Prognosis of oral pre-malignant lesions: significance of clinical, histopathological, and molecular biological characteristics

Investigation of adhesion status of Candida species to the surface of resin materials produced at different angles with additive manufacturing

BACKGROUND

The aim of this study was to evaluate the adhesion of Candida glabrata, Candida albicans, Candida krusei, Candida parapsilosis and Candida tropicalis yeasts to disk-shaped resin materials produced from resin which used in the production of surgical guide with 0, 45 and 90-degrees printing orientations by Liquid Crystal Display additive manufacturing technology.

METHODS

Disk-shaped specimens were printed with surgical guide resin using the Liquid Crystal Display production technique in 3 printing orientations (0, 45 and 90-degrees). Surface roughness and contact angle values were evaluated. Real-Time PCR analysis was performed to evaluate Candida adhesion (C. glabrata, C. albicans, C. krusei, C. parapsilosis and C. tropicalis) Field emission scanning electron microscope (FESEM) images of the materials were obtained.

RESULTS

Specimens oriented at 45-degrees demonstrated higher surface roughness (P < .05) and lower contact angle values than other groups. No significant difference was found in the adhesion of C. glabrata, C. albicans, and C. parapsilosis among specimens printed at 0, 45, and 90-degrees orientations (P > .05). A higher proportion of C. krusei and C. tropicalis was found in the specimens printed at orientation degrees of 45 = 90 < 0 with statistical significance. Analyzing the adhesion of all Candida species reveals no statistical disparity among the printing orientations.

CONCLUSIONS

The surface roughness, contact angle, and adhesion of certain Candida species are affected by printing orientations. Hence, careful consideration of the printing orientation is crucial for fabricating products with desirable properties. In 45-degree production, roughness increases due to the layered production forming steps, whereas in 0-degree production, certain Candida species exhibit high adhesion due to the formation of porous structures. Consequently, considering these factors, it is advisable to opt for production at 90-degrees, while also considering other anticipated characteristics.

Clinicopathological evaluation of oral leukoplakia: a single-center study of 676 cases in Japan

OBJECTIVES

To analyze the clinical and histopathological characteristics of oral leukoplakia (OL) in the Japanese population and investigate the prevalence and risk factors for epithelial dysplasia (ED) and carcinoma within lesions.

STUDY DESIGN

Data, including age, sex, lesion site, and histopathological features, of 676 cases diagnosed with OL over the previous 10 years were analyzed. Dysplasia and carcinoma prevalence were determined.

RESULTS

In male patients, the most affected site was the gingiva (42.7%), whereas in females, it was the tongue (47.6%). Moreover, ED was more prevalent in males (41.9%), whereas epithelial hyperplasia was more common in females (44.7%). A significant difference was observed between affected sites with regard to the presence of dysplasia. The ED rates by site were 64.6% and 33.7% for the tongue and gingiva, respectively (P < 0.05). The squamous cell carcinoma rates by site were 23.4%, 5.4%, and 3.4% for the tongue, buccal mucosa, and gingiva, respectively (P < 0.05). Logistic regression analysis revealed a higher prevalence of dysplasia in males than it did in females and that the risk for both dysplasia and carcinoma was highest in the tongue.

CONCLUSIONS

Dysplasia is common in OL cases, often showing carcinoma. Early biopsy and interventions are key in OL management.

OralImmunoAnalyser: a software tool for immunohistochemical assessment of oral leukoplakia using image segmentation and classification models

Oral cancer ranks sixteenth amongst types of cancer by number of deaths. Many oral cancers are developed from potentially malignant disorders such as oral leukoplakia, whose most frequent predictor is the presence of epithelial dysplasia. Immunohistochemical staining using cell proliferation biomarkers such as ki67 is a complementary technique to improve the diagnosis and prognosis of oral leukoplakia. The cell counting of these images was traditionally done manually, which is time-consuming and not very reproducible due to intra- and inter-observer variability. The software presently available is not suitable for this task. This article presents the OralImmunoAnalyser software (registered by the University of Santiago de Compostela-USC), which combines automatic image processing with a friendly graphical user interface that allows investigators to oversee and easily correct the automatically recognized cells before quantification. OralImmunoAnalyser is able to count the number of cells in three staining levels and each epithelial layer. Operating in the daily work of the Odontology Faculty, it registered a sensitivity of 64.4% and specificity of 93% for automatic cell detection, with an accuracy of 79.8% for cell classification. Although expert supervision is needed before quantification, OIA reduces the expert analysis time by 56.5% compared to manual counting, avoiding mistakes because the user can check the cells counted. Hence, the SUS questionnaire reported a mean score of 80.9, which means that the system was perceived from good to excellent. OralImmunoAnalyser is accurate, trustworthy, and easy to use in daily practice in biomedical labs. The software, for Windows and Linux, with the images used in this study, can be downloaded from https://citius.usc.es/transferencia/software/oralimmunoanalyser for research purposes upon acceptance.

Rates of Occult Invasive Disease in Patients With Biopsy-Proven Oral Cavity Squamous Cell Carcinoma in Situ

Importance

The likelihood that an oral cavity lesion harbors occult invasive disease after biopsy demonstrating carcinoma in situ (CIS) is unknown. While de-escalated treatment strategies may be appealing in the setting of CIS, knowing whether occult invasive disease may be present and its association with survival outcomes would lead to more informed management decisions.

Objective

To evaluate rate of occult invasive disease and clinical outcomes in patients with oral cavity CIS.

Design, Setting, and Participants

This was a retrospective population-based cohort study using the National Cancer Database and included adults with biopsy-proven oral cavity CIS as the first diagnosis of cancer between 2004 and 2020. Data were analyzed from October 10, 2022, to June 25, 2023.

Exposures

Surgical resection vs no surgery.

Main Outcomes and Measures

Analyses calculated the rate of occult invasive disease identified on resection of a biopsy-proven CIS lesion. Univariate and multivariate logistic regression with odds ratios and 95% CIs were used to identify significant demographic and clinical characteristics associated with risk of occult invasion (age, year of diagnosis, sex, race and ethnicity, oral cavity subsite, and comorbidity status). Kaplan-Meier curves for overall survival (OS) were calculated for both unresected and resected cohorts (stratified by presence of occult invasive disease).

Results

A total of 1856 patients with oral cavity CIS were identified, with 122 who did not undergo surgery (median [range] age, 65 [26-90] years; 48 female individuals [39.3%] and 74 male individuals [60.7%]) and 1458 who underwent surgical resection and had documented pathology (median [range] age, 62 [21-90] years; 490 female individuals [33.6%] and 968 male individuals [66.4%]). Of the 1580 patients overall, 52 (3.3%) were Black; 39 (2.5%), Hispanic; 1365 (86.4%), White; and 124 (7.8%), other, not specified. Among those who proceeded with surgery with documented pathology, 408 patients (28.0%) were found to have occult invasive disease. Higher-risk features were present in 45 patients (11.0%) for final margin positivity, 16 patients (3.9%) for lymphovascular invasion, 13 patients (3.2%) for high-grade invasive disease, and 14 patients (3.4%) for nodal involvement. For those patients with occult disease, staging according to the American Joint Committee on Cancer's AJCC Cancer Staging Manual, eighth edition, was pT1 in 341 patients (83.6%), pT2 in 41 (10.0%), and pT3 or pT4 disease in 26 (6.4%). Factors associated with greater odds of occult invasive disease at resection were female sex, Black race, and alveolar ridge, vestibule, and retromolar subsite. With median 66-month follow-up, 5-year OS was 85.9% in patients who proceeded with surgical resection vs 59.7% in patients who did not undergo surgery (difference, 26.2%; 95% CI, 19.0%-33.4%).

Conclusions and Relevance

This cohort study assessed the risk of concurrent occult invasion with biopsy-proven CIS of the oral cavity, demonstrating that 28.0% had invasive disease at resection. Reassuringly, even in the setting of occult invasion, high-risk disease features were rare, and 5-year OS was nearly 80% with resection. The findings support the practice of definitive resection if feasible following biopsy demonstrating oral cavity CIS.

Early Detection of Oral Potentially Malignant Disorders: A Review on Prospective Screening Methods with Regard to Global Challenges

Oral cancer is a cancer type that is widely prevalent in low-and middle-income countries with a high mortality rate, and poor quality of life for patients after treatment. Early treatment of cancer increases patient survival, improves quality of life and results in less morbidity and a better prognosis. To reach this goal, early detection of malignancies using technologies that can be used in remote and low resource areas is desirable. Such technologies should be affordable, accurate, and easy to use and interpret. This review surveys different technologies that have the potentials of implementation in primary health and general dental practice, considering global perspectives and with a focus on the population in India, where oral cancer is highly prevalent. The technologies reviewed include both sample-based methods, such as saliva and blood analysis and brush biopsy, and more direct screening of the oral cavity including fluorescence, Raman techniques, and optical coherence tomography. Digitalisation, followed by automated artificial intelligence based analysis, are key elements in facilitating wide access to these technologies, to non-specialist personnel and in rural areas, increasing quality and objectivity of the analysis while simultaneously reducing the labour and need for highly trained specialists.

Development and validation of a multivariable model for prediction of malignant transformation and recurrence of oral epithelial dysplasia

BACKGROUND

Oral epithelial dysplasia (OED) is the precursor to oral squamous cell carcinoma which is amongst the top ten cancers worldwide. Prognostic significance of conventional histological features in OED is not well established. Many additional histological abnormalities are seen in OED, but are insufficiently investigated, and have not been correlated to clinical outcomes.

METHODS

A digital quantitative analysis of epithelial cellularity, nuclear geometry, cytoplasm staining intensity and epithelial architecture/thickness is conducted on 75 OED whole-slide images (252 regions of interest) with feature-specific comparisons between grades and against non-dysplastic/control cases. Multivariable models were developed to evaluate prediction of OED recurrence and malignant transformation. The best performing models were externally validated on unseen cases pooled from four different centres (n = 121), of which 32% progressed to cancer, with an average transformation time of 45 months.

RESULTS

Grade-based differences were seen for cytoplasmic eosin, nuclear eccentricity, and circularity in basal epithelial cells of OED (p < 0.05). Nucleus circularity was associated with OED recurrence (p = 0.018) and epithelial perimeter associated with malignant transformation (p = 0.03). The developed model demonstrated superior predictive potential for malignant transformation (AUROC 0.77) and OED recurrence (AUROC 0.74) as compared with conventional WHO grading (AUROC 0.68 and 0.71, respectively). External validation supported the prognostic strength of this model.

CONCLUSIONS

This study supports a novel prognostic model which outperforms existing grading systems. Further studies are warranted to evaluate its significance for OED prognostication.

The Potential of Nano-Based Photodynamic Treatment as a Therapy against Oral Leukoplakia: A Narrative Review

Oral leukoplakia is a predominantly white lesion of the oral mucosa that cannot be classified as any other definable lesion with the risk of progressing into malignancy. Despite the advancements in conventional therapy, the rates of malignant transformation remain notably high, affecting 4.11% of adults, due to the difficulty of accurate diagnosis and indistinct treatment. Photodynamic therapy (PDT), being a minimally invasive surgical intervention, employs a variety of factors, including light, nano-photosensitizers (PSs) and oxygen in the management of precancerous lesions. PDT faces limitations in administering photosensitizers (PSs) because of their low water solubility. However, these challenges could be effectively resolved through the incorporation of PSs in nanostructured drug delivery systems, such as gold nanoparticles, micelles, liposomes, metal nanoparticles, dendrimers and quantum dots. This review will give an overview of the different innovative PS approaches in the management of premalignant lesions, highlighting the most recent advancements. From a clinical perspective, it is expected that nanotechnology will overcome barriers faced by traditional therapeutics and will address critical gaps in clinical cancer care.

Elevated translationally controlled tumour protein promotes oral cancer progression and poor outcome

BACKGROUND

Translationally controlled tumour protein (TCTP) is a multifunctional protein elevated in multiple cancers. However, studies on its role in oral carcinogenesis and prognosis are rare. We recently reported the role of its interacting partner, MCL1, in oral cancer progression and outcome. Hence, the present study aimed to assess TCTP expression in oral tumorigenesis and its association with patient outcomes alone and in combination with MCL1.

METHODS

TCTP expression was assessed by immunohistochemistry and immunoblotting in oral tissues and cells, respectively. Cell viability post siRNA/dihydroartemisinin treatment was analysed by tetrazolium salt assay. Cell survival, invasion and tumorigenic potential post TCTP knockdown were assessed by clonogenic, Matrigel and soft-agar assays, respectively. The association of TCTP with patient outcome was analysed by Kaplan-Meier and Cox regression.

RESULTS

TCTP was significantly overexpressed in oral premalignant lesions (p < 0.0001), oral tumours (p < 0.0001) and oral dysplastic and cancer cells versus normal oral mucosa and also in recurrent (p < 0.05) versus non-recurrent oral tumours. Further, elevated TCTP was significantly (p < 0.05) associated with poor recurrence free survival (RFS) and poor overall survival (OS; hazard ratio = 2.29; p < 0.05). Intriguingly, the high co-expression of TCTP and MCL1 further reduced the RFS (p < 0.05) and OS (p < 0.05; hazard-ratio = 3.49; p < 0.05). Additionally, TCTP knockdown decreased survival (p < 0.05), invasion (p < 0.01) and in vitro tumorigenic potential (p < 0.0001). Dihydroartemisinin treatment reduced TCTP levels and viability of oral cancer cells.

CONCLUSION

Our studies demonstrate an oncogenic role of TCTP in oral cancer progression and poor outcome. Thus, TCTP may be a potential prognostic marker and therapeutic target in oral cancers.

Recurrence in Oral Squamous Cell Carcinoma Associated with Wide Field of Cancerization: Analysis of 93 Cases

Background

The late presentation of oral squamous cell carcinoma (OSCC) patients in the Sudan, with advanced stages and wide field of cancerization, have a negative impact on both the morbidity and the mortality of these patients. The present study aimed to investigate the clinicopathological behavior of OSCC and predictors of development of recurrence in these patients.

Methods

This a prospective longitudinal study of 93 OSCC patients surgically treated at Khartoum Teaching Dental Hospital. Tumor's associated field of cancerization was identified. The patients were followed clinically on regular basis, for a year, for the development of recurrence.

Results

Out of the 93 patients, 57 (61.3%) were males and 36 (38.7%) were females. 82% of the patients presented with stage IV tumors, and 58 (62.4%) of the cases had nodal metastasis. Twenty-eight (30%) patients developed recurrence. Of them 17 (18.3%) had regional recurrence, eight (8.6%) had local recurrence and three (3.2%) had locoregional recurrence. Multivariate cox regression analysis showed that Toombak dipping (P.value = 0.001), tumor staging (P.value = 0.039) and presence of mucosal filed changes (P.value = 0.001) were independent predictors for local recurrence and positive pathological lymph nodes (P.value = 0.00) and extranodal extension (P.value = 0.040) were independent predictors for regional recurrence.

Conclusion

The present study showed that OSCC patients in the Sudan present with advanced lesions, mostly associated with wide field of cancerization particularly Toombak dippers. Overall recurrences were identified in 30% of the cases, regional recurrence was the commonest type followed by local recurrence.

Early Diagnosis of Oral Cancer: A Complex Polyhedral Problem with a Difficult Solution

Oral and oropharyngeal cancers are a growing problem, accounting for 377,713 and 98,412 new cases per year all over the world and 177,757 and 48,143 deaths annually, respectively. Despite the substantial improvement in diagnostic procedures and treatment techniques in recent years, the mortality rate has not decreased substantially in the last 40 years, which is still close to 50% of cases. The major cause responsible for this high mortality is associated with the high percentage of oral cancers diagnosed in advanced stages (stages III and IV) where the treatment harbors poor efficacy, resulting in challenges, mutilations, or disability. The main reason for cancer to be diagnosed at an advanced stage is a diagnostic delay, so it is critical to reduce this delay in order to improve the prognosis of patients suffering from oral cancer. The causes of oral cancer diagnostic delay are complex and concern patients, healthcare professionals, and healthcare services. In this manuscript, oral cancer diagnostic delay is critically reviewed based on current evidence, as well as their major causes, main problems, and potential improvement strategies.

Ki-67 Expression as a Prognostic Marker: A Comparative Immunohistochemical Analysis of Oral Epithelial Dysplasia and Oral Squamous Cell Carcinoma

Introduction Oral dysplasia is a frequent precancerous condition that may lead to oral cancer. The histopathologic abnormalities exhibited in a chronic, progressive, and premalignant condition of the oral mucosa are referred to as oral epithelial dysplasia (OED). It might show up as erythroplakia, leukoplakia, or leukoerythroplakia. OED is a premalignancy histologic marker that predicts a higher likelihood of squamous cell carcinoma development. Aims and objectives The aim of this study is to identify an association between Ki-67 protein expression and histological grading of OED and oral squamous cell carcinoma (OSCC) and to compare the expression of Ki-67 in different grades of OED and OSCC with the prognosis. Materials and methods The current retrospective research is focused on evaluating epithelial dysplasia and analyzing the function of Ki-67 as a prognostic marker after receiving institutional ethical approval. Group I - normal oral mucosa (NOM), Group II - OED, and Group III - OSCC were included in the study. For statistical analysis, SPSS Statistics version 21.0 (IBM Corp. Released 2021. IBM SPSS Statistics for Windows, Version 28.0. Armonk, NY: IBM Corp) was utilized. The Cox regression model was employed to look at interactions between various prognostic variables. At p<0.05, differences were deemed statistically significant. Results Ki-67 expression was confined to the basal layers in the normal oral epithelium and in the basal, suprabasal, and spinous layers in OED. Ki-67 positive cells were mostly found on the perimeter of well, moderate, and poorly differentiated OSCC tumor nests with Ki-67 positive cells scattered throughout OSCC. According to statistical analysis, there is a substantial difference in expression between OED and NOM, OSCC and NOM, and OED and OSCC. Conclusion Our study showed that there is a progressive increase in Ki-67 expression across various grades of OED, and the highest expression was noted in OSCC. Early identification and prompt treatment will help in improving the quality of life of such patients.

Developmental synergism in the management of oral potentially malignant disorders

Oral potentially malignant disorders (OPMDs) are associated with an increased risk of occurrence of cancers of the oral cavity or lips. The unifying theme of OPMDs is their potential risk for cancer development. Therefore, the primary objective of the management should be to prevent carcinogenesis. Beyond diagnosis, current strategies for the management of OPMDs predominantly include non-surgical and surgical interventions and a "watch-and-see" approach, such as disease monitoring or surveillance, and preventive strategies. Though no optimal clinical treatment has gained universal approval for reducing or preventing malignant development of OPMDs. Therefore, an urgent need exits for improved treatment properties and effective predictive markers for OPMDs treatment. This review aims to outline recent synergism regarding to the management of OPMDs. Developing new technologies and improved application parameters to promote the treatment efficacy and a novel management prescription approach to OPMDs are proposed.

Pepsin enhances glycolysis to promote malignant transformation of vocal fold leukoplakia epithelial cells with dysplasia

PURPOSE

The mechanism underlying malignant transformation of vocal fold leukoplakia (VFL) and the precise role of the expression of pepsin in VFL remain unclear. This study aimed to investigate the effects of acidified pepsin on VFL epithelial cell growth and migration, and also identify pertinent molecular mechanisms.

METHODS

Immunochemistry and Western blotting were performed to measure glucose transporter type 1 (GLUT1), monocarboxylate transporters 4 (MCT4), and Hexokinase-II (HK-II) expressions. Cell viability, cell cycle, apoptosis, and migration were investigated by CCK-8 assay, flow cytometry and Transwell chamber assay, respectively. Glycolysis-related contents were determined using the corresponding kits. Mitochondrial HK-II was photographed under a confocal microscope using Mito-Tracker Red.

RESULTS

It was found: the expression of pepsin and proportion of pepsin+ cells in VFL increased with the increased dysplasia grade; acidified pepsin enhanced cell growth and migration capabilities of VFL epithelial cells, reduced mitochondrial respiratory chain complex I activity and oxidative phosphorylation, and enhanced aerobic glycolysis and GLUT1 expression in VFL epithelial cells; along with the transfection of GLUT1 overexpression plasmid, 18FFDG uptake, lactate secretion and growth and migration capabilities of VFL epithelial cell were increased; this effect was partially blocked by the glycolysis inhibitor 2-deoxy-glucose; acidified pepsin increased the expression of HK-II and enhanced its distribution in mitochondria of VFL epithelial cells.

CONCLUSION

It was concluded that acidified pepsin enhances VFL epithelial cell growth and migration abilities by reducing mitochondrial respiratory complex I activity and promoting metabolic reprogramming from oxidative phosphorylation to aerobic glycolysis.

Deep learning-based pathology image analysis predicts cancer progression risk in patients with oral leukoplakia

BACKGROUND

Oral leukoplakia (OL) is associated with an increased risk for oral cancer (OC) development. Prediction of OL cancer progression may contribute to decreased OC morbidity and mortality by favoring early intervention. Current OL progression risk assessment approaches face large interobserver variability and is weakly prognostic. We hypothesized that convolutional neural networks (CNN)-based histology image analyses could accelerate the discovery of better OC progression risk models.

METHODS

Our CNN-based oral mucosa risk stratification model (OMRS) was trained to classify a set of nondysplastic oral mucosa (OM) and a set of OC H&E slides. As a result, the OMRS model could identify abnormal morphological features of the oral epithelium. By applying this model to OL slides, we hypothesized that the extent of OC-like features identified in the OL epithelium would correlate with its progression risk. The OMRS model scored and categorized the OL cohort (n = 62) into high- and low-risk groups.

RESULTS

OL patients classified as high-risk (n = 31) were 3.98 (95% CI 1.36-11.7) times more likely to develop OC than low-risk ones (n = 31). Time-to-progression significantly differed between high- and low-risk groups (p = 0.003). The 5-year OC development probability was 21.3% for low-risk and 52.5% for high-risk patients. The predictive power of the OMRS model was sustained even after adjustment for age, OL site, and OL dysplasia grading (HR = 4.52, 1.5-13.7).

CONCLUSION

The ORMS model successfully identified OL patients with a high risk of OC development and can potentially benefit OC early diagnosis and prevention policies.

Associations between clinical and histopathological characteristics in oral leukoplakia

OBJECTIVES

To identify possible associations between patients' demographics and habits and the clinical aspects and histopathological characteristics of oral leukoplakia (OL) at patients' first visit.

METHOD

A total of 140 consecutive patients with OL at a single institute between 1997 and 2019. All biopsies were microscopically examined for classic dysplasia (CD) (WHO definition oral epithelial dysplasia) and differentiated dysplasia (DD) known from differentiated vulvar intraepithelial neoplasia. Clinical characteristics were correlated to histopathological diagnosis and odds ratios (OR) were calculated.

RESULTS

A total of 96 females and 44 males, mean age 58 years, were presented. OLs were found mainly on the tongue (41%) and floor of mouth (FOM) (18%). Homogeneous OLs (58%) were associated with smoking, FOM and size <2cm and non-homogeneous OLs (42%) with non-smokers. No dysplasia was present in 40% and any dysplasia (AD) in 60%. Tongue OLs were correlated with AD (OR:6.0) and CD (OR:5.7). FOM OLs were correlated with CD (OR:4.5). DD was correlated with non-homogeneous OLs (OR:2.6).

CONCLUSIONS

CD was most frequently observed in tongue and FOM OLs, while DD was associated with non-homogeneous OLs. In this series of patients, there was no consistent reliable association between the clinical and histopathological features and clinical characteristics can therefore not substitute microscopic examination of biopsies.

Evaluation of EGFR in prognostic characterization in histopathological variants of oral squamous cell carcinoma

AIM OF THE STUDY

Epidermal growth factor receptor (EGFR) is a tyrosine kinase receptor of the Erb B family contributing to proliferation, invasion, and metastasis. EGFR overexpression is frequently associated with poor clinical outcome in malignant neoplasms.• To evaluate and compare immunoexpression of EGFR in histopathological variants of oral squamous cell carcinoma (OSCC).• To hypothesize the role of EGFR in determining biological behavior and prognostic course of histopathological variants of OSCC.

MATERIALS AND METHODS

The study comprised a total of 40 cases including 10 cases each of Squamous cell carcinoma, Verrucous carcinoma, Adenosquamous cell carcinoma, and Adenoid squamous cell carcinoma. EGFR immunoexpression was observed qualitatively as low (1), moderate (2) and strong (3) and quantitatively as score 1 for <10%, 2 for 10%-50%, and 3 for >50% positive cells. The resulting data were analyzed using SPSS software version 19. Data have been expressed as mean and standard deviation. Differences between the different variables were analyzed using ANOVA, and Pearson's Chi-square. (p ≤ 0.05).

RESULT

The study results revealed that the EFGR immunoexpression was highest in adenosquamous cell carcinoma followed by adenoid squamous cell carcinoma then conventional squamous cell carcinoma followed by lowest immunoexpression in verrucous carcinoma. The results were statistically significant. (p ≤ 0.05).

CONCLUSION

Expression of EGFR could be established as a valuable biomarker with significant association in predicting aggressive potential and treatment response in various histopathological variants of OSCC. Further studies where EGFR could be linked to predictive indicators and tumor prognosis could be undertaken.

Histopathological findings of oral epithelial dysplasias and their relation to malignant transformation

OBJECTIVES

Oral squamous cell carcinomas (OSCCs) are often diagnosed late. This study aimed to determine how frequently oral epithelial dysplasia (OED) transforms to OSCC and to identify histological features that could influence the rate of malignant transformation.

MATERIALS AND METHODS

The study was a retrospective analysis of OED over 29 years at the Institute of Dentistry, University of Turku, Finland. OEDs with co-existing carcinomas were excluded from the data (5.8%). OED patients who developed carcinoma were identified from the Finnish Cancer Registry database.

RESULTS

Altogether 681 OED patients had a mean age of 59.0 years, and the male:female ratio was 0.67. Of all OED samples, 21.8% were on the tongue, followed by lining mucosa (21.3%), lip (5.3%), and masticatory mucosa (4.85%). In addition, 46.7% had no location cited. The prevalence of mild dysplasia was 62.4%, moderate dysplasia 29.1%, and severe dysplasia 3.2%. Of the patients, 94.7% had an additional histological diagnosis alongside OED. Candidiasis, lichenoid inflammation, and ulcer were found in 18.2%, 0.0%, and 22.7% of severe dysplasias, in 12.1%, 12.2%, and 22.7% of moderate dysplasias, and in 6.6%, 12.2%, and 15.8% of mild dysplasias, respectively. An additional histopathological diagnosis did not increase the risk for OED to transform to OSCC. In a mean time of 5.2 (range 0.7-29.0) years, 7.5% of OED patients developed OSCC.

CONCLUSIONS

Location on the tongue and the more severe OED grades increased the risk of malignant transformation of OED. These patients may benefit from an intensified follow-up schedule to ensure early diagnosis of OSCC.

Clinical predictors of malignant transformation and recurrence in oral potentially malignant disorders: A systematic review and meta-analysis

OBJECTIVE

We performed a systematic review dedicated to pooling evidence for the associations of clinical features with malignant transformation (MT) and recurrence of 3 oral potentially malignant disorders (OPMDs) (actinic cheilitis [AC], oral leukoplakia [OL], and proliferative verrucous leukoplakia [PVL]).

STUDY DESIGN

We selected studies that included clinical features and risk factors (age, sex, site, size, appearance, alcohol intake, tobacco use, and sun exposure) of OL, PVL, and AC associated with recurrence and/or MT.

RESULTS

Based on the meta-analysis results, non-homogeneous OL appears to have a 4.53 times higher chance of recurrence after treatment. We also found 6.52 higher chances of MT of non-homogeneous OL. Another clinical feature related to higher MT chances is the location (floor of the mouth and tongue has 4.48 higher chances) and the size (OL with >200 mm2 in size has 4.10 higher chances of MT). Regarding habits, nonsmoking patients with OL have a 3.20 higher chance of MT. The only clinical feature related to higher chances of MT in patients with PVL was sex (females have a 2.50 higher chance of MT).

CONCLUSIONS

Our study showed that some clinical features may indicate greater chances of recurrence after treatment and MT of OPMD.

Automated detection of premalignant oral lesions on whole slide images using convolutional neural networks

INTRODUCTION

Oral epithelial dysplasia (OED) is a precursor lesion to oral squamous cell carcinoma, a disease with a reported overall survival rate of 56 percent across all stages. Accurate detection of OED is critical as progression to oral cancer can be impeded with complete excision of premalignant lesions. However, previous research has demonstrated that the task of grading of OED, even when performed by highly trained experts, is subject to high rates of reader variability and misdiagnosis. Thus, our study aims to develop a convolutional neural network (CNN) model that can identify regions suspicious for OED whole-slide pathology images.

METHODS

During model development, we optimized key training hyperparameters including loss function on 112 pathologist annotated cases between the training and validation sets. Then, we compared OED segmentation and classification metrics between two well-established CNN architectures for medical imaging, DeepLabv3+ and UNet++. To further assess generalizability, we assessed case-level performance of a held-out test set of 44 whole-slide images.

RESULTS

DeepLabv3+ outperformed UNet++ in overall accuracy, precision, and segmentation metrics in a 4-fold cross validation study. When applied to the held-out test set, our best performing DeepLabv3+ model achieved an overall accuracy and F1-Score of 93.3 percent and 90.9 percent, respectively.

CONCLUSION

The present study trained and implemented a CNN-based deep learning model for identification and segmentation of oral epithelial dysplasia (OED) with reasonable success. Computer assisted detection was shown to be feasible in detecting premalignant/precancerous oral lesions, laying groundwork for eventual clinical implementation.

Predicting Progression of Oral Lesions to Malignancy Using Machine Learning

OBJECTIVE

To use large-scale electronic health record (EHR) data to develop machine learning models predicting malignant transformation of oral lesions.

METHODS

A multi-institutional health system database was used to identify a retrospective cohort of patients with biopsied oral lesions. The primary outcome was malignant transformation. Chart review and automated system database queries were used to identify a range of demographic, clinical, and pathologic variables. Machine learning was used to develop predictive models for progression to malignancy.

RESULTS

There were 2192 patients with a biopsied oral lesion, of whom 1232 had biopsy proven oral dysplasia. There was malignant transformation in 34% of patients in the oral lesions dataset, and in 54% of patients in the dysplasia subset. Multiple machine learning-based models were trained on the data in two experiments, (a) including all patients with biopsied oral lesions and (b) including only patients with biopsy-proven dysplasia. In the first experiment, the best machine learning models predicted malignant transformation among the biopsied oral lesions with an area under the curve (AUC) of 86%. In the second experiment, the random forest model predicted malignant transformation among lesions with dysplasia with an AUC of 0.75. The most influential features were dysplasia grade and the presence of multiple lesions, with smaller influences from other features including anemia, histopathologic description of atypia, and other prior cancer history.

CONCLUSION

With diverse features from EHR data, machine learning approaches are feasible and allow for generation of models that predict which oral lesions are likely to progress to malignancy.

LEVEL OF EVIDENCE

3 Laryngoscope, 2022.

Non-invasive imaging of oral potentially malignant and malignant lesions: A systematic review and meta-analysis

Non-invasive (NI) imaging techniques have been developed to overcome the limitations of invasive biopsy procedures, which is the gold standard in diagnosis of oral dysplasia and Oral Squamous Cell Carcinoma (OSCC). This systematic review and meta- analysis was carried out with an aim to investigate the efficacy of the NI-imaging techniques in the detection of dysplastic oral potentially malignant disorders (OPMDs) and OSCC. Records concerned in the detection of OPMDs, Oral Cancer were identified through search in PubMed, Science direct, Cochrane Library electronic database (January 2000 to October 2020) and additional manual searches. Out of 529 articles evaluated for eligibility, 56 satisfied the pre-determined inclusion criteria, including 13 varying NI-imaging techniques. Meta-analysis consisted 44 articles, wherein majority of the studies reported Autofluorescence (AFI-38.6%) followed by Chemiluminescence (CHEM), Narrow Band Imaging (NBI) (CHEM, NBI-15.9%), Fluorescence Spectroscopy (FS), Diffuse Reflectance Spectroscopy (DRS), (FS, DRS-13.6%) and 5aminolevulinic acid induced protoporphyrin IX fluorescence (5ALA induced PPIX- 6.8%). Higher sensitivities (Sen) and specificities (Spe) were obtained using FS (Sen:74%, Spe:96%, SAUC=0.98), DRS (Sen:79%, Spe:86%, SAUC = 0.91) and 5 ALA induced PPIX (Sen:91%, Spe:78%, SAUC = 0.98) in the detection of dysplastic OPMDs from non-dysplastic lesions(NDLs). AFI, FS, DRS, NBI showed higher sensitivities and SAUC (>90%) in differentiating OSCC from NDLs. Analysed NI-imaging techniques suggests the higher accuracy levels in the diagnosis of OSCC when compared to dysplastic OPMDs. 5 ALA induced PPIX, DRS and FS showed evidence of superior accuracy levels in differentiation of dysplastic OPMDs from NDLs, however results need to be validated in a larger number of studies.

Epigenetic Deregulation of Protein Tyrosine Kinase 6 Promotes Carcinogenesis of Oral Squamous Cell Carcinoma

Oral squamous cell carcinoma (OSCC) accounts for over 90% of oral cancers and causes considerable morbidity and mortality. Epigenetic deregulation is a common mechanism underlying carcinogenesis. DNA methylation deregulation is the epigenetic change observed during the transformation of normal cells to precancerous and eventually cancer cells. This study investigated the DNA methylation patterns of PTK6 during the development of OSCC. Bisulfite genomic DNA sequencing was performed to determine the PTK6 methylation level. OSCC animal models were established to examine changes in PTK6 expression in the different stages of OSCC development. The DNA methylation of PTK6 was decreased during the development of OSCC. The mRNA and protein expression of PTK6 was increased in OSCC cell lines compared with human normal oral keratinocytes. In mice, the methylation level of PTK6 decreased after treatment with 4-nitroquinoline 1-oxide and arecoline, and the mRNA and protein expression of PTK6 was increased. PTK6 hypomethylation can be a diagnostic marker of OSCC. Upregulation of PTK6 promoted the proliferation, migration, and invasion of OSCC cells. PTK6 promoted carcinogenesis and metastasis by increasing STAT3 phosphorylation and ZEB1 expression. The epigenetic deregulation of PTK6 can serve as a biomarker for the early detection of OSCC and as a treatment target.

Utility of Keratins as Biomarkers for Human Oral Precancer and Cancer

Human oral cancer is the single largest group of malignancies in the Indian subcontinent and the sixth largest group of malignancies worldwide. Squamous cell carcinomas (SCC) are the most common epithelial malignancy of the oral cavity, constituting over 90% of oral cancers. About 90% of OSCCs arise from pre-existing, potentially malignant lesions. According to WHO, OSCC has a 5-year survival rate of 45–60%. Late diagnosis, recurrence, and regional or lymph nodal metastases could be the main causes of the high mortality rates. Biomarkers may help categorize and predict premalignant lesions as high risk of developing malignancy, local recurrence, and lymph nodal metastasis. However, at present, there is a dearth of such markers, and this is an area of ongoing research. Keratins (K) or cytokeratins are a group of intermediate filament proteins that show paired and differentiation dependent expression. Our laboratory and others have shown consistent alterations in the expression patterns of keratins in both oral precancerous lesions and tumors. The correlation of these changes with clinicopathological parameters has also been demonstrated. Furthermore, the functional significance of aberrant keratins 8/18 expression in the malignant transformation and progression of oral tumors has also been documented. This article reviews the literature that emphasizes the value of keratins as biomarkers for the prognostication of human oral precancers and cancers.

Proliferation and Apoptosis Pathways and Factors in Oral Squamous Cell Carcinoma

Oral cancer is the most common form of head and neck squamous cell carcinoma (HNSCC) and most frequently presents as oral squamous cell carcinoma (OSCC), which is associated with an alarmingly high mortality rate. Internationally, a plethora of research to further our understanding of the molecular pathways related to oral cancer is performed. This research is of value for early diagnosis, prognosis, and the investigation of new drugs that can ameliorate the harmful effects of oral cancer and provide optimal patient outcomes with minimal long-term complications. Two pathways on which the progression of OSCC depends on are those of proliferation and apoptosis, which overlap at many junctions. Herein, we aim to review these pathways and factors related to OSCC progression. Publicly available search engines, PubMed and Google Scholar, were used with the following keywords to identify relevant literature: oral cancer, proliferation, proliferation factors, genes, mutations, and tumor suppressor. We anticipate that the use of information provided through this review will further progress translational cancer research work in the field of oral cancer.

Photodynamic therapy for oral potentially malignant disorders: A Systematic Review and Meta-analysis

OBJECTIVES

To evaluate the effectiveness of Photodynamic Therapy (PDT) in the treatment of Oral Potentially Malignant Disorders (OPMDs) patients.

METHODOLOGY

An electronic search was conducted to retrieve articles published until September 2021. Meta-analyses were conducted for the outcomes of complete response (CR) and any response (AR) after treatment with PDT using data from single-arm studies, case series and non-randomised controlled trials (NRCTs).

RESULTS

In total, 49 articles were included. RCTs revealed insignificant mean difference (MD) in efficacy index between PDT and comparison groups (MD: 1.32; 95% CI:-28.10-30.72, p=0.930). The likelihood of CR (OR:0.84; 95% CI: 0.42-1.71, p=0.637) or AR (OR:2.10; 95% CI: 0.31-14.25, p=0.448) was not different in PDT group when compared with any comparison treatments in NRCTs. CR/AR among single arm studies was 60.6% (95% CI: 50.5-70.7, P<0.001) and 93.7% (95% CI:91.5-95.8, P<0.001) respectively. Higher prevalence of CR and AR was observed for dysplasia or carcinoma insitu (CIS) (CR: 81%, 95% CI: 70.8-91.3, P<0.001; AR: 94.3%; 95% CI: 89-99.6, P<0.001) and actinic cheilitis (AC) (CR: 73.9%, 95% CI: 65.9-81.9, P<0.001; AR:97%; 95% CI:94.9-99, P<0.001).

CONCLUSIONS

More than half of the patients receiving PDT showed CR, with more than 90% responding to the treatment. PDT was most effective on oral dysplasias, followed by AC.

Tiwari R, Javed M, Tiwari H. Evaluation of efficiency of dyes in detection of cancer cells: An original research

Introduction:

The early detection of the cancer will dramatically improve the prognosis. There are many diagnostic aids that can be employed for screening. Hence, in our study, we aim to evaluate the efficiency of dyes in detection of cancer cells.

Materials and Methods:

We piloted a prospective clinical study among 30 subjects to detect the efficiency of two dyes—Lugol's iodine and toluidine blue. They were grouped equally for potentially malignant and malignant lesions. The areas were analyzed for the diagnostic accuracy of the dyes using the histopathological examination and compared using chi square test deliberating P < 0.05 as significant.

Results:

We observed that both the dyes showed a diagnostic accuracy of over 90% when used alone or in combination. Both the dyes had greater sensitivity while specificity was 20%.

Conclusion:

The combination of these two dyes can be used as an efficient screening aid for the identification of the cancer cells.

Immunoexpression of PD-L1, CD4+ and CD8+ cell infiltrates and tumor-infiltrating lymphocytes (TILs) in the microenvironment of actinic cheilitis and lower lip squamous cell carcinoma

Lower lip squamous cell carcinomas (LLSCC) could be associated with a previous history of potentially malignant oral diseases (PMOD), especially actinic cheilitis (AC), with high sun exposure being a well-described risk factor. Immune evasion mechanisms, such as the PD-1/PD-L1 (programmed cell death protein 1/programmed death-ligand 1) pathway has been gaining prominence since immunotherapy with immune checkpoint inhibitors showed a positive effect on the survival of patients with different types of neoplasms. Concomitant with the characterization of the tumor microenvironment, the expression of either or both PD-1 and PD-L1 molecules may estimate mutual relations of progression or regression of the carcinoma and prognostic values of the patient.

Clinical assessment for the detection of oral cavity cancer and potentially malignant disorders in apparently healthy adults

BACKGROUND

The early detection of oral cavity squamous cell carcinoma (OSCC) and oral potentially malignant disorders (OPMD), followed by appropriate treatment, may improve survival and reduce the risk for malignant transformation respectively. This is an update of a Cochrane Review first published in 2013.

OBJECTIVES

To estimate the diagnostic test accuracy of conventional oral examination, vital rinsing, light-based detection, mouth self-examination, remote screening, and biomarkers, used singly or in combination, for the early detection of OPMD or OSCC in apparently healthy adults.

SEARCH METHODS

Cochrane Oral Health's Information Specialist searched the following databases: Cochrane Oral Health's Trials Register (to 20 October 2020), MEDLINE Ovid (1946 to 20 October 2020), and Embase Ovid (1980 to 20 October 2020). The US National Institutes of Health Trials Registry (ClinicalTrials.gov) and the World Health Organization International Clinical Trials Registry Platform were searched for ongoing trials. No restrictions were placed on the language or date of publication when searching the electronic databases. We conducted citation searches, and screened reference lists of included studies for additional references.

SELECTION CRITERIA

We selected studies that reported the test accuracy of any of the aforementioned tests in detecting OPMD or OSCC during a screening procedure. Diagnosis of OPMD or OSCC was provided by specialist clinicians or pathologists, or alternatively through follow-up.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened titles and abstracts for relevance. Eligibility, data extraction, and quality assessment were carried out by at least two authors independently and in duplicate. Studies were assessed for methodological quality using the Quality Assessment of Diagnostic Accuracy Studies 2 (QUADAS-2). We reported the sensitivity and specificity of the included studies. We provided judgement of the certainty of the evidence using a GRADE assessment.

MAIN RESULTS

We included 18 studies, recruiting 72,202 participants, published between 1986 and 2019. These studies evaluated the diagnostic test accuracy of conventional oral examination (10 studies, none new to this update), mouth self-examination (four studies, two new to this update), and remote screening (three studies, all new to this update). One randomised controlled trial of test accuracy directly evaluated conventional oral examination plus vital rinsing versus conventional oral examination alone. There were no eligible studies evaluating light-based detection or blood or salivary sample analysis (which tests for the presence of biomarkers for OPMD and OSCC). Only one study of conventional oral examination was judged as at overall low risk of bias and overall low concern regarding applicability. Given the clinical heterogeneity of the included studies in terms of the participants recruited, setting, prevalence of the target condition, the application of the index test and reference standard, and the flow and timing of the process, the data could not be pooled within the broader categories of index test. For conventional oral examination (10 studies, 25,568 participants), prevalence in the test accuracy sample ranged from 1% to 51%. For the seven studies with prevalence of 10% or lower, a prevalence more comparable to the general population, the sensitivity estimates were variable, and ranged from 0.50 (95% confidence interval (CI) 0.07 to 0.93) to 0.99 (95% CI 0.97 to 1.00); the specificity estimates were more consistent and ranged from 0.94 (95% CI 0.88 to 0.97) to 0.99 (95% CI 0.98 to 1.00). We judged the overall certainty of the evidence to be low, and downgraded for inconsistency and indirectness. Evidence for mouth self-examination and remote screening was more limited. We judged the overall certainty of the evidence for these index tests to be very low, and downgraded for imprecision, inconsistency, and indirectness. We judged the evidence for vital rinsing (toluidine blue) as an adjunct to conventional oral examination compared to conventional oral examination to be moderate, and downgraded for indirectness as the trial was undertaken in a high-risk population.

AUTHORS' CONCLUSIONS

There is a lack of high-certainty evidence to support the use of screening programmes for oral cavity cancer and OPMD in the general population. Frontline screeners such as general dentists, dental hygienists, other allied professionals, and community healthcare workers should remain vigilant for signs of OPMD and OSCC.

Downregulated microRNA-149-3p triggers malignant development and predicts worse prognosis in oral squamous cell carcinoma

OBJECTIVE

Accumulating evidence reveals that aberrant expression of microRNAs contributes to the tumorigenesis and development of diverse human cancers. In the current study, we aimed to evaluate the functional role and prognostic value of miR-149-3p in oral squamous cell carcinoma (OSCC).

METHODS

Real-time polymerase chain reaction (PCR) analysis was performed to detect the expression of miR-149-3p in 70 OSCC patients (64.10 ± 11.97 years; 31 males and 39 females). The prognostic ability of miR-149-3p in OSCC patients was assessed by Kaplan-Meier survival analysis. Transwell assays and cell adhesion assays were used to investigate the impact of miR-149-3p on cell migration and invasion. The regulation of MMP2 expression by miR-149-3p was determined by real-time PCR, western blotting and dual luciferase reporter assay.

RESULTS

Our results revealed a lower level of miR-149-3p in OSCC tissues than in adjacent normal tissues. Downregulation of miR-149-3p was correlated with malignant development and poor outcomes in patients with OSCC. MiR-149-3p repressed the migratory and invasive abilities of OSCC cells. We confirmed that miR-149-3p targeted the 3'-untranslated region of MMP2 mRNA to suppress MMP2 expression. Moreover, the miR-149-3p-mediated decrease in metastasis was reversed by overexpression of MMP2 in OSCC cells.

CONCLUSION

Our findings provide an important molecular mechanism by which miR-149-3p inhibits OSCC cell migration and invasion via negative regulation of MMP2 and implicate miR-149-3p as a prospective biomarker and therapeutic target for OSCC.

Predictive value of tissue p53 protein expression and serum p53 antibodies in oral potentially malignant disorders: Relative to oral squamous cell carcinoma

Objective

This study aims to assess and report the predictive value of tissue p53 protein expression and serum p53 antibodies as a screening tool for oral potentially malignant disorders (OPMDs) cases with risk of malignant transformation.

Methods

A case–control study was jointly conducted at the Department of Pathology and Oral and Maxillofacial Surgery in several dental institutes in the country from April 2016 to March 2017. A total of 180 eligible subjects (60 cases of OPMDs, 60 cases of oral squamous cell carcinoma, and 60 controls) were included in the study. Tissue p53 immunoreactivity was determined by immunohistochemistry, and serum concentrations of p53 antibodies were determined by enzyme-linked immunosorbent assay. Specimens were collected for laboratory investigations after obtaining written consent from both patients and controls.

Results

Among the study participants, the recorded male to female ratio was close to 2:1, and most participants fell in the age range of 41–60 years and above. Of the 60 cases of OPMDs, the observed tissue p53 immunopositivity was 73.3% (n = 44) while for the p53 antibody, the seropositivity was 96.7% (n = 58). The sensitivity for p53 immunoreactivity was 73%, and specificity was 98.3% between OPMDs and healthy individuals.

Conclusion

The present study provides evidence (for OPMDs) that serum p53 antibodies and p53 immunoreactivity could be used as a sensitivity test and a specific test, respectively, and may contribute to determining the potential of OPMD for malignant transformation risk.

Oral Cancer Discrimination and Novel Oral Epithelial Dysplasia Stratification Using FTIR Imaging and Machine Learning

The Fourier transform infrared (FTIR) imaging technique was used in a transmission model for the evaluation of twelve oral hyperkeratosis (HK), eleven oral epithelial dysplasia (OED), and eleven oral squamous cell carcinoma (OSCC) biopsy samples in the fingerprint region of 1800–950 cm⁻¹. A series of 100 µm × 100 µm FTIR imaging areas were defined in each sample section in reference to the hematoxylin and eosin staining image of an adjacent section of the same sample. After outlier removal, signal preprocessing, and cluster analysis, a representative spectrum was generated for only the epithelial tissue in each area. Two representative spectra were selected from each sample to reflect intra-sample heterogeneity, which resulted in a total of 68 representative spectra from 34 samples for further analysis. Exploratory analyses using Principal component analysis and hierarchical cluster analysis showed good separation between the HK and OSCC spectra and overlaps of OED spectra with either HK or OSCC spectra. Three machine learning discriminant models based on partial least squares discriminant analysis (PLSDA), support vector machines discriminant analysis (SVMDA), and extreme gradient boosting discriminant analysis (XGBDA) were trained using 46 representative spectra from 12 HK and 11 OSCC samples. The PLSDA model achieved 100% sensitivity and 100% specificity, while both SVM and XGBDA models generated 95% sensitivity and 96% specificity, respectively. The PLSDA discriminant model was further used to classify the 11 OED samples into HK-grade (6), OSCC-grade (4), or borderline case (1) based on their FTIR spectral similarity to either HK or OSCC cases, providing a potential risk stratification strategy for the precancerous OED samples. The results of the current study support the application of the FTIR-machine learning technique in early oral cancer detection.

The Relationship of Tobacco, Alcohol, and Betel Quid with the Formation of Oral Potentially Malignant Disorders: A Community-Based Study from Northeastern Thailand

This study's objective was to describe the relationship between the main risk factors for oral cancer, including tobacco (in the form of cigarettes, smokeless tobacco (SLT), secondhand smoking (SS)), alcohol, and betel quid (BQ), and the occurrence of oral potentially malignant disorders (OPMDs). A community-based case-control study was conducted with a population of 1448 adults aged 40 years or above in northeastern Thailand. Patients aged 60 years or above (OR 1.79, p < 0.001) and female patients (OR 2.17, p < 0.001) had a significant chance of having OPMDs. Our multivariate analysis showed that the most potent risk factor for OPMDs occurrence was betel quid (BQ) (adjusted OR 4.65, p < 0.001), followed by alcohol (OR 3.40, p < 0.001). Even former users were at risk of developing OPMDs. The synergistic effect between these main risk factors was significantly shown in the group exposed to SLT, SS, BQ, and alcohol. The most potent synergistic effect was found in the group exposed to SLT, BQ and alcohol with the OR = 20.96.

Predicting the clinical outcome of oral potentially malignant disorders using transcriptomic-based molecular pathology

BACKGROUND

This study was undertaken to develop and validate a gene expression signature that characterises oral potentially malignant disorders (OPMD) with a high risk of undergoing malignant transformation.

METHODS

Patients with oral epithelial dysplasia at one hospital were selected as the 'training set' (n = 56) whilst those at another hospital were selected for the 'test set' (n = 66). RNA was extracted from formalin-fixed paraffin-embedded (FFPE) diagnostic biopsies and analysed using the NanoString nCounter platform. A targeted panel of 42 genes selected on their association with oral carcinogenesis was used to develop a prognostic gene signature. Following data normalisation, uni- and multivariable analysis, as well as prognostic modelling, were employed to develop and validate the gene signature.

RESULTS

A prognostic classifier composed of 11 genes was developed using the training set. The multivariable prognostic model was used to predict patient risk scores in the test set. The prognostic gene signature was an independent predictor of malignant transformation when assessed in the test set, with the high-risk group showing worse prognosis [Hazard ratio = 12.65, p = 0.0003].

CONCLUSIONS

This study demonstrates proof of principle that RNA extracted from FFPE diagnostic biopsies of OPMD, when analysed on the NanoString nCounter platform, can be used to generate a molecular classifier that stratifies the risk of malignant transformation with promising clinical utility.

Diagnostic efficiency of methylene blue and lugol's iodine double staining method in oral leukoplakia in detecting dysplasia

Objectives

Early detection of dysplasia in oral potentially malignant disorders (PMD) might facilitate screening for possible subsequent malignant transformation. Vital staining is a non-invasive clinical adjunct used for determining the biopsy site, which facilitates early detection of dysplastic changes in PMD. Some authors suggested that double staining method has superior results over staining with a single dye.

Aim

The aim of the study was to evaluate the accuracy of in vivo staining with methylene blue (MB) and Lugol's iodine (LI) double staining method in comparison with MB staining alone.

Materials and Methods

Fifty patients of oral leukoplakia were recruited for the study. After obtaining written informed consent from the patients, the lesions were stained consecutively with 5% MB and 3% LI. The pattern of dye retention of MB alone, followed by MB and LI was noted. Incisional biopsy from the lesion was taken based on the retention of MB and the absence of staining of LI or by clinical judgement in case both stains were not retained. The clinical uptake of the stains was correlated with the degree of dysplasia on histopathological examination.

Results

Out of 50 subjects, MB was retained in 47 cases (94%), while 3 cases (6%) failed to retain the dye. However, out of 47 cases, 20 cases had dark blue stain and were considered as MB positive, while the rest 27 cases had pale blue stain and were considered to be negative for MB staining. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and diagnostic accuracy (DA) of MB staining were 57.82%, 100%, 100%, 26.53% and 46%, respectively. After applying both stains, i.e., double staining method, the outline of the lesion was better defined. Out of 50 PMD cases, 3 patients retained only LI and showed no dysplasia. Out of 47 cases which showed dysplasia, 27 cases showed pale blue retention of MB (-) and also were negative for LI. The rest 20 cases were positive for MB but negative for LI. The sensitivity, specificity, PPV and NPV with double staining technique were 100%.

Conclusion

The accuracy and reliability of double staining method was superior to MB staining.

Clinical Relevance

Increased accuracy of double staining method aids in better detection of dysplasia and is of great help to the clinician in deciding the nature of PMD in question.

Oral Squamous Cell Carcinoma Associated with Precursor Lesions

Oral squamous cell carcinoma (OSCC) may be associated with precursor lesions known as oral potentially malignant disorders (OPMD). Few studies have reported on how OPMD diagnosis affects early detection and outcome of OSCC. We reviewed a large series of OSCC to determine the proportion that was associated with preceding OPMD and to compare the outcome of OSCC with or without precursor. Cases of oral-oropharyngeal carcinoma diagnosed between 2005 and 2015 were retrieved from the Ontario Cancer Registry (OCR) and matched to records of OPMD between 2001 and 2015 in two large oral pathology diagnostic services and the pathology databases of two hospitals with oral pathology services, to identify cases with precursor. Of 10,987 cancer cases, 378 (3.44%) had a preceding OPMD. Patients living in Central Ontario were more likely to have OPMD diagnosed before carcinoma than those in North Ontario (4.73% vs. 1.63%, P = 0.05). 329 of 5,257 cases of oral cancer were linked to a precursor, compared with 24 of 4,174 cases of oropharyngeal cancer (6.26% vs. 0.57%, P < 0.0001). Oral cancers with precursor were predominantly diagnosed at stage I (49.30%), compared with those without precursor, where stage IV disease predominated (41.28%). Sixty-nine of 309 (22.33%) patients with precursor-associated oral cancer have died of disease, compared with 1,551 of 4,656 (33.31%) patients without a precursor (P = 0.02). We conclude that patients with OSCC associated with a precursor had significantly lower odds of dying from disease. The beneficial effect of precursor lesion diagnosis on outcome is related to a higher proportion of stage I disease. PREVENTION RELEVANCE: OSCC causes significant morbidity and mortality, especially if diagnosed at late stages. Precursor lesions to OSCC can be recognized by clinical examination. Our study shows that early diagnosis of OSCC at the precursor stage can improve the outcome of oral cancer.

Human papillomavirus, Epstein-Barr virus, and Candida albicans co-infection in oral leukoplakia with different degrees of dysplasia

OBJECTIVES

To identify human papillomavirus (HPV), Epstein-Barr virus (EBV), and Candida albicans in oral leukoplakia with different degrees of dysplasia.

MATERIALS AND METHODS

An observational, cross-sectional, descriptive study was performed using 30 formalin-fixed and paraffin-embedded tissues from patients with clinical suspicion of leukoplakia and confirmed diagnosis of oral dysplasia. Histological analyses were performed by two pathologists (interobserver) and dysplasias were classified as mild, moderate, or severe. Conventional PCR was used to detect HPV and EBV viruses and C. albicans. To determine the association between each microorganism with different degrees of dysplasia a Chi-square test was employed.

RESULTS

The tongue was the most common site for leukoplakias (71.4%) in females with a mean age of 50 years (ranging between 30 to 50 years old; 57.1%). EBV was the most frequently detected (73.3%), followed by HPV (43.3%), mainly of type 16 (40%), and C. albicans (23.3%). Significant differences were observed between degrees of dysplasia and HPV presence (p = 0.005). In lesions positive for HPV, EBV, and C. albicans the most frequent histological changes were hyperkeratosis, irregular interpapillary ridges, and loss of basal stratum cell polarity.

CONCLUSION

Co-infection with human papillomavirus, Epstein Barr virus, and Candida albicans in oral leukoplakia could be associated with dysplastic changes.

Retraction: Oral leukoplakia, a clinical-histopathological study in 412 patients

The authors detected some minor errors in the published manuscript (Rubert A, Bagán L, Bagán JV. Oral leukoplakia, a clinical-histopathological study in 412 patients. J Clin Exp Dent. 2020 Jun 1;12(6):e540-e546. doi: 10.4317/jced.57091. PMID: 32665812; PMCID: PMC7335600.) and have requested that the entire article be republished with these errors already rectified.

Background

A retrospective clinical-histopathological study was made of the evolution of oral leukoplakia over time, staging the disease according to the classification of van der Waal.

Material and Methods

A study was made of 412 patients with oral leukoplakia, analyzing the corresponding clinical factors and histopathological findings; assessing associations between the different clinical presentations and epithelial dysplasia; and evaluating the factors influencing malignant transformation of the lesions.

Results

Clinically, homogeneous presentations were seen to predominate (n = 336, 81.6%), while histologically most of the lesions exhibited no dysplastic changes (n = 271; 65.7%). Stage 1 of the van der Waal classification was the most common presentation (n = 214; 51.9%). The lesion malignization rate was 8.5%, and the factors associated to a significantly increased malignization risk were non-homogeneous OL lesions (p=0.00), lesion location in the tongue (p=0.00), and the presence of epithelial dysplasia (p=0.00).

Conclusions

In our series of patients with oral leukoplakia, malignization was associated to the less common clinical presentations of the disease, i.e., non-homogeneous lesions, and the latter tended to exhibit high grade epithelial dysplasia. Key words:Oral leukoplakia, potentially malignant disorders, malignant transformation.

Simultaneous Expression of Th1- and Treg-Associated Chemokine Genes and CD4+, CD8+, and Foxp3+ Cells in the Premalignant Lesions of 4NQO-Induced Mouse Tongue Tumorigenesis

Chemokines and cytokines in the tumor microenvironment influence immune cell infiltration and activation. To elucidate their role in immune cell recruitment during oral cancer development, we generated a mouse tongue cancer model using the carcinogen 4-nitroquinoline 1-oxide (4NQO) and investigated the carcinogenetic process and chemokine/cytokine gene expression kinetics in the mouse tongue. C57/BL6 mice were administered 4NQO in drinking water, after which tongues were dissected at 16 and 28 weeks and subjected to analysis using the RT² Profiler PCR Array, qRT-PCR, and pathologic and immunohistochemical analyses. We found that Th1-associated chemokine/cytokine (Cxcl9, Cxcl10, Ccl5, and Ifng) and Treg-associated chemokine/cytokine (Ccl17, Ccl22, and Il10) mRNA levels were simultaneously increased in premalignant lesions of 4NQO-treated mice at 16 weeks. Additionally, although levels of Gata3, a Th2 marker, were not upregulated, those of Cxcr3, Ccr4, and Foxp3 were upregulated in the tongue tissue. Furthermore, immunohistochemical analysis confirmed the infiltration of CD4⁺, CD8⁺, and Foxp3⁺ cells in the tongue tissue of 4NQO-treated mice, as well as significant correlations between Th1- or Treg-associated chemokine/cytokine mRNA expression and T cell infiltration. These results indicate that CD4⁺, CD8⁺, and Foxp3⁺ cells were simultaneously recruited through the expression of Th1- and Treg-associated chemokines in premalignant lesions of 4NQO-induced mouse tongue tissue.

Oral Potentially Malignant Disorders (OPMD): What is the clinical utility of dysplasia grade?

INTRODUCTION

Oral epithelial dysplasia is considered a potential histologic precursor of subsequent squamous cell cancer. As standard clinical practice, pathologists grade dysplasia to assess risk for progression to malignancy. Except for the most advanced grade, severe dysplasia, dysplasia grading has failed to correlate well with the risk to develop invasive cancer. The questions of what process dysplasia grading best represents and what clinical utility dysplasia grading may have are explored.

AREAS COVERED

This narrative review is based on PubMed search with emphasis on papers since 2010. Epithelial dysplasia as a precursor lesion of cancer and dysplasia grading as a risk assessment tool for progression to cancer are discussed. The close clinical association of dysplasia with known carcinogens, alcohol, and tobacco products is presented.

EXPERT OPINION

Oral epithelial dysplasia is often, associated with prolonged exposure to tobacco and alcohol products. With reduction of carcinogen exposure, dysplasia is known to regress in some cases. It is proposed that histologic dysplasia grade together with macroscopic images of dysplastic clinical lesions be used as an educational tool to incentivize patients to reduce their known carcinogen exposure. This strategy has the potential to reduce lesion progression thereby reducing the disease burden of oral cancer.

Immunohistochemical Differences in Squamous Precancerous and Cancerous Lesions of the Oral Cavity and the Larynx: Preliminary Data

The aim of this study is to assess immune cell populations in squamous precancerous (preinvasive) and cancerous lesions of the oral cavity and larynx. Qualitative and quantitative immunohistochemical analyses were performed to determine the expressions of CD4, CD8, CD15, CD57 and CD68. The expressions of programmed death-ligand 1 (PD-L1), p16 and Ki67 were also assessed. Squamous cell lesions from forty-one patients were included in the study. Sixteen samples were categorized as precancerous (preinvasive) lesions and twenty-five as invasive squamous cell carcinoma. Invasive lesions showed a negative correlation with CD57+ cells (ρ = −0.69) and a positive correlation with Ki67 (ρ = 0.61). The amount of CD4+ lymphocytes was higher in invasive lesions. There were no differences in PD-L1 and p16 immunoreactivity. Our analysis showed differences in the immunohistochemical profile between preinvasive and invasive squamous cell lesions. In the near future, this study should be useful in driving treatment strategy in both preinvasive and invasive squamous cell lesions of the oral cavity and larynx. However, studies on larger series of patients focusing on site-specific lesions are required.

Importance of the PD-1/PD-L1 Axis for Malignant Transformation and Risk Assessment of Oral Leukoplakia

Background: The programmed cell death ligand 1/programmed cell death receptor 1 (PD-L1/PD-1) Immune Checkpoint is an important modulator of the immune response. Overexpression of the receptor and its ligands is involved in immunosuppression and the failure of an immune response against tumor cells. PD-1/PD-L1 overexpression in oral squamous cell carcinoma (OSCC) compared to healthy oral mucosa (NOM) has already been demonstrated. However, little is known about its expression in oral precancerous lesions like oral leukoplakia (OLP). The aim of the study was to investigate whether an increased expression of PD-1/PD-L1 already exists in OLP and whether it is associated with malignant transformation. Material and Methods: PD-1 and PD-L1 expression was immunohistologically analyzed separately in the epithelium (E) and the subepithelium (S) of OLP that had undergone malignant transformation within 5 years (T-OLP), in OLP without malignant transformation (N-OLP), in corresponding OSCC and in NOM. Additionally, RT-qPCR analysis for PD-L1 expression was done in the entire tissues. Additionally, the association between overexpression and malignant transformation, dysplasia and inflammation were examined. Results: Compared to N-OLP, there were increased levels of PD-1 protein in the epithelial and subepithelial layers of T-OLP (p_E = 0.001; p_S = 0.005). There was no significant difference in PD-L1 mRNA expression between T-OLP and N-OLP (p = 0.128), but the fold-change increase between these groups was significant (Relative Quantification (RQ) = 3.1). In contrast to N-OLP, the PD-L1 protein levels were significantly increased in the epithelial layers of T-OLP (p = 0.007), but not in its subepithelial layers (p = 0.25). Importantly, increased PD-L1 levels were significantly associated to malignant transformation within 5 years. Conclusion: Increased levels of PD-1 and PD-L1 are related to malignant transformation in OLP and may represent a promising prognostic indicator to determine the risk of malignant progression of OLP. Increased PD-L1 levels might establish an immunosuppressive microenvironment, which could favor immune escape and thereby contribute to malignant transformation. Hence, checkpoint inhibitors could counteract tumor development in OLP and may serve as efficient therapeutic strategy in patients with high-risk precancerous lesions.

Inflammatory Response Mechanisms of the Dentine-Pulp Complex and the Periapical Tissues

The macroscopic and microscopic anatomy of the oral cavity is complex and unique in the human body. Soft-tissue structures are in close interaction with mineralized bone, but also dentine, cementum and enamel of our teeth. These are exposed to intense mechanical and chemical stress as well as to dense microbiologic colonization. Teeth are susceptible to damage, most commonly to caries, where microorganisms from the oral cavity degrade the mineralized tissues of enamel and dentine and invade the soft connective tissue at the core, the dental pulp. However, the pulp is well-equipped to sense and fend off bacteria and their products and mounts various and intricate defense mechanisms. The front rank is formed by a layer of odontoblasts, which line the pulp chamber towards the dentine. These highly specialized cells not only form mineralized tissue but exert important functions as barrier cells. They recognize pathogens early in the process, secrete antibacterial compounds and neutralize bacterial toxins, initiate the immune response and alert other key players of the host defense. As bacteria get closer to the pulp, additional cell types of the pulp, including fibroblasts, stem and immune cells, but also vascular and neuronal networks, contribute with a variety of distinct defense mechanisms, and inflammatory response mechanisms are critical for tissue homeostasis. Still, without therapeutic intervention, a deep carious lesion may lead to tissue necrosis, which allows bacteria to populate the root canal system and invade the periradicular bone via the apical foramen at the root tip. The periodontal tissues and alveolar bone react to the insult with an inflammatory response, most commonly by the formation of an apical granuloma. Healing can occur after pathogen removal, which is achieved by disinfection and obturation of the pulp space by root canal treatment. This review highlights the various mechanisms of pathogen recognition and defense of dental pulp cells and periradicular tissues, explains the different cell types involved in the immune response and discusses the mechanisms of healing and repair, pointing out the close links between inflammation and regeneration as well as between inflammation and potential malignant transformation.

Effect of Denture Base Fabrication Technique on Candida albicans Adhesion In Vitro

Denture stomatitis is a common manifestation of oral candidiasis affecting some 65% of denture wearers. This condition is initiated by the adherence of Candida albicans to denture base acrylic resin. The present study aimed to test the in vitro effect of traditional and novel fabrication methods on Candida albicans adhesion to denture base samples. Denture based acrylic discs were fabricated using: (i) computerized milling, (ii) 3D printing, (iii) heat curing, and (iv) cold curing. Discs were tested for surface roughness (Ra), hydrophobicity (contact angle), mucin adsorption (Bradford assay), and Candida albicans adhesion. 3D printing significantly increased microbial cell adhesion as compared with heat curing, and computerized milling significantly decreased it. These results were associated with mucin adsorption levels rather than surface roughness. Results suggest that 3D printing may increase the risk for developing denture stomatitis, whereas computerized milling may decrease it as compared with traditional heat curing denture base fabrication.

Toward Regulatory Effects of Curcumin on Transforming Growth Factor-Beta Across Different Diseases: A Review

Immune response, proliferation, migration and angiogenesis are juts a few of cellular events that are regulated by transforming growth factor-β (TGF-β) in cells. A number of studies have documented that TGF-β undergoes abnormal expression in different diseases, e.g., diabetes, cancer, fibrosis, asthma, arthritis, among others. This has led to great fascination into this signaling pathway and developing agents with modulatory impact on TGF-β. Curcumin, a natural-based compound, is obtained from rhizome and roots of turmeric plant. It has a number of pharmacological activities including antioxidant, anti-inflammatory, anti-tumor, anti-diabetes and so on. Noteworthy, it has been demonstrated that curcumin affects different molecular signaling pathways such as Wnt/β-catenin, Nrf2, AMPK, mitogen-activated protein kinase and so on. In the present review, we evaluate the potential of curcumin in regulation of TGF-β signaling pathway to corelate it with therapeutic impacts of curcumin. By modulation of TGF-β (both upregulation and down-regulation), curcumin ameliorates fibrosis, neurological disorders, liver disease, diabetes and asthma. Besides, curcumin targets TGF-β signaling pathway which is capable of suppressing proliferation of tumor cells and invading cancer cells.

Oral Cancer and Precancer: A Narrative Review on the Relevance of Early Diagnosis

Oral cancer (OC) is an uncommon malignancy in Western countries, being one of the most common cancers in some high-risk areas of the world. It is a largely preventable cancer, since most of the different risk factors identified, such as tobacco use, alcohol consumption, and betel nut chewing, are behaviors that increase the likelihood of the disease. Given its high mortality, early diagnosis is of utmost importance. Prevention and the anticipation of diagnosis begin with identification of potentially malignant lesions of the oral mucosa and with local conditions promoting chronic inflammation. Therefore, every lesion must be recognized promptly and treated adequately. The clinical recognition and evaluation of oral mucosal lesions can detect up to 99% of oral cancers/premalignancies. As stated by the World Health Organization, any suspicious lesion that does not subside within two weeks from detection and removal of local causes of irritation must be biopsied. Surgical biopsy remains the gold standard for diagnosis of oral cancer. Adjunctive tools have been developed and studied to help clinicians in the diagnostic pathway, such as toluidine blue vital staining and autofluorescence imaging. In the near future other methods, i.e., identification of salivary markers of progression may help in reducing mortality due to oral cancer.

Comparative evaluation of survivin expression in leukoplakia, lichen planus, and oral squamous cell carcinoma: An immunohistochemical study

Background

Screening for oral squamous cell carcinomas (OSCCs) and oral premalignant lesions may decrease the devastating morbidity and mortality associated with the disease. This has led to widespread research for the identification of molecular-based biomarkers. Among them, survivin is a recently characterized protein which is a member of the inhibitor of apoptosis family. The aim of this study is evaluating the expression of survivin in oral leukoplakia, oral lichen planus, and OSCC compared with normal mucosa.

Materials and Methods

The retrospective study consisted of twenty cases of oral leukoplakia, oral lichen planus, and OSCC in the age group of 20-70 years. Twenty cases of normal mucosa made up the control group. Immunohistochemical staining was performed with the use of survivin polyclonal antibody. Grades of expression of survivin were evaluated. Kruskal-Wallis test was used for statistical analysis.

Results

The expression of survivin was higher in OSCC (80%) when compared to oral leukoplakia (70%), oral lichen planus (45%), and normal mucosa (35%). The variation in the expression of survivin between the samples was statistically significant with P = 0.015 (Kruskal-Wallis test significant at 0.01 level).

Conclusion

It is concluded that survivin can be identified as a useful tool for the identification of potentially malignant disorders at higher risk for progression into invasive carcinoma.