Leukoplakia Lesions Research Articles

Targeted Treatment of Head and Neck (Pre)Cancer: Preclinical Target Identification and Development of Novel Therapeutic Applications.

Simple SummaryHead and neck squamous cell carcinomas (HNSCCs) develop from mucosal cells in the oral cavity, pharynx and larynx after either prolonged exposure to tobacco and alcohol, or a transforming infection with high-risk human papillomavirus (HPV). HPV-negative HNSCCs develop in a zone of premalignant mucosal cells centimeters in diameter and characterized by tumor-associated genetic changes, also referred to as ‘fields’, which can present as white leukoplakia lesions but are mostly invisible. Patients with HPV-negative HNSCC have an overall 5-years survival rate of 50–60%, despite application of intense treatment protocols, and current treatment regimens seem to have reached their plateau. Recently, immunotherapy using immune checkpoint inhibitors has been introduced, but seems effective in only some patients. Targeted treatments have failed to find their way into the clinic while novel therapies are urgently awaited that could target the tumor as well as the precancerous cells. However, recent data suggest that we are at the dawn of a new era. This review focusses on the preclinical identification of druggable targets for therapy for HPV-negative HNSCC and their preceding precancerous changes.Head and neck squamous cell carcinomas (HNSCC) develop in the mucosal lining of the upper-aerodigestive tract. In carcinogen-induced HNSCC, tumors emerge from premalignant mucosal changes characterized by tumor-associated genetic alterations, also coined as ‘fields’ that are occasionally visible as leukoplakia or erythroplakia lesions but are mostly invisible. Consequently, HNSCC is generally diagnosed de novo at more advanced stages in about 70% of new diagnosis. Despite intense multimodality treatment protocols, the overall 5-years survival rate is 50–60% for patients with advanced stage of disease and seems to have reached a plateau. Of notable concern is the lack of further improvement in prognosis despite advances in treatment. This can be attributed to the late clinical presentation, failure of advanced HNSCC to respond to treatment, the deficit of effective targeted therapies to eradicate tumors and precancerous changes, and the lack of suitable markers for screening and personalized therapy. The molecular landscape of head and neck cancer has been elucidated in great detail, but the absence of oncogenic mutations hampers the identification of druggable targets for therapy to improve outcome of HNSCC. Currently, functional genomic approaches are being explored to identify potential therapeutic targets. Identification and validation of essential genes for both HNSCC and oral premalignancies, accompanied with biomarkers for therapy response, are being investigated. Attentive diagnosis and targeted therapy of the preceding oral premalignant (preHNSCC) changes may prevent the development of tumors. As classic oncogene addiction through activating mutations is not a realistic concept for treatment of HNSCC, synthetic lethality and collateral lethality need to be exploited, next to immune therapies. In recent studies it was shown that cell cycle regulation and DNA damage response pathways become significantly altered in HNSCC causing replication stress, which is an avenue that deserves further exploitation as an HNSCC vulnerability for treatment. The focus of this review is to summarize the current literature on the preclinical identification of potential druggable targets for therapy of (pre)HNSCC, emerging from the variety of gene knockdown and knockout strategies, and the testing of targeted inhibitors. We will conclude with a future perspective on targeted therapy of HNSCC and premalignant changes.

Assessment of Pattern of Oral Prosthetic Treatment and Prevalence of Oral Diseases in Edentulous Patients in North Indian Population: A Cross-sectional Study.

Background:The present study was undertaken for assessing the pattern of oral prosthetic treatment and prevalence of dental diseases in edentulous patients in North Indian population.Materials and Methods:A survey was carried out in North Indian population, and screening of the edentulous patients was done. Five hundred edentulous patients were enrolled. Complete oral and general examination was carried out. Pro forma was framed, and clinical details were recorded. Using mouth mirror and explorer, complete oral examination was carried out. Demographic profile was also evaluated. Prosthetic rehabilitation pattern of all the participants was also recorded.Results:Complete removable denture and removable partial denture were method of rehabilitation in 28% and 31% of the participants. Dental implant-supported complete denture was used in 8% of the patients, whereas dental implant-supported overdenture was used in 33% of the participants. Ulcerative lesions were present in 5% of the patients, whereas oral leukoplakia was present in 4% of the patients. Oral lichen planus and torus were present in 2% and 1% of the patients.Conclusion:Majority of the geriatric patients prefer having removable denture. Furthermore, due to nutritional deficiency associated with geriatric age, oral leukoplakia and ulcerative lesions are more common in them.

A phase II open label, single arm study to evaluate the efficacy of pembrolizumab for leukoplakia.

TPS10606 Background: The presence of pre-cancerous oral lesions such as leukoplakia or erythroleukoplakia are known risk factors for the development of squamous cell carcinoma of the head and neck (SCCHN), however preventative agents have not yet shown clinical benefit. The risk of malignant transformation varies but has been quoted as high as 36% in some studies. While the primary mode of treatment of these lesions is largely surgical, recurrence rates are high. Pembrolizumab is a potent and selective humanized monoclonal antibody that is designed to directly block the interaction between PD-1 and PD-L1 (as well as PD-L2) that is currently FDA-approved for treatment of SCCHN. We have hypothesized that the treatment of oral premalignant lesions with pembrolizumab would be an effective and well-tolerated strategy to prevent transformation to invasive cancer. Methods: This study is an open-label, phase II study that will accrue 26 patients with leukoplakia, erythroleukoplakia, or proliferative verrucous leukoplakia with documented moderate to severe dysplasia or carcinoma in situ to be treated with pembrolizumab 200mg every 3 weeks for a total of 6 months. Patients must have visible and measurable lesions that will be both photographed and measured in two dimensions at each visit from the start of treatment until 12 months post-enrollment. Biopsies will be required at diagnosis and following the final treatment, with an optional biopsy following cycle 2 and at progression of disease. Major exclusion criteria include patients with mild dysplasia or hyperplasia, prior chemotherapy, targeted small molecule therapy, or radiation therapy within 2 weeks of Day 1 of study, or patients with a known additional malignancy that is active. Patients will also be excluded if they have received anti-PD-1, anti-PD-L1 or anti-PD-L2 treatments in the past. The primary objective is clinical response rate at 6 months, and will be quantified as the percentage of patients with a complete response (CR) and partial response (PR) at 6 months. A CR is defined as complete resolution by visual inspection for 4 weeks of more and a PR is defined as 50% or greater reduction of the product of the 2 dimensions of a single lesions or the sum of all lesions. Progressive disease (PD) is defined as unequivocal increase (greater than or equal to 5mm in one dimension and greater than 20% increase) or the development of new lesions. Secondary objectives will include histologic response rate at 6 months, change in clinical impression based on photographs, clinical response rate at 9 and 12 months, and toxicity. Additional exploratory objectives will include PD-L1 expression in leukoplakia lesions as well as p16 expression, presence of tumor infiltrating lymphocytes, and immunohistochemical as well as RNA sequencing gene expression profiling which may allow for the identification of novel biomarkers. Enrollment began in June 2019 and is ongoing. Clinical trial information: NCT03603223 .

Immunohistochemical Characterization of Bcl-2 in Oral Potentially Malignant Disorders.

Bcl-2 is a group of apoptotic proteins that play a key role in cellular homeostasis. Overexpression of Bcl-2 has been associated with the poor prognosis of oral squamous cell carcinoma (OSCC). The aim of this study is to analyze the immunohistochemical expression of Bcl-2 in healthy oral mucosa, different oral potentially malignant disorders and OSCC, and to determine its diagnostic value. A retrospective observational study was carried out in the Oral Medicine Unit of the University of Santiago de Compostela. All the clinicopathologic data were collected and paraffin-embedded blocks were available to perform the immunohistochemistry study with Bcl-2. We studied 18 fibromas, 15 OSCC, 29 oral leukoplakia lesions (OL), 59 oral lichen planus (OLP) cases, and 16 healthy controls. OL with epithelial dysplasia (31.2%) showed the highest expression of Bcl-2 and OLP (1.9%) showed the lowest expression of Bcl-2 (P=0.025). Receiver operating characteristics curves showed that the detection of Bcl-2 enables discrimination between OL and OLPs (sensitivity: 58.6%, specificity of 99.32%). Bcl-2 negative expression in the OLP diagnosis obtained an odds ratio of 13.750 (95% confidence interval: 3.354-56.369; P<0.0001) and the positive expression in the OL 4.468 (95% confidence interval: 1.889-10.565; P=0.001). Bcl-2 could be used as a diagnostic biomarker to study their malignant transformation.

Squamous cell carcinoma of the tongue in 5-year-old girl with dyskeratosis congenita

Dyskeratosis congenita is a rare inherited bone marrow failure syndrome with three distinct clinical features: nail dystrophy, reticular skin pigmentation, and oral leukoplakia. The case of a 5-year-old female patient diagnosed with squamous cell carcinoma of the tongue is reported here. An autosomal dominant type 3 TINF2 mutation subsequently confirmed the diagnosis of dyskeratosis congenita. The traditional tongue cancer treatment was adapted for this young patient. While the tongue cancer lesions and leukoplakia were removed, the deep margins were minimized to preserve the tongue muscles and flap surgery was avoided. Additional conservative measures were applied to suppress new leukoplakia lesions.

Relationship of the XRCC1 rs25487 polymorphism with demographic, behavioral, clinical, and histological parameters in oral potentially malignant disorders and oral squamous cell carcinoma in a Colombian population

ObjectivesTo evaluate the salivary detection of XRCC1 rs25487 single-nucleotide polymorphism (SNP), its relationship with clinicopathological characteristics, and the interactions with demographic/behavioral variables in the etiopathogenesis of oral potentially malignant disorders (OPMD) and oral squamous cell carcinoma (OSCC) in a Colombian population. MethodsDemographic/behavioral data and saliva samples were obtained from patients with oral leukoplakia (OL, n = 17) and oral lichenoid lesions with epithelial dysplasia (OLL-ED, n = 10), or OSCC (n = 45), along with healthy controls (n = 40). Tissue biopsies were obtained for histological assessment and genetic analysis was performed using polymerase chain reaction-restriction fragment length polymorphism. Descriptive analyses were used to compare the distribution of genotypes/alleles between study groups alongside an analysis of the interaction between genetic findings and demographic/behavioral variables. ResultsNo association was observed between the genotype and allele frequencies in OPMD or OSCC. The AG genotype was significantly more frequent in OL with high-grade dysplasia, acanthotic epithelial lining, moderate-to-severe mitotic count, and negative-to-mild apoptotic count; and in OSCC cases with stage III/IV, poorly differentiated, perineural/lymphovascular invasion, severe cellular atypia, moderate-to-severe mitotic count, and negative-to-mild apoptotic counts. Significant interaction effects were detected in the AG genotype with regard to ageing, smoking habits, and alcohol consumption in both OL and OSCC. ConclusionAlthough rs25487 SNP appeared to not modulate the risk of OPMD/OSCC independently, its significant association with clinicopathological characteristics in OL and OSCC, and the synergistic interaction between ageing and smoking/alcohol consumption, might play a role in these two diseases.

Inferior Surface Leukoplakia of Vocal Folds: Risk of Recurrence: A Preliminary Study.

This study aimed to identify vocal fold leukoplakia (VFL) lesions on the inferior surface as a risk factor for recurrence. This was a retrospective study with data collected from 2001 to 2018. The study comprised 37 patients with VFL, divided into the nonrecurrent and recurrent groups. We examined the clinicopathological characteristics and the surgical procedures performed in each patient. Among the 37 patients, 15 (40.5%) had residual (3) or recurrent (12) VFL. Of those patients with and without recurrence, 8 of 12 (66.7%) and 6 of 22 (27.3%), respectively, had inferior surface lesions of the vocal fold at the initial operation (P = .036). Recurrences were significantly higher in patients with inferior surface lesions. Other evaluated factors did not show significance for recurrence. The presence of VFL lesions on the inferior surface is a significant risk factor for recurrence.

Lichenoid morphology could be an early feature of oral proliferative verrucous leukoplakia

Recognition and differentiation of early forms of proliferative verrucous leukoplakia (PVL) could be a challenge to both clinicians and pathologists. To report on a retrospective study that was carried out on 51 cases of PVL that were initially diagnosed as frictional keratosis, oral leukoplakia or oral lichen planus. A secondary objective is to report on the outcome of malignant transformation during follow-up. Records of patients seen at an oral medicine clinic with the final clinical diagnosis of PVL were audited for early clinical and histopathologic features in their biopsy at first presentation, and for subsequent malignant transformation. Fifty-one patients (25 men and 26 women) with a mean age 51years (men) and 53years (women) at initial presentation were studied. 28% men and 11.5% women were current smokers. Initial clinical diagnoses were frictional keratoses (n=4), Leukoplakia (n=17) and lichen planus (n=30). Epithelial dysplasia was reported in the initial biopsy in 12 cases and lichen planus/lichenoid features in 22 cases (22/51; 43%). Malignant transformation occurred in 11/51 patients (21.5%). Lichen planus or lichenoid lesions could be the initial presentation of many PVL cases that later develop multiple leukoplakic lesions with a final diagnosis of PVL.

Proliferative Verrucous Leukoplakia: An Expert Consensus Guideline for Standardized Assessment and Reporting

The many diverse terms used to describe the wide spectrum of changes seen in proliferative verrucous leukoplakia (PVL) have resulted in disparate clinical management. The objective of this study was to produce an expert consensus guideline for standardized assessment and reporting by pathologists diagnosing PVL related lesions. 299biopsies from 84 PVL patients from six institutions were selected from patients who had multifocal oral leukoplakic lesions identified over several years (a minimum follow-up period of 36 months). The lesions demonstrated the spectrum of histologic features described in PVL, and in some cases, patients developed oral cavity squamous cell carcinoma (SCC). An expert working group of oral and maxillofacial and head and neck pathologists reviewed microscopic features in a rigorous fashion, in combination with review of clinical photographs when available. The working group then selected 43 single slide biopsy cases for whole slide digital imaging (WSI) review by members of the consensus conference. The digital images were then reviewed in two surveys separated by a washout period of at least 90 days. Fivenon-PVL histologic mimicswere included as controls. Cases were re-evaluated during a consensus conference with 19 members reporting on the cases. The best inter-observer diagnostic agreement relative to PVL lesions were classified as "corrugated ortho(para)hyperkeratotic lesion, not reactive" and "SCC" (chi-square p = 0.015). There was less than moderate agreement (kappa < 0.60) for lesions in the "Bulky hyperkeratotic epithelial proliferation, not reactive" category. There was ≥ moderate agreement (> 0.41 kappa) for 35 of 48 cases. This expert consensus guideline has been developed with support and endorsement from the leadership of the American Academy of Oral and Maxillofacial Pathology and the North American Society of Head and Neck Pathologists to recommend the use of standardized histopathologic criteria and descriptive terminology to indicate three categories of lesions within PVL: (1) "corrugated ortho(para)hyperkeratotic lesion, not reactive;" (2) "bulky hyperkeratotic epithelial proliferation, not reactive;" and (3) "suspicious for," or "squamous cell carcinoma." Classification of PVL lesions based on a combination of clinical findings and these histologic descriptive categories is encouraged in order to standardize reporting, aid in future research and potentially guide clinical management.

Computational Filters for Dental and Oral Lesion Visualization in Spectral Images

Clinically interesting low-contrast dental and oral features can be challenging to detect. In visual observation and clinical photographs, identification of low-contrast features can be hard or even impossible. Imaging methods, e.g., X-ray and magnetic resonance imaging, provide more information but often require use of ionizing radiation, expensive equipment, and specialized personnel to operate the devices. A cost-effective, non-ionizing, contrast-enhancing imaging method that can be used at any dental clinic is in great demand. Here we show a dental and oral feature visibility-enhancement based on a portable spectral camera and computational filters derived from principal component analysis. By applying computational filters on oral and dental spectral images, selected features of clinical interest can be highlighted against their surroundings. Due to the lack of information available in standard color images, this visibility-enhancement technique can only be realized using spectral images. Oral and dental spectral imaging does not use ionizing radiation, and modern spectral cameras are small, portable, and can be used without specialized training. In this paper, spectral image-based visibility-enhancement is demonstrated for the following cases: gingival recession, calculus, gingivitis, root caries, secondary caries, Fordyce’s granules, leukoplakia, and pigmentous lesions. The results gained with spectral images and computational filters from principal component analysis are compared against regular color images and grayscale images computed with band-pass filters from our earlier work. The results are promising as the visibility and contrast of the features of interests are enhanced in all the studied cases. This study provides a starting point for future research and demonstrates the applicability of spectral imaging-based methods for practical use at dental clinics.

Grading of Oral Leukoplakia: Can It be Improvised Using Immunohistochemical Markers p63 and CD31.

Introduction:Oral squamous cell carcinoma is usually preceded by potentially malignant disorders (PMDs), the most common being oral leukoplakia. A conservative management protocol is followed for milder dysplastic cases, while severe dysplastic lesions are surgically excised. Several classification systems have been developed based mainly on histopathological features with a lot of inter-observer variations. The present study was done to assess the use of immunohistochemical (IHC) markers in grading leukoplakic lesions in addition to histopathological grading.Aims and Objectives:To grade leukoplakia using different grading systems and assess if IHC markers can aid in categorizing leukoplakia.Materials and Methods:Thirty-five cases of leukoplakia were graded using Ljubljana, 2005 World Health Organization (WHO), and Binary System followed by IHC staining with p63 and CD31.Results and Statistics:Variation was noted in 12 cases while using WHO, 11 using Ljubljana, and 7 using Binary System and was significant on Cohen-Kappa statistics, with the least significant variation noted on Binary System. p63 staining assisted to group doubtful cases and even identify variation in cases graded positively on histopathology. In total, 17 cases stained one-third (mild/low), while 15 cases stained one-half or more (higher grade) epithelial thickness. A weak correlation was observed between all grading systems and p63 on Kendall's Tau-b analysis and the weak correlation was significant for the WHO and binary grading systems. Analyzing p63 and CD31 using Kruskal–Wallis test, an increase in mean vessel density (MVD) was noted for mild/moderate cases but decreased for severe cases.Conclusion:Addressing histological categorization of PMDs assisted by IHC markers to understand the biological behavior of the tissues is currently essential with studies on more markers to assist in the management protocol.

Role of carbon dioxide laser in the treatment of oral leukoplakia

The aim of the present study is to evaluate the treatment results of carbon dioxide (CO2) laser vaporisation in the well-defined cohort patients with oral leukoplakia. The group consisted of 20 patients. Before treatment, a clinical photograph and an incisional biopsy were performed in all the cases. Also, post treatment results were documented with clinical photographs. The mean follow-up period was 12 months. 18 out of 20 patients treated for cure (90%) achieved local control after one treatment. The remaining 2 patients required (10%) 2nd and 3rd vaporisations. The rate of malignant transformation after CO2 laser treatment is found to be 2.27% which is comparable to the other studies. CO2 laser vaporisation in the treatment of oral leukoplakia lesions is an excellent procedure in not only preventing the local recurrence and the malignant transformation but also in preventing the post-operative dysfunction. It is a time saving procedure with a negligible intra operative bleeding. The wound healing procedure after CO2 laser is extremely good causing the least post procedure morbidity.

Immune expression profile identification in a group of proliferative verrucous leukoplakia patients: a pre-cancer niche for oral squamous cell carcinoma development.

To explore the pathophysiology of proliferative verrucous leukoplakia, a rare oral disorder that exhibits high rates of recurrence and malignant transformation, through a RNAseq case-control study. We obtained oral biopsies from 10 patients with verrucous leukoplakia lesions and from the mucosa of 5 healthy individuals for sequencing using RNAseq technology. Using bioinformatic methods, we investigated gene expression and enrichment differences between patients both with and without the disorder. We applied network biology methods to investigate functional relations among those genes that were differentially deregulated. We detected 140 differentially expressed genes with distinct roles in immune surveillance, tissue and organ morphogenesis, development, and organization. Of these 140 genes, 111 have been previously described as cancer expression biomarkers, being oral squamous cell carcinoma the most represented type of cancer among them. Of these 140 genes, 26 were prioritized for further investigation as biomarkers using larger sample sizes. The gene expression patterns of healthy and unhealthy patients differed in 140 genes whose deregulation has a functional impact on normal functioning of the immune system. This immune expression profile provides a plausible hypothesis to explain the transformation to oral squamous cell carcinoma observed in 6 of the 10 assayed cases. By determining the molecular bases of the proliferative verrucous leukoplakia disorder and identifying early biomarkers of malignancy, this can allow us to develop new treatment strategies.

Profiling risk factors of micro-invasive carcinoma within oral potentially malignant disorders: a cross-sectional study

To investigate the clinicopathological profile and risk factors of micro-invasive carcinoma within oral potentially malignant disorders (OPMD). Micro-invasive carcinomas were identified in a large prospective series of OPMD patients (n = 810) from eastern China. Logistic regression was applied to evaluate odds ratios (OR) with 95% confidence interval (CI) for indicative of malignant risk in general OPMD. Leukoplakia (41.4%), lichen planus (28.0%), and lichenoid lesion (23.7%) were the most 3 clinical subtypes of OPMD. A total of 62 (7.7%) micro-invasive carcinomas within OPMD were identified, and 96.8% of micro-invasive carcinoma was found within leukoplakia and erythroplakia. Multivariate regression analysis revealed that the risk of malignant change within OPMD located on lateral/ventral tongue (OR, 15.1; 95% CI, 1.85-122.8; P = 0.011) was higher than other sites. The risk of malignant change within non-homogenous type (OR, 103.3; 95% CI, 13.39-796.7; P < 0.001) was strikingly higher than other subtypes of OPMD, respectively. Intriguingly, the risk of micro-invasive carcinoma diagnosed in current smoker (OR, 3.96; 95% CI, 1.31-12.02; P = 0.015) was higher than non-smoker. This large-scale cross-sectional study elucidated the clinical factors and risk assessment of micro-invasive carcinoma within OPMD. Non-homogenous lesions located on lateral/ventral tongue might be monitored at closer intervals, and the need for rigorous management to detect malignant changes.

PATIENT WITH SQUAMOUS CELL CARCINOMA AND SECOND PRIMARY TUMOR ON THE LIPS: A CASE REPORT

A patient, 71 years old, attended the office for a lip biopsy. At the intra-oral clinical examination, a lesion on the right side of the lip was observed, with no defined limits, erythroleukoplakia, symptomatic, hemorrhagic crust, and necrotic tissue. Leukoplakic lesions, flat, with no defined limits, were observed asymptomatic on the hard palate, jugal mucosa, and floor of the mouth, all on the right side. The patient had a medical history of squamous cell carcinoma in 2011 on the floor of the mouth, and radiotherapy and chemotherapy were performed without any surgery. In 2018, a biopsy of the lip lesion was performed, and the patient was diagnosed with squamous cell carcinoma and referred to the head and neck surgeon, who removed the lesion. The patient started chemotherapy, and home visits are performed to follow the lesions of the oral cavity. A patient, 71 years old, attended the office for a lip biopsy. At the intra-oral clinical examination, a lesion on the right side of the lip was observed, with no defined limits, erythroleukoplakia, symptomatic, hemorrhagic crust, and necrotic tissue. Leukoplakic lesions, flat, with no defined limits, were observed asymptomatic on the hard palate, jugal mucosa, and floor of the mouth, all on the right side. The patient had a medical history of squamous cell carcinoma in 2011 on the floor of the mouth, and radiotherapy and chemotherapy were performed without any surgery. In 2018, a biopsy of the lip lesion was performed, and the patient was diagnosed with squamous cell carcinoma and referred to the head and neck surgeon, who removed the lesion. The patient started chemotherapy, and home visits are performed to follow the lesions of the oral cavity.

PROLIFERATIVE VERRUCOUS LEUKOPLAKIA IN MAN: A CASE REPORT

Proliferative verrucous leukoplakia (PVL) is an aggressive form of oral leukoplakia that has a high morbidity and is more common in a woman with no smoking habit. A 68-year-old Caucasian male patient presented with a history of use of a removable dental prosthesis and reported to be a heavy smoker for the last 53 years, with a recent interruption of alcohol and other drug abuse. Clinical examination revealed a widespread leukoplakia lesion with 4 major intra-oral sites at the upper superior alveolar ridge and palate. Two sites were characterized as a homogeneous plaque, and 2 presented an exophytic verrucous surface. The first biopsy revealed hyperkeratosis and papillomatosis. The patient was referred to laser surgery treatment. Histologic findings revealed hyperkeratosis and papillomatosis, but now 1 of the sites revealed mild dysplasia. The final diagnosis was PVL, and the patient is still in follow-up, with no signs of new lesions 3 months after surgical intervention.

Photodynamic therapy using topical toluidine blue for the treatment of oral leukoplakia: A prospective case series.

Photodynamic therapy (PDT) is a minimally invasive method for the treatment of oral leukoplakia (OL) through the activation of a photosensitizer, after exposure to a specific wavelength light source. To investigate the effectiveness of toluidine blue as topical photosensitizer. Eleven patients participated in this study; fifteen oral leukoplakia lesions were treated, in several sessions, with 2.5 % toluidine blue and an LED source of 630 nm wavelength. Patients were evaluated at baseline (t0), at the end of treatment cycles (t1) and one year from the end of treatment (t2). All the treated sites were photographed at each visit. Images were processed with ImageJ 1.52 software in order to obtain the areas (mm2) of the treated lesions. Comparison between data at different follow-up was performed using a paired T-test. At t1, complete response was obtained in six lesions, partial response in seven lesions while only two lesions showed no response. At t2, a further improvement was observed in two patients. The analysis of the areas showed significant reduction of the lesion size from t0 to t1 (p = 0.003), and from t1 to t2 (p = 0.01). Toluidine blue appears to be a promising photosensitizer in the photodynamic therapy of oral leukoplakia.

Ocular surface squamous neoplasia: Population demographics, pathogenesis and risk factors

Background: Ocular surface squamous neoplasia (OSSN) is a unifying term used to describe conjunctival intra-epithelial neoplasia, squamous cell carcinoma in situ and invasive squamous cell carcinoma.Aim: The aim of this article was to describe the demographics, clinical features, pathogenesis and risk factors of OSSN.Method: A literature search was conducted using the search criteria ‘ocular surface squamous neoplasia’, ‘diagnosis’, ‘epidemiology’, ‘pathogenesis’ and ‘risk factors’.Results: Ocular surface squamous neoplasia is the most common ocular tumour, with incidence rates ranging from 0.01 to 3.4 per 100 000 persons/year. There are two main patterns of disease presentation: older white males in temperate climates where human immunodeficiency virus (HIV) and human papilloma virus (HPV) are not associated; and a younger patient population in tropical climates where HIV and HPV are more prevalent. The pathogenesis primarily revolves around ultraviolet B exposure and HPV infection that cause genetic mutations and uncontrolled cellular proliferation, whilst HIV infection and vitamin A impair tumour surveillance mechanisms. Ocular surface squamous neoplasia is first suspected clinically before formal confirmation of the diagnosis. Morphologically, it can be divided into three groups: placoid, nodular and diffuse. Placoid lesions can further be sub-divided into gelatinous, leukoplakic and papilliform lesions. Nodular lesions have the poorest prognosis, with the highest risk of metastasis and recurrence.Conclusion: Ocular surface squamous neoplasia is a common ocular tumour associated with ultraviolet radiation, HPV and HIV infection. The pathogenesis revolves around acquired genetic mutations, unregulated cellular proliferation and impaired tumour surveillance mechanisms.

Study of Caspase 8 mutation in oral cancer and adjacent precancer tissues and implication in progression.

It is hypothesized that same driver gene mutations should be present in both oral leukoplakia and cancer tissues. So, we attempted to find out mutations at one of the driver genes, CASP8, in cancer and adjacent leukoplakia tissues. Patients (n = 27), affected by both of cancer and adjacent leukoplakia, were recruited for the study. Blood and tissue DNA samples were used to identify somatic mutations at CASP8 by next generation sequencing method. In total, 56% (15 out of 27) cancer and 30% (8 out of 27) leukoplakia tissues had CASP8 somatic mutations. In 8 patients, both cancer and adjacent leukoplakia tissues, located within 2-5 cm of tumor sites, had identical somatic mutations. But, in 7 patients, cancer samples had somatic mutations but none of the leukoplakia tissues, located beyond 5cm of tumor sites, had somatic mutations. Mutated allele frequencies at CASP8 were found to be more in cancer compared to adjacent leukoplakia tissues. This study provides mutational evidence that oral cancer might have progressed from previously grown leukoplakia lesion. Leukoplakia tissues, located beyond 5cm of cancer sites, were free from mutation. The study implies that CASP8 mutation could be one of the signatures for some of the leukoplakia to progress to oral cancer.

Effect of tobacco in human oral leukoplakia: a cytomorphometric analysis

ObjectivesTobacco use is one of the most critical risk factors for different oral diseases. The aim of this study is to demonstrate the effect of tobacco on oral mucosa by cytomorphometric analysis of cells with the help of exfoliative cytology and to find out the improvement in diagnostic sensitivity of exfoliative cytology in the detection of dysplastic changes and early oral malignancy.MethodsThe nuclear area (NA) and cytoplasmic area (CA) of cells were measured within cytological smear obtained from leukoplakia lesions of buccal mucosa of 90 tobacco users, 30 smokers (TS), 30 chewers (TC) and 30 with combined habit of smoking and chewing (TSC) and from normal buccal mucosa of 30 non users (NU) of tobacco. Each habit group consisted of 30 tobacco users with oral leukoplakia lesion with mild epithelial dysplasia only. The 30 non-users of tobacco served as controls. The mean values of the CA and NA were obtained for each case, and the nuclear/cytoplasmic area (NA/CA) ratio was calculated.ResultsThe results showed a statistically significant increase (P<0.001) in mean NA and a statistically significant decrease (P<0.001) in mean CA values of tobacco users with leukoplakia as compared to non-users, hence NA/CA ratio value was significantly higher in tobacco users with the lesion.ConclusionThe changes in cellular morphology caused by tobacco use can be visualized by use of exfoliative cytology with the help of cytomorphometric analysis. The evaluation of parameters (NA, CA and NA/CA ratio) may increase the sensitivity of exfoliative cytology for the early diagnosis of oral premalignant and malignant lesions.