Artificial intelligence for oral squamous cell carcinoma detection based on oral photographs: A comprehensive literature review

INTRODUCTION

Oral squamous cell carcinoma (OSCC) presents a significant global health challenge. The integration of artificial intelligence (AI) and computer vision holds promise for the early detection of OSCC through the analysis of digitized oral photographs. This literature review explores the landscape of AI-driven OSCC automatic detection, assessing both the performance and limitations of the current state of the art.

MATERIALS AND METHODS

An electronic search using several data base was conducted, and a systematic review performed in accordance with PRISMA guidelines (CRD42023441416).

RESULTS

Several studies have demonstrated remarkable results for this task, consistently achieving sensitivity rates exceeding 85% and accuracy rates surpassing 90%, often encompassing around 1000 images. The review scrutinizes these studies, shedding light on their methodologies, including the use of recent machine learning and pattern recognition approaches coupled with different supervision strategies. However, comparing the results from different papers is challenging due to variations in the datasets used.

DISCUSSION

Considering these findings, this review underscores the urgent need for more robust and reliable datasets in the field of OSCC detection. Furthermore, it highlights the potential of advanced techniques such as multi-task learning, attention mechanisms, and ensemble learning as crucial tools in enhancing the accuracy and sensitivity of OSCC detection through oral photographs.

CONCLUSION

These insights collectively emphasize the transformative impact of AI-driven approaches on early OSCC diagnosis, with the potential to significantly improve patient outcomes and healthcare practices.

[Oral cavity cancer: A distinct entity]

Oral Squamous cell carcinoma represent the 17th most frequent cancer in the world. The main risk factors are alcohol and tobacco consumption but dietary, familial, genetic, or oral diseases may be involved in oral carcinogenesis. Diagnosis is made on biopsy, but detection remains late, leading to a poor prognosis. New technologies could reduce these delays, notably Artificial Intelligence and the quantitative evaluation of salivary biological markers. Currently, management of oral cancer consists in surgery, which can be mutilating despite possible reconstructions. In the future, immunotherapies could become a therapeutic alternative and the immune microenvironment could constitute a source of prognostic markers.

An Unusual Case of Recurrent Gingival Epstein-Barr Virus-Positive B-Cell Lymphoproliferation

Epstein-Barr virus (EBV)-positive mucocutaneous ulceration commonly presents as a B-cell lymphoproliferative process with manifold aspects. There is scarce data on its oral manifestation in the scientific literature. We report the case of a 57-year-old male immunocompromised renal transplant patient who developed recurrent chronic and symptomatic mucosal ulceration facing the mandibular incisor teeth. Pathological examination with microscopic and immunohistochemistry studies revealed a B plasma cell infiltration as well as positive staining for EBV, leading to a diagnosis of EBV-positive mucocutaneous ulceration with B-cell lymphoproliferation after extensive workup. Treatment with rituximab was implemented and led to the healing of the lesion. This lesion develops in geriatric and immunodeficient patients and may require oncological therapies. While it is generally associated with an excellent prognosis, it may be indicative of underlying immunosuppression, and hence oral cavity specialists must be aware of this particular entity.

A Giant Posterior Maxillary Intra-Sinusal Complex Odontoma: A Clinical Case

Odontomas are the most common odontogenic neoplasms. They are generally small and asymptomatic. This article presents an unusual case of a giant maxillary complex odontoma, which obscured a part of the maxillary antrum and impacted a tooth. This was discovered during an episode of maxillofacial cellulitis. In this case, surgical excision of the lesion was performed under general anesthesia, and the closure was performed with a fat pad pedicled flap. A brief review of the literature was performed to analyze the characteristics of this clinical entity and their implication in the treatment.

Lingual fasciculation: A point of call for the diagnosis of amyotrophic lateral sclerosis

A 60-year-old female patient, with no notable medical history, was referred by the internal medicine department for a dry mouth workup. The clinical examination revealed an absence of dryness, and the presence of lingual fasciculations, associated with difficulties in mastication and phonation. These symptoms appeared spontaneously 9 months before the consultation, after leaving confinement. Given the presence of lingual fasciculations, the diagnostic hypothesis of a neurological pathology, in particular amyotrophic lateral sclerosis (ALS), was suspected. After performing an electromyogram (EMG), the diagnosis of ALS was retained. Riluzole treatment was then started, and physical therapy sessions were scheduled. Riluzole allows an average gain of 4 to 6 months of life expectancy. Speech therapy and physical therapy allow to maintain the functions as long as possible and to improve the end-of-life conditions. The interest of early detection of ALS allows delaying the progression of the disease.

Cytomegalovirus-induced oral ulcers: A case report and literature review

Cytomegalovirus (CMV) ulcerations are rare clinical entities, but their occurrence is favored in immunocompromised patients who present a favorable environment for opportunistic infections. We describe the case of a patient treated for a systemic lupus erythematosus suffering from deep oral ulcerations. The case illustrates the complexity of establishing a precise etiological diagnosis of CMV lesions, as the diagnostic hypothesis can be varied: related to an immunodeficiency disorder or drug-induced toxidermia.

"Plasma cell gingivitis" encompasses multiple entities: a retrospective series of 37 cases

BACKGROUND

Plasma cell gingivitis is defined as gingival inflammation comprised of plasma cell infiltrates. This diagnostic criterion is non-specific and underlying mechanisms remain unknown.

OBJECTIVES

We performed a multidisciplinary clinico-pathological review of cases previously identified as "gingivitis with plasma cell infiltrates", with assessment of putative contributing factors and critical appraisal of the final diagnosis.

MATERIALS & METHODS

Cases previously identified as "gingivitis with plasma cell infiltrates" between 2000 and 2020 were included from archives from the GEMUB group, a French multidisciplinary network of physicians with expertise on oral mucosa.

RESULTS

Among the 37 included cases, multidisciplinary clinico-pathological review allowed differential diagnosis in seven cases (oral lichen planus n=4, plasma cell granuloma n=1, plasmacytoma n=1, and mucous membrane pemphigoid n=1). The remaining cases were classified as "reactive plasma cell gingivitis" (induced by drugs, trauma/irritation or periodontal disease) (n=18) or "idiopathic plasma cell gingivitis" when no contributing factors were identified (n=12). Clinico-pathological characteristics did not differ significantly between "reactive" and "idiopathic" cases, preventing us from identifying specific features of "idiopathic" plasma cell gingivitis.

CONCLUSION

"Plasma cell gingivitis" is a polymorphous, non-specific entity with various aetiologies, of which the diagnosis requires multidisciplinary anatomo-clinical correlation for exclusion of secondary causes of plasma cell infiltration. Although our study was limited by its retrospective design, most cases of "plasma cell gingivitis" appeared to be associated with an underlying cause. We propose a diagnostic algorithm to properly investigate such cases.

Oral giant cell tumor or giant cell granuloma: How to know?

Introduction

The distinction between giant cell tumors and giant cell granulomas is challenging, as both entities have overlapping diagnostic criteria, especially in oral locations. The two entities have similar clinical and radiological presentations, but they differ in their prognoses.

Objective

The main objective of this study was to list the clinical, radiological, histological, and prognostic features of maxillomandibular giant cell tumors and giant cell granulomas cases n order to assess their value as a diagnostic referral factor that may allow the distinction between maxillo-mandibular giant cell granuloma and giant cell tumor.

Study design

Data of maxillomandibular giant cell granulomas and giant cell tumors were assessed through a scoping review and a pre-existing systematic review of literature. We have also realized a bicentric retrospective study.

Results

Various criteria facilitate the differential diagnosis like age, size, locularity and presence of necrosis zone but not the gender. The most discriminating factors was symptomatology (reported in 72% of GCTs while only 15% of GCGs) and the distribution pattern of giant cells in the stroma (homogeneously dispersed in 80% of GCTs versus grouped in clusters in 86.7% of GCGs). Recurrences were most described for giant cell tumors than giant cell granulomas. Malignant transformation and pulmonary metastasis were exclusively reported for giant cell tumors.

Conclusion

As clinical and radiological elements are not sufficient to distinguish between these two entities, immunohistochemistry and molecular genetics can be represent diagnostic biomarkers to distinguish giant cell granulomas and giant cell tumors in oral cavity. We have attempted to define the main criteria for the differentiation of giant cell tumor and giant cell granuloma and propose a decision tree for the management of single maxillomandibular giant cell lesions.

Oral Lichen Planus in Patients With Good's Syndrome: A Literature Review

Good's syndrome is defined as the association of a thymoma with an immune deficiency. Many patients with Good's syndrome also have oral lichen planus involvement, and some authors have even considered it to be one of the clinical signs of Good's syndrome. In the literature, to our knowledge, clinical forms of oral lichen planus associated with Good's syndrome have not been described. We therefore aimed to characterize the forms of oral lichen planus occurring in the context of Good's syndrome. To this end, we carried out a scoping review of the literature according to the Joanna Briggs Institute guide and included 17 articles on the theme of "the forms and clinical locations of oral lichen planus associated with Good's syndrome". A total of 17 articles were selected, and 19 patients with Good's syndrome including oral lichen planus were identified. Most of them were women aged 60 years with erosive oral lichen planus of the tongue and inner cheeks. The treatments used were thymectomy, to which immunoglobulin infusions were added in some cases. All these treatments resulted in improvement of the oral lichen planus in 70.6% of cases. The management of Good's syndrome allows the improvement of oral lichen. In patients over 50 years of age with acute erosive oral lichen planus refractory to conventional therapies, Good's syndrome should be investigated.

Defining biomarkers in oral cancer according to smoking and drinking status

Introduction

Oral Squamous Cell Carcinomas (OSCC) are mostly related to tobacco consumption eventually associated to alcohol (Smoker/Drinker patients: SD), but 25-30% of the patients have no identified risk factors (Non-Smoker/Non-Drinker patients: NSND). We hypothesized that these patients have distinguishable immune profiles that could be useful for prognosis.

Materials and Methods

Cells present in immune tumor microenvironment (TME) and blood from 87 OSCC HPV-negative patients were analyzed using a multiparameter flow cytometry assay, in a prospective case-control study. Cytokine levels in tumor supernatants and blood were determined by a cytometric bead array (CBA) assay.

Results

Normal gingiva and blood from healthy donors (HD) were used as controls. A significant increase of granulocytes (p<0.05 for blood), of monocytes-macrophages (p<0.01 for blood) and of CD4⁺ T cells expressing CD45RO and CCR6 (p<0.001 for blood; p<0.0001 for TME) as well as higher levels of IL-6 (p<0.01 for sera, p<0.05 for tumor supernatant) were observed in SD patients as compared to NSND OSCC patients and HD. High percentages of CD4⁺ T cells expressing CD45RO and CCR6 cells in tumor tissue (p=0.05) and blood (p=0.05) of SD OSCC patients were also associated with a poorer prognosis while a high percentage of regulatory T cells (Treg) in tumor tissue was associated with a more favorable prognostic factor (p=0.05). Also, a higher percentage of blood CD8⁺ T lymphocytes among CD45⁺ cells in NSND patients was associated with a better disease-free survival (p=0.004).

Conclusion

Granulocytes, monocytes-macrophages, and CD4⁺ T cells expressing CD45RO and CCR6 in blood and TME as well as serum IL-6 can therefore distinguish OSCC SD and NSND patients. Quantifying the proportion of CD4⁺ T cells expressing CD45RO and CCR6 and of Treg in SD patients and CD8⁺ T cells in NSND patients could help defining the prognostic of OSCC patients.

Multiple oral papillomas after antiretroviral treatment resumption

Lesions of the oral mucosa due to human papillomavirus (HPV) present in various clinical forms. The case of a man in his 50s is reported. This patient was referred for multiple whitish oral lesions, unresponsive to antifungal drugs, in a context of pneumocystis having revealed a therapeutic break of an HIV antiretroviral treatment. The lesions had appeared a few days after treatment resumption. Clinical examination revealed multiple lesions on the lips, the inner sides of the cheeks and lips and on the tongue. The patient reported burning sensations in the mouth. The diagnosis of multiple papillomas was made in view of the characteristic clinical picture and history of the disease: appearance of oral papular lesions with multiple locations, which may reveal a context of severe immunodeficiency. HPV lesions are more frequent in HIV-positive patients and may increase on initiation of antiretroviral therapy.

Abstract 2105: PD-L1 high ICOSL low Secretory dendritic cells infiltrate human solid tumors

Background: Human conventional dendritic cells (cDC) are essential for the anti-tumor immune response. Their immunogenic and tolerogenic states in cancer remain controversial. Our objective was to define the range of DC activation states in vitro and to determine their relevance ex vivo in cancer.

Methods: First, in vitro, we activated healthy donor cDC with 16 different stimuli and measured cDC and T cells cytokine and chemokine secretion upon co-culture (n = 130 individual experiments) to define new maturation archetypes. Second, we established the relevance of these archetypes in cancer, ex vivo in human. We performed in depth analysis of cDC infiltrating head and neck cancer (HNSCC) by flow cytometry (n = 22 patients), transcriptomic analysis (n = 6 patients), and cDC-enriched single-cell transcriptomics (ScRNAseq) (n = 10503 cells from 2 patients). Then we performed a merged analysis of cDC from in house and public ScRNAseq datasets (n = 36 tumor samples from HNSCC, Lung, and Breast cancer, and, as comparator, n = 33 blood and juxtatumor samples, n = 19 healthy donor samples, and n = 23 samples from inflammatory diseases).

Results: In vitro, we identified two archetypes of cDC activation: (i) PD-L1highICOSLlow cDC that produce large amounts of inflammatory cytokines and chemokines, labeled Secretory cDC; (ii)PD-L1lowICOSLhigh cDC that induce a broad range of Th cytokines, labeled Helper cDC. This functional dichotomy of cDC was mutually exclusive and not receptor specific. In cancer, we identified Secretory cDC, and these cells aligned with mature LAMP3+cDC. Helper cDC were not found ex vivo. Secretory cDC simultaneously expressed stimulatory (CD40, TNFRSF9 (4-1BB)), inhibitory (CD274, CD200, IDO1), and mixed (PVR) checkpoints. Secretory cDC were associated with T cell inflammation in HNSCC, triple-negative breast cancer (TNBC), and melanoma (all p &lt; 1.10-15), with improved overall survival in HNSCC and TNBC (all p &lt; 0.01), and with response to checkpoint blockade in 2 melanoma cohorts (all p &lt; 0.01).

Conclusion: We identify and characterize Secretory cDC in several solid cancers. This novel phenotypic and functional dichotomy of human cDC activation states has broad implications for all types of immunotherapies and provides rational for drug combinations.

Citation Format: Caroline Hoffmann, Floriane Noël, Maximilien Grandclaudon, Lucile Massenet-Regad, Paula Michea, Philemon Sirven, Lilith Faucheux, Aurore Surun, Olivier Lantz, Mylene Bohec, Jian Ye, Weihua Guo, Juliette Rochefort, Jerzy Klijanienko, Sylvain Baulande, Charlotte Lecerf, Maud Kamal, Christophe Le Tourneau, Maude Guillot-Delost, Vassili Soumelis. PD-L1 high ICOSL low Secretory dendritic cells infiltrate human solid tumors [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 2105.

PD-L1 and ICOSL discriminate human Secretory and Helper dendritic cells in cancer, allergy and autoimmunity

Dendritic cells (DC) are traditionally classified according to their ontogeny and their ability to induce T cell response to antigens, however, the phenotypic and functional state of these cells in cancer does not necessarily align to the conventional categories. Here we show, by using 16 different stimuli in vitro that activated DCs in human blood are phenotypically and functionally dichotomous, and pure cultures of type 2 conventional dendritic cells acquire these states (termed Secretory and Helper) upon appropriate stimuli. PD-L1highICOSLlow Secretory DCs produce large amounts of inflammatory cytokines and chemokines but induce very low levels of T helper (Th) cytokines following co-culturing with T cells. Conversely, PD-L1lowICOSLhigh Helper DCs produce low levels of secreted factors but induce high levels and a broad range of Th cytokines. Secretory DCs bear a single-cell transcriptomic signature indicative of mature migratory LAMP3+ DCs associated with cancer and inflammation. Secretory DCs are linked to good prognosis in head and neck squamous cell carcinoma, and to response to checkpoint blockade in Melanoma. Hence, the functional dichotomy of DCs we describe has both fundamental and translational implications in inflammation and immunotherapy.

Phenotypic and functional states of dendritic cells critically influence the outcome of cancer and inflammation. Authors here show by single cell transcriptomics and in vitro validation assays that dichotomous PD-L1 and ICOSL expression assign dendritic cells to secretory and helper functions, with respective predominance of inflammatory cytokine expression or T helper cytokine induction.

French guidelines for the management of oral lichen planus (excluding pharmacological therapy)

INTRODUCTION

Oral lichen is a chronic inflammatory disease for which diagnostic management and follow-up are heterogeneous given the absence of specific guidelines in France. Our objective was to develop French multidisciplinary guidelines for the management of oral lichen.

MATERIALS AND METHODS

Working groups from the Groupe d'Etude de la Muqueuse Buccale (GEMUB) formulated a list of research questions and the corresponding recommendations according to the "formal consensus" method for developing practice guidelines. These recommendations were submitted to a group of experts and the degree of agreement for each recommendation was assessed by a scoring group.

RESULTS

Twenty-two research questions, divided into 3 themes (nosological classification and initial assessment, induced oral lichenoid lesions, and follow-up) resulted in 22 recommendations. Initial biopsy for histology is recommended in the absence of reticulated lesions. Biopsy for direct immunofluorescence is recommended for ulcerated, erosive, bullous types and for diffuse erythematous gingivitis. Management should include a periodontal and dental check-up, and investigation for extra-oral lesions. Hepatitis C testing is recommended only if risk factors are present. Definitions, triggering factors and the management of "induced oral lichenoid lesions" were clarified. Oral lichen must be monitored by a practitioner familiar with the disease at least once a year, using objective tools.

CONCLUSION

This formalised consensus of multidisciplinary experts provides clinical practice guidelines on the management and monitoring of oral lichen.

Oral manifestation of lymphomatoid papulosis: systematic review

Introduction: Lymphomatoid Papulosis (LyP) is a lymphoproliferative disorder with typical histopathological criteria and a spontaneous regression. Only few cases of oral involvement have been reported. We wondered about their clinical characteristics and their association with lymphoma. Method: This systematic review is conducted according to the PRISMA statement. The Oxford Centre for Evidence Based Medicine table (OCEBM) and the scoring from the National Agency for Accreditation and Assessment in Health (ANAES) was assigned to each study. Results: We have included 16 references. LyP can occur at any age with a female predilection. Oral lesions were unique ulcer and tongue was mostly affected. Histological types A, and C were dominant and LyP resolved spontaneously. 1 case was associated with a lymphoma. Discussion: Cutaneous LyP more affects men and are mostly classified as type A while those orals are type A or C. Oral LyP is probably a progressive lesion whose evolution is not illustrated by the histological aspect which often reflects only the initial acute period. Conclusion: Our literature review has shown that the epidemiological aspects between oral and cutaneous LyP are not the same. LyP may be associated with an increased risk of developing systemic lymphoproliferative disorders.

Clinical photography: attitudes of practitioners specialized in oral mucosal diseases

Introduction: Clinical photography is an important tool for clinical practice, training and research frequently used across medical specialties. It may provide snapshot images of evolving clinical situations. The aim of this work was to record its contribution in the management of oral mucosal diseases and, to identify the methods of using this tool by carrying out a survey with practitioners specialized in oral pathologies. This allowed us to make recommendations for appropriate use of this tool. Material and methods: An online anonymous questionnaire was sent via email, to practitioners who were member of two associations of French specialists. Results: 51 oral medicine specialists completed the survey. Among them, 48 (94%) used photography in their daily practice. Lack of time or interest was the reasons given by the 3 practitioners who did not use photography. Pictures were mostly taken with smartphones, which provide precise and accurate images, and stored on personal or professional computers. Sharing of images was performed mostly by secured professional or personal email addresses. Consent was obtained verbally in most cases. Conclusion: Photography could be a valuable asset in the practice of oral medicine. However, recommendations for the safety of patient personal data are not always followed.

French recommendations for the management of systemic sclerosis

Systemic sclerosis (SSc) is a generalized disease of the connective tissue, arterioles, and microvessels, characterized by the appearance of fibrosis and vascular obliteration. There are two main phenotypical forms of SSc: a diffuse cutaneous form that extends towards the proximal region of the limbs and/or torso, and a limited cutaneous form where the cutaneous sclerosis only affects the extremities of the limbs (without passing beyond the elbows and knees). There also exists in less than 10% of cases forms that never involve the skin. This is called SSc sine scleroderma. The prognosis depends essentially on the occurrence of visceral damage and more particularly interstitial lung disease (which is sometimes severe), pulmonary arterial hypertension, or primary cardiac damage, which represent the three commonest causes of mortality in SSc. Another type of involvement with poor prognosis, scleroderma renal crisis, is rare (less than 5% of cases). Cutaneous extension is also an important parameter, with the diffuse cutaneous forms having less favorable prognosis.

Tumor-Associated Tertiary Lymphoid Structures: From Basic and Clinical Knowledge to Therapeutic Manipulation

The tumor microenvironment is a complex ecosystem almost unique to each patient. Most of available therapies target tumor cells according to their molecular characteristics, angiogenesis or immune cells involved in tumor immune-surveillance. Unfortunately, only a limited number of patients benefit in the long-term of these treatments that are often associated with relapses, in spite of the remarkable progress obtained with the advent of immune checkpoint inhibitors (ICP). The presence of “hot” tumors is a determining parameter for selecting therapies targeting the patient immunity, even though some of them still do not respond to treatment. In human studies, an in-depth analysis of the organization and interactions of tumor-infiltrating immune cells has revealed the presence of an ectopic lymphoid organization termed tertiary lymphoid structures (TLS) in a large number of tumors. Their marked similarity to secondary lymphoid organs has suggested that TLS are an “anti-tumor school” and an “antibody factory” to fight malignant cells. They are effectively associated with long-term survival in most solid tumors, and their presence has been recently shown to predict response to ICP inhibitors. This review discusses the relationship between TLS and the molecular characteristics of tumors and the presence of oncogenic viruses, as well as their role when targeted therapies are used. Also, we present some aspects of TLS biology in non-tumor inflammatory diseases and discuss the putative common characteristics that they share with tumor-associated TLS. A detailed overview of the different pre-clinical models available to investigate TLS function and neogenesis is also presented. Finally, new approaches aimed at a better understanding of the role and function of TLS such as the use of spheroids and organoids and of artificial intelligence algorithms, are also discussed. In conclusion, increasing our knowledge on TLS will undoubtedly improve prognostic prediction and treatment selection in cancer patients with key consequences for the next generation immunotherapy.

Knowledge and perception of the French ANSM recommendations for acute odontogenic cellulitis in French private dental practices: a national survey

Introduction: Caring for acute odontogenic cellulitis involves drainage, treatment of the tooth and the administration of antibiotic therapy (ANSM 2011). The emergence of bacterial resistance mechanisms has led to formulating actions to promote better use of antibiotics, but France stay one of the largest consumers in Europe. Objectives: Evaluate the impact of ANSM's recommendations on dental surgeons in France for treatment of this affection. Methods: We performed a national survey with 12365 practitioners who received the questionnaire by email. Results: On 690 responder practitioners, 13% followed the recommendations to the letter and 70.5% performed a clinical intervention on the day of emergency. Only 1/3 of cases involved the prescription of amoxicillin alone for first line treatment. Conclusion: Few data exist on the evaluation of the impact of recommendations regarding this subject, but it is generally accepted it they are seldom followed. The reasons expressed are many: disagreement between practitioners on the efficiency of recommendations, lack of time and organizational constraints.

Knowledge and practices of dentists in France regarding oral mucosal diseases: a national survey

Introduction:One of the dental surgeon's roles is to identify, diagnose and supervise the treatment of oral pathologies (OP), and/or to refer patients to the appropriate specialists. Today, the delay in diagnosing patients with OP is very long and may impact their prognosis.Objective:We conducted a national survey of French practitioners to estimate their knowledge and practices regarding the management of these pathologies.Methods:About 15,000 dentists were contacted by email to complete a questionnaire designed to assess the diagnoses and management of OP.Results:Overall, for 560 answers (3.8%), DS did not declare any significant difficulties in diagnosing and managing any kind of pathologies. However, we were able to distinguish statistical differences among practitioners depending on the type of lesions and between the practitioners themselves. The associated factors were gender, graduation year, mode of practice and continuing education over the last 5 years. The majority of DS justified their diagnostic difficulties by the fact that they do not encounter patients with these types of pathology frequently enough, and by insufficient education.Conclusion:According to our study, it is necessary to reinforce the training and the continuing medical education of DS regarding OP, especially through the use of practical cases.

Management of mTOR inhibitors oral mucositis: current state of knowledge

Introduction: Mucositis is a well-known side effect of classic anticancer treatments (chemotherapy and radiotherapy). Thanks to the major developments in personalizing treatments through the development of targeted treatment, various specific intraoral lesions have been described. Purpose: mTOR inhibitors are targeted anticancer treatments that are used to treat various cancer types. They can cause intraoral ulcerations that can be serious, and that can lead to a dose reduction or the anticancer treatment being stopped altogether. The management of these disabling and painful lesions is a major part of ensuring the efficiency of the cancer treatments. The objective of this article is to evaluate the current knowledge about the different treatments used nowadays, especially the preventive treatments. Conclusion: An efficient management of the lesions is a major part of the management of patients treated with mTOR inhibitors and should be carried out by the oral cavity specialists.

Preclinical evaluation of mRNA trimannosylated lipopolyplexes as therapeutic cancer vaccines targeting dendritic cells

Clinical trials with direct administration of synthetic mRNAs encoding tumor antigens demonstrated safety and induction of tumor-specific immune responses. Their proper delivery to dendritic cells (DCs) requires their protection against RNase degradation and more specificity for dose reduction. Lipid-Polymer-RNA lipopolyplexes (LPR) are attractive mRNA delivery systems and their equipment with mannose containing glycolipid, specific of endocytic receptors present on the membrane of DCs is a valuable strategy. In this present work, we evaluated the capacity of LPR functionalized with a tri-antenna of α-d-mannopyranoside (triMN-LPR) concerning (i) their binding to CD209/DC-SIGN and CD207/Langerin expressing cell lines, human and mouse DCs and other hematopoietic cell populations, (ii) the nature of induced immune response after in vivo immunization and (iii) their therapeutic anti-cancer vaccine efficiency. We demonstrated that triMN-LPR provided high induction of a local inflammatory response two days after intradermal injection to C57BL/6 mice, followed by the recruitment and activation of DCs in the corresponding draining lymph nodes. This was associated with skin production of CCR7 and CXCR4 at vaccination sites driving DC migration. High number of E7-specific T cells was detected after E7-encoded mRNA triMN-LPR vaccination. When evaluated in three therapeutic pre-clinical murine tumor models such as E7-expressing TC1 cells, OVA-expressing EG7 cells and MART-1-expressing B16F0 cells, triMN-LPR carrying mRNA encoding the respective antigens significantly exert curative responses in mice vaccinated seven days after initial tumor inoculation. These results provide evidence that triMN-LPR give rise to an efficient stimulatory immune response allowing for therapeutic anti-cancer vaccination in mice. This mRNA formulation should be considered for anti-cancer vaccination in Humans.

A hair on the tongue

INTRODUCTION

Human hairs are generally localized on the cutaneous part of the head, neck, torso, armpits, pubis and limbs. Sometimes it can be found in an unusual localization and is then called heterotopic.

OBSERVATION

A 30-year-old man presented with a hair in the middle of the dorsum of the tongue. It was decided to perform an excision under local anesthesia.

DISCUSSION

Few reports exist that describe hair growing on mucosa. Only one other case has been published concerning the tongue.

CCR2 Influences T Regulatory Cell Migration to Tumors and Serves as a Biomarker of Cyclophosphamide Sensitivity

The CCL2 chemokine receptor CCR2 drives cancer by mediating the recruitment of monocytes and myeloid-derived suppressor cells to the tumor microenvironment. In this study, we extend the significance of CCR2 in this setting by identifying a new role for it in mediating recruitment of CD4⁺ T regulatory cells (Treg). Following tumor initiation, an expanded population of CCR2⁺ Tregs required CCR2 expression to traffic between draining lymph nodes (dLN) and the tumor. This Treg subset was enriched in the fraction of tumor antigen-specific cells in the dLN, where they displayed an activated immunosuppressive phenotype. Notably, in mouse models, low-dose cyclophosphamide treatment preferentially depleted CCR2⁺ Treg, enhancing priming of tumor-specific CD8⁺ T cells. In the MMTV-PyMT transgenic mouse model of breast cancer and in oral squamous cell carcinoma patients, tumor development was associated with decreased blood frequency and inversely increased tumor frequency of CCR2⁺ Tregs. Our results define a novel subset of CCR2⁺ Treg involved in tumoral immune escape, and they offer evidence that this Treg subset may be preferentially eradicated by low-dose cyclophosphamide treatment. Cancer Res; 76(22); 6483-94. ©2016 AACR.

Intra-cheek immunization as a novel vaccination route for therapeutic vaccines of head and neck squamous cell carcinomas using plasmo virus-like particles

Despite current therapy, head and neck squamous cell carcinomas (HNSCCs) arising from various mucosal sites of the upper aero-digestive tract frequently relapse in a loco-regional manner and have a poor prognosis. Our objective was to validate an innovative mucosal route of vaccination using plasmo virus-like particles (pVLPs) in a pre-clinical orthotopic model of HNSCCs. For this purpose, we used pVLP-E7, that are plasmid DNA encoding retroviral virus-like particles carrying a truncated E7 oncoprotein from HPV-16 as antigen model, to vaccinate mice bearing pre-established TC-1 tumors implanted into the buccal mucosa. pVLP-E7 were combined with clinical grade TLR agonists (Imiquimod and CpG-ODN). In this pre-clinical orthotopic model, whose tumor microenvironment resembles to those of human HNSCCs, different mucosal vaccination routes were tested for their ability to elicit efficient immune and antitumoral responses. Results showed that mucosal intra-cheek (IC) vaccinations using pVLP-E7, comparatively to intradermic vaccinations (ID), gave rise to higher mobilization of mucosal (CD49a(+)) CD8(+) specific effector T cells in both tumor draining lymph nodes (TdLNs) and tumor microenvironment resulting in better antitumor effects and in a long-term protection against tumor rechallenge. In vivo CD8(+) depletion demonstrated that antitumoral effects were fully dependent upon the presence of CD8(+) T cells. Validation of IC mucosal vaccinations with pVLPs combined with adjuvants using a pre-clinical orthotopic model of HNSCC provides valuable pre-clinical data to rapidly envision the use of such therapeutic vaccines in patients with HNSCCs, inasmuch as vaccinal components and adjuvants can be easily obtained as clinical grade reagents.

High hepatitis C virus prevalence and incidence among Canadian intravenous drug users

We used data and leftover samples collected through the SurvUDI network to describe the epidemiology of hepatitis C virus (HCV) infection among injection drug users (IDUs) in Eastern Central Canada. Among the 1380 selected IDUs, having participated twice or more between 1997 and 2003, the overall HCV prevalence rate was 60.4% (95% confidence interval [CI]: 57.7-63.0%). Among the 543 initially uninfected participants, the HCV incidence rate was 27.1 per 100 person-years (95% CI: 23.4-30.9 per 100 person-years). Independent predictors of seroconversion, identified among 359 participants, were age, injecting for a year or less, injecting with a syringe previously used by someone else, injecting most often cocaine, engaging in prostitution, and being recruited in a major urban centre. The HCV epidemic severely affects IDUs in this area. Actions to prevent HCV transmission, such as distribution of sterile injection equipment, have to be reinforced. Special efforts have to be targeted towards starting IDUs.