Molecular and Cellular Mechanisms of Perineural Invasion in Oral Squamous Cell Carcinoma: Potential Targets for Therapeutic Intervention

Histopathologic Features of Mucosal Head and Neck Cancer Cachexia

Objective

Determine the histopathologic features that correlate with head and neck cancer (HNC) cachexia.

Methods

A single-institution, retrospective study was performed on adults with HPV-negative, mucosal squamous cell carcinoma of the aerodigestive tract undergoing resection and free flap reconstruction from 2014 to 2019. Patients with distant metastases were excluded. Demographics, comorbidities, preoperative nutrition, and surgical pathology reports were collected. Comparisons of histopathologic features and cachexia severity were made.

Results

The study included 222 predominantly male (64.9%) patients aged 61.3 ± 11.8 years. Cachexia was identified in 57.2% patients, and 18.5% were severe (≥15% weight loss). No differences in demographics were identified between the groups. Compared to control, patients with severe cachexia had lower serum hemoglobin (p=0.048) and albumin (p < 0.001), larger tumor diameter (p < 0.001), greater depth of invasion (p < 0.001), and elevated proportions of pT4 disease (p < 0.001), pN2-N3 disease (p=0.001), lymphovascular invasion (p=0.009), and extranodal extension (p=0.014). Multivariate logistic regression identified tumor size (OR [95% CI] = 1.36 [1.08-1.73]), oral cavity tumor (OR [95% CI] = 0.30 [0.11-0.84]), and nodal burden (OR [95% CI] = 1.16 [0.98-1.38]) as significant histopathologic contributors of cancer cachexia.

Conclusions

Larger, more invasive tumors with nodal metastases and aggressive histologic features are associated with greater cachexia severity in mucosal HNC.

Context-Dependent Regulation of Peripheral Nerve Abundance by the PI3K Pathway in the Tumor Microenvironment of Head and Neck Squamous Cell Carcinoma

Recent studies have highlighted neurons and their associated Schwann cells (SCs) as key regulators of cancer development. However, the mode of their interaction with tumor cells or other components of the tumor microenvironment (TME) remains elusive. We established an SC-related 43-gene set as a surrogate for peripheral nerves in the TME. Head and neck squamous cell carcinoma (HNSCC) from The Cancer Genome Atlas (TCGA) were classified into low, intermediate and high SC score groups based on the expression of this gene set. Perineural invasion (PNI) and TGF-β signaling were hallmarks of SChigh tumors, whereas SClow tumors were enriched for HPV16-positive OPSCC and higher PI3K-MTOR activity. The latter activity was partially explained by a higher frequency of PTEN mutation and PIK3CA copy number gain. The inverse association between PI3K-MTOR activity and peripheral nerve abundance was context-dependent and influenced by the TP53 mutation status. An in silico drug screening approach highlighted the potential vulnerabilities of HNSCC with variable SC scores and predicted a higher sensitivity of SClow tumors to DNA topoisomerase inhibitors. In conclusion, we have established a tool for assessing peripheral nerve abundance in the TME and provided new clinical and biological insights into their regulation. This knowledge may pave the way for new therapeutic strategies and impart proof of concept in appropriate preclinical models.

Perineural invasion as a predictor of local recurrence in cats with squamous cell carcinoma treated with electrochemotherapy

Introduction

Squamous cell carcinoma (SCC) is a malignant neoplasm that accounts for approximately 15-25% and 70-80% of all feline cutaneous and oral tumors, respectively. Similar to that in humans, feline SCC can be highly invasive locally; however, its metastasis rate is low. Thus, effective local treatment may be curative for most patients, and includes surgery, electrochemotherapy (ECT), cryosurgery, or a combination of these. However, this neoplasia can manifest more aggressively in some patients, leading to higher recurrence rates. In humans, perineural invasion (PNI) has been described as a relevant tumor dissemination pathway associated with high-risk SCC, resulting in higher recurrence rates, resistance to local treatments, and short survival. However, PNI and its prognostic value have not been described in feline SCC. This study aimed to evaluate the PNI in a feline population with SCC treated with ECT and correlate its presence with the occurrence of local recurrence and other clinical variables.

Methods

Twenty-four cats histopathologically diagnosed with SCC between 2013 and 2021 were retrospectively selected from the medical records of the Oncological Center Vet Cancer (São Paulo, SP, Brazil). The inclusion criteria were ECT as the sole therapy, histopathological evaluation of PNI, and absence of distant metastatic disease.

Results

The complete response rate was 96% (23/24), and PNI was identified in 33% of the cats (8/24, PNI-positive group), whereas 67% were free of this invasion (16/24, PNI-negative group). All PNI-positive cats developed local recurrence, whereas only five PNI-negative cats experienced recurrence. Local recurrence was significantly associated with PNI (p = 0.03).

Discussion

The results of this study are preliminary but promising. The data obtained are the first regarding PNI occurrence in feline SCC and pave the way for further studies, mainly to correlate the PNI with survival data and better define its prognostic value.

Prognostic Analysis Combining Histopathological Features and Clinical Information to Predict Colorectal Cancer Survival from Whole-Slide Images

BACKGROUND

Colorectal cancer (CRC) is a malignant tumor within the digestive tract with both a high incidence rate and mortality. Early detection and intervention could improve patient clinical outcomes and survival.

METHODS

This study computationally investigates a set of prognostic tissue and cell features from diagnostic tissue slides. With the combination of clinical prognostic variables, the pathological image features could predict the prognosis in CRC patients. Our CRC prognosis prediction pipeline sequentially consisted of three modules: (1) A MultiTissue Net to delineate outlines of different tissue types within the WSI of CRC for further ROI selection by pathologists. (2) Development of three-level quantitative image metrics related to tissue compositions, cell shape, and hidden features from a deep network. (3) Fusion of multi-level features to build a prognostic CRC model for predicting survival for CRC.

RESULTS

Experimental results suggest that each group of features has a particular relationship with the prognosis of patients in the independent test set. In the fusion features combination experiment, the accuracy rate of predicting patients' prognosis and survival status is 81.52%, and the AUC value is 0.77.

CONCLUSION

This paper constructs a model that can predict the postoperative survival of patients by using image features and clinical information. Some features were found to be associated with the prognosis and survival of patients.

Interactions between MDSCs and the Autonomic Nervous System: Opportunities and Challenges in Cancer Neuroscience

Myeloid-derived suppressor cells (MDSC) are a population of heterogeneous immune cells that are involved in precancerous conditions and neoplasms. The autonomic nervous system (ANS), which is composed of the sympathetic nervous system and the parasympathetic nervous system, is an important component of the tumor microenvironment that responds to changes in the internal and external environment mainly through adrenergic and cholinergic signaling. An abnormal increase of autonomic nerve density has been associated with cancer progression. As we discuss in this review, growing evidence indicates that sympathetic and parasympathetic signals directly affect the expansion, mobilization, and redistribution of MDSCs. Dysregulated autonomic signaling recruits MDSCs to form an immunosuppressive microenvironment in chronically inflamed tissues, resulting in abnormal proliferation and differentiation of adult stem cells. The two components of the ANS may also be responsible for the seemingly contradictory behaviors of MDSCs. Elucidating the underlying mechanisms has the potential to provide more insights into the complex roles of MDSCs in tumor development and lay the foundation for the development of novel MDSC-targeted anticancer strategies.

Assessment of Bone Invasion and Its Correlation With Brandwein-Gensler Criteria in Oral Squamous Cell Carcinoma

Background The most prevalent form of head-neck cancer is squamous cell carcinoma (SCC). Apart from all sites like the tongue, labial mucosa, and buccal mucosa, the prevalence of oral squamous cell carcinoma (OSCC) is more common in gingivobuccal sulcus due to the habit of keeping tobacco quid. With regards to anatomical relationships in the mouth and proximity to bone, OSCC invades the maxilla and mandible. However, bone invasion significantly influences the pathological staging of OSCC. Histological parameters such as Brandwein-Gensler worst pattern of invasion (WPOI), lymphocytic host response (LHR), and perineural invasion (PNI) hold significance for determining the need for adjuvant therapy. This study aims to correlate Brandwein-Gensler Criteria (BGC) with bone invasion and also to include the bone invasion criteria as a prognostic parameter in OSCC. This study aimed to assess bone invasion and correlate it with Brandwein-Gensler criteria in OSCC. Methods The research was conducted retrospectively, analyzing 65 cases of OSCC that underwent surgical intervention. Data was gathered from the Oral Pathology department's archives at Sharad Pawar Dental College (SPDC), Wardha. Pathologists assessed bone invasion without the knowledge of other factors to minimize bias. Subsequently, the cases were classified into well-differentiated (WDSCC), moderately differentiated (MDSCC), and poorly differentiated squamous cell carcinomas (PDSCC) based on histological grading, followed by the evaluation of WPOI, LHR, and PNI using the Brandwein-Gensler risk scoring system. Results This study found a notable association between bone invasion and BGC, with a calculated significance level of p = 0.047. LHR shows patterns as 1, 2, and 3. There were five (7.6%) cases with pattern III, 45 (69.23%) cases with pattern II, and 15 (23.08%) cases with pattern I. Similarly, PNI is scored as 0, 1, and 3. There were seven (10.77%) cases with score 3, 17 (26.15%) with score 1, and 41 (63.03%) with score 0. In the case of the WOPI, which is classified as patterns I to V, there were seven (10.77%) cases with pattern V, 27 (41.54%) cases with pattern IV, 23 (35.38%) cases with pattern III, and eight (12.231%) cases with pattern II, whereas no cases were noted with pattern I. Conclusion Although bone invasion and BGC are independent parameters, the BGC score should be considered in treatment planning. Patients with bone invasion and those with a higher BGC score should be strongly considered for adjuvant treatment.

Study of the association of the known prognostic variables with EGFR expression in head and neck squamous cell carcinomas

Context

: Head and neck squamous cell carcinomas (HNSCCs) are the sixth most frequent malignancy in the world. Epidermal growth factor receptors (EGFRs) are members of Erb B family of receptors. EGFR is known to act as a driver of tumorigenesis in various carcinomas. Over expression of EGFR in HNSCC is associated with poor prognosis and resistance to radiotherapy. It is a useful prognostic marker, marker for response to therapy, and also a therapeutic target.

Aim

To study the association of the known prognostic variables with EGFR expression in HNSCCs and to correlate it with the clinical outcome.

Settings and Design

Cross-sectional observational study.

Materials and Methods

A total of 170 patients of HNSCC were evaluated for EGFR expression and followed up for at least two years, with correlation of EGFR expression with various histopathological factors and their clinical outcome.

Statistical Analysis Used

: Chi-square test.

Results

The expression of EGFR in HNSCC in this study population was 88.82%. Statistical significance was noted between EGFR reactivity and age of the patient, its histological grade and perineural invasion. Statistical significance was also noted between EGFR reactivity and recurrence of malignancy as well as the site of recurrence.

Conclusion

EGFR expression in patients with HNSCC is a poor prognostic biomarker and has a comparatively lower survival outcome as compared to non-EGFR expressing HNSCC cases. Hence, it will be helpful for all those patients diagnosed with HNSCC to ideally undergo an additional EGFR immunohistochemical evaluation, which, in turn, will help the oncologists in management of the tumor with anti-EGFR therapy combined with radiotherapy, to obtain a better response and a survival outcome.

Improving oral squamous cell carcinoma diagnosis and treatment with fluorescence molecular imaging

Timely identification and complete removal of oral squamous cell carcinoma (OSCC) through surgery is crucial for effective treatment. However, current diagnostic methods that rely on physical abnormalities are not very informative and practical in clinical settings, leading to the late detection of oral cancer. Furthermore, no dependable intraoperative tools available for assessing surgical margins in real-time. Fluorescence imaging allows the visualization of biological processes occurring in the early stages of cancer, and as a result, small tumors can be detected at an early stage. Fluorescence imaging can effectively aid in assessing excised edges during surgery for OSCC as it possesses high sensitivity and spatial resolution. This review focuses on tongue cancer as a representation of OSCC and delves into various fluorescence techniques that can aid in early diagnosis and surgical guidance. The review also discusses the potential clinical applications of these techniques in the future.

Establishment of a Machine Learning Model for the Risk Assessment of Perineural Invasion in Head and Neck Squamous Cell Carcinoma

Perineural invasion is a prevalent pathological finding in head and neck squamous cell carcinoma and a risk factor for unfavorable survival. An adequate diagnosis of perineural invasion by pathologic examination is limited due to the availability of tumor samples from surgical resection, which can arise in cases of definitive nonsurgical treatment. To address this medical need, we established a random forest prediction model for the risk assessment of perineural invasion, including occult perineural invasion, and characterized distinct cellular and molecular features based on our new and extended classification. RNA sequencing data of head and neck squamous cell carcinoma from The Cancer Genome Atlas were used as a training cohort to identify differentially expressed genes that are associated with perineural invasion. A random forest classification model was established based on these differentially expressed genes and was validated by inspection of H&E-stained whole image slides. Differences in epigenetic regulation and the mutational landscape were detected by an integrative analysis of multiomics data and single-cell RNA-sequencing data were analyzed. We identified a 44-gene expression signature related to perineural invasion and enriched for genes mainly expressed in cancer cells according to single-cell RNA-sequencing data. A machine learning model was trained based on the expression pattern of the 44-gene set with the unique feature to predict occult perineural invasion. This extended classification model enabled a more accurate analysis of alterations in the mutational landscape and epigenetic regulation by DNA methylation as well as quantitative and qualitative differences in the cellular composition in the tumor microenvironment between head and neck squamous cell carcinoma with or without perineural invasion. In conclusion, the newly established model could not only complement histopathologic examination as an additional diagnostic tool but also guide the identification of new drug targets for therapeutic intervention in future clinical trials with head and neck squamous cell carcinoma patients at a higher risk for treatment failure due to perineural invasion.

Prognostic Value of Perineural Invasion on Survival and Recurrence in Oral Squamous Cell Carcinoma

A diagnosis of perineural invasion (PNI) is widely accepted as an unfavorable prognostic factor in various solid malignancies. Although PNI has been described as a high-risk parameter in oral squamous cell carcinoma (OSCC), its role in the current staging manuals of the American Joint Committee on Cancer (AJCC) is rather subordinate. We analysed the prognostic value of PNI on survival and recurrence in a large, multicenter OSCC cohort and a population-based approach. A total of 493 OSCC patients with primary tumor resection to negative margins and concomitant neck dissection between 2010 and 2017 were enrolled. PNI was evaluated in relation to overall survival (OAS) and recurrence-free survival (RFS) using uni- and multi-variable Cox regression. The median follow-up time was 5.0 years and PNI was diagnosed in 48 patients (9.7%). A pathohistological verification of PNI correlated significantly with a deteriorated OAS in uni- (HR 2.312; 95% CI 2.312–3.493, p = 0.001) and multivariable Cox regression (HR 1.820; 95% CI 1.164–2.847, p = 0.009). Additionally, a diagnosis of PNI correlated with increased cumulative, as well as distant, metastasis 5-year-recurrence rates (p = 0.027 and p = 0.011, respectively). The application of adjuvant radiotherapy (RT) or radiochemotherapy (RCT) in patients with PNI did not alter OAS or RFS in survival analysis when compared to patients without PNI. The results underline the adverse impact of PNI on the survival and recurrence of surgically treated OSCC patients. Based on our findings, we highly recommend an emphasis on PNI in the TNM staging concept.

Long Noncoding RNA LINC00941 Promotes Cell Proliferation and Invasion by Interacting with hnRNPK in Oral Squamous Cell Carcinoma

Oral squamous cell carcinoma (OSCC) is a prevalent carcinoma of the head, neck and mouth. Recently studies involving the role of long noncoding RNAs (lncRNAs) that play key regulatory roles in altering gene expression has been reported in the context of promoting tumorigenesis. However, the functions of lncRNAs in the context of oral squamous cell carcinoma have not been extensively described. In this study, we report a never identified before lncRNA, LINC00941, which was highly expressed in OSCC tissues and cells. Expression of LINC00941 promoted cell proliferation, migration, invasion, and metastasis of OSCC cells In Vitro by inducing epithelial-mesenchymal transition (EMT) and activating the Wnt/β-catenin signaling cascade. In silico analyses revealed heterogeneous nuclear ribonucleoprotein K (hnRNPK) to be a strong positive regulator of LINC00941 activity. Experimental verification of this association revealed a direct interaction of LINC00941 and hnRNPK to induce cell growth and invasion by activating EMT in OSCC cells. Therefore, our study reports that LINC00941 promotes progression of OSCC by its interaction with hnRNPK, and it may present a promising strategy for diagnosis and treatment of OSCC.