Disseminating cells in human oral tumours possess an EMT cancer stem cell marker profile that is predictive of metastasis in image-based machine learning

Cancer stem cells (CSCs) undergo epithelial-mesenchymal transition (EMT) to drive metastatic dissemination in experimental cancer models. However, tumour cells undergoing EMT have not been observed disseminating into the tissue surrounding human tumour specimens, leaving the relevance to human cancer uncertain. We have previously identified both EpCAM and CD24 as CSC markers that, alongside the mesenchymal marker Vimentin, identify EMT CSCs in human oral cancer cell lines. This afforded the opportunity to investigate whether the combination of these three markers can identify disseminating EMT CSCs in actual human tumours. Examining disseminating tumour cells in over 12,000 imaging fields from 74 human oral tumours, we see a significant enrichment of EpCAM, CD24 and Vimentin co-stained cells disseminating beyond the tumour body in metastatic specimens. Through training an artificial neural network, these predict metastasis with high accuracy (cross-validated accuracy of 87-89%). In this study, we have observed single disseminating EMT CSCs in human oral cancer specimens, and these are highly predictive of metastatic disease.

Abstract 5629: Spatial genomics and proteomics enable multimodal analyses of oral SCC clonal heterogeneity and interactions with tumor microenvironment

Cancer progression is an evolutionary process governed by the clonal evolution of the genetic mutations acquired during tumor growth, together with the co-evolution of the tumour ecosystem. The nature of cancer subclonal mutations and their effects on the tumour microenvironment are the major drivers of intratumor heterogeneity and contribute to cancer progression, metastasis, therapy resistance and disease recurrence. Therefore, a spatially resolved genetic and cellular profiling of tumors is crucial to investigate tumor architecture and cellular diversity. Oral squamous cell carcinoma (OSCC), a subset of head and neck cancer, accounts for 355,000 new cases annually worldwide and has a 5-year survival rate of only 50%. We recently conducted a multi-level analysis of OSCC genetic and microenvironment heterogeneity (Sequeira et al, 2020, NatComms). Computational analysis of tumour clonal dynamics from DNA sequencing data revealed that high genetic heterogeneity to be a feature of early-stage lesions that are likely to progress to more aggressive tumors (Williams et al 2018, NatGen; Sequeira et al, 2020, NatComms). These tools can be used to predict tumour behavior and for early diagnosis of aggressive lesions. The goal of this study is to elucidate the functional and spatial intratumor heterogeneity, tumor clonal dynamics and evolutionary landscape of human OSCC, and to study the interaction of tumour cells with the microenvironment, in particular the role of specific mutations in promoting epithelial-to-mesenchymal transition and tumor progression, using an interdisciplinary approach that combines spatial integrative genome analysis and deep single-cell phenotyping of tumor microenvironment. We performed whole-exome sequencing from multifocal OSCC tumor regions and matched metastasis, and used computational methods to investigate the tumor subclonal organization, construct phylogenetic trees for each tumor and assess the genetic diversity of the different tumour regions and metastasis. We then combined Single cell Spatial Phenotyping on the PhenoCycler platform (Akoya Biosciences) (Black et al, 2021, NatProtocols) with the subclonal genomic analysis to investigate how different mutational landscapes affect tumor microenvironment and metastasis, at unprecedented detail. Together, this multi-modal integrated spatial genomics and proteomics analysis of the tumor ecosystem highlights the importance of spatial cellular organization and provides a comprehensive human OSCC spatial atlas of tumour heterogeneity, providing a foundation for exploring cancer evolution, heterogeneity and progression.

Citation Format: Raju Kumar, Rana Ibrahim, Bassem Ben Cheikh, Emma Bailey, Hannah Cottom, Oliver Braubach, Trevor Graham, Jun Wang, Ines Sequeira. Spatial genomics and proteomics enable multimodal analyses of oral SCC clonal heterogeneity and interactions with tumor microenvironment. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 5629.

Sinonasal carcinosarcoma with cartilaginous and rhabdomyoblastic components: A previously undescribed entity

Carcinosarcomas are rare, aggressive tumors seldom found in the sinonasal region. They classically consist of sarcomatous spindle cell and carcinomatous squamous cell elements. A 61-year-old woman presented reporting right-sided nasal discharge and obstruction. Examination demonstrated a large right-sided nasal mass, from which a biopsy was taken. Computed tomography and magnetic resonance imaging revealed a mass arising from the maxillary antrum and extending into the nasal cavity, ethmoid air cells, and frontal sinus. Right total maxillectomy with resection of the nasal tumour component was performed. Histological analysis demonstrated a high-grade malignancy with features consistent with carcinosarcoma with cartilaginous and rhabdomyoblastic elements, a histologic pattern that has not previously been described at this site. Magnetic resonance imaging 5 weeks postoperatively showed sizeable recurrence. Adjuvant chemotherapy and radiotherapy were commenced to excellent effect. Carcinosarcomas, though very rare at sinonasal sites, should be considered if biopsy demonstrates undifferentiated high-grade neoplasm with cytokeratin expression. These tumors require aggressive multimodal therapy for optimal outcomes.

Quantitative Assessment and Prognostic Associations of the Immune Landscape in Ovarian Clear Cell Carcinoma

Ovarian clear cell carcinoma (OCCC) is a rare subtype of epithelial ovarian cancer characterised by a high frequency of loss-of-function ARID1A mutations and a poor response to chemotherapy. Despite their generally low mutational burden, an intratumoural T cell response has been reported in a subset of OCCC, with ARID1A purported to be a biomarker for the response to the immune checkpoint blockade independent of micro-satellite instability (MSI). However, assessment of the different immune cell types and spatial distribution specifically within OCCC patients has not been described to date. Here, we characterised the immune landscape of OCCC by profiling a cohort of 33 microsatellite stable OCCCs at the genomic, gene expression and histological level using targeted sequencing, gene expression profiling using the NanoString targeted immune panel, and multiplex immunofluorescence to assess the spatial distribution and abundance of immune cell populations at the protein level. Analysis of these tumours and subsequent independent validation identified an immune-related gene expression signature associated with risk of recurrence of OCCC. Whilst histological quantification of tumour-infiltrating lymphocytes (TIL, Salgado scoring) showed no association with the risk of recurrence or ARID1A mutational status, the characterisation of TILs via multiplexed immunofluorescence identified spatial differences in immunosuppressive cell populations in OCCC. Tumour-associated macrophages (TAM) and regulatory T cells were excluded from the vicinity of tumour cells in low-risk patients, suggesting that high-risk patients have a more immunosuppressive microenvironment. We also found that TAMs and cytotoxic T cells were also excluded from the vicinity of tumour cells in ARID1A-mutated OCCCs compared to ARID1A wild-type tumours, suggesting that the exclusion of these immune effectors could determine the host response of ARID1A-mutant OCCCs to therapy. Overall, our study has provided new insights into the immune landscape and prognostic associations in OCCC and suggest that tailored immunotherapeutic approaches may be warranted for different subgroups of OCCC patients.

Oral pemphigus vulgaris: dentists take-home message

Pemphigus is a life-threatening disease but timely recognition of oral lesions is critical to prevent serious cutaneous and fatal complications.

3D Functional Genomics Screens Identify CREBBP as a Targetable Driver in Aggressive Triple-Negative Breast Cancer

Triple-negative breast cancers (TNBC) are resistant to standard-of-care chemotherapy and lack known targetable driver gene alterations. Identification of novel drivers could aid the discovery of new treatment strategies for this hard-to-treat patient population, yet studies using high-throughput and accurate models to define the functions of driver genes in TNBC to date have been limited. Here, we employed unbiased functional genomics screening of the 200 most frequently mutated genes in breast cancer, using spheroid cultures to model in vivo-like conditions, and identified the histone acetyltransferase CREBBP as a novel tumor suppressor in TNBC. CREBBP protein expression in patient tumor samples was absent in 8% of TNBCs and at a high frequency in other tumors, including squamous lung cancer, where CREBBP-inactivating mutations are common. In TNBC, CREBBP alterations were associated with higher genomic heterogeneity and poorer patient survival and resulted in upregulation and dependency on a FOXM1 proliferative program. Targeting FOXM1-driven proliferation indirectly with clinical CDK4/6 inhibitors (CDK4/6i) selectively impaired growth in spheroids, cell line xenografts, and patient-derived models from multiple tumor types with CREBBP mutations or loss of protein expression. In conclusion, we have identified CREBBP as a novel driver in aggressive TNBC and identified an associated genetic vulnerability in tumor cells with alterations in CREBBP and provide a preclinical rationale for assessing CREBBP alterations as a biomarker of CDK4/6i response in a new patient population. SIGNIFICANCE: This study demonstrates that CREBBP genomic alterations drive aggressive TNBC, lung cancer, and lymphomas and may be selectively treated with clinical CDK4/6 inhibitors.

The Spatiotemporal Evolution of Lymph Node Spread in Early Breast Cancer

Purpose: The most significant prognostic factor in early breast cancer is lymph node involvement. This stage between localized and systemic disease is key to understanding breast cancer progression; however, our knowledge of the evolution of lymph node malignant invasion remains limited, as most currently available data are derived from primary tumors.Experimental Design: In 11 patients with treatment-naïve node-positive early breast cancer without clinical evidence of distant metastasis, we investigated lymph node evolution using spatial multiregion sequencing (n = 78 samples) of primary and lymph node deposits and genomic profiling of matched longitudinal circulating tumor DNA (ctDNA).Results: Linear evolution from primary to lymph node was rare (1/11), whereas the majority of cases displayed either early divergence between primary and nodes (4/11) or no detectable divergence (6/11), where both primary and nodal cells belonged to a single recent expansion of a metastatic clone. Divergence of metastatic subclones was driven in part by APOBEC. Longitudinal ctDNA samples from 2 of 7 subjects with evaluable plasma taken perioperatively reflected the two major evolutionary patterns and demonstrate that private mutations can be detected even from early metastatic nodal deposits. Moreover, node removal resulted in disappearance of private lymph node mutations in ctDNA.Conclusions: This study sheds new light on a crucial evolutionary step in the natural history of breast cancer, demonstrating early establishment of axillary lymph node metastasis in a substantial proportion of patients. Clin Cancer Res; 24(19); 4763-70. ©2018 AACR.

Abstract 788: Modeling tumor microenvironmental heterogeneity identifies CREBBP as a novel tumor suppressor in breast cancer

Solid tumors display significant histological, genetic and micro-environmental intra-tumor heterogeneity that can change substantially over the course of their evolutionary trajectory. In particular, changes in the micro-environmental complexity within breast cancer such as hypoxic and nutrient deplete environments are associated with aggressive disease and a poor patient outcome.

We sought to identify novel driver alterations in aggressive disease by employing a functional genomics screen in a 3-dimensional model of breast cancer progression that more accurately recapitulates in vivo micro-environmental heterogeneity. Screening of the top 200 recurrently mutated genes in breast cancer in cancer cell line spheroids identified several genes whose silencing impacted growth. A second targeted validation screen in a larger panel of triple negative cell line models showed that silencing of the histone acetyltransferase CREBBP, promoted growth in 3D but had limited effect under traditional 2D culture conditions.

Investigation of TCGA and METABRIC datasets showed that CREBBP was more frequently mutated in triple negative breast cancers (TNBCs) and at least a third of TNBCs also displayed gene haploinsufficiency or complete loss of CREBBP. Interrogation of expression and proteomic datasets showed that loss of CREBBP resulted in the upregulation of the pro-proliferative transcription factor FOXM1. Significantly, this conserved FOXM1-driven transcriptional programme was also seen in multiple solid tumors with CREBBP alterations including lung, oesophageal, bladder and endometrial cancers. This was recapitulated in several CREBBP deficient cells where we identified that FOXM1 is driving altered metabolism, allowing cancer cells to grow under nutrient stress conditions.

In summary, CREBBP is a bona fide tumor suppressor in up to a third of TNBCs, as well as a wide range of other solid tumors. CREBBP-altered tumors display up-regulation of FOXM1, which alters cancer cell metabolism under nutrient stress conditions. Moreover, CREBBP-altered tumors are selectively sensitive to small molecule inhibitors that target FOXM1 activity, suggesting that this maybe a viable targeted therapeutic approach for CREBBP altered cancers.

Citation Format: Barrie Peck, Philip J. Bland, Patty T. Wai, Hannah Cottom, Sarah L. Maguire, Eamonn Morrison, Holly E. Barker, Divya Kriplani, Rebecca Marlow, Kalnisha Naidoo, Gareth Muirhead, Syed Haider, Frances Daley, Frederik Wallberg, Andrew N. Tutt, Rachael C. Natrajan. Modeling tumor microenvironmental heterogeneity identifies CREBBP as a novel tumor suppressor in breast cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 788.

Are plasma cell-rich inflammatory conditions of the oral mucosa manifestations of IgG4-related disease?

Aim

The aim of this study was to characterise plasma cell infiltrates, in terms of IgG4 positivity, in specific and non-specific plasma cell-rich chronic inflammatory conditions of the oral mucosa. Exploring the possibility that specific plasma cell-rich oral inflammatory conditions have association with or represent an oral manifestation of immunoglobulin G4-related disease (IgG4-RD).

Methods

Ten patients with plasma cell-rich chronic inflammatory conditions of the oral mucosa were identified (seven—plasma cell mucositis and three—non-specific diffuse oral mucosal inflammation with ulceration). For each patient, the clinical record and H&E-stained sections were reviewed. Immunohistochemistry for IgG and IgG4 antibodies was performed on sections from the corresponding paraffin block, permitting calculation of the mean number of IgG4+ plasma cells per high-power field (HPF) and the IgG4+/IgG+ plasma cell ratio.

Results

In all the cases, only one histological hallmark of IgG4-RD—a dense lymphoplasmacytic infiltrate—was seen. Review of the medical histories did not reveal any features representing other manifestations of IgG4-RD. The number of IgG4+ plasma cells exceeded 100 per HPF in half of the cases. Only two cases had an IgG4+/IgG+ plasma cell ratio of >40%; both of which were in the non-specific oral inflammatory group.

Conclusions

Our study suggests that plasma cell mucositis does not meet microscopic criteria for IgG4-RD. It importantly reinforces the opinion that IgG4+ plasma cells are major components of chronic inflammation in the oral cavity and the pertinence of correct contextual interpretation of histopathological features with clinical findings.

Intraductal papilloma in an axillary lymph node of a patient with human immunodeficiency virus: a case report and review of the literature

Introduction

Inclusions of ectopic breast tissue in axillary lymph nodes are reported very infrequently and typically are only identified microscopically as an incidental finding. Furthermore the development of a benign proliferative lesion in the form of an intraductal papilloma from intranodal ectopic breast tissue is an extremely rare phenomenon with only three previous cases reported. This report describes an unusual and rare case of an intraductal papilloma arising in an axillary lymph node of a patient known to have the human immunodeficiency virus.

Case presentation

A 40-year-old Black African woman underwent excision of an enlarged palpable axillary lymph node. In the preceding 7 years she had received at least six separate surgical excisions to her ipsilateral breast for papillomatosis. The last surgical intervention was performed 1 year prior to presentation with an enlarged axillary lymph node. Histological examination of her axillary lymph node revealed a papillomatous proliferative epithelial lesion within an apparent encompassing duct, resembling a mammary intraductal papilloma. In the surrounding lymphoid tissue small groups of duct-like structures were additionally noted. Immunostaining with a panel of myoepithelial markers in conjunction with oestrogen receptor produced a mixed heterogeneous staining pattern in both the papillomatous lesion and the peripheral duct-like structures. This confirmed the diagnosis of a benign intraductal papilloma within an axillary lymph node, considered to have arisen from ectopic breast tissue.

Conclusions

This case demonstrates that intranodal ectopic breast tissue has the potential to undergo benign proliferative change albeit extremely rarely. Therefore this possibility must be considered to ensure the correct diagnosis is made. In addition, to the best of our knowledge, this is the first case report which has described recurrent intraductal papillomas and the subsequent development of an intraductal papilloma within an ipsilateral axillary lymph node, in a patient who is human immunodeficiency virus positive. There is minimal literature investigating the specific types of breast pathologies experienced by patients infected with human immunodeficiency virus and it remains unexplored as to whether human immunodeficiency virus may lead to proliferative papillomatous epithelial changes. This report considers the role of the human papillomavirus and recommends that further investigatory studies are required.

Odontogenic cervico-fascial infections: a continuing threat

STATEMENT OF THE PROBLEM

Dental abscesses are common and occasionally can progress to life-threatening cervico-fascial infections. Despite medical advances, odontogenic cervico-fascial infections (OCFIs) continue to be a threat. The potential seriousness of odontogenic infections (Ols), or dental abscesses, is frequently underestimated. General dental practitioners (GDPs) in primary care face the challenging decision of whether to refer patients to secondary care or to manage them in the community.

PURPOSE OF THE REVIEW

This paper reviews the relevant aspects of Ols that might be helpful to primary care dental practitioners in providing a better understanding of the anatomy and pathology and aims to assist in clinical decision.

METHOD

An up-to-date review of literature on OCFIs, highlighting their potential risks with clinical examples.

RESULTS AND CONCLUSION

Dental abscesses are common and continue to be a major cause for emergency hospital admission to oral and maxillofacial surgery departments. They occasionally spread to fascial spaces of the neck, potentially posing significant morbidity and mortality. GDPs are usually the first point of contact and face the challenge of recognising those at risk of developing OCFIs, which are potentially life threatening and require urgent referral for hospital treatment. We propose a patient care pathway to be used in primary care.