Phenotypic plasticity and inflammation, two well-established hallmarks of cancer, play key roles in local invasion and distant metastasis by enabling the rapid adaptation of tumor cells to dynamic micro-environmental changes. Here, we show that in oral squamous carcinoma cell carcinoma (OSCC), the competition between the NuRD and SWI/SNF chromatin remodeling complexes plays a pivotal role in regulating both epithelial-mesenchymal plasticity (EMP) and inflammation. By perturbing these complexes, we demonstrated their opposing downstream effects on the inflammatory pathways and EMP regulation. In particular, downregulation of the BRG1-specific SWI/SNF complex deregulates key inflammatory genes, such as TNF-α and IL6, in opposite ways when compared with the loss of CDK2AP1, a key member of the NuRD complex. We showed that CDK2AP1 genetic ablation triggers a pro-inflammatory secretome encompassing several chemokines and cytokines, thus promoting the recruitment of monocytes into the tumor microenvironment (TME). Furthermore, CDK2AP1 deletion stimulates their differentiation into M2-like macrophages, as validated on tumor microarrays from OSCC patient-derived tumor samples. Further analysis of the inverse correlation between CDK2AP1 expression and TME immune infiltration revealed specific downstream effects on the abundance and localization of CD68+ macrophages. Our study sheds light on the role of chromatin remodeling complexes in OSCC locoregional invasion and highlights the potential of CDK2AP1 and other members of NuRD and SWI/SNF chromatin remodeling complexes as prognostic markers and therapeutic targets.

Simple Summary A total laryngectomy and/or pharyngectomy is an important therapy modality for advanced primary and recurrent laryngeal and hypopharyngeal squamous cell carcinoma. The surgical margins are an important prognostic factor. Resection margins for head and neck cancer surgery are clear >5 mm, close 1–5 mm and positive <1 mm. However, the anatomy of the larynx and hypopharynx is complex and resections are constrained by the anatomical relationship with the surrounding structures. The aim of this study is to investigate if a margin >5 mm is feasible. Clear resection margins are not always feasible in some resection surfaces in laryngeal and hypopharyngeal surgery, due to the anatomy of the larynx and tumor location. However, striving for a maximum feasible margin is still the main goal. We propose a new guideline for the maximum feasible but adequate resection margins in larynx and hypopharynx tumor surgery. Abstract Background: Resection margins are an important prognostic factor for patients with head and neck cancer. In general, for head and neck surgery, a margin >5 mm is advised by the Royal College of Pathologists. However, this cannot always be achieved during laryngeal and hypopharyngeal surgery. The aim of this study is to identify the resection surfaces and measure the maximum feasible margins per subsite. The clinical relevance of these maximum feasible resection margins were analyzed in this descriptive anatomical study. Methods: head and neck surgeons and a pathologist from the Erasmus MC performed a total laryngectomy and laryngopharyngectomy on a head and neck specimen specifically available for research. Results: For a total laryngectomy, resection margins >5 mm were not feasible for the ventral and dorsal resection surface. For a total laryngopharyngectomy, resection margins >5 mm were not feasible for the ventral, dorsal and lateral resection surface. Conclusion: Clear resection margins, defined as a margin >5 mm, are not always feasible in laryngeal and hypopharyngeal surgery, due to the anatomy of the larynx and tumor location. However, striving for a maximum feasible margin is still the main goal. We propose a new guideline for maximum feasible but adequate resection margins in larynx and hypopharynx tumor surgery.

Simple Summary Achieving margins of >5 mm is challenging in the larynx and hypopharynx because resections are constrained by their complex anatomy. The aim of this study was to retrospectively assess the clinical relevance of resection margins defined by the RCP in total laryngectomies (TLs) and total laryngopharyngectomies (TLPs). Similar survival rates for close and clear margins for primary and recurrent LSCC were found. This may suggest that a margin > 5 mm is not clinically relevant in terms of survival, therefore a margin of 1–5 mm should be accepted in certain subsites. Margins < 1 mm are related to significantly worse outcomes and should be avoided. Abstract Background: Laryngeal and hypopharyngeal cancer is complex and resection margins are therefore constrained. The aim of this study was to investigate the clinical relevance of resection margins in laryngeal and hypopharyngeal surgery. Methods: A retrospective cohort study was performed for patients treated with a total laryngectomy (TL) or laryngopharyngectomy (TLP) for laryngeal or hypopharyngeal squamous cell carcinoma (LSCC and HSCC, respectively). Within the groups primary LSCC, recurrent LSCC, primary HSCC, and recurrent HSCC the relationship between the status of the resection margin according to the Royal Collage of Pathology and the recurrence and survival rates were investigated. Results: Positive resection margins were found in 54% for primary LSCC, 29% for recurrent LSCC, 62% for primary HSCC, and 44% for recurrent HSCC. For primary and recurrent LSCC, there was a linear association between total recurrence and narrowing margins (p = 0.007 resp. p = 0.008). Multivariate survival analysis for primary and recurrent LSCC showed a significantly worse disease free and disease-specific survival in case of positive margins compared to clear margins. Conclusion: Similar survival rates were recorded for close and clear margins for primary and recurrent LSCC. This may suggest that a margin > 5 mm is not clinically relevant in terms of survival. Therefore, a margin of 1–5 mm should be accepted in certain subsites. Margins < 1 mm are related to significantly worse outcomes and should be avoided.

As for many solid cancers, laryngeal cancer is treated surgically, and adequate resection margins are critical for survival. Raman spectroscopy has the capacity to accurately differentiate between cancer and non-cancerous tissue based on their molecular composition, which has been proven in previous work. The aim of this study is to investigate whether Raman spectroscopy can be used to discriminate laryngeal cancer from surrounding non-cancerous tissue. Patients surgically treated for laryngeal cancer were included. Raman mapping experiments were performed ex vivo on resection specimens and correlated to histopathology. Water concentration analysis and CH-stretching region analysis were performed in the high wavenumber range of 2500–4000 cm^−1. Thirty-four mapping experiments on 22 resection specimens were used for analysis. Both laryngeal cancer and all non-cancerous tissue structures showed high water concentrations of around 75%. Discriminative information was only found to be present in the CH-stretching region of the Raman spectra of the larynx (discriminative power of 0.87). High wavenumber region Raman spectroscopy can discriminate laryngeal cancer from non-cancerous tissue structures. Contrary to the findings for oral cavity cancer, water concentration is not a discriminating factor for laryngeal cancer.

Patients with oral cavity cancer are almost always treated with surgery. The goal is to remove the tumor with a margin of more than 5 mm of surrounding healthy tissue. Unfortunately, this is only achieved in about 15% to 26% of cases. Intraoperative assessment of tumor resection margins (IOARM) can dramatically improve surgical results. However, current methods are laborious, subjective, and logistically demanding. This hinders broad adoption of IOARM, to the detriment of patients. Here we present the development and validation of a high-wavenumber Raman spectroscopic technology, for quick and objective intraoperative measurement of resection margins on fresh specimens. It employs a thin fiber-optic needle probe, which is inserted into the tissue, to measure the distance between a resection surface and the tumor. A tissue classification model was developed to discriminate oral cavity squamous cell carcinoma (OCSCC) from healthy oral tissue, with a sensitivity of 0.85 and a specificity of 0.92. The tissue classification model was then used to develop a margin length prediction model, showing a mean difference between margin length predicted by Raman spectroscopy and histopathology of -0.17 mm.

Cyclin-dependent kinase 2-associated protein 1 (CDK2AP1; also known as deleted in oral cancer or DOC1) is a tumor suppressor gene known to play functional roles in both cell cycle regulation and in the epigenetic control of embryonic stem cell differentiation, the latter as a core subunit of the nucleosome remodeling and histone deacetylation (NuRD) complex. In the vast majority of oral squamous cell carcinomas (OSCC), expression of the CDK2AP1 protein is reduced or lost. Notwithstanding the latter (and the DOC1 acronym), mutations or deletions in its coding sequence are extremely rare. Accordingly, CDK2AP1 protein-deficient oral cancer cell lines express as much CDK2AP1 mRNA as proficient cell lines. Here, by combining in silico and in vitro approaches, and by taking advantage of patient-derived data and tumor material in the analysis of loss of CDK2AP1 expression, we identified a set of microRNAs, namely miR-21-5p, miR-23b-3p, miR-26b-5p, miR-93-5p, and miR-155-5p, which inhibit its translation in both cell lines and patient-derived OSCCs. Of note, no synergistic effects were observed of the different miRs on the CDK2AP1–3-UTR common target. We also developed a novel approach to the combined ISH/IF tissue microarray analysis to study the expression patterns of miRs and their target genes in the context of tumor architecture. Last, we show that CDK2AP1 loss, as the result of miRNA expression, correlates with overall survival, thus highlighting the clinical relevance of these processes for carcinomas of the oral cavity.