Oral Pharynx Research Articles

Histoanatomy of Malpighian tubules and the digestive tract of adult of biocontrol agent Calosoma sycophanta L. (Coleoptera: Carabidae)

Calosoma sycophanta L. is a voracious predatory beetle that feeds on several important lepidopteran pests such as the gypsy moth (Lymantria dispar L.), the brown-tail moth (Euproctis chrysorrhoea L.) and the pine processionary moths (Thaumetopoea pityocampa). It is mass reared in laboratory breeding and released against forest pests. So, C. sycophanta are important predators with the potential to be used in the biological control in agriculture. Although some studies provide important data on the gut anatomy in Carabidae, they are limited to few species. In the present study, we investigated the structure of the Malpighian tubules and digestive tract by means of light and electron microscopies. According to the results obtained, in C. sycophanta, the digestive tract consists of 3 basic parts: foregut, midgut and hindgut. The foregut consists of the oral cavity, pharynx, esophagus, crop, and proventriculus. The esophagus is tubular and has a convoluted surface. Crop bulb-like is an enlarged channel. The proventriculus is connected to the mid-gut. The midgut extends from the foregut at the anterior end to the hindgut at the posterior end. Midgut surface is densely covered with crypts which is finger-shaped. The hindgut consists of the ileum, the colon and the rectum. The anterior end of ileum is marked by the entrance of the four Malpighian tubules. Malpighian tubules are surrounded by a monolayer cubic epithelium. Colon is located between the posterior end of the ileum and the anterior of the rectum. The rectum is lined lumen, intima, a single layer convoluted epithelium and a muscle layer. In addition, in this species, a pair of anal gland, anal gland reservoir and thin-long reservoir ducts are connected with the genital chamber. These data are discussed in comparison with the digestive tract in other Coleopteran species.

Role of Focal Adhesion Kinase in Head and Neck Squamous Cell Carcinoma and Its Therapeutic Prospect.

Head and neck cancers are one of the most prevalent cancers globally. Among them, head and neck squamous cell carcinoma (HNSCC) accounts for approximately 90% of head and neck cancers, which occurs in the oral cavity, oral pharynx, hypopharynx and larynx. The 5-year survival rate of HNSCC patients is only 63%, mainly because about 80–90% of patients with advanced HNSCC tend to suffer from local recurrence or even distant metastasis. Despite the more in-depth understanding of the molecular mechanisms underlying the occurrence and progression of HNSCC in recent years, effective targeted therapies are unavailable for HNSCC, which emphasize the urgent demand for studies in this area. Focal adhesion kinase (FAK) is an intracellular non-receptor tyrosine kinase that contributes to oncogenesis and tumor progression by its significant function in cell survival, proliferation, adhesion, invasion and migration. In addition, FAK exerts an effect on the tumor microenvironment, epithelial–mesenchymal transition, radiation (chemotherapy) resistance, tumor stem cells and regulation of inflammatory factors. Moreover, the overexpression and activation of FAK are detected in multiple types of tumors, including HNSCC. FAK inhibition can induce cell cycle arrest and apoptosis, significantly decrease cell growth, invasion and migration in HNSCC cell lines. In this article, we mainly review the research progress of FAK in the occurrence, development and metastasis of HNSCC, and put forward the prospects for the therapeutic targets of HNSCC.

Portrait of a CAF: The story of cancer-associated fibroblasts in head and neck cancer.

Complex interactions take place during cancer formation and progression. In this regard, there has been increasing focus on the non-malignant cells that make up the tumour microenvironment (TME), and how they interact with malignant tumour cells. TME is highly heterogeneous and has a major influence on tumour behaviour and therapy response. Cancer-associated fibroblasts (CAFs), one of the main components of the TME, establish dangerous liaisons with cancer cells and other components of the TME to shape a tumour-supportive environment in many types of cancer. Head and neck squamous cell carcinoma (HNSCC) encompass the malignant neoplasms arising from the mucosal lining of the oral cavity, pharynx and larynx. The TME of HNSCC contributes to tumour progression and this stromal compartment may be an interesting target for treatment. There is an emerging picture of the behaviour of CAFs in HNSCC; how they affect and are affected by the TME. We aim to summarise and discuss the current understanding of CAFs in head and neck cancer, exploring CAF activation and heterogeneity, and interaction with cancer cells and other cells within the TME.

TMPRSS2, a SARS-CoV-2 internalization protease is downregulated in head and neck cancer patients

BackgroundSARS-coronavirus-2 enters host cells through binding of the Spike protein to ACE2 receptor and subsequent S priming by the TMPRSS2 protease. We aim to assess differences in both ACE2 and TMPRSS2 expression in normal tissues from oral cavity, pharynx, larynx and lung tissues as well as neoplastic tissues from the same areas.MethodsThe study has been conducted using the TCGA and the Regina Elena Institute databases and validated by experimental model in HNSCC cells. We also included data from one COVID19 patient who went under surgery for HNSCC.ResultsTMPRSS2 expression in HNSCC was significantly reduced compared to the normal tissues. It was more evident in women than in men, in TP53 mutated versus wild TP53 tumors, in HPV negative patients compared to HPV positive counterparts. Functionally, we modeled the multivariate effect of TP53, HPV, and other inherent variables on TMPRSS2. All variables had a statistically significant independent effect on TMPRSS2. In particular, in tumor tissues, HPV negative, TP53 mutated status and elevated TP53-dependent Myc-target genes were associated with low TMPRSS2 expression. The further analysis of both TCGA and our institutional HNSCC datasets identified a signature anti-correlated to TMPRSS2. As proof-of-principle we also validated the anti-correlation between microRNAs and TMPRSS2 expression in a SARS-CoV-2 positive HNSCC patient tissues Finally, we did not find TMPRSS2 promoter methylation.ConclusionsCollectively, these findings suggest that tumoral tissues, herein exemplified by HNSCC and lung cancers might be more resistant to SARS-CoV-2 infection due to reduced expression of TMPRSS2. These observations may help to better assess the frailty of SARS-CoV-2 positive cancer patients.

Comparison of daily low dose cisplatin versus weekly cisplatin concurrently with radiotherapy during head and neck cancer

Head and neck cancers can arise in the oral cavity, pharynx, larynx, nasal cavity, paranasal sinuses, thyroid, and salivary glands and include a variety of histopathologic tumours. Squamous cell cancer (SCC) is the most common pathological type of head and neck cancer.This is prospective, Observational and comparative study.The diagnosis of untreated squamous cell carcinoma of the head and neck region, i.e., oral cavity, oropharynx, hypopharynx, or larynx in advanced stage III, IVA or IVB SCCHN was confirmed by a radiation oncologist prior to the initiation of the treatment. Patients were considered to comply with radiation treatment if they completed 70 Gy within 45 days. Chemotherapy compliance (six cycles in weekly or 28–30 cycles in daily cisplatin) were 63% and 73%, respectively. The primary reason for noncompliance toward chemotherapy (37% vs. 27% in weekly vs. daily Cisplatin studies, respectively) was due to the development of excessive toxicity. This also included those who left treatment midway (due to any reason) or died during therapy.Therefore, if an intensified treatment protocol has to be used, i.e. modest acceleration along with either “weekly” or “daily” cisplatin, both can be used, provided patients are selected properly and due attention is paid to timely and adequate supportive care.

Deciphering the Genetic Aberrations in DNA Damage Response Genes and Their Possible Association with HNSCC

Head and neck squamous cell carcinoma (HNSCC) includes carcinomas in the oral cavity, pharynx and larynx. It is considered as the sixth most common form of cancer in the world. Several studies have confirmed that smoking and alcohol consumption are the major risk factors for HNSCC. DNA damage response genes play an important role in the maintenance of the genome. Defects in cell cycle checkpoint and DNA repair mechanisms, such as mutation or abnormalities, may lead to the wide spectrum of human diseases. The present study employs databases and computational tools to identify the genetic abnormalities associated with DNA damage related genes which might have a direct or indirect association with HNSCC. The demographic details of HNSCC patients was obtained from The Cancer Gene Atlas (TCGA, Firehose Legacy) dataset hosted by the cBioportal database. The oncoprint data analysis revealed the highest frequency of gene alteration in the ATR gene (15%), followed by ATM, BRCA2 and CHEK2 (5%). Other genes showed less than 5% alteration. The gene expression profile of ATR gene revealed its differential expression pattern in different grades of tumor relative to normal samples. The survival curve analysis using Kaplan-Meier method revealed that a high level expression of the ATR gene leads to poor survival rate in the female HNSCC patients when compared to males. Thus the present study has identified gross and single nucleotide variants in the ATR gene which could have a putative role in the development of tumor. Further experimental research is required to confirm this association.

Abstract 2794: A novel HNSCC organoid-on-a-chip platform for preclinical investigation and drug screening

Abstract Head and neck squamous cell carcinoma (HNSCC) cancer is a broad category of tumor types arising from the inner lining of various anatomic structures including the oral cavity, pharynx, larynx and salivary glands. Treatment often involves an intensive combination of surgery, radiotherapy and chemotherapy. Despite this, tumor recurrence rates remain high and survival rates are relatively poor. Here, we describe a novel high throughput drug screening platform combining the OrganoPlate®, a microfluidic based 3D-culture system, and HN cancer-derived organoids. MIMETAS develops Organ-on-a-Chip-based models for evaluation of new medicines. Our unique microfluidic technology enables testing of compounds on miniaturized 3D organ models in high-throughput. Hereby we show the establishment of HNSCC cancer-derived organoids in 2-lane OrganoPlate®, and its usefulness for phenotypic drug screenings. The aim of the study is to capture differential sensitivity of HN organoid lines to either a common platinum-based chemotherapy or to a targeted drug still not used in the clinic. Organoid lines (T1, T3 and T5) were embedded in the 2-lane OrganoPlate® as single cells in an extracellular matrix gel. At day 2, cultures were treated with cisplatin or PARP-inhibitor niraparib for 120 hours. Additionally, cultures exposed to high doses of cisplatin were evaluated after one week of recovery in order to determine treatment failure and recapitulate potential patient relapse. Drug response was evaluated by assessment of morphology (phase contrast), cell viability (total nuclei count, alamar blue assay), proliferation (EdU incorporation) and DNA damage (phosphorylated histone H2AX). Organoid cultures grow well under medium perfusion in the 2-lane OrganoPlate® and selective sensitivity to cisplatin and niraparib is revealed by the used readouts. The high-throughput, microfluidic 2-lane OrganoPlate® platform offers an attractive method for growing HNSCC cancer-derived organoids, supporting development of individualized tumour models for phenotypic drug screenings. Citation Format: Silvia Bonilla, Else Driehuis, Henriëtte Lanz, Hans Clevers, Jos Joore, Karla Queiroz, Paul Vulto. A novel HNSCC organoid-on-a-chip platform for preclinical investigation and drug screening [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 2794.

Anatomical classification of upper gastrointestinal organs under various image capture conditions using AlexNet

BackgroundMachine learning has led to several endoscopic studies about the automated localization of digestive lesions and prediction of cancer invasion depth. Training and validation dataset collection are required for a disease in each digestive organ under a similar image capture condition; this is the first step in system development. This data cleansing task in data collection causes a great burden among experienced endoscopists. Thus, this study classified upper gastrointestinal (GI) organ images obtained via routine esophagogastroduodenoscopy (EGD) into precise anatomical categories using AlexNet. MethodIn total, 85,246 raw upper GI endoscopic images from 441 patients with gastric cancer were collected retrospectively. The images were manually classified into 14 categories: 0) white-light (WL) stomach with indigo carmine (IC); 1) WL esophagus with iodine; 2) narrow-band (NB) esophagus; 3) NB stomach with IC; 4) NB stomach; 5) WL duodenum; 6) WL esophagus; 7) WL stomach; 8) NB oral–pharynx–larynx; 9) WL oral–pharynx–larynx; 10) WL scaling paper; 11) specimens; 12) WL muscle fibers during endoscopic submucosal dissection (ESD); and 13) others. AlexNet is a deep learning framework and was trained using 49,174 datasets and validated using 36,072 independent datasets. ResultsThe accuracy rates of the training and validation dataset were 0.993 and 0.965, respectively. ConclusionsA simple anatomical organ classifier using AlexNet was developed and found to be effective in data cleansing task for collection of EGD images. Moreover, it could be useful to both expert and non-expert endoscopists as well as engineers in retrospectively assessing upper GI images.

The lateral arm free flap for head and neck reconstruction.

The aim of this study was to review the recent literature on the utilization of the lateral arm free flap use in head and neck reconstruction. The lateral arm free flap provides a reliable fasciocutaneous free tissue transfer option ideally suited for reconstruction of the oral cavity, pharynx and parotid. Primary donor site closure, compartmentalized fat and excellent colour match make it an excellent option for head and neck reconstruction. Donor site morbidity is low, and the primary limitation is the short and narrow vascular pedicle. The lateral arm free flap should be considered in cases of oral cavity and skin reconstruction, particularly in cases wherein pedicle length is not restrictive.

Use of barometric pressure and electromyography measurement techniques to elucidate the mechanisms by which bolus passes from the oral cavity to the oropharynx during swallowing

Objectives: The exact timings associated with swallowing are difficult to measure with the currently available methods. In this study, we aimed to elucidate the timings of action of the swallowing organs in the oral and pharyngeal stages of swallowing by recording the barometric pressure (BP) and tongue muscle activities. Methods: Dry and water swallows were studied in 10 adults using electromyography and small barometers. BPs were recorded during swallowing in the oral cavity (BP-o) and pharynx (BP-p), associated with muscle activities of the anterior (TA) and posterior (TP) parts of the tongue and of the suprahyoid (SHy) muscle. To analyze the temporal pattern of each activity, times of onset, cessation, and peak were measured. Results: Two characteristic waveforms were obtained. BP-o peaked immediately after onset and decreased to atmospheric pressure following a short plateau. However, BP-p gradually increased, reached a peak, and returned to the atmospheric pressure immediately before the end of BP-o. Since pressure increments indicated that the sensor was compressed in a closed space, onset and cessation of BP-p could correspond to the duration of nasopharyngeal closure. The onset of BP-p and the peak time of BP-o occurred in close succession. Thus, nasopharyngeal closure could be evaluated from BP-o. The sensor and EMG measured durations of oral and pharyngeal stages as 0.4 and 0.6 sec, respectively. TA activation began earlier than the TP. TA and TP peaks appeared before the BP-o peak, suggesting that the tongue begins the activity for swallowing before nasopharyngeal closure. Conclusions: This study revealed movements of swallowing organs in the two stages with high temporal resolution. BP-o detected the duration of nasopharyngeal closure.

Risk of second primary malignancy in adults with pulmonary high-grade neuroendocrine carcinoma (HGNEC)

BackgroundPulmonary high-grade neuroendocrine carcinoma (HGNEC) has a rising incidence of developing second primary malignancies (SPMs). This study is the first population-based analysis to quantify the SPM risks among survivors of lung HGNEC.MethodsWe used the Surveillance, Epidemiology, and End Results (SEER) database to calculate standardized incidence ratio (SIR) and absolute excess risk (AER) between 2000 and 2016 for patients with pulmonary HGNEC. ResultsThe data of 1161 patients with SPMs were retrieved from the SEER database. The ratio of observed/expected number of SPMs in pulmonary HGNEC was 1.53. Solid tumours comprised 91% of all second malignancies in lung HGNEC patients, with the most common cancers reported in the oral cavity and pharynx, the urinary and respiratory systemsConclusionsOur study observed an increased risk of SPMs among patients with pulmongnancies.

Evaluation and validation of Physiological and Operative Severity Score for the enumeration of mortality and morbidity and Portsmouth-POSSUM scores in predicting morbidity and mortality in patients undergoing head and neck cancer surgeries.

Identification of risk factors for perioperative complications helps in the prognostication. We wanted to determine whether Physiological and Operative Severity Score for the enumeration of mortality and morbidity (POSSUM) and Portsmouth-POSSUM (P-POSSUM) can be used in patients undergoing head and neck oncosurgery. We conducted a retrospective analysis of 1265 patients after they had major head and neck oncosurgeries. Demographic, surgical and outcome data was collected. We separately analyzed data for patients who had undergone cancer surgery for oral cavity, pharynx, and larynx. We calculated the POSSUM and P-POSSUM scores. POSSUM scoring system had moderate discrimination (AUC = 0.61) and good calibration (P = .36) for the entire study cohort and in the subgroup. Since there were no deaths in the entire cohort, we were not able to check predictive ability of the scores, for mortality. We found that POSSUM had moderate discrimination and good calibration for morbidity prediction in head and neck cancer surgeries, as well as for the selected subgroup.

A Comparative Study of Two Split Course Accelerated Hypo-fractionated Radiation Therapy (SCAHRT) Schedules in Locally Advanced Head and Neck Carcinoma

Introduction: Head and neck cancers include malignant neoplasms that develop in the oral cavity, nasal cavity, paranasal sinuses, pharynx, larynx and salivary glands. Out of the newly diagnosed patients of head and neck carcinoma in India, most of the patients present in locally advanced stage. Because of extensive local disease and associated co-morbidities and compromised KPS, palliative radiation therapy is preferred treatment for these patients. Material and methods: The study was conducted on 60 previously untreated, histo-pathologically proven patients of locally advanced head and neck cancer who were randomized in two equal groups by draw of lots. Study group received radiation dose of 30 Gy/ 10 fractions / 2 weeks followed by repeat dose of 30 Gy/ 10 fractions / 2 weeks (Total dose 60 Gy in 20 fractions delivered with a gap of 4 weeks). Control group received radiation dose of 20 Gy/ 5 fractions/ 5 days followed by repeat dose of 20 Gy/ 5 fractions/ 5 days followed by repeat dose of 20 Gy/ 5 fractions/ 5 days (Total dose 60 Gy in 3 sessions with a gap of 3 weeks each). Objectives were to compare efficacy of above schedules based on symptomatic relief and overall tumor response and to compare the toxicities of the above schedules. Results and Conclusion: To expedite the treatment time in tertiary care centres, control group (20 Gy / 5 fractions / 1 week; 3 weekly X 3) was better than the study group (30 Gy / 10 fractions / 2 weeks; 4 weekly X 2) as it had comparable local control and toxicity (acute mucosal reactions being slightly higher in the study group) with the added advantage of only 15 total fractions (machine days) in control group rather than 20 total fractions (machine days) in study group. This reduced the patient visits to the hospital by one week (i.e. 5 fractions) with comparable local control and toxicity.

Society of swallowing and dysphagia of Japan: Position statement on dysphagia management during the COVID-19 outbreak

On April 14, the Society of Swallowing and Dysphagia of Japan (SSDJ) proposed its position statement on dysphagia treatment considering the ongoing spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2).The main routes of transmission of SARS-CoV-2 are physical contact with infected persons and exposure to respiratory droplets. In cases of infection, the nasal cavity and nasopharynx have the highest viral load in the body. Swallowing occurs in the oral cavity and pharynx, which correspond to the sites of viral proliferation. In addition, the possibility of infection by aerosol transmission is also concerning.Dysphagia treatment includes a broad range of clinical assessments and examinations, dysphagia rehabilitation, oral care, nursing care, and surgical treatments. Any of these can lead to the production of droplets and aerosols, as well as contact with viral particles. In terms of proper infection control measures, all healthcare professionals involved in dysphagia treatment must be fully briefed and must appropriately implement all measures. In addition, most patients with dysphagia should be considered to be at a higher risk for severe illness from COVID-19 because they are elderly and have complications including heart diseases, diabetes, respiratory diseases, and cerebrovascular diseases.This statement establishes three regional categories according to the status of SARS-CoV-2 infection. Accordingly, the SSDJ proposes specific infection countermeasures that should be implemented considering 1) the current status of SARS-CoV-2 infection in the region, 2) the patient status of SARS-CoV-2 infection, and 3) whether the examinations or procedures conducted correspond to aerosol-generating procedures, depending on the status of dysphagia treatment. This statement is arranged into separate sections providing information and advice in consideration of the COVID-19 outbreak, including “terminology”, “clinical swallowing assessment and examination“, “swallowing therapy”, “oral care”, “surgical procedure for dysphagia”, “tracheotomy care”, and “nursing care”. In areas where SARS-CoV-2 infection is widespread, sufficient personal protective equipment should be used when performing aerosol generation procedures.The current set of statements on dysphagia management in the COVID-19 outbreak is not an evidence-based clinical practice guideline, but a guide for all healthcare workers involved in the treatment of dysphagia during the COVID-19 epidemic to prevent SARS-CoV-2 infection.

Disparate survival of late-stage male oropharyngeal cancer in Appalachia

The United States Appalachian region harbors a higher cancer burden than the rest of the nation, with disparate incidence of head and neck squamous cell carcinomas (HNSCC), including oral cavity and pharynx (OC/P) cancers. Whether elevated HNSCC incidence generates survival disparities within Appalachia is unknown. To address this, HNSCC survival data for 259,737 tumors from the North American Association for Central Cancer Registries 2007–2013 cohort were evaluated, with age-adjusted relative survival (RS) calculated based on staging, race, sex, and Appalachian residence. Tobacco use, a primary HNSCC risk factor, was evaluated through the Behavioral Risk Factor Surveillance System from Appalachian states. Decreased OC/P RS was found in stage IV Appalachian white males within a subset of states. The survival disparity was confined to human papillomavirus (HPV)-associated oropharyngeal cancers, specifically the oropharynx subsite. This correlated with significantly higher smoking and male smokeless tobacco use in most Appalachian disparity states. Lower survival of Appalachian males with advanced-stage HPV-associated oropharyngeal cancers suggests pervasive tobacco consumption likely generates more aggressive tumors at HPV-associated oropharynx subsites than national averages. Comprehensive tobacco and HPV status should therefore be evaluated prior to considering treatment de-intensification regimens for HPV-associated oropharyngeal cancers in populations with high tobacco consumption.

The oral cavity and pharynx

The oral cavity and pharynx

Voltage and e-liquid composition affect nicotine deposition within the oral cavity and carbonyl formation

IntroductionThe diversity of e-liquids along with higher powered e-cigarette nicotine delivery devices are increasing. This study evaluated the effect of voltage and e-liquid composition on particle size, nicotine deposition in...

An unusual presentation of hereditary angioedema type II with amnesia, poor concentration, and headache

Hereditary angioedema (HAE) is a rare disease characterized by repeated episodes of bradykinergic-driven angioedema that can involve the oral mucosa, pharynx, larynx, gastrointestinal system, and extremities.1 The prevalence estimates for HAE range between 1 in 10,0002 and 1 in 150,000.3 HAE is categorized into the following 3 distinct subtypes: (1) HAE type I, the most common type, with a reduced quantity of C1 esterase inhibitor protein; (2) HAE type II, with decreased function of C1 esterase inhibitor protein; and (3) HAE with normal C1-inhibitor function (HAE nC1-INH) (previously known as HAE type III).

Industrial pollution and mortality from digestive cancers at the small area level in a Spanish industrialized province.

The province of Cadiz, Spain, is a highly industrialized area with numerous registered industrial plants, which has led to major concern regarding the possible influence of these facilities on the high rate of cancer-related mortality observed. Our objective was to evaluate the association between digestive cancer mortality and proximity to industrial installations in the province of Cadiz over the period 1992-2014 and to analyse this risk according to different categories of carcinogenic substances. An ecological study at the census tract level was carried out. Mortality due to digestive cancer (involving the oral cavity, pharynx, oesophagus, stomach, liver, pancreas, gallbladder, colon and rectum) was analysed. Using the spatial Besag, York and Mollié (BYM) approach, we assessed the relative risk of dying from these cancers for people living between 500 m and 5 km from industrial installations. The models were adjusted to account for socioeconomic deprivation. We detected a significant, excess risk of dying due to cancer in the following organs (expressed as relative risk with 95% confidence intervals): colon/rectum (1.13; 1.04-1.22 at 4 km), stomach (1.13; 1.00-1.29 at 2 km), liver (1.28; 1.02-1.61 at 1 km), pancreas (1.19; 1.03-1.39 at 2 km), oral and pharyngeal (1.40; 1.08-1.82 at 1 km), oesophagus (2.05; 1.18-3.56 at 500 m) and gallbladder (2.80; 1.14-6.89 at 500 m) for men; and from colorectal (1.21; 1.00-1.46 at 1 km), stomach (1.15; 1.01-1.31 at 4 km) and liver (1.58; 1.20- 2.07 at 1 km) cancers for women. The results support the hypothesis of an association between several digestive cancers and proximity to polluting industrial plants.

Abstract A11: STAT1 mediates resistance to experimental oral cancer that is associated with enhanced antitumor T-cell responses

Abstract Cancers of the oral cavity and pharynx remain among the 10 most prevalent cancers in the United States. Signal Transducer and Activation of Transcription 1 (STAT1) is a transcription factor primarily involved in mediating responses to IFNs, as well as interleukin (IL) 21, 27, and 35. STAT1 has been shown to promote or suppress tumors in different cancer types, but its role in oral cavity cancers has not been examined. We examined the role of STAT1 in oral cancer using orthotopic models in wild-type (WT) and STAT1-deficient BALB/c mice. Metastatic (LY2) or nonmetastatic (B4B8) HNSCC cell lines were injected into the oral cavity and tumor development was monitored over a period of three or six weeks, respectively. At terminal sacrifice, tumors, spleens, draining lymph nodes, and bone marrow tissues were analyzed for tumor growth, metastasis, and immunologic responses. Tumors from STAT1-deficient mice injected with B4B8 cells were twice as large as tumors from WT mice. Interestingly, LY2-injected STAT1-deficient mice possessed tumors that were five times as large as tumors from LY2-injected WT mice. The increased tumor burdens in metastatic tumors were associated with a decrease in CD4+ and CD8+ T-cell infiltration into the draining lymph nodes of tumor-bearing STAT1-deficient mice compared to WT mice. Further, lymph node and splenic CD4+ and CD8+ T cells in tumor-bearing STAT1-deficient mice produced significantly lower TNF-alpha compared to WT mice. Finally, tumor-bearing STAT1-deficient mice displayed a significant accumulation of CD11b+ Ly6G+ myeloid cells in the spleens and bone marrow compared to WT counterparts in both metastatic and nonmetastatic HNSCC models. Our results demonstrate that STAT1 mediates resistance to oral tumor development that is associated with enhanced T-cell migration, TNF-alpha mediated antitumor T-cell responses, and diminished accumulation of tumor-promoting CD11b+ Ly6G+ myeloid cells. Citation Format: Nathan Ryan, Kelvin Anderson, Greta Volpedo, Omar Hamza, Sanjay Varikuti, Abhay Satoskar, Steve Oghumu. STAT1 mediates resistance to experimental oral cancer that is associated with enhanced antitumor T-cell responses [abstract]. In: Proceedings of the AACR-AHNS Head and Neck Cancer Conference: Optimizing Survival and Quality of Life through Basic, Clinical, and Translational Research; 2019 Apr 29-30; Austin, TX. Philadelphia (PA): AACR; Clin Cancer Res 2020;26(12_Suppl_2):Abstract nr A11.