challenges of gastrointestinal metastases in lung adenocarcinoma: a case report highlighting diagnostic dilemmas and therapeutic innovations

BackgroundLung cancer, the primary cause of cancer-related deaths, often metastasizes early, commonly affecting the liver, brain, bones, and adrenal glands. Although gastrointestinal (GI) metastasis is rare, it poses significant diagnostic and therapeutic challenges and is frequently linked to severe complications.Case descriptionWe present a case of a 61-year-old male with a history of lung cancer who presented with intestinal obstruction. The initial diagnosis of poorly differentiated adenocarcinoma was confirmed by computed tomography (CT) and bronchoscopic biopsy. The patient underwent chemotherapy, after which he developed intestinal obstruction. Further imaging and histopathological analysis indicated GI metastasis. Despite treatment with both chemotherapy and immunotherapy, the patient experienced recurrent obstruction, necessitating surgical intervention. Postoperatively, he had another episode of perforation, which was addressed with an emergency laparotomy, revealing metastatic adenocarcinoma at the site of perforation.ConclusionsThis case highlights the complexities in diagnosing and treating GI metastases from lung cancer. It underscores the necessity for multimodal treatment strategies and underscores the urgent need for research focused on early detection methods to improve patient outcomes.

Spatial interactions of immune cells as potential predictors to efficacy of toripalimab plus chemotherapy in locally advanced or metastatic pancreatic ductal adenocarcinoma: a phase Ib/II trial

Advanced pancreatic ductal adenocarcinoma (PDAC) has a dismal prognosis. Immunotherapy alone offers limited efficacy, but it is still unknown whether its combination with chemotherapy could offer synergistic anti-tumor effects. This phase Ib/II study evaluated the safety and efficacy of combining toripalimab with the gemcitabine plus nab-paclitaxel (GnP) regimen as first-line treatment for locally advanced or metastatic PDAC and explored predictive biomarkers (ChiCTR2000032293). The primary endpoints were safety and overall survival (OS). The secondary outcomes were objective response rate (ORR), disease control rate (DCR), and progression-free survival (PFS). Immune-related biomarkers including programmed death-ligand 1 (PD-L1) expression, genetic status, cytokine levels, and spatial features of the tumor immune microenviroment (TIME) were investigated. Neither serious treatment-related adverse events nor grade 4 immune-related adverse events were reported. Among the 72 patients, the median OS was 8.9 months, 12-month OS rate was 31.9%, with median PFS of 5.6 months, ORR of 33.3%, and DCR of 90.3%. Higher PD-L1 expression, without liver metastases were associated with higher ORR, however these factors could not effectively distinguish responders and non-responders. Importantly, dendritic cells - T helper cells - cytotoxic T lymphocytes (DC-Th-CTL) enriched immune niche and their spatial interactions were dominant predictors of response based on TIME analysis using a cyclic multiplex tissue staining assay, with an area under the curve value of 0.8. Overall, GnP plus toripalimab exhibited good safety and differentiated efficacy in selected population, and the spatial interactions of DC-Th-CTL represent promising predictors to efficacy of immunochemotherapy in locally advanced or metastatic PDAC.

Surgical Site Infections in Simultaneous Colorectal and Liver Resections for Metastatic Colorectal Adenocarcinoma.

Surgical site infections (SSIs) are a major driver of morbidity after combined liver and colorectal surgery for metastatic colorectal cancer. Available literature is inadequate to characterize risk factors and benchmarks for quality improvement. Consecutive cases of simultaneous liver and colorectal surgery for colorectal adenocarcinoma from November 2013 through September 2022 were reviewed for SSIs per National Surgical Quality Improvement Program (NSQIP) and National Healthcare Safety Network (NHSN) criteria. Univariable and multivariable logistic regression evaluated associations with NSQIP 30-day organ-space SSIs. In 580 procedures, the rate of 30-day organ-space SSIs was 16% (n=94) using NSQIP criteria and 11% (n=64) using NHSN criteria; 4% (n=24) had incisional SSIs by both criteria. Most organ-space SSIs were perihepatic, and a minority were associated with bile (26%) or anastomotic (15%) leak. Independent risk factors for organ-space SSIs included major liver resection, upper abdominal (compared with lower abdominal/pelvic) colorectal procedure, and ostomy reversal. Organ-space SSI rates increased over time by approximately 16% per calendar year (p=0.02) despite a declining rate of major liver resection; incisional SSI rates remained low. Overall, major morbidity was 22%, with 7-day median length of stay (interquartile range 6-9) and 0.3% 90-day mortality. Organ-space SSIs are a significant driver of postoperative morbidity in simultaneous liver and colorectal resections for metastatic colorectal adenocarcinoma. Our findings confirm simultaneous resection remains safe and interventions to mitigate the risk of perihepatic organ-space SSIs in high-risk patients are warranted.

Pigmented Syringomatous Carcinoma/Sweat Gland Carcinoma of the Vulva With Melanocytic Colonization: An Uncommon Presentation of a Rare Sweat Gland Neoplasm

Abstract: Primary vulvar carcinomas are rare and constitute a diverse group of neoplasms. These primary tumors are typically classified based on their presumed tissue of origin or histological characteristics. Among these, carcinomas of sweat gland origin are particularly significant. They closely resemble similar malignancies in nonvulvar skin, including various cutaneous adnexal-type cancers such as apocrine and eccrine adenocarcinomas. Syringomatous carcinoma of the vulva is a rare malignant sweat gland neoplasm known for its infiltrative growth and tendency for local recurrence. Typically, these malignancies manifest as nonulcerated nodules or plaques, primarily in the head and neck region. The occurrence of syringomatous carcinoma in the vulvar region is exceptionally rare. Herein, we present a unique case of a 35-year-old woman with a dark mole measuring 1.5 × 1.0 cm on the vulva. Complete excision was performed to exhibit an infiltrative haphazard proliferation of elongated ductules and tubules, displaying significant cytologic atypia characterized by irregular nuclear contours and variably prominent nucleoli. Extensive melanocytic pigment deposition and stromal fibrosis were also observed. Immunohistochemical staining demonstrated positive expression of epithelial markers, including keratins (AE1/AE3) and epithelial membrane antigen, supporting the diagnosis of syringomatous carcinoma. CK7 and carcinoembryonic antigen were negative, whereas SOX10 and pan melanin highlighted admixed, cytologically bland melanocytes within the epidermis and neoplastic nests. This case represents a highly unusual presentation of syringomatous carcinoma associated with melanocyte colonization. Due to limited data on the optimal management strategies, a multidisciplinary approach involving gynecologic oncologists, dermatopathologists, and radiation oncologists is essential for treatment decisions. Long-term follow-up is crucial, considering the potential for local recurrence and metastatic spread, emphasizing the importance of comprehensive clinical management for favorable patient outcomes of this rare malignancy.

Thyroid cancer metastasis to the pituitary fossa: A clinical analysis and literature review.

A 71-year-old man presented with a history of headaches, blurred vision, diplopia, and right-sided ptosis. Magnetic resonance imaging (MRI) of the head revealed a 2.5 cm pituitary fossa lesion distorting the optic chiasm, with cavernous sinus invasion and frontal, temporal, and parieto-occipital lesions. Computed tomography (CT) found a retrosternal thyroid goiter. Biopsy of the occipital lobe lesion revealed metastatic papillary adenocarcinoma. Ultrasound-guided fine needle aspiration of the goiter and abnormal lymph nodes revealed Thy5. The patient underwent endoscopic transsphenoidal resection of the pituitary tumor, confirming papillary carcinoma of the thyroid. We sought to understand the clinico-radiological and histopathological features, treatment strategies, and outcomes of patients with thyroid cancer metastasis to the pituitary fossa. A date- and language-unrestricted literature search was performed across the MEDLINE, Embase, and Scopus databases using keywords relating to metastasis, the pituitary and thyroid glands, and the brain. Citations reporting patients with thyroid metastasis to the pituitary fossa were included. A proforma was used to extract and store data from the included citations. After deduplication, 2,833 citations were screened for eligibility, and 49 citations were included in the analysis. We present a rare case illustration and comprehensive literature review of patients with thyroid cancer metastasis to the pituitary fossa.

PRIM2 promotes proliferation and metastasis of pancreatic ductal adenocarcinoma through interactions with FAM111B

PRIM2 promotes proliferation and metastasis of pancreatic ductal adenocarcinoma through interactions with FAM111B

Clinicopathological features and outcomes of rare lung adenocarcinoma metastasis to the thyroid gland: A single-center, 11-year experience.

Metastasis to the thyroid gland from lung adenocarcinoma is rare and challenging to diagnose due to similar histopathological features. This study aimed to analyze the clinicopathological characteristics of and treatment strategies for lung adenocarcinoma metastasis to the thyroid based on 11 years of institutional experience. A retrospective study included patients with lung adenocarcinoma metastasis to the thyroid at our center from 2010 to 2023. Clinicopathological features and clinical outcomes were analyzed. Among 9714 lung adenocarcinoma patients, nine patients (five females, 55.6%) were diagnosed with thyroid metastasis, presenting primarily with cough symptoms. Most patients (88.9%) had synchronous tumors, whereas a minority (11.1%) had metachronous tumors. The median time from primary tumor diagnosis to metastasis was 4.8 months. Most patients developed bilateral thyroid metastases (88.9%). Diagnosis of thyroid metastasis was primarily through fine-needle aspiration (FNA), with one case misdiagnosed as papillary thyroid carcinoma. Immunohistochemical staining revealed thyroid transcription factor-1 (TTF-1) and novel aspartic proteinase of pepsin family A (Napsin-A) positivity and paired box 8 (PAX8) negativity. Genetic testing found epidermal growth factor receptor mutations in 71.4% of patients. The individualized comprehensive therapy included surgery, chemotherapy, immunotherapy, and targeted and supportive therapy. The median overall survival was 56.0 months, with a progression-free survival of 12.7 months. Kaplan-Meier (K-M) analysis suggested improved survival with no advanced symptoms (p = 0.03) and targeted therapies (p = 0.05). Lung adenocarcinoma metastasis to the thyroid is a rare disease, with an incidence of 0.1% among lung adenocarcinoma patients. Early treatment after symptom onset and personalized targeted therapies may improve prognosis. Despite rapid disease progression, favorable outcomes can be achieved with comprehensive treatment.

Intracerebral Solitary Fibrous Tumor in Collision With Metastatic Colonic Adenocarcinoma

Intracerebral Solitary Fibrous Tumor in Collision With Metastatic Colonic Adenocarcinoma

Abstract A007: Emergence of metastasis-initiating cells during lung adenocarcinoma progression

Abstract Metastatic lung adenocarcinoma (LUAD) is responsible for the most cancer-related deaths worldwide, and only a subset of cells is capable of metastasizing. Our lab has previously shown that these metastasis-initiating cells express the transmembrane glycoprotein called L1CAM and exhibit characteristics of a fetal lung developmental continuum, ranging from early progenitor states to more differentiated states. The exact signal by which progenitor cells with high metastatic potentials are generated remains unknown. Here, we demonstrate that L1CAM facilitates the signaling cascades necessary to initiate and maintain metastasis-initiating cells in LUAD. Mechanistically, L1CAM interacts with the planar cell polarity (PCP) complex and activates the transcription factor c-Jun. Activated c-Jun, as part of the AP-1 complex, binds to enhancer sites of progenitor genes and promotes the emergence of a metastasis-capable progenitor state. Pharmacological ablation of these metastatic progenitor cells by a cytotoxic L1CAM antibody effectively eliminated LUAD metastasis in vivo. Our findings identify a novel L1CAM-mediated mechanism that maintains a progenitor state essential for metastasis and can be targeted therapeutically. Citation Format: Jin Suk Park, Yasemin Kaygusuz, Carson Kenum, Mohamed I. Gatie, Lan He, Roshan Sharma, Ronan Chaligné, Abdul G. Khan, Ivo C. Lorenz, Paul J. Balderes, Tuomas Tammela, Anna-Katerina Hadjantonakis, Karuna Ganesh, Charles M. Rudin, Joan Massagué. Emergence of metastasis-initiating cells during lung adenocarcinoma progression [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Tumor-body Interactions: The Roles of Micro- and Macroenvironment in Cancer; 2024 Nov 17-20; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2024;84(22_Suppl):Abstract nr A007.

Modulation of SRC by SNTB1 activates the Hippo-YAP pathway during colon adenocarcinoma metastasis

BackgroundColon adenocarcinoma (COAD) ranks as the third most prevalent and lethal cancer in 2020, with metastasis being the primary cause of cancer-related mortality. A comprehensive understanding of the mechanism underlying distant metastasis is imperative for enhancing the prognosis and quality of life of patients with COAD.MethodsThis study employed gene set enrichment analysis (GSEA) on RNA-sequencing data from 408 patients with COAD in The Cancer Genome Atlas (TCGA) database. GSEA analysis was applied to find the significant hallmark gene set, and genes in the significant hallmark gene set was performed by univariate Cox regression to select the key gene. Then, multivariate Cox regression model was constructed. And various databases were utilized to validate and find the significant oncoprotein and hallmark gene set of the key gene. In addition, the expression of key regulators in para-carcinoma tissue, colon cancer and distant metastases samples were detected by real-time PCR, Immunohistochemistry and Western blot. Additionally, the biological functions were examined by in vitro and in vivo experiments. The scRNA-seq and CellphoneDB were performed to explore cell characters in COAD and the potential mechanism of metastasis.ResultsThe regulatory network analysis revealed SRC/YAP1 as the most significant oncoprotein and signature gene set associated with SNTB1. Moreover, significant SNTB1 overexpression in COAD metastatic tissues was observed compared to para-carcinoma and primary COAD tissues. Co-immunoprecipitation assays demonstrated the formation of a complex between SNTB1 and SRC proteins. Furthermore, the overexpression of SNTB1 enhanced the proliferation, migration and invasion capacities of COAD cell lines. Caudal vein injection of COAD cells overexpressing SNTB1 in nude mice resulted in increased tumour growth and metastasis to the lung, liver and bone. Finally, single cell RNA-seq revealed alterations in the cellular subtypes of COAD, and CellphoneDB indicated that the interaction between cancer cells exhibiting high SNTB1 expression and enterocytes promoted EMT through cellular communications involving TGF-β, accelerating metastasis in COAD.ConclusionThis study postulates that SNTB1 interacts with SRC to activate the Hippo-YAP pathway, thereby promoting COAD metastasis. Furthermore, cellular communication with enterocytes promotes EMT, facilitating metastasis. These findings propose novel therapeutic targets for preventing or treating metastatic COAD.

Multi-omics with dynamic network biomarker algorithm prefigures organ-specific metastasis of lung adenocarcinoma

Efficacious strategies for early detection of lung cancer metastasis are of significance for improving the survival of lung cancer patients. Here we show the marker genes and serum secretome foreshadowing the lung cancer site-specific metastasis through dynamic network biomarker (DNB) algorithm, utilizing two clinical cohorts of four major types of lung cancer distant metastases, with single-cell RNA sequencing (scRNA-seq) of primary lesions and liquid chromatography-mass spectrometry data of sera. Also, we locate the intermediate status of cancer cells, along with its gene signatures, in each metastatic state trajectory that cancer cells at this stage still have no specific organotropism. Furthermore, an integrated neural network model based on the filtered scRNA-seq data is successfully constructed and validated to predict the metastatic state trajectory of cancer cells. Overall, our study provides an insight to locate the pre-metastasis status of lung cancer and primarily examines its clinical application value, contributing to the early detection of lung cancer metastasis in a more feasible and efficacious way.

Abstract B013: Investigation of a novel lncRNA, TROLL-9, in breast cancer formation and progression

Abstract Breast cancer (BC) is the most diagnosed cancer and the second leading cancer-related cause of mortality among women in the US. Despite advances in treatment, BC remains a challenge due to its metastatic potential. The most aggressive BC subtype, triple negative (TN), often harbors mutations in the tumor suppressor gene, p53. One of the effects of mutant p53 involves the inhibition of the tumor and metastatic suppressive functions of TAp63, a p53 family member. Loss of TAp63 leads to the formation of metastatic mammary adenocarcinomas in mice, in part through the regulation of a group of nine long non-coding RNAs (lncRNAs), that we identified and named TAp63 regulated oncogenic lncRNAs (TROLLs). We previously characterized two TROLLs, TROLL-2 and TROLL-3, as markers of tumor progression in multiple cancer types via the activation of the AKT pathway. Currently we are investigating the role of another member, TROLL-9. To investigate the biological role of TROLL-9, we performed in vivo experiments using preclinical mouse models. Specifically, MCF-DCIS, MCF-CA1D, and MDA-MB-231 triple negative breast cancer (TNBC) cells constitutively expressing TROLL-9 were generated and utilized for two mouse models: orthotopic xenografts for primary tumor growth and spontaneous metastasis. The former was designed to identify the potential role of TROLL-9 in tumor formation, whereas the latter involved the resection of a primary tumor and monitoring for metastases via bioluminescence imaging. Notably, TROLL-9 overexpression led to increased formation of lung and livers metastases in all these models, suggesting a role for TROLL-9 in the metastatic cascade. In order to elucidate the mechanism of function of TROLL-9, two complementary approaches were used. Firstly, pulldown using MS2-TRAP followed by mass spectrometry (MS) was performed and led to the identification of putative protein interactors. In parallel, Laser Capture Microscopy (LCM) of the lung metastases followed by RNA-sequencing was used to assess for any gene expression changes due to TROLL-9 overexpression. Integration of the two datasets is currently being performed to unveil the network of genes and proteins perturbed by TROLL-9. Furthermore, to understand the relevance in BC patients, TROLL-9 expression levels were analyzed in the TCGA BC dataset. Interestingly, differences in TROLL-9 levels across BC subtypes were observed, thus supporting its putative role in TNBC. Overall, our data suggest a role for TROLL-9 in BC progression. Our findings provide evidence for further characterizing its mechanism of function as a potential therapeutic target for the treatment of invasive BC, particularly TNBC harboring TP53 mutations. Citation Format: Avani A Deshpande, Marco Napoli, John H Lockhart, Christina L Carr, Jaden R Baldwin, Elsa R Flores. Investigation of a novel lncRNA, TROLL-9, in breast cancer formation and progression [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: RNAs as Drivers, Targets, and Therapeutics in Cancer; 2024 Nov 14-17; Bellevue, Washington. Philadelphia (PA): AACR; Mol Cancer Ther 2024;23(11_Suppl):Abstract nr B013.

Abstract A011: Identifying surface biomarkers from colorectal cancer-derived extracellular vesicles using a bead-based approach

Abstract Colorectal cancer (CRC) accounts for the second most common cause of cancer-related mortality globally. The search for prognostic biomarkers subserving to detected cancer at an early stage, to improve tumor classification and to stratify therapeutic patient management groups is actively ongoing. Surgical resections and chemotherapeutics remain a mainstay in the cure and control of solid tumors. Despite their usefulness in the clinical scenario, shortcomings are well recognized, leading researchers to investigate for a circulating source of tumor-derived materials in biofluids, including mostly circulating tumor DNA (ctDNA), circulating tumor cells (CTCs) and extracellular vesicles (EVs). Characterization of EVs surface markers and assessment of their molecular cargo, can lead to the identification of early metastatic colorectal cancer signatures. Cell surface markers of three CRC cell lines (HCT116, DLD1 and LOVO) were characterized using flow cytometry. EVs were isolated from 48-hour serum-deprived cell lines using the polymer pull down method (20% Polyethelene glycol (PEG)). The concentration and particle size distribution of isolated EVs was checked by the NanoSight NS300. Avidin-coated Polystyrene beads were conjugated with CD9 biotin antibodies; and were used to immunoprecipitated (IP) CD9+ EVs. Following a 2-hour incubation and a series of washing steps, the PE-labelled antibodies of interest (CD9, CD63, EpCAM, Vim, CD44, CD133 and CD29) were added and read using xMAP technology. To increase the number of surface markers that can be read in tandem, IP was multiplexed using EpCAM, CD9 and CD63. This was followed by the isolation of EVs from plasma of metastatic CRC patients (N=3) using size exclusion chromatography (Izon qEV1 columns-35nm in conjunction with the automatic fraction collector) and polymer pull down. The concentration and size were assessed by Nanosight NS300 and surface markers of tumor-derived EVs were assessed using the immunoprecipitation technique on the Luminex system. Comparison of signals between EVs isolated from cell lines and matched originator cells showed that cell surface signatures in EVs match closely with their originator cells. The mean fluorescence intensities quantified cell surface marker expression in the different exosome-bead complexes. Interestingly, one of the metastatic cancer patients with invasive colorectal adenocarcinoma and lung metastasis showed EpCAM and Vimentin positivity suggesting epithelial-mesenchymal plasticity. These results show the importance of multiplexing both at the level of immunoprecipitation and at end-measurement, given the dynamics of cell surface marker changes during disease progression. The use of the mesenchymal marker; Vimentin in a panel for cell surface markers stems from studies on biotinylated cell surface markers on various cancer cell lines and identification of Vimentin in such models. Interestingly we find Vimentin on EVs surface in this study. Citation Format: Jessica Debattista, Laura Grech, Christian Scerri, Malcolm Buhagiar, Godfrey Grech. Identifying surface biomarkers from colorectal cancer-derived extracellular vesicles using a bead-based approach [abstract]. In: Proceedings of the AACR Special Conference: Liquid Biopsy: From Discovery to Clinical Implementation; 2024 Nov 13-16; San Diego, CA. Philadelphia (PA): AACR; Clin Cancer Res 2024;30(21_Suppl):Abstract nr A011.

Abstract B034: Prevalence and implication of aflatoxin B1 expression in colon cancers diagnosed in Southern Nigeria

Abstract Introduction: Mounting evidence shows that there is a high prevalence of late-stage, aggressive, and metastatic adenocarcinoma of the colon (AdCC) in Africa, with high mortality and low survival rate among patients. Literature finger food contaminants such as mycotoxin, especially Aflatoxin, as an attributable factor to the high incidence of abdominal cancers. However, there is a paucity of studies to confirm the hypothesis. Hence, this study determined the prevalence of Aflatoxin B1 in AdCC in Southern Nigeria. Citation Format: Chiagoziem Moral Delu-mozie, Jude Ogechukwu Okoye. Prevalence and implication of aflatoxin B1 expression in colon cancers diagnosed in Southern Nigeria [abstract]. In: Proceedings of the AACR Special Conference: Liquid Biopsy: From Discovery to Clinical Implementation; 2024 Nov 13-16; San Diego, CA. Philadelphia (PA): AACR; Clin Cancer Res 2024;30(21_Suppl):Abstract nr B034.

Entinostat in combination with nivolumab in metastatic pancreatic ductal adenocarcinoma: a phase 2 clinical trial

Pancreatic ductal adenocarcinoma (PDA) is characterized by low cytotoxic lymphocytes, abundant immune-suppressive cells, and resistance to immune checkpoint inhibitors (ICI). Preclinical PDA models showed the HDAC inhibitor entinostat reduced myeloid cell immunosuppression, sensitizing tumors to ICI therapy. This phase II study combined entinostat with nivolumab (PD1 inhibitor) in patients with advanced PDA (NCT03250273). Patients received entinostat 5 mg orally once weekly for 14-day lead-in, followed by entinostat and nivolumab. The primary endpoint was the objective response rate (ORR) by RECIST v1.1. Secondary endpoints included safety, duration of response, progression free-survival and overall survival. Between November 2017 and November 2020, 27 evaluable patients were enrolled. Three showed partial responses (11% ORR, 95% CI, 2.4%-29.2%) with a median response duration of 10.2 months. Median progression-free survival (PFS) and overall survival (OS) were, respectively, 1.89 (95% CI, 1.381-2.301) and 2.729 (95% CI, 1.841-5.622) months. Grade ≥3 treatment-related adverse events occurred in 19 patients (63%), including decreased lymphocyte count, anemia, hypoalbuminemia, and hyponatremia. As exploratory analysis, peripheral and tumor immune profiles changes were assessed using CyTOF, mIHC, and RNA-seq. Entinostat increased dendritic cell activation and maturation. Gene expression analysis revealed an enrichment in inflammatory response pathways with combination treatment. Although the primary endpoint was not met, entinostat and nivolumab showed durable responses in a small subset of PDA patients. Myeloid cell immunomodulation supported the preclinical hypothesis, providing a basis for future combinatorial therapies to enhance clinical benefits in PDA.