Tumor Mutational Burden Research Articles

Integrin β5, a noninvasive diagnostic biomarker, is associated with unfavorable prognosis and immunotherapy efficacy in gastric cancer

BackgroundIntegrin β5 (ITGB5) is a pivotal player in the pathogenesis of gastric cancer (GC). We aimed to explore the potential value of ITGB5 as a predictor of diagnosis and immunotherapy in gastric cancer.MethodsThe expression of ITGB5 in GC was assessed using The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) databases, and verified through quantitative polymerase chain reaction (qPCR) and immunohistochemistry. Kaplan-Meier curves were conducted to evaluate the prognostic significance. The immune cells infiltration, tumor mutational burden (TMB), and immunophenoscore (IPS) were examined using CIBERSORT, TIMER, and TISIDB. In addition, colony formation, scratch assays, and transwell assays were employed to determine the impact on tumor progression and metastasis. CD276 expression was detected by western blotting following the knockdown of ITGB5. ELISA was utilized to measure serum ITGB5 levels.ResultsThe expression of ITGB5 in GC tissue surpassed that in normal tissue, it might contribute to GC pathogenesis through pathways including PI3K-AKT, ECM-receptor interaction, and TGF-beta. The elevated ITGB5 expression is associated with poor prognosis in GC patients. In addition, a strong positive association between ITGB5 overexpression and the infiltration levels of macrophages and monocytes, and it significantly influenced immune response. Moreover, lower expression of ITGB5 was associated with better immunotherapy efficacy. Subsequent investigation demonstrated that silencing of ITGB5 suppressed the proliferation and migration of GC cell lines in vitro. ITGB5 expression was positively correlated with CD276 expression and the knockdown of ITGB5 resulted a notable decrease CD276 expression. Futhermore, a significantly high level of serum ITGB5 was observed in GC patients. The combined assessment of ITGB5, CEA, and CA19-9 improved the diagnostic accuracy.ConclusionsITGB5 potentially serve as both a diagnostic biomarker and therapeutic target in managing GC.

Personalized Treatment Strategies via Integration of Gene Expression Biomarkers in Molecular Profiling of Laryngeal Cancer.

Laryngeal cancer poses a substantial challenge in head and neck oncology, and there is a growing focus on customized medicine techniques. The present state of gene expression indicators in laryngeal cancer and their potential to inform tailored therapy choices are thoroughly examined in this review. We examine significant molecular changes, such as TP53, CDKN2A, PIK3CA, and NOTCH1 mutations, which have been identified as important participants in the development of laryngeal cancer. The study investigates the predictive and prognostic significance of these genetic markers in addition to the function of epigenetic changes such as the methylation of the MGMT promoter. We also go over the importance of cancer stem cell-related gene expression patterns, specifically CD44 and ALDH1A1 expression, in therapy resistance and disease progression. The review focuses on indicators, including PD-L1, CTLA-4, and tumor mutational burden (TMB) in predicting immunotherapy responses, highlighting recent developments in our understanding of the intricate interactions between tumor genetics and the immune milieu. We also investigate the potential for improving prognosis accuracy and treatment selection by the integration of multi-gene expression panels with clinicopathological variables. The necessity for uniform testing and interpretation techniques is one of the difficulties, in implementing these molecular insights into clinical practice, that are discussed. This review seeks to provide a comprehensive framework for promoting personalized cancer therapy by combining the most recent data on gene expression profiling in laryngeal cancer. Molecularly guided treatment options may enhance patient outcomes.

Updated EANO guideline on rational molecular testing of gliomas, glioneuronal, and neuronal tumors in adults for targeted therapy selection - Update 1.

The standard of care for adult patients with gliomas, glioneuronal and neuronal tumors consists of combinations of surgery, radiotherapy, and chemotherapy. For many systemic cancers, targeted treatments are a major part of the standard treatment, however, the predictive significance of most of the targets for treatment in systemic cancer are less well established in central nervous system (CNS) tumors . In 2023 the EANO Guideline Committee presented evidence based recommendations for rational testing of molecular targets for targeted treatments. From all targets reviewed, only testing for BRAF V600E mutations was of proven clinical benefit; despite regulatory approvals for tumor agnostic treatment of NTRK gene fusions and high Tumor Mutational Burden (TMB) for patients with adult brain tumors, the evidence of clinical benefit for patients was still limited . This guideline has a modular structure, allowing regular updating of individual sections and adding new ones. The present version (Update 1) presents a review of the rationale of testing for PTEN, H3F3A, MTAP, RET and IDH, and presents an update of the text on TMB high and mismatch repair deficiency. It also presents an overview of therapeutic yield of routine next generation sequencing for mutations and fusion detection. The supplement accompanying this version contains the in depth review of all targets, whereas in the main manuscript the final recommendations of the revised and new targets are presented. Updates will be made on a regular basis.

Pan-cancer analysis and experimental validation of FPR3 as a prognostic and immune infiltration-related biomarker for glioma.

Formyl peptide receptor 3 (FPR3) is known to have implications in the progression of various cancer types. Despite this, its biological significance within pan-cancer datasets has yet to be investigated. In this investigation, we scrutinized FPR3's expression profiles, genetic alterations, prognostic significance, immune-related characteristics, methylation status, tumor mutation burden (TMB), and microsatellite instability (MSI) across different types of cancer. We utilized TISCH's single-cell data to identify immune cells closely associated with FPR3. The predictive significance of FPR3 was evaluated independently in gliomas using data from TCGA and CGGA datasets, leading to the development of a prognostic nomogram. Immunohistochemistry and Western blot analysis confirmed FPR3 expression in gliomas. Lastly, the CCK-8 and wound-healing assays were employed to assess the impact of FPR3 on the proliferation and metastasis of GBM cell lines. In numerous cancer types, heightened FPR3 expression correlated with adverse outcomes, immune cell infiltration, immune checkpoints, TMB, and MSI. In glioma, FPR3 emerged as a notable risk factor, with the prognostic model effectively forecasting patient results. The potential biological relevance of FPR3 was confirmed in glioma, and it was shown to have significant involvement in the processes of glioma growth, immune infiltration, and metastasis. Our results imply a potential association of FPR3 with tumor immunity, indicating its viability as a prognostic indicator in glioma.

High-Throughput Transcriptomics Identifies Chemoresistance-Associated Gene Expression Signatures in Human Angiosarcoma

Angiosarcomas, clinically aggressive cancers of endothelial origin, are a rare subtype of soft-tissue sarcomas characterized by resistance to chemotherapy and dismal prognosis. In this study, we aim to identify the transcriptomic biomarkers of chemoresistance in angiosarcoma. We examined 72 cases of Asian angiosarcomas, including 35 cases treated with palliative chemotherapy, integrating information from NanoString gene expression profiling, whole transcriptome profiling (RNA-seq), immunohistochemistry, cell line assays, and clinicopathological data. In the chemoresistant cohort (defined as stable disease or progression), we observed the significant overexpression of genes, including SPP1 (log2foldchange 3.49, adj. p = 0.0112), CXCL13, CD48, and CLEC5A, accompanied by the significant enrichment of myeloid compartment and cytokine and chemokine signaling pathways, as well as neutrophils and macrophages. RNA-seq data revealed higher SPP1 expression (p = 0.0008) in tumor tissues over adjacent normal compartments. Immunohistochemistry showed a significant moderate positive correlation between SPP1 protein and gene expression (r = 0.7016; p < 0.00110), while higher SPP1 protein expression correlated with lower chemotherapeutic sensitivity in patient-derived angiosarcoma cell lines MOLAS and ISOHAS. In addition, SPP1 mRNA overexpression positively correlated with epithelioid histology (p = 0.007), higher tumor grade (p = 0.0023), non-head and neck location (p = 0.0576), and poorer overall survival outcomes (HR 1.84, 95% CI 1.07–3.18, p = 0.0288). There was no association with tumor mutational burden, tumor inflammation signature, the presence of human herpesvirus-7, ultraviolet exposure signature, and metastatic state at diagnosis. In conclusion, SPP1 overexpression may be a biomarker of chemoresistance and poor prognosis in angiosarcoma. Further investigation is needed to uncover the precise roles and underlying mechanisms of SPP1.

Primary adenocarcinoma of the spermatic cord: a case report and review of the literature

BackgroundPrimary malignant neoplasms of the spermatic cord are extremely rare, with most reported cases being sarcomas or metastatic carcinomas. However, primary adenocarcinoma of the spermatic cord has not been previously reported.Case presentationA 34-year-old male with a solid mass in the right spermatic cord, was eventually diagnosed with primary adenocarcinoma. Histological examination revealed a moderately-to-poorly differentiated adenocarcinoma exhibiting glandular, cribriform, or nested growth patterns, characterized by medium to large-sized cells and focal extracellular mucus. Immunohistochemical analysis demonstrated positive staining for CK (AE1/AE3), CK8/18, CK19, MOC31 (EP-CAM), and Ber-EP4, while negative staining was observed for CK7, D2-40, WT-1, MC, PAX-8, NKX3.1, PSA, CEA, TTF-1, and NapsinA. Furthermore, a complete loss of INI-1 expression and consistent BRG1 expression were noted in all tumor cells. Next-generation sequencing revealed SMARCB1 deletion, low tumor mutation burden (TMB-L), and microsatellite stability (MSS).ConclusionWe reported the first case of primary adenocarcinoma of the spermatic cord with SMARCB1 (INI-1) deficiency. This case contributes to the expanding understanding of rare neoplasms and underscores the importance of further research into therapeutic strategies targeting SMARCB1-deficient tumors.

A basement membrane-related signature for prognosis and immunotherapy benefit in bladder cancer based on machine learning

BackgroundBladder cancer has a poor clinical outcome because of its high aggressiveness. Basement membrane plays vital functions in tumor invasion and migration. Invasion and distant metastasis of cancer are facilitated by degradation of the basement membrane and extracellular matrix.MethodsTen machine learning methods were utilized to develop the basement membrane-related signature (MRS) using datasets from TCGA, GSE13507, GSE31684, GSE32984 and GSE48276. Three anti-PD1 or anti-CTLA4 datasets and several predicting scores were used to investigate the performance of MRS in predicting the immunotherapy benefits.ResultsA predicting model based on the Enet algorithm (alpha = 0.1) was chosen as the optimal MRS since it had the highest average C-index being 0.72. According to TCGA data, the MRS showed good performance in predicting bladder cancer patients' clinical outcomes, with area under curves of 0.744, 0.766 and 0.817 for 1, 3, and 5-year receiver operating characteristic curve, respectively. PD1 and CTLA4 immunophenoscopes were associated with a low MRS score, as well as a lower tumor immune dysfunction and exclusion score. As MRS score increased, immune-activated cells levels decreased, tumor immune dysfunction and exclusion score decreased, immune escape score decreased, intratumor heterogeneity score decreased, PD1&CTLA4 immunophenoscore increased, and tumor mutational burden score increased in bladder cancer, suggesting better immunotherapy benefits. Bladder cancer cases with high MRS score was correlated with higher cancer related hallmark scores, including NOTCH and glycolysis signaling.ConclusionA new MRS has been developed for bladder cancer, which could be used to predict prognosis and the success of immunotherapy.

Clinical and Technical Validation of OncoIndx® Assay-A Comprehensive Genome Profiling Assay for Pan-Cancer Investigations.

Comprehensive next-generation sequencing (NGS) assays enable the identification of clinically relevant mutations, enhancing the capability for targeted therapeutic interventions. In addition, genomic alterations driving the oncogenic roadmap and leading to resistance mechanisms are reshaping precision oncology. We report the workflow and clinical and technical validation of the OncoIndx® NGS platform-a comprehensive genomic profiling (CGP)-based assay for pan-cancer investigation. We evaluated the concordance between the OncoIndx® test findings and clinically established hotspot detection using SeraSeq reference standards. OncoIndx is a hybridization capture-based NGS assay for the targeted deep sequencing of all exons and selected introns of 1080 cancer-related genes. We show the outcome in the form of tier I and tier II single nucleotide variants (SNVs), copy number alterations (CNAs), and specific gene fusions. OncoIndx® also informs genome-wide tumor mutational burden (TMB), microsatellite instability (MSI), homologous recombination deficiency (HRD), and genomic loss of heterozygosity (gLOH). A total of 63 samples were utilized for validation with reference standards, clinical samples, and orthogonal assessment for genomic alterations. In addition, 49 cross-laboratory samples were validated for microsatellite instability (MSI), and for the tumor mutation burden (TMB), 18 samples as reference standards, 6 cross-laboratory samples, and 29 TCGA samples were utilized. We show a maximum clinical sensitivity of 98% and a positive predictive value (PPV) of 100% for the clinically actionable genomic variants detected by the assay. In addition, we demonstrate analytical validation with the performance of the assay, limit of detection (LoD), precision, and orthogonal concordance for various types of SVs, CNAs, genomic rearrangements, and complex biomarkers like TMB, MSI, and HRD. The assay offers reliable genomic predictions with the high-precision detection of actionable variants, validated by established reference standards.

Role of Immunotherapy in Non-Small Cell Lung Cancer (NSCLC)

Background: Non-small cell lung cancer accounts for approximately 85% of all lung cancers and presents a serious public health challenge due to an increasing incidence and poor prognosis, with only a 5-year survival rate of 5-10% in advanced disease stages. Objective: The aim of this work is an overview of the clinical efficacy and safety profile of ICIs in NSCLC patients, mainly focusing on the predictive role played by PD-L1 expression and tumor mutational burden as predictive biomarkers of treatment response. Methods: A total of 63 NSCLC patients treated with ICIs at a Department of Respiratory Medicine, Dhaka National Medical Institute Hospital, Dhaka, Bangladesh and National Institute of Diseases of the Chest and Hospital (NIDCH), and National Institute of Cancer Research & Hospital (NICRH), Mohakhali, Dhaka, Bangladesh from July 2023 to December 2023, were retrospectively analyzed. Demographical information, treatment regimens, and clinical outcomes were collected and analyzed. Treatment responses were evaluated based on Response Evaluation Criteria in Solid Tumors, and safety was assessed through monitoring adverse events. Results: The median age of the cohort was 62 years, with presentation in advanced stages, III and IV in 70%. An objective response rate of 42% was observed; median PFS was 8.5 months. Of note, patients with high PD-L1 expression of ≥ 50% had a response rate of 60%, whereas those with lower expression had a rate of 30%. It was observed in TMB analysis that high mutational burden is associated with a median PFS of 10 months versus 5 months in the case of low TMB. About 15% of patients developed adverse events, mostly immune-mediated. Conclusion: This study has exemplified the promising efficacy of ICIs in the improvement of treatment outcomes for patients with NSCLC and underlined critical roles that PD-L1 expression and TMB have played in guiding personalized treatment strategies. Although encouraging, these findings are retrospective and ..

A disulfidptosis-related lncRNA signature for analyzing tumor microenvironment and clinical prognosis in hepatocellular carcinoma.

Disulfidptosis is a recently identified form of non-apoptotic programmed cell death which distinguishes itself from classical cell death pathways. However, the prognostic implications of disulfidptosis-related long non-coding RNAs (DRLs) and their underlying mechanisms in hepatocellular carcinoma (HCC) remain largely unexplored. In this study, we leveraged RNA-sequencing data and clinical information of HCC patients from the TCGA database. Through expression correlation and prognostic correlation analyses, we identified a set of top-performing long non-coding RNAs. Subsequently, a 5-DRLs predictive signature was established by conducting a Lasso regression analysis. This signature effectively stratified patients into high- and low-risk groups, revealing notable differences in survival outcomes. Further validation through univariate and multivariate Cox regression analyses confirmed that the risk score derived from our signature independently predicted the prognosis of HCC patients. Moreover, we observed significant disparities in immune cell infiltration and tumor mutation burden (TMB) between the two risk groups, shedding light on the potential connection between immune-related mechanisms and disulfidptosis. Notably, the signature also exhibited predictive value in the context of chemotherapeutic drug sensitivity and immunotherapy efficacy for HCC patients. Finally, we performed experimental validation at both cellular and patient levels and successfully induced a disulfidptosis phenotype in HCC cells. In general, this multifaceted approach provides a comprehensive overview of DRLs profiles in HCC, culminating in the establishment of a novel risk signature that holds promise for predicting prognosis and therapy outcomes of HCC patients.

Identification of an immune-related genes signature in lung adenocarcinoma to predict survival and response to immune checkpoint inhibitors

BackgroundAlthough advances in immune checkpoint inhibitor (ICI) research have provided a new treatment approach for lung adenocarcinoma (LUAD) patients, their survival is still unsatisfactory, and there are issues in the era of response prediction to immunotherapy.MethodsUsing bioinformatics methods, a prognostic signature was constructed, and its predictive ability was validated both in the internal and external datasets (GSE68465). We also explored the tumor-infiltrating immune cells, mutation profiles, and immunophenoscore (IPS) in the low-and high-risk groups.ResultsAs far as we are aware, this is the first study which introduces a novel prognostic signature model using BIRC5, CBLC, S100P, SHC3, ANOS1, VIPR1, LGR4, PGC, and IGKV4.1. According to multivariate analysis, the 9-immune-related genes (IRGs) signature provided an independent prognostic factor for the overall survival (OS). The low-risk group had better OS, and the tumor mutation burden (TMB) was significantly lower in this group. Moreover, the risk scores were negatively associated with the tumor-infiltrating immune cells, like CD8+ T cells, macrophages, dendritic cells, and NK cells. In addition, the IPS were significantly higher in the low-risk group as they had higher gene expression of immune checkpoints, suggesting that ICIs could be a promising treatment option for low-risk LUAD patients.ConclusionThe combination of these 9-IRGs not only could efficiently predict overall survival of LUAD patients but also show a powerful association with the expression of immune checkpoints and response to ICIs based on IPS; hoping this model paves the way for better stratification and management of patients in clinical practice.

Towards a framework for predicting immunotherapy outcome: a hybrid multiscale mathematical model of immune response to vascular tumor growth.

Studying tumor immune microenvironment (TIME) is pivotal to understand the mechanism and predict the outcome of cancer immunotherapy. Systems biology mathematical models can consider and control various factors of TIME and therefore explore the anti-tumor immune response meticulously. However, the role of tumor vasculature in the recruitment of T cells and the mechanism of T cell migration through TIME have not been studied comprehensively. In this work, we developed a hybrid discrete-continuum multi-scale model to study TIME. The mathematical model includes angiogenesis and T cell recruitment via tumor vasculature. Moreover, solid tumor growth, vascular growth and remodeling, interstitial fluid flow, hemodynamics, and blood rheology are all considered in the model. In addition, different aspects of T cells, including their migration, proliferation, subtype conversion, and interaction with tumor cells are thoroughly included. The model reproduces spatiotemporal distribution of tumor infiltrating T cells that mimics histopathological patterns. Furthermore, TIME model robustly recapitulates different phases of tumor immunoediting. We also examined a number of biomarkers to predict the outcome of immune checkpoint blockade (ICB) treatment. The results demonstrated that although tumor mutational burden (TMB) may predict non-responders to ICB, a combination of different biomarkers is essential to predict the majority of the responders. Based on our results, the ICB response rate varies significantly from 28 to 89% depending on the values of different parameters, even in the cases with high TMB.

Unraveling the mechanisms of RECQL4-mediated cervical cancer progression through the PI3K/AKT pathway

BackgroundRECQL4 is a member of the DNA helicase family and is critical for DNA replication, DNA damage repair, and tumor progression. However, its specific role in cervical cancer remains uncertain. MethodsIn this study, we aimed to investigate the impact of RECQL4 on cervical cancer prognosis using clinical specimens from The Cancer Genome Atlas. We evaluated the malignant effects of RECQL4 through various experimental assays including cell Cell Counting Kit-8, EdU, colony formation, cell cycle analysis, cell apoptosis, scratch, and Transwell assays. We explored the mechanisms of RECQL4-regulated malignancy using analyses of bioinformatics, RNA sequencing data, polymerase chain reaction (PCR), western blotting, and cell immunofluorescence experiments. Furthermore, we validated the effects of RECQL4 knockdown on tumor growth using subcutaneous tumor models in nude mice. ResultsRECQL4 was upregulated in cervical cancer and correlated with prognosis, demonstrating a positive relationship with tumor mutational burden. Knockdown of RECQL4 inhibits cervical cancer cell proliferation, migration, and invasion, suppresses epithelial-mesenchymal transition status, induces cell cycle arrest, and promotes apoptosis. Mechanistically, RECQL4 mediated malignancy through the PI3K/AKT pathway and reduced nuclear β-catenin expression. In vivo studies further confirmed that RECQL4 knockout significantly inhibited tumor growth. ConclusionsOur findings provide novel insights into the mechanism behind RECQL4-mediated cervical cancer progression through the PI3K/AKT pathway. Furthermore, our study suggests potential therapeutic strategies for targeting RECQL4 in cervical cancer treatment.

Amplifying mutational profiling of extracellular vesicle mRNA with SCOPE.

Sequencing of messenger RNA (mRNA) found in extracellular vesicles (EVs) in liquid biopsies can provide clinical information such as somatic mutations, resistance profiles and tumor recurrence. Despite this, EV mRNA remains underused due to its low abundance in liquid biopsies, and large sample volumes or specialized techniques for analysis are required. Here we introduce Self-amplified and CRISPR-aided Operation to Profile EVs (SCOPE), a platform for EV mRNA detection. SCOPE leverages CRISPR-mediated recognition of target RNA using Cas13 to initiate replication and signal amplification, achieving a sub-attomolar detection limit while maintaining single-nucleotide resolution. As a proof of concept, we designed probes for key mutations in KRAS, BRAF, EGFR and IDH1 genes, optimized protocols for single-pot assays and implemented an automated device for multi-sample detection. We validated SCOPE's ability to detect early-stage lung cancer in animal models, monitored tumor mutational burden in patients with colorectal cancer and stratified patients with glioblastoma. SCOPE can expedite readouts, augmenting the clinical use of EVs in precision oncology.

A Review of Immunotherapy for Head and Neck Cancer.

The introduction of immune checkpoint inhibitors (ICIs) to oncological care has transformed the management of various malignancies, including head and neck squamous cell carcinoma (HNSCC), offering improved outcomes. The first-line treatment of recurrent and malignant HNSCC for many years was combined platinum, 5-fluorouracil, and cetuximab. Recently, the ICI pembrolizumab was approved as a first-line treatment, with or without chemotherapy, based on tumor and immune cell percentage of programmed-death ligand 1 (PD-L1). Multiple head and neck (HN) cancer trials have subsequently explored immunotherapies in combination with surgery, chemotherapy, and/or radiation. Immunotherapy regimens may be personalized by tumor biomarker, including PD-L1 content, tumor mutational burden, and microsatellite instability. However, further clinical trials are needed to refine biomarker-driven protocols and standardize pathological methods to guide combined regimen timing, sequencing, and deescalation. Gaps remain for protocols using immunotherapy to reverse oral premalignant lesions, particularly high-risk leukoplakias. A phase II nonrandomized controlled trial, using the ICI nivolumab, showed a 2-y cancer-free survival of 73%, although larger trials are needed. Guidelines are also needed to standardize the role of dental evaluation and care before, during, and after immunotherapy, specifically in regard to oral immune-related adverse events and their impact on cancer recurrence. Standardized diagnostic and oral care coordination strategies to close these gaps are needed to ensure continued success of HN cancer immunotherapy.

8592 Parathyroid Carcinoma: A Rare Cause of Primary Hyperparathyroidism

Abstract Disclosure: S.E. Koshy: None. C.F. Mulcahy: None. P.S. Kothari: None. E.M. Jacobi: None. T.D. Cubb: None. Introduction: Parathyroid carcinoma (PC) is a rare malignancy that accounts for <1% of cases of primary hyperparathyroidism (PHPT). Patients often present with symptoms of hypercalcemia, serum calcium (Ca) >14 mg/dL, large tumor size, and a very high parathyroid hormone (PTH) level. We report a case of an asymptomatic patient with incidentally found hypercalcemia consistent with PHPT who was ultimately diagnosed with PC. Clinical Case: A 31yo male was found to have elevated serum Ca of 12.7 mg/dL (8.6-10.3 mg/dL) on labs obtained during routine physical exam. He had no known significant medical or family history and notably had no laboratory evaluation within the prior 10 years. He denied constipation, polyuria, confusion, depression, bone pain, and history of fractures or nephrolithiasis. Workup showed an inappropriately elevated PTH of 505 pg/mL (16-77 pg/mL). Neck ultrasound demonstrated a left inferior 3.9 cm complex thyroid nodule. Sestamibi scan confirmed increased uptake in the inferior left thyroid. Left neck exploration was performed. Intraoperatively, a 3.7 cm left parathyroid mass weighing 13.0 grams was encountered and excised in an en bloc fashion. The left superior parathyroid gland was evaluated and found to be normal. Intraoperative PTH level decreased from 529 pg/mL to 48 pg/mL 10 minutes after excision. Left hemithyroidectomy was not performed. Surgical pathology revealed PC with lymphovascular invasion, suspected capsular invasion, and negative margins. Immunohistochemical staining showed a Ki67 proliferation index up to 5% and complete loss of nuclear staining for parafibromin. Next generation sequencing demonstrated a somatic CDC73 p.L8fs mutation, tumor mutational burden 4.7m/MB, and stable microsatellite instability. Germline testing was negative for a CDC73 mutation. Postoperative staging did not demonstrate evidence of metastatic disease in the neck or chest. Serum Ca remained within normal limits. After multidisciplinary discussion, no further surgical intervention was recommended and plan was for ongoing biochemical and imaging surveillance. Conclusion: Though rare, PC should be considered as a cause of PHPT. The primary treatment is complete surgical resection. Unfortunately, there is a high rate of recurrence, >50%, with most occurring 2-5 years after initial surgery with a median overall survival of 14 years. Thus, long-term surveillance is of utmost importance. Treatment of recurrent disease is surgical resection when feasible as well as medical management of hypercalcemia. Further research is needed to better understand the role of targeted systemic therapy in addition to immunotherapy. PC is most commonly sporadic but can be hereditary, thus genetic evaluation is recommended. Given its rarity and complexity, PC is best managed in a multidisciplinary setting. Presentation: 6/1/2024

8592 Parathyroid Carcinoma: A Rare Cause of Primary Hyperparathyroidism

Abstract Disclosure: S.E. Koshy: None. C.F. Mulcahy: None. P.S. Kothari: None. E.M. Jacobi: None. T.D. Cubb: None. Introduction: Parathyroid carcinoma (PC) is a rare malignancy that accounts for <1% of cases of primary hyperparathyroidism (PHPT). Patients often present with symptoms of hypercalcemia, serum calcium (Ca) >14 mg/dL, large tumor size, and a very high parathyroid hormone (PTH) level. We report a case of an asymptomatic patient with incidentally found hypercalcemia consistent with PHPT who was ultimately diagnosed with PC. Clinical Case: A 31yo male was found to have elevated serum Ca of 12.7 mg/dL (8.6-10.3 mg/dL) on labs obtained during routine physical exam. He had no known significant medical or family history and notably had no laboratory evaluation within the prior 10 years. He denied constipation, polyuria, confusion, depression, bone pain, and history of fractures or nephrolithiasis. Workup showed an inappropriately elevated PTH of 505 pg/mL (16-77 pg/mL). Neck ultrasound demonstrated a left inferior 3.9 cm complex thyroid nodule. Sestamibi scan confirmed increased uptake in the inferior left thyroid. Left neck exploration was performed. Intraoperatively, a 3.7 cm left parathyroid mass weighing 13.0 grams was encountered and excised in an en bloc fashion. The left superior parathyroid gland was evaluated and found to be normal. Intraoperative PTH level decreased from 529 pg/mL to 48 pg/mL 10 minutes after excision. Left hemithyroidectomy was not performed. Surgical pathology revealed PC with lymphovascular invasion, suspected capsular invasion, and negative margins. Immunohistochemical staining showed a Ki67 proliferation index up to 5% and complete loss of nuclear staining for parafibromin. Next generation sequencing demonstrated a somatic CDC73 p.L8fs mutation, tumor mutational burden 4.7m/MB, and stable microsatellite instability. Germline testing was negative for a CDC73 mutation. Postoperative staging did not demonstrate evidence of metastatic disease in the neck or chest. Serum Ca remained within normal limits. After multidisciplinary discussion, no further surgical intervention was recommended and plan was for ongoing biochemical and imaging surveillance. Conclusion: Though rare, PC should be considered as a cause of PHPT. The primary treatment is complete surgical resection. Unfortunately, there is a high rate of recurrence, >50%, with most occurring 2-5 years after initial surgery with a median overall survival of 14 years. Thus, long-term surveillance is of utmost importance. Treatment of recurrent disease is surgical resection when feasible as well as medical management of hypercalcemia. Further research is needed to better understand the role of targeted systemic therapy in addition to immunotherapy. PC is most commonly sporadic but can be hereditary, thus genetic evaluation is recommended. Given its rarity and complexity, PC is best managed in a multidisciplinary setting. Presentation: 6/1/2024

Single-Hit and Multi-hit PIK3CA Short Variant Genomic Alterations in Clinically Advanced Prostate Cancer: A Genomic Landscape Study.

Tumors harboring two or more PIK3CA short variant (SV) ("multi-hit") mutations have been linked to improved outcomes with anti-PIK3CA-targeted therapies in breast cancer. The landscape and clinical implications of multi-hit PIK3CA alterations in clinically advanced prostate cancer (CAPC) remains elusive. To evaluate the genomic landscape of single-hit and multi-hit PIK3CA genomic alterations in CAPC. The Foundation Medicine FoundationCore database was used to identify 19,978 CAPC tumors that underwent hybrid capture-based comprehensive genomic profiling to evaluate all classes of genomic alterations (GA) and determine tumor mutational burden (TMB), microsatellite instability (MSI), genomic ancestry, single-base substitution mutational signatures, and homologous recombination deficiency signature (HRDsig). Tumor cell PD-L1 expression was determined by IHC (Dako 22C3). 18,741 (93.8%) tumors were PIK3CA wild type (WT), 1155 (5.8%) featured single PIK3CA SV, and 82 (0.4%) featured multi-hit PIK3CA SVs. Single-hit (6.6 versus 3.8; p < 0.0001) and multi-hit (12.8 versus 3.8; p < 0.0001) featured more driver GA per tumor than PIK3CA WT CAPC, as well as higher prevalence of MMR mutational signature, MSI high status, and TMB levels versus PIK3CA WT (p < 0.0001). Other differences in GA included higher frequencies of GA in BRCA2 in multi-hit versus WT (18.3% versus 8.5%; p = 0.0191), ATM in multi-hit versus WT (13.4% versus 5.6%; p = 0.02) and PTEN in single-hit versus WT (40.2% versus 30.1%; p < 0.0001). Homologous recombination deficiency signatures were higher in PIK3CA WT versus single-hit (11.2% versus 7.6%; p = 0.0002). There were no significant differences in PD-L1 expression among the three groups. Identification of multi-hit PIK3CA GA in CAPC highlights a potentially unique phenotype that may be associated with response to anti-PIK3CA targeted therapy and checkpoint inhibition, supporting relevant clinical trial designs.

Predictive value of ZFHX4 mutation for the efficacy of immune checkpoint inhibitors in non-small cell lung cancer and melanoma.

Studies have shown that the Zinc finger homeobox 4 (ZFHX4) might be a factor in the prognosis of malignancies. However, little is known about the association between the ZFHX4 mutation and the effectiveness of immune checkpoint inhibitors (ICIs) in non-small cell lung cancer (NSCLC) and melanoma. Three public ICIs-treated NSCLC cohorts were divided into discovery cohort (n=75) and validation cohort (n=62), which were used to evaluate the relationship between ZFHX4 mutation and ICIs effectiveness in NSCLC. Seven ICIs-treated melanoma cohorts (n = 418) were used to analyze the relationship between ZFHX4 mutation and immunotherapy efficacy in melanoma. NSCLC and skin cutaneous melanoma (SKCM) cohorts from The Cancer Genome Atlas (TCGA) were used to investigate underlying mechanism. Patients with ZFHX4 mutant-type (ZFHX4-Mut) showed a superior objective response rate (ORR) (P < 0.01) and longer progression-free survival (PFS) (P < 0.05) than patients with ZFHX4 wild-type (ZFHX4-WT) in NSCLC cohorts. In the melanoma cohorts, patients carrying ZFHX4-Mut had a higher ORR (P = 0.042) and longer overall survival (OS) (P = 0.011). Besides, patients with NSCLC and melanoma harboring ZFHX4-Mut had a higher tumor mutation burden (TMB) (P<0.001) and tumor neoantigen burden (TNB) (P<0.001) than those harboring ZFHX4-WT. ZFHX4 mutation was associated with higher levels of plasma B cells, activated CD4+ memory T cells, and CD8+ T cells. Seven DNA damage repair pathways were significantly enriched in the ZFHX4-Mut group. ZFHX4 mutation could serve as a predicter for the efficacy of ICIs therapy in NSCLC and melanoma.

Immune-related glycosylation genes based classification predicts prognosis and therapy options of osteosarcoma

Osteosarcoma is the most common primary bone malignancy, with a very poor prognosis. Aberrant glycosylation is close involvement in osteosarcoma. Accordingly, this study aimed at investigating the role of glycosylation genes in the prognosis and therapy options of osteosarcoma. The microenvironment of osteosarcoma was assessed using estimate algorithm. A total of 20 immune-related glycosylation genes (IRGGs) was identified using Pearson correlation analysis. Accordingly, osteosarcoma patients were divided into C1 and C2 type using consensus clustering. Multiple algorithms (Xcell, MCP-counter, ssGSEA, epic, quantiseq), cancer immune cycle analysis, and GSVA were applied to estimate the immune, molecule and metabolism characteristics of osteosarcoma, indicating that C1 type was featured with high immune infiltration, high glycosylation, enriched MEK signaling, and good prognosis, while C2 type was characterized by more metastasis, enriched immunotherapy-positive gene signatures, high tumor mutation burden, and poor prognosis. Results from TIDE algorithm and immunotherapy datasets suggested the C2 type’s preference of immune checkpoint inhibitors (ICIs), while data of GDSC, CMap analysis and cell experiments indicated that C1 type was sensitivity to MEK inhibitor PD0325901. In addition, univariate Cox and Lasso analysis was combined to establish an IRGGs’ risk score containing 6 genes (B3GNT8, FUT7, GAL3ST4, GALNT14, HS3ST2, and MFNG). The data of DCA and ROC indicated its well prediction of prognosis in osteosarcoma. Finally, cellular location analysis showed that the 6 genes not only distributed in tumor cells but also in immune cells. In summary, the classification and risk score based on IRGGs effectively predicted the prognosis and therapy options of osteosarcoma. Further studies on IRGGs may contribute to the understanding of cancer immunity in osteosarcoma.