Epidemiology and pathology of oral squamous cell carcinoma in a multi-ethnic population: Retrospective study of 154 cases over 7 years in Qatar

Targeting of 3D oral cancer spheroids by αVβ6 integrin using near-infrared peptide-conjugated IRDye 680

BACKGROUND

In the treatment of oral cavity cancer, margin status is one of the most critical prognostic factors. Positive margins are associated with higher local recurrence and lower survival rates. Therefore, the universal goal of oral surgical oncology is to achieve microscopically clear margins. Near-infrared fluorescence guided surgery (FGS) could improve surgical resection using fluorescent probes. αVβ6 integrin has shown great potential for cancer targeting due to its overexpression in oral cancers. Red fluorescent contrast agent IRDye 680 coupled with anti-αVβ6 peptide (IRDye-A20) represents an asset to improve FGS of oral cancer. This study investigates the potential of IRDye-A20 as a selective imaging agent in 3D three-dimensional tongue cancer cells.

METHODS

αVβ6 integrin expression was evaluated by RT-qPCR and Western Blotting in 2D HSC-3 human tongue cancer cells and MRC-5 human fibroblasts. Targeting ability of IRDye-A20 was studied in both cell lines by flow cytometry technique. 3D tumor spheroid models, homotypic (HSC-3) and stroma-enriched heterotypic (HSC-3/MRC-5) spheroids were produced by liquid overlay procedure and further characterized using (immuno)histological and fluorescence-based techniques. IRDye-A20 selectivity was evaluated in each type of spheroids and each cell population.

RESULTS

αVβ6 integrin was overexpressed in 2D HSC-3 cancer cells but not in MRC-5 fibroblasts and consistently, only HSC-3 were labelled with IRDye-A20. Round shaped spheroids with an average diameter of 400 μm were produced with a final ratio of 55%/45% between HSC-3 and MRC-5 cells, respectively. Immunofluorescence experiments demonstrated an uniform expression of αVβ6 integrin in homotypic spheroid, while its expression was restricted to cancer cells only in heterotypic spheroid. In stroma-enriched 3D model, Cytokeratin 19 and E-cadherin were expressed only by cancer cells while vimentin and fibronectin were expressed by fibroblasts. Using flow cytometry, we demonstrated that IRDye-A20 labeled the whole homotypic spheroid, while in the heterotypic model all cancer cells were highly fluorescent, with a negligible fluorescence in fibroblasts.

CONCLUSIONS

The present study demonstrated an efficient selective targeting of A20FMDV2-conjugated IRDye 680 in 3D tongue cancer cells stroma-enriched spheroids. Thus, IRDye-A20 could be a promising candidate for the future development of the fluorescence-guided surgery of oral cancers.

Enhancing oral squamous cell carcinoma prediction: the prognostic power of the worst pattern of invasion and the limited impact of molecular resection margins

Objective

Oral squamous cell carcinoma (OSCC) originates from the mucosal lining of the oral cavity. Almost half of newly diagnosed cases are classified as advanced stage IV disease, which makes resection difficult. In this study, we investigated the pathological features and mutation profiles of tumor margins in OSCC.

Methods

We performed hierarchical clustering of principal components to identify distinct patterns of tumor growth and their association with patient prognosis. We also used next-generation sequencing to analyze somatic mutations in tumor and marginal tissue samples.

Results

Our analyses uncovered that the grade of worst pattern of invasion (WPOI) is strongly associated with depth of invasion and patient survival in multivariable analysis. Mutations were primarily detected in the DNA isolated from tumors, but several mutations were also identified in marginal tissue. In total, we uncovered 29 mutated genes, mainly tumor suppressor genes involved in DNA repair including BRCA genes; however none of these mutations significantly correlated with a higher chance of relapse in our medium-size cohort. Some resection margins that appeared histologically normal harbored tumorigenic mutations in TP53 and CDKN2A genes.

Conclusion

Even histologically normal margins may contain molecular alterations that are not detectable by conventional histopathological methods, but NCCN classification system still outperforms other methods in the prediction of the probability of disease relapse.

A snapshot of miRNAs in oral squamous cell carcinoma: Difference between cancer cells and corresponding normal cells

Oral squamous cell carcinoma (OSCC) constitutes the most aggressive tumors of the oral cavity and is one of the leading causes of cancer mortality worldwide. Although recent clinical treatment strategies have improved the survival rate, the outcome of OSCC patients still remains dismal because of the lack of efficient diagnostic and treatment tools. As one of the main actors of OSCC scenario, microRNAs (miRNAs) are involved in triggering, progression and metastasis through the regulation of various cancer-related signaling pathways. Identification followed by precise study of the biology and mechanism of action of miRNAs will greatly help to provide valuable insights regarding OSCC development and can be considered as an anti-OSCC target. In the current review, we have provided a focused summary of the latest published papers on the role of miRNAs in apoptosis, cell cycle, proliferation, EMT and metastasis of OSCC as well as the role of long noncoding RNAs in the modulation of miRNAs in OSCC.

Radiomics-Based Analysis in the Prediction of Occult Lymph Node Metastases in Patients with Oral Cancer: A Systematic Review

BACKGROUND

Tumor extension and metastatic cervical lymph nodes' (LNs) number and dimensions are major prognostic factors in patients with oral squamous cell carcinoma (OSCC). Radiomics-based models are being integrated into clinical practice in the prediction of LN status prior to surgery in order to optimize the treatment, yet their value is still debated.

METHODS

A systematic review of the literature was conducted according to the PRISMA guideline. Baseline study characteristics, and methodological items were extracted and summarized.

RESULTS

A total of 10 retrospective studies were included into the present study, each of them exploiting a single imaging modality. Data from a cohort of 1489 patients were analyzed: the highest AUC value was 99.5%, ACC ranges from 68% to 97.5%, and sensibility and specificity were over 0.65 and 0.70, respectively.

CONCLUSION

Radiomics may be a noninvasive tool to predict occult LN metastases (LNM) in OSCC patients prior to treatment; further prospective studies are warranted to create a reproducible and reliable method for the detection of LNM in OSCC.

Interactions between circRNAs and miR-141 in Cancer: From Pathogenesis to Diagnosis and Therapy

The function of non-coding RNAs (ncRNAs) in the pathogenesis and development of cancer is indisputable. Molecular mechanisms underlying carcinogenesis involve the aberrant expression of ncRNAs, including circular RNAs (circRNAs), and microRNAs (miRNAs). CircRNAs are a class of single-stranded, covalently closed RNAs responsible for maintaining cellular homeostasis through their diverse functions. As a part of the competing endogenous RNA (ceRNAs) network, they play a central role in the regulation of accessibility of miRNAs to their mRNA targets. The interplay between these molecular players is based on the primary role of circRNAs that act as miRNAs sponges, and the circRNA/miRNA imbalance plays a central role in different pathologies including cancer. Herein, we present the latest state of knowledge about interactions between circRNAs and miR-141, a well-known member of the miR-200 family, in malignant transformation, with emphasis on the biological role of circRNA/miR-141/mRNA networks as a future target for novel anti-cancer therapies.

Oral Squamous Cell Carcinoma (OSCC) Imitates Denosumab-Induced Osteonecrosis of the Mandibular Alveolus: A Diagnostic Challenge

Oral squamous cell carcinoma (OSCC) may arise in the the alveolar ridge (in a minority of cases). Smoking, chronic mucosal injuries, and poor oral hygiene are involved in its pathogenesis. It mostly occurs to men instead of women and affects the mandible on a 3:2 ratio to the maxilla. The objective of the current study is to present an interesting case of an OSCC of the alveolar ridge mimicking jaw osteonecrosis due to denosumab, resulting in differential diagnostic dilemmas. A 78-year-old female patient, edentulous and bearing total dentures, was referred with a persistent (four months), severely painful, ulcerative lesion in the anterior lateral (right) region of the residual alveolar ridge of the mandible. Medical history referred to a long-term systemic steroid use due to sarcoidosis as well as the subcutaneous use of denosumab for osteoporosis one/month for one year. Cone-beam CT (CBCT) examination was performed where bone resorption was detected and a differential diagnosis of osteonecrosis of the jaws (ONJs) from denosumab or neoplasia was made. A biopsy was carried out, and the histological examination showed that soft tissues and underlying bone were infiltrated by abnormal, confluent, compact islands of malignant squamous cells with intense atypia and numerous mitoses indicating a moderately differentiated OSCC. Denosumab inhibits the binding of receptor activator of nuclear factor ligand (RANKL) to receptor activator of nuclear factor-kappa (RANK); this decreases bone resorption and results in increased bone density. However, denosumab may induce ONJ. The area of exposed bone and abnormal soft tissue alterations may resemble both benign and malignant diseases. Osteonecrosis may mimic OSCC or may even provide the suitable substrate for the development of OSCC. Biopsy as well as bone imaging examination are required to accurately determine the possibility of neoplastic formation and its boundaries in cases of osteonecrosis especially in patients under treatment with denosumab or bisphosphonate-related ONJ (BRONJ).

A rare case of cavernous sinus thrombosis following oral squamous cell carcinoma - The etiology and management dilemma

Intracranial cavernous sinus metastases of oral squamous cell carcinoma (OSCC) are rare, with a reported incidence of 0.4 %. Due to their extremely infrequent presentation the etiology and management modalities of such complications are not clearly represented in the literature. Here we present a case of a 58-year-old male diagnosed with OSCC of Right Lower Alveolus with underlying bone invasion, cT4aN1M0, Stage IV. He underwent Right Hemi-mandibulectomy with Modified Neck Dissection, Pectoralis Major Myocutaneous Flap, and 60 Gy/30# adjuvant radiotherapy. Six months later, the patient was diagnosed with recurrence involving the right infratemporal fossa with associated right cavernous sinus thrombosis. Immunohistochemistry block review showed PDL1 - Positive. The patient was subjected to Cisplatin and Pembrolizumab immunotherapy. After receiving 35 cycles of Pembrolizumab over a period of 2 years the patient is doing well with no recurrence.

Epidemiology and incidence of oral squamous cell carcinoma in the Iraqi population over 5 years (2014-2018)

Background

Oral squamous cell carcinoma is one of the most common and life-threatening neoplasms worldwide, and is responsible for approximately 90% of all oral malignancies.

Aim

This study was aimed at providing updated information on oral squamous cell carcinoma in all Iraqi governorates for the 5-year period from 2014 to 2018, including the annual incidence and demographic variables.

Materials and Methods

The total number of oral squamous cell carcinoma cases in Iraq, along with associated demographic information (age, sex, and site), for the 5-year period from 2014 to 2018 was obtained. The statistical analysis consisted of descriptive analysis, including frequency, percentage, and mean ± standard deviation. A χ ² test was performed to compare frequencies between male and female patients, among age groups, and among different OSCC sites. The χ ² test was also used to assess the association of each OSCC site with age and sex. The significance threshold was set at p < 0.05, and the confidence interval was set at 95%. The incidence rate of oral squamous cell carcinoma for each year was calculated by dividing the number of OSCC cases per year by the population of Iraq, then multiplying the result by 100,000.

Results

A total of 722 cases were recorded. Statistically, oral squamous cell carcinoma was found to be more prevalent in males and individuals over 40 years of age. The tongue was the most common site of occurrence. Lip squamous cell carcinoma cases were high in males. The incidence rate of oral squamous cell carcinoma was estimated to be 0.4 per 100,000 people.

Conclusion

Males and older people are at relatively higher risk of developing oral cancer. The tongue is the most affected site, but any site in the oral cavity may be involved. Further exploration of the causes of oral malignancy in Iraq is necessary to improve prevention strategies.

Epidemiology of tongue squamous cell carcinoma: A retrospective cohort study

OBJECTIVE

To analyze the epidemiological profile and the specific survival of patients diagnosed with tongue squamous cell carcinoma at the National Cancer Institute (INCA).

MATERIALS AND METHODS

Hospital Cancer Registry System Data and Mortality Information from 2007 to 2009 were retrieved in a retrospective cohort study of patients diagnosed with tongue squamous cell carcinoma. Specific survival was estimated using the Kaplan-Meier method. The association between independent variables and the risk of death was explored in a Cox proportional hazards regression model.

RESULTS

A total of 346 patients were eligible, mostly male (77.5%), smokers (87.6%), with alcohol consumption (80.9%), with low education (65.6%), advanced staging at the time of diagnosis (71.1%), and presenting a high mortality rate (72.5%). In total, 44.5% of patients underwent a surgical approach alone or associated with another treatment modality, of which 85.1% of patients underwent neck dissection and 90.1% had free surgical margins. Specific survival was 40.6% in two years and 31.2% in five years.

CONCLUSION

The 5-year specific survival was considered worse in individuals over 60 years, and who did not undergo surgical treatment or had surgery associated with another treatment, compared to patients undergoing isolated surgery.

Stain color translation of multi-domain OSCC histopathology images using attention gated cGAN

Oral Squamous Cell Carcinoma (OSCC) is the most prevalent type of oral cancer across the globe. Histopathology examination is the gold standard for OSCC examination, where stained histopathology slides help in studying and analyzing the cell structures under a microscope to determine the stages and grading of OSCC. One of the staining methods popularly known as H&E staining is used to produce differential coloration, highlight key tissue features, and improve contrast, which makes cell analysis easier. However, the stained H&E histopathology images exhibit inter and intra-variation due to staining techniques, incubation times, and staining reagents. These variations negatively impact computer-aided diagnosis (CAD) and Machine learning algorithm's accuracy and development. A pre-processing procedure called stain normalization must be employed to reduce stain variance's negative impacts. Numerous state-of-the-art stain normalization methods are introduced. However, a robust multi-domain stain normalization approach is still required because, in a real-world situation, the OSCC histopathology images will include more than two color variations involving several domains. In this paper, a multi-domain stain translation method is proposed. The proposed method is an attention gated generator based on a Conditional Generative Adversarial Network (cGAN) with a novel objective function to enforce color distribution and the perpetual resemblance between the source and target domains. Instead of using WSI scanner images like previous techniques, the proposed method is experimented on OSCC histopathology images obtained by several conventional microscopes coupled with cameras. The proposed method receives the L* channel from the L*a*b* color space in inference mode and generates the G(a*b*) channel, which are color-adapted. The proposed technique uses mappings learned during training phases to translate the source domain to the target domain; mapping are learned using the whole color distribution of the target domain instead of one reference image. The suggested technique outperforms the four state-of-the-art methods in multi-domain OSCC histopathological translation, the claim is supported by results obtained after assessment in both quantitative and qualitative ways.

Prevalence and factors associated with oral potentially malignant disorders and oral squamous cell carcinoma: An institutional study

INTRODUCTION

Incidence & prevalence of OPMDs & OSCC is increasing day by day, thereby escalating the burden of oral cancer in India. Oral cancer ranks in the top three of all cancers in India and is quickly becoming a health priority. This study aims to assess prevalence and associated factors of OPMDs and OSCC in patients attending dental OPD and its association with age, gender, habit (type & duration), clinical presentation and site of involvement.

MATERIAL AND METHODS

A prospectively 12 months study was conducted in the outpatient department. Patient's data whether suspected or proven cases of OPMDs & OSCC and fits in clinical criteria were reviewed and analysed for demographic data, oral adverse habit, clinical presentation and site of involvement.

RESULTS

Overall 38,588 patient's data were analysed for 12 month time duration. Out of this 552 (1.43%) cases of OPMDs and 58 (0.15%) cases of OSCC were reported. Out of 552 maximum patients were reported with OSMF (34.4%), followed by other lesions and minimum with LP (7.9%). Age group most commonly affected was above 45 years (44.9%) of age. Males (81.1%) were affected more than females. OPMDs (92%) and OSCC (96.5%) were mostly associated with smokeless or smoking form of tobacco.

CONCLUSION

Present study evaluated the prevalence rates and associated factors of OPMDs & OSCC, which is beneficial for general practitioner in early diagnosis, formulating better treatment plan and to educate general population about risk factors, early signs and symptoms of these lesions.

Clinical Presentation of Wide Field of Cancerization Associated with Oral Squamous Cell Carcinoma

Background

The late presentation of oral squamous cell carcinoma (OSCC) patients in Sudan, with advanced stages and wide field of cancerization (WFC), has a negative impact on these patients. The present study aimed to investigate the different clinical presentations of mucosal changes in WFC associated with OSCC in Sudanese patients.

Methods

This a prospective longitudinal study of 93 OSCC cases. Tumor's associated field of cancerization was identified and related clinical mucosal changes were described.

Results

Out of the 93 patients, 57 (61.3%) were males and 36 (38.7%) were females. Eighty-two percent of the patients presented with stage IV tumors. Ninety-two patients had multiple sites involved in the oral cavity with overlap of sites involved. The Gingivobuccal mucosa (74.2%) was the most frequent site involved. Eighty-three (89.2%) of the lesions were surrounded by mucosal changes, of them 32 (38%) surrounded by a grizzle (mixed dark and white) discoloration and 21 (26%) were surrounded by a white-smoke discoloration followed by 17 (20%) and 13 (16%) surrounded by cotton-white and Café au lait discolorations, respectively. Forty-four (47.3%) lesions had overlapping presentations and surrounded by erythematous patches.

Conclusion

The present study showed that OSCC patients in Sudan present with advanced lesions, mostly associated with WFC, particularly the Toombak dippers. The different mucosal changes seen in the WFC associated with OSCC in these cases are in accordance with the known five mucosal presentations.

The Occurrence of Activated Leukocyte Cell Adhesion Molecule (ALCAM) and Its Predictive Factors in Patients with Oral Squamous Cell Carcinoma

OBJECTIVES

To determine the occurrence of Activated Leukocyte Cell Adhesion Molecule (ALCAM) and its predictive factors in patients with oral squamous cell carcinoma (OSCC).

METHODS

This cross sectional study was concocted on 102 patients with OSCC referred to Imam Khomeini Hospital of Tehran during 1997-2015. The data collection tool a checklist consisted of demographic and pathologic (lymph node involvement, differentiation, tumor size and tumor location) characteristics which extracted from patients' medical records. To evaluate ALCAM, a new sample of tumor tissue was prepared from archive. Finally, the multivariable logistic regression model was used to determine the predictive factors of ALCAM by STATA14.

RESULTS

the number (%) of men and women were 70 (68.6) and 32 (31.4%), respectively. The mean age (S.D) of participants was 61.7 (15.6) years. Of the total samples, 32 (38.2), 19 (18.6), 36 (35.3) and 8 (7.8%) samples were related to the tongue, oral mucosa, skin and lips, respectively. More than half of the tumors had good differentiation and lymph node involvement and 74.5% were ≥20 mm. Also, 79.41% of the samples were positive for the overall incidence of ALCAM. The most important predictors of the overall incidence of ALCAM were tumor size (OR: 3.46, 95% CI: 1.71 - 7.01) and tumor location (OR: 3, 95% CI: 1.03 - 8.72). Similarly, for incidence of cytoplasmic ALCAM were age (OR: 2.56, 95% CI: 1.38 - 4.76) and location of the tumor (OR: 3.23, 95% CI: 1.08 - 9.64). However, the only predictor of membranous ALCAM incidence was lymph node involvement (OR: 0.36, 95% CI: 0.19 - 0.66).

CONCLUSION

The results of our study suggest preliminary evidence for the potential clinical application of ALCAM as a prognostic biomarker for OSCC which may be the basis for future clinical application, however further studies are recommended.

Proanthocyanidins-loaded complex coacervates-based drug delivery attenuates oral squamous cell carcinoma cells metastatic potential through down-regulating the Akt signaling pathway

Oral cancer, constituted up to 90% by squamous cell carcinomas, is a significant health burden globally. Grape seed proanthocyanidins (PA) have been suggested as a potential chemopreventive agent for oral cancer. However, their efficacy can be restricted due to the low bioavailability and bioaccessibility. Inspired by sandcastle worm adhesive, we adapted the concept of complex coacervation to generate a new type of drug delivery platform. Complex coacervates are a dense liquid phase formed by the associative separation of a mixture of oppositely charged polyelectrolytes, can serve as a drug delivery platform to protect labile cargo. In this study, we developed a complex coacervates-based delivery of PA. The release kinetics was measured, and anticancer effects were determined in two human tongue squamous cell carcinoma cell lines. The results showed that complex coacervate successfully formed and able to encapsulate PA. Additionally, PA were steadily released from the system in a pH-dependent manner. The drug delivery system could significantly inhibit the cell proliferation, migration, and invasion of cancer cells. Moreover, it could markedly reduce the expression of certain matrix metalloproteinases (MMP-2, 9, and 13) crucial to metastatic processes. We also found that suppression of protein kinase B (Akt) pathway might be the underlying mechanism for these anticancer activities. Taken together, complex coacervates-based delivery of PA can act as an effective anticancer approach for oral cancer therapy.

Clinicopathological characteristics predicting advanced stage and surgical margin invasion of oral squamous cell carcinoma: A single‑center study on 10 years of cancer registry data

The incidence profile of oral squamous cell carcinoma (OSCC) has not previously been comprehensively reported in Indonesia. The present study aimed to identify clinicopathological characteristics of patients with OSCC according to sex and age, to analyze histological differentiation patterns specific to tumor subsites, to highlight the role of lymphovascular invasion (LVI) in metastasis, and to develop a model to predict advanced stage and margin invasion. A retrospective cross-sectional study was performed using 581 medical records and pathological specimens from cancer registry data in the Dr Cipto Mangunkusumo Hospital (Jakarta, Indonesia), between January 2011 and December 2020. Clinicopathological characteristics were analyzed using parametric and non-parametric tests. Multivariate logistic regression analyses were performed for eligible parameters, identified using bivariate analysis, to predict advanced stage and margin invasion. Calibration of the prediction model was evaluated using the Hosmer-Lemeshow test, its discrimination value assessed using the receiver operating characteristic and area under the receiver operating characteristic curve (AUC). Sex-specific patterns in tumor subsites and differences in clinical staging according to age were demonstrated in the patients with OSCC. The proportion of well-differentiated cases was significantly higher in most tumor subsites, except in the buccal mucosa (more moderately differentiated cases) and floor of the mouth (well and moderately differentiated cases being equal). LVI was significantly associated with nodal metastasis but not distant metastasis. Multivariate analysis demonstrated that age ≤45 years [odds ratio (OR), 2.26] and LVI (OR, 8.42) predicted patients having advanced-stage OSCC among general populations (AUC, 0.773); however, LVI (OR, 8.28) was the sole predictor of advanced stage amongst young patients (AUC, 0.737). Margin invasion was predicted solely by tumor subsite, including mouth not otherwise specified (OR, 3.04) and palate (OR, 6.13), in the general population (AUC, 0.711). Furthermore, margin invasion was predicted by the palate subsite (OR, 38.77) and LVI (OR, 11.61) in young patients (AUC, 0.762). Investigating young patients thoroughly when finding SCC in the mouth and palate, and assessing LVI, especially among young patients, is critical to prevent advanced staging and margin invasion.

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.

Extracellular Vesicle-Mediated Chemoresistance in Oral Squamous Cell Carcinoma

Oral Squamous Cell Carcinoma (OSCC) remains a cancer with poor prognosis and high recurrence rate. Even with multimodal treatment options available for OSCC, tumor drug resistance is still a persistent problem, leading to increased tumor invasiveness among OSCC patients. An emerging trend of thought proposes that extracellular vesicles (EVs) play a role in facilitating tumor progression and chemoresistance via signaling between tumor cells. In particular, exosomes and microvesicles are heavily implicated in this process by various studies. Where primary studies into a particular EV-mediated chemoresistance mechanism in OSCC are limited, similar studies on other cancer cell types will be used in the discussion below to provide ideas for a new line of investigation into OSCC chemoresistance. By understanding how EVs are or may be involved in OSCC chemoresistance, novel targeted therapies such as EV inhibition may be an effective alternative to current treatment options in the near future. In this review, the current understandings on OSCC drug mechanisms under the novel context of exosomes and microvesicles were reviewed, including shuttling of miRNA content, drug efflux, alteration of vesicular pH, anti-apoptotic signaling, modulation of DNA damage repair, immunomodulation, epithelial-to-mesenchymal transition and maintenance of tumor by cancer stem cells.