Single-cell RNA sequencing highlights the immunosuppression of IDO1+ macrophages in the malignant transformation of oral leukoplakia.

Rationale: Immunosuppressive tumor microenvironment (iTME) plays an important role in carcinogenesis, and some macrophage subsets are associated with iTME generation. However, the sub-population characterization of macrophages in oral carcinogenesis remains largely unclear. Here, we investigated the immunosuppressive status with focus on function of a macrophage subset that expressed indoleamine 2,3 dioxygenase 1 (Macro-IDO1) in oral carcinogenesis. Methods: We built a single cell transcriptome atlas from 3 patients simultaneously containing oral squamous cell carcinoma (OSCC), precancerous oral leukoplakia (preca-OLK) and paracancerous tissue (PCA). Through single-cell RNA sequencing and further validation using multicolor immunofluorescence staining and the in vitro/in vivo experiments, the immunosuppressive cell profiles were built and the role of a macrophage subset that expressed indoleamine 2,3 dioxygenase 1 (Macro-IDO1) in the malignant transformation of oral leukoplakia was evaluated. Results: The iTME formed at preca-OLK stage, as evidenced by increased exhausted T cells, Tregs and some special subsets of macrophages and fibroblasts. Macro-IDO1 was predominantly enriched in preca-OLK and OSCC, distributed near exhausted T cells and possessed tumor associated macrophage transformation potentials. Functional analysis revealed the established immunosuppressive role of Macro-IDO1 in preca-OLK and OSCC: enriching the immunosuppression related genes; having an established level of immune checkpoint score; exerting strong immunosuppressive interaction with T cells; positively correlating with the CD8-exhausted. The immunosuppression related gene expression of macrophages also increased in preca-OLK/OSCC compared to PCA. The use of the IDO1 inhibitor reduced 4NQO induced oral carcinogenesis in mice. Mechanistically, IFN-γ-JAK-STAT pathway was associated with IDO1 upregulation in OLK and OSCC. Conclusions: These results highlight that Macro-IDO1-enriched in preca-OLK possesses a strong immunosuppressive role and contributes to oral carcinogenesis, providing a potential target for preventing precancerous legions from transformation into OSCC.

Serum mRNA levels of cytokeratin-19 and vascular endothelial growth factor in oral squamous cell carcinoma and oral potentially malignant disorders using RT-PCR.

BACKGROUND: Oral cancers, which include tumors of the oral cavity, salivary glands, and pharynx, are becoming increasingly prevalent worldwide. Squamous cell carcinoma accounts for over 90% of malignant oral lesions, with oral squamous cell carcinoma (OSCC) being notably common in the Indian subcontinent and other regions of Asia. This is especially true in South-Central Asia, including Sri Lanka, where it is particularly prevalent among men. This study aims to evaluate the levels of Vascular Endothelial Growth Factor-A (VEGF-A) and Cytokeratin-19 (CK-19) mRNAs in whole blood as a potential method for the early detection of OSCC. METHODS: The study included 40 patients (each from OSCC, Oral Submucous Fibrosis (OSF), Oral Leukoplakia (OLK), Oral Lichen Planus (OLP), and 10 healthy controls. The expression levels of VEGF-A and CK-19 mRNAs were measured from extracellular RNA extracted from whole blood samples using real-time reverse transcription polymerase chain reaction (RT-PCR) with sequence-specific primers. Receiver operating characteristic (ROC) curve analysis was used to evaluate the effectiveness of these biomarkers in detecting OSCC. RESULTS: The results demonstrated a significant increase in blood transcripts of the candidate mRNAs CK-19 and VEGF-A in patients with OSCC, OSF, OLK, and OLP. The Wilcoxon signed-rank test revealed a p-value of 0.002 for each specific comparison between diseased patients and healthy controls (i.e., OSCC vs. HC, OSF vs. HC, OLP vs. HC, OLK vs. HC) for both CK-19 and VEGF-A. When these two biomarkers were used together, they provided a 60% predictive probability for patients with OSCC (p = 0.023). CONCLUSION: This study highlights the efficacy of blood mRNA transcriptome diagnostics in detecting OSCC. This innovative clinical approach has the potential to be a robust, efficient, and reliable tool for early cancer detection. Blood-based transcriptomes could be further explored for their effectiveness in various health contexts and for routine health monitoring.

Differences in the landscape of colonized microorganisms in different oral potentially malignant disorders and squamous cell carcinoma: a multi-group comparative study.

BACKGROUND: The role of microbes in diseases, especially cancer, has garnered significant attention. However, research on the oral microbiota in oral potentially malignant disorders (OPMDs) remains limited. Our study investigates microbial communities in OPMDs. MATERIALS AND METHODS: Oral biopsies from19 oral leukoplakia (OLK) patients, 19 proliferative verrucous leukoplakia (PVL) patients, 19 oral lichen planus (OLP) patients, and 19 oral lichenoid lesions (OLL) patients were obtained. 15 SCC specimens were also collected from PVL patients. Healthy individuals served as controls, and DNA was extracted from their paraffin-embedded tissues. 2bRAD-M sequencing generated taxonomic profiles. Alpha and beta diversity analyses, along with Linear Discriminant Analysis effect size analysis, were conducted. RESULTS: Our results showed the microbial richness and diversity were significantly different among groups, with PVL-SCC resembling controls, while OLK exhibited the highest richness. Each disease group displayed unique microbial compositions, with distinct dominant bacterial species. Noteworthy alterations during PVL-SCC progression included a decline in Fusobacterium periodonticum and an elevation in Prevotella oris. CONCLUSIONS: Different disease groups exhibited distinct dominant bacterial species and microbial compositions. These findings offer promise in elucidating the underlying mechanisms of this disease.

Oral leukoplakia and erythroplakia in young patients: a southern Brazilian multicenter study.

The objective of the present study was to investigate the frequency of oral leukoplakia and oral erythroplakia among young patients from three Brazilian reference centers in Oral and Maxillofacial Pathology. A retrospective study was carried out from 2011 to 2021 on 861 patients diagnosed with oral leukoplakia and oral erythroplakia. Demographic and clinicopathological data were evaluated. Fisher's exact test was used to evaluate the association among sex, age, anatomical location, and histopathological diagnosis. A total of 83 (9.64%) cases involved young patients (aged <40 years). Among these, biopsy records were included in 31 (37.34%) cases, all of which received a clinical diagnosis of oral leukoplakia. Seventeen (54.84%) patients were female, mostly in their fourth decade of life (n = 22/70.97%), and their mean age at diagnosis was 32.61(± 5.21) years. Among informed cases, seven (22.58%) patients were smokers. The lateral border of the tongue (n = 9/29.03%) was the most affected site. In 13 (41.94%) cases, oral leukoplakias showed a homogeneous appearance. The mean size of the lesions was 1.47 cm (0.2-3.0 cm) and the mean time of disease progression was 64.37 (± 65.90) months. The histopathological analysis showed that 11 cases (35.48%) exhibited some degree of epithelial dysplasia. Acanthosis and/or hyperkeratosis were observed in 20 cases (64.52%). No significant associations were observed between sex and anatomical location, age and anatomical location, nor between sex and histological diagnosis (p > 0.05). Oral leukoplakia and oral erythroplakia are uncommon diseases in young patients. In this population, oral leukoplakia shows a slight predilection for women aged between 30 and 39 years.

Effects of artemisinin and cisplatin on the malignant progression of oral leukoplakia. In vitro and in vivo study.

OBJECTIVES: Chemoprevention can be a treatment for potentially malignant lesions (PMLs). We aimed to evaluate whether artemisinin (ART) and cisplatin (CSP) are associated with apoptosis and immunogenic cell death (ICD) in vitro, using oral leukoplakia (OL) and oral squamous cell carcinoma (OSCC) cell lines, and whether these compounds prevent OL progression in vivo. METHODS: Normal keratinocytes (HaCat), Dysplastic oral cells (DOK), and oral squamous cell carcinoma (SCC-180) cell lines were treated with ART, CSP, and ART + CSP to analyze cytotoxicity, genotoxicity, cell migration, and increased expression of proteins related to apoptosis and ICD. Additionally, 41 mice were induced with OL using 4NQO, treated with ART and CSP, and their tongues were histologically analyzed. RESULTS: In vitro, CSP and CSP + ART showed dose-dependent cytotoxicity and reduced SCC-180 migration. No treatment was genotoxic, and none induced expression of proteins related to apoptosis and ICD; CSP considerably reduced High-mobility group box-1 (HMGB-1) protein expression in SCC-180. In vivo, there was a delay in OL progression with ART and CSP treatment; however, by the 16th week, only CSP prevented progression to OSCC. CONCLUSION: Expression of proteins related to ICD and apoptosis did not increase with treatments, and CSP was shown to reduce immunogenic pathways in SCC-180, while reducing cell migration. ART did not prevent the malignant progression of OL in vivo; CSP did despite significant adverse effects.

Leukoplakia and erythroplakia in youngers versus older individuals: a clinicopathological retrospective study.

BACKGROUND: The incidence of oral cancer has exhibited a rise within the young population. Considering that oral potentially malignant disorders (OPMDs) can precede the development of oral cancer, it is imperative to conduct studies in this particular younger population. This study aimed to evaluate the frequency and conduct a comparative analysis of the clinical-demographic characteristics of OPMDs in two distinct age groups. MATERIAL AND METHODS: A retrospective analysis was conducted with patients diagnosed with leukoplakia, erythroplakia, and leukoerythroplakia between 1965 and 2020. The individuals were categorized into two groups: those aged up to 40 years (Group Younger) and those aged 41 years and above (Group Older). RESULTS: A total of 640 lesions were subjected to analysis. Among these, patients aged up to 40 years constituted 10.63% of the sample, however, this proportion decreased significantly to 6.9% between 2010 and 2020. A predominant male representation was observed in both groups, with white lesions being the most common in both as well. However, the frequency of red or mixed lesions was significantly higher (p=0.034) in the older group, along with a higher prevalence of dysplastic lesions (26.9% versus 11.8%, p=0.01). Moreover, the older group exhibited a relatively higher percentage of smokers/ex-smokers (78.6%), compared to the younger group (61.5%, p=0.085) and alcohol consumers/ex-consumers (54.9% versus 22.7%, p=0.028). Elderly individuals exhibited an unfavorable progression (p=0.028). However, a logistic regression analysis identified as significant variables associated with malignant transformation, the presence of epithelial dysplasia, and red lesions diagnosed as erythroplakia. CONCLUSIONS: A declining frequency of OPMDs in young adults was observed over the years, whereas in older adults, these disorders exhibited an unfavorable progression.

Oral health-related quality of life in Fanconi anemia: a cross-sectional study.

PURPOSE: To evaluate the oral health-related quality of life (OHRQoL) of individuals diagnosed with Fanconi anemia (FA). METHODS: A cross-sectional study was conducted with FA patients from two Brazilian referral centers. Participants underwent a complete dental, periodontal, and oral mucosa examination, as well as assessment of resting salivary flow. The short version of the Oral Health Impact Profile (OHIP-14) questionnaire was administered. Descriptive and bivariate analyses were performed, followed by multivariate analysis to examine the impact of independent variables on OHRQoL. RESULTS: The study included 20 (57.1%) males and 15 (42.9%) females, with a mean age of 18.9 years. Oral leukoplakia (OL) was found in 18 individuals. The overall OHIP-14 score was 9.9 ± 10.5. Individuals aged ≥ 16 years had higher OHIP-14 scores, indicating worse OHRQoL for physical pain (p = 0.007), psychological discomfort (p = 0.001), physical disability (p = 0.03), psychological disability (p = 0.001), handicap (p = 0.004), and overall score (p = 0.007). Females reported more negative OHRQoL than males for physical pain (p = 0.02), psychological discomfort (p = 0.03), psychological disability (p = 0.009), and overall score (p = 0.02). Individuals with OL had an overall OHIP-14 score 1.83 times higher than those without OL (95% CI: 1.02-3.28; p = 0.04). Lower salivary flow correlated with higher overall OHIP-14 scores (95% CI: 0.14-0.84; p = 0.01). CONCLUSION: This study represents the first attempt to evaluate OHRQoL in individuals with FA. The presence of OL and reduced salivary flow were identified as predictors of a negative impact on OHRQoL. It is imperative to integrate patients' quality of life in the clinical treatment protocols for the FA population.

Diseases with oral malignant potential: Need for change to inform research, policy, and practice.

This manuscript critically examines the current classification of oral potentially malignant disorders, questioning the practicality and implications of labeling such a large population as precancerous, given that the actual progression to oral cancer is significantly low for most disorders. The paper advocates for a revised classification system that accurately reflects the varying malignancy risks associated with different disorders. It suggests a reassessment of the diagnostic and management approaches to mitigate overdiagnosis and alleviate patient burdens. We propose categorizing diseases with oral malignant potential as follows: Oral Precancerous Diseases, encompassing high-risk lesions and conditions like erythroplakia, non-homogeneous leukoplakia, proliferative leukoplakia, and actinic keratosis; Oral Potentially Premalignant Diseases, covering lesions, conditions, and systemic diseases with distinct oral manifestations harboring a limited or undefined risk of transformation, such as homogeneous leukoplakia, oral submucous fibrosis, oral lichenoid diseases, chronic hyperplastic candidosis, keratosis of known aetiology (smokeless tobacco, khat), palatal lesions in reverse smokers, and dyskeratosis congenita; and Systemic Conditions with Oral Malignant Potential including Fanconi's anemia, xeroderma pigmentosum, and chronic immunosuppression (including patients post-bone marrow transplantation), which are associated with an increased risk of oral cancer without preceding precursor lesions. We provide illustrative examples to demonstrate how this framework offers practical guidance for research, policy-making, and clinical practice.

Serum and salivary interleukin-1ß level in oral precancer: An observational study.

BACKGROUND AND AIM: Precancer biomarkers help in early detection and management of oral potentially malignant disorders (OPMDs). Interleukin-1ß (IL-1ß), a biomarker, is known to be altered in oral submucous fibrosis (OSMF) and oral leukoplakia (OL). Therefore, we evaluated and compared the serum and salivary IL-1ß levels in patients with OSMF/oral leukoplakia and in gender- and age-matched healthy individuals. MATERIALS AND METHODS: An in vivo, prospective, observational study was conducted on 40 subjects. Subjects were divided into two groups with 20 individuals in each group, that is, Group I: OSMF/oral leukoplakia and Group II: control group. Salivary and serum IL-1ß levels were quantitatively estimated using enzyme-linked immunosorbent assay (ELISA). The statistical tests used were unpaired t-test and Chi-square test. RESULTS: The serum IL-1ß levels were significantly (P 0.001) lesser in Group I in comparison to Group II. The salivary IL-1ß levels remained insignificant between both the groups. However, in both the groups, the salivary IL-1ß levels were significantly higher compared to the serum IL-1ß levels. CONCLUSION: We found that the serum IL-1ß level can be considered as a prospective biomarker for dysplasia, whereas salivary IL-1ß alone needs more elaborated studies to account for its application as a potential biomarker in OPMD.

Treatment outcomes of oral leukoplakia on the irradiated or nonirradiated mucosa among survivors of head and neck cancer in the papulation where practice of betel nut chewing and cigarette smoking are widespread.

BACKGROUND: Radiotherapy (RT) has numerous effects on the oral mucosa, primarily genetic alterations and changes in the microenvironment. The characteristics of oral leukoplakia (OL) may differ between patients who have received previous head and neck cancer (HNC) treatment with radiation therapy and those who have not. Due to a lack of data on this scenario, we aimed to investigate the surgical outcomes of OL by comparing these two patient groups. METHODS: This retrospective cohort study enrolled a total of 224 OL lesions in 124 patients who underwent carbon dioxide laser (CO2 laser) surgery from July 2002 to Aug 2021. All patients had received previous treatments for HNC, with 59 patients undergoing only surgical approach, 65 patients undergoing RT, and 46 patients undergoing concurrent chemotherapy during RT. The analysis was performed on a per-lesion basis, not a per-capita basis. We investigated the associations of clinicopathological characteristics and treatment outcomes of OL lesions that developed from irradiated or nonirradiated oral mucosa. RESULTS: The median follow-up time was 5.87 years. Postoperative recurrence of OL occurred in 30 patients. Malignant transformation occurred in 17 patients with the incidence rate 4.19% annually and 13.7% cumulatively. The average time for OL transforming into squamous cell carcinoma was 3.27 ± 3.26 years (median 1.82, range 0.11 - 11.90). In univariate analysis, non-homogeneous morphology (P = 0.042), moderate to high-grade dysplasia (P = 0.041), and nonirradiated oral mucosa (P = 0.0047) were predictors for malignant transformation. However, in the Cox proportional hazard model, only nonirradiated oral mucosa remained an independent prognostic factor related to postoperative malignant transformation of OL (P = 0.031, HR 5.08, CI95 1.16 - 22.25). CONCLUSION: In the population whose OL is strongly aetiologically linked to environmental carcinogens such as betel nut and tobacco, OL lesions that develop on previously irradiated oral mucosa have a lower risk for postoperative malignant transformation compared to those that develop on nonirradiated mucosa. This finding highlights the potential impacts of radiation on OL. Further research is needed to confirm this observation and elucidate the underlying mechanism.

Sensitive Detection of Oral Leukoplakia: Analyzing P90 Biomarkers in Saliva and Tissue.

Oral cancer represents a significant global public health challenge, contributing substantially to the incidence and mortality of cancer. Despite established risk factors such as tobacco use and alcohol consumption, early detection remains crucial for effective treatment. This study introduces a novel approach using a transistor-based biosensor system for detecting the P90 (CIP2A) protein. We tested the presence of CIP2A in human leukoplakia samples, which can undergo malignant conversion into aggressive oral squamous cell carcinoma. The method used commercially available glucose test strips functionalized with P90 antibodies, providing high sensitivity and a low limit of detection which was five orders lower than that of commercial ELISA kits. A specially designed printed circuit board (PCB) facilitated accurate measurements, and the device's performance was optimized through characteristic tests. Human sample testing validated the biosensor's effectiveness in distinguishing samples after cell lysis. This study contributes to advancing accurate and cost-effective diagnostic approaches for oral pre-cancer and cancer tissues.

Prediction of the short-term efficacy and recurrence of photodynamic therapy in the treatment of oral leukoplakia based on deep learning.

BACKGROUND: The treatment of oral leukoplakia (OLK) with aminolaevulinic acid photodynamic therapy (ALA-PDT) is widespread. Nonetheless, there is variation in efficacy. Therefore, this study constructed a model for predicting the short-term efficacy and recurrence of OLK after ALA-PDT. METHODS: The short-term efficacy and recurrence of ALA-PDT were calculated by statistical analysis, and the relevant influencing factors were analyzed by Logistic regression and COX regression model. Finally, prediction models for total response (TR) rate, complete response (CR) rate and recurrence in OLK patients after ALA-PDT treatment were established. Features from pathology sections were extracted using deep learning autoencoder and combined with clinical variables to improve prediction performance of the model. RESULTS: The logistic regression analysis showed that the non-homogeneous (OR: 4.911, P: 0.023) OLK and lesions with moderate to severe epithelial dysplasia (OR: 4.288, P: 0.042) had better short-term efficacy. The area under receiver operating characteristic curve (AUC) of CR, TR and recurrence predict models after the ALA-PDT treatment of OLK patients is 0.872, 0.718, and 0.564, respectively. Feature extraction revealed an association between inflammatory cell infiltration in the lamina propria and recurrence after PDT. Combining clinical variables and deep learning improved the performance of recurrence model by more than 30 %. CONCLUSIONS: ALA-PDT has excellent short-term efficacy in the management of OLK but the recurrence rate was high. Prediction model based on clinicopathological characteristics has excellent predictive effect for short-term efficacy but limited effect for recurrence. The use of deep learning and pathology images greatly improves predictive value of the models.

Advancements in diagnosing oral potentially malignant disorders: leveraging Vision transformers for multi-class detection.

OBJECTIVES: Diagnosing oral potentially malignant disorders (OPMD) is critical to prevent oral cancer. This study aims to automatically detect and classify the most common pre-malignant oral lesions, such as leukoplakia and oral lichen planus (OLP), and distinguish them from oral squamous cell carcinomas (OSCC) and healthy oral mucosa on clinical photographs using vision transformers. METHODS: 4,161 photographs of healthy mucosa, leukoplakia, OLP, and OSCC were included. Findings were annotated pixel-wise and reviewed by three clinicians. The photographs were divided into 3,337 for training and validation and 824 for testing. The training and validation images were further divided into five folds with stratification. A Mask R-CNN with a Swin Transformer was trained five times with cross-validation, and the held-out test split was used to evaluate the model performance. The precision, F1-score, sensitivity, specificity, and accuracy were calculated. The area under the receiver operating characteristics curve (AUC) and the confusion matrix of the most effective model were presented. RESULTS: The detection of OSCC with the employed model yielded an F1 of 0.852 and AUC of 0.974. The detection of OLP had an F1 of 0.825 and AUC of 0.948. For leukoplakia the F1 was 0.796 and the AUC was 0.938. CONCLUSIONS: OSCC were effectively detected with the employed model, whereas the detection of OLP and leukoplakia was moderately effective. CLINICAL RELEVANCE: Oral cancer is often detected in advanced stages. The demonstrated technology may support the detection and observation of OPMD to lower the disease burden and identify malignant oral cavity lesions earlier.

Prx1/PHB2 axis mediates mitophagy in oral leukoplakia cellular senescence.

BACKGROUND: Oral leukoplakia (OLK) is the most common oral potentially malignant disorder (OPMD), which can be malignantly transformed into oral squamous cell carcinoma (OSCC). Peroxiredoxin1(Prx1) has been predicted to bind to Prohibitin2 (PHB2), which confers to affect OLK progression; however, the mechanism of Prx1/PHB2 mediated mitophagy involved in OLK remains unclear. METHODS: This study aimed to explore the mechanism of the Prx1/PHB2 axis on senescence in OLK through mediating mitophagy. The positive rate of Ki67 and the expression of p21, p16, PHB2, and LC3 in human normal, OLK, and OSCC tissues were detected by immunohistochemical staining. The mitophagy and mitochondrial function changes were then analyzed in Prx1 knockdown and Prx1C52S mutations in dysplastic oral keratinocyte (DOK) cells treated with H2O2. In situ Proximity Ligation Assay combined with co-immunoprecipitation was used to detect the interaction between Prx1 and PHB2. RESULTS: Clinically, the positive rate of Ki67 progressively increased from normal to OLK, OLK with dysplasia, and OSCC. Higher p21, p16, PHB2, and LC3 expression levels were observed in OLK with dysplasia than in normal and OSCC tissues. In vitro, PHB2 and LC3II expression gradually increased with the degree of DOK cell senescence. Prx1/PHB2 regulated mitophagy and affected senescence in H2O2-induced DOK cells. Furthermore, Prx1C52S mutation specifically reduced interaction between Prx1 and PHB2. Prx1Cys52 is associated with mitochondrial reactive oxygen species (ROS) accumulated and cell cycle arrest. CONCLUSION: Prx1Cys52 functions as a redox sensor that binds to PHB2 and regulates mitophagy in the senescence of OLK, suggesting its potential as a clinical target.

Unraveling the Keratin Expression in Oral Leukoplakia: A Scoping Review.

Intermediate filaments are one of three polymeric structures that form the cytoskeleton of epithelial cells. In the epithelium, these filaments are made up of a variety of keratin proteins. Intermediate filaments complete a wide range of functions in keratinocytes, including maintaining cell structure, cell growth, cell proliferation, cell migration, and more. Given that these functions are intimately associated with the carcinogenic process, and that hyperkeratinization is a quintessential feature of oral leukoplakias, the utility of keratins in oral leukoplakia is yet to be fully explored. This scoping review aims to outline the current knowledge founded on original studies on human tissues regarding the expression and utility of keratins as diagnostic, prognostic, and predictive biomarkers in oral leukoplakias. After using a search strategy developed for several scientific databases, namely, PubMed, Scopus, Web of Science, and OVID, 42 papers met the inclusion and exclusion criteria. One more article was added when it was identified through manually searching the list of references. The included papers were published between 1989 and 2024. Keratins 1-20 were investigated in the 43 included studies, and their expression was assessed in oral leukoplakia and dysplasia cases. Only five studies investigated the prognostic role of keratins in relation to malignant transformation. No studies evaluated keratins as a diagnostic adjunct or predictive tool. Evidence supports the idea that dysplasia disrupts the terminal differentiation pathway of primary keratins. Gain of keratin 17 expression and loss of keratin 13 were significantly observed in differentiated epithelial dysplasia. Also, the keratin 19 extension into suprabasal cells has been associated with the evolving features of dysplasia. The loss of keratin1/keratin 10 has been significantly associated with high-grade dysplasia. The prognostic value of cytokeratins has shown conflicting results, and further studies are required to ascertain their role in predicting the malignant transformation of oral leukoplakia.

Clinical and mycological analysis of colonization by Candida spp. in oral leukoplakia and oral lichen planus.

OBJECTIVE: This study aims to analyze the prevalence of Candida spp. colonization in oral leukoplakia and oral lichen planus lesions, verify the influence of systemic and local factors, besides identify and determine the in vitro antifungal susceptibility profile of Candida species. MATERIALS AND METHODS: Samples were collected by swabbing from oral lesions and healthy mucosa and cultured on Sabouraud Dextrose and CHROMagar® Candida plates. Species identification was confirmed with MALDI-TOF MS analysis. RESULTS: Candida spp. was found in 36.8% of cases of oral leukoplakia and 18.2% of cases of oral lichen planus. Candida albicans was the only species found in oral lichen planus lesions (n = 2, 100%) and the most prevalent in oral leukoplakia (n = 5, 76.4%). Among the non-albicans Candida species found in oral leukoplakia were C. parapsilosis (n = 2, 25.5%) and C. tropicalis (n = 1, 14.1%). Candida isolates were susceptible to all antifungals tested. CONCLUSION: C. albicans was the most commonly found species in the studied lesions. No correlation was found between systemic and local factors with positive cases of oral lichen planus. However, smoking and alcohol consumption may be associated with positive cases of oral leukoplakia, especially the non-homogeneous clinical form. In addition, there is a possible predisposition to associated Candida colonization in cases of epithelial dysplasia found in oral leukoplakia. The antifungal medications tested showed excellent efficacy against isolates.

Detection of oral cancer and oral potentially malignant disorders using artificial intelligence-based image analysis.

BACKGROUND: We aimed to construct an artificial intelligence-based model for detecting oral cancer and dysplastic leukoplakia using oral cavity images captured with a single-lens reflex camera. SUBJECTS AND METHODS: We used 1043 images of lesions from 424 patients with oral squamous cell carcinoma (OSCC), leukoplakia, and other oral mucosal diseases. An object detection model was constructed using a Single Shot Multibox Detector to detect oral diseases and their locations using images. The model was trained using 523 images of oral cancer, and its performance was evaluated using images of oral cancer (n = 66), leukoplakia (n = 49), and other oral diseases (n = 405). RESULTS: For the detection of only OSCC versus OSCC and leukoplakia, the model demonstrated a sensitivity of 93.9% versus 83.7%, a negative predictive value of 98.8% versus 94.5%, and a specificity of 81.2% versus 81.2%. CONCLUSIONS: Our proposed model is a potential diagnostic tool for oral diseases.

Genome-wide characterization of the mutational landscape of proliferative verrucous leukoplakia.

OBJECTIVES: Proliferative verrucous leukoplakia (PVL) is a rare but highly aggressive variant of oral leukoplakia that almost inevitably progresses to oral squamous cell carcinoma (OSCC). The aims of this study were to perform whole exome sequencing of a cohort of patients diagnosed with PVL and identify potential mutational profiles and pathways in this disorder. STUDY DESIGN: A total of 12 oral cavity mucosal biopsies from 6 patients with oral lesions clinically compatible with PVL were used. Of these, 9 were diagnosed as dysplasia, 1 OSCC, and 2 hyperkeratosis/hyperplasia. Exome sequencing used the Ion AmpliSeq Exome platform. Ion Reporter software was used for variant calling, annotation, and filtering. Analysis and visualization of somatic mutations was carried out using the MAFtools R package. RESULTS: Following exome sequencing and mutational profiling, we analyzed the profiles for cancer associated genes and signatures. Genes previously associated with OSCC, including HYDIN, MUC16, MAML3, CDKN2A, FAT1, and CASP8, were mutated in multiple samples. Several DNA damage repair genes including PARP1 were mutated in PVL samples. NOTCH and Hippo pathways were the most frequently impacted by mutation. CONCLUSIONS: This genome wide characterization of premalignant PVL identifies both known and potentially novel oncogenic mechanisms in this disorder.

Clinical, histopathological characteristics and malignant transformation of proliferative verrucous leukoplakia with 36 patients: a retrospective longitudinal study.

BACKGROUND: Proliferative verrucous leukoplakia (PVL), distinguished by its malignant transformation rate of 43.87% to 65.8%, stands as the oral potentially malignant disorder with the highest propensity for malignancy. PVL is marked by distinctive heterogeneity regarding the clinical or histopathological characteristics as well as prognostic factors pertinent to this condition. The purpose of this study is to compile and assess the clinicopathological features, malignant transformation, and associated risk factors in patients diagnosed with PVL. METHODS: This study is a hospital-based retrospective longitudinal study of 36 patients diagnosed with PVL from 2013 to 2023. We conducted complete clinical and histopathological evaluations of the patients. RESULTS: The cohort comprised 16 males and 20 females, yielding a male-to-female ratio of 1:1.25. The follow-up period ranged from 8 to 125 months, with an average of 47.50 months. The most common clinical type of lesion was the verrucous form (58.33%), and the gingiva was the most common site (44.44%). Each patient had between 2 to 7 lesions, averaging 3.36 per patient. During the follow-up period, twelve patients (33.3%) developed oral cancer, with an average time to malignant transformation of 35.75 months. Kaplan-Meier survival analysis indicated that patients with complaints of pain, roughness, or a rough sensation, with diabetes, and the presence of cytologic atypia histologically showed a higher risk of malignant transformation (p < 0.05). In this study, the rate of malignant transformation in the treatment group (5/23) was lower than that in the untreated group (7/13), however, no statistically significant difference (p = 0.05). CONCLUSION: The main complaints of pain, roughness, or foreign body sensation, coupled with cytologic atypia histologically are indicative of an increased risk of malignant transformation in PVL. Further research is needed to elucidate the influence of these clinicopathological parameters on the malignant progression of PVL.

Cancer Precursor Syndromes and Their Detection in the Head and Neck.

This article explores the multifaceted landscape of oral cancer precursor syndromes. Hereditary disorders like dyskeratosis congenita and Fanconi anemia increase the risk of malignancy. Oral potentially malignant disorders, notably leukoplakia, are discussed as precursors influenced by genetic and immunologic facets. Molecular insights delve into genetic mutations, allelic imbalances, and immune modulation as key players in precancerous progression, suggesting potential therapeutic targets. The article navigates the controversial terrain of management strategies of leukoplakia, encompassing surgical resection, chemoprevention, and immune modulation, while emphasizing the ongoing challenges in developing effective, evidence-based preventive approaches.