Evaluation of Oral Mucosal Lesions in Iranian Smokers and Non-smokers.

BACKGROUND: Tobacco smoking statistics are alarming and the oral mucosa is the first human part of the body that is exposed to the toxic substances of smoking. AIMS: Considering the high prevalence rate of tobacco-associated problems in the oral cavity and few studies on the Iranian population regarding the effects of smoking on the oral cavity, this study aimed to evaluate the relationship between smoking and oral lesions in the Iranian population. MATERIALS AND METHODS: Observational study. In this observational study, the oral cavities of 200 participants (smokers = 100 and non-smokers = 100) were examined by a trained dental student under the supervision of an oral and maxillofacial medicine expert, and the presence of coated tongue, leukoedema, leukoplakia, smoker's palate, smoker's melanosis, erythroplakia, frictional hyperkeratosis, acute pseudomembranous candidiasis, and erythematous candidiasis were recorded. Xerostomia was evaluated based on participants' self-reporting through a questionnaire. All data were analyzed using T-test, Chi-square test, odd ratio, 95% confidence interval, Fisher's exact test, and Spearman's rank correlation coefficient. RESULTS: The results of this study showed smoking is significantly associated with an increased risk of coated tongue (OR: 1.80, 95% CI: 1.32-3.54, P = 0.005), smoker's melanosis (OR: 6.176, 95% CI: 3.28-11.62, P = 0.00002), and frictional hyperkeratosis (OR: 1.33, 95% CI: 0.68-2.60, P = 0.005). However, no significant association was observed between smoking and leukoedema (OR: 1, 95% CI: 0.51-1.94, P = 1). None of the participants presented smoker's palate, erythroplakia, and candidiasis. CONCLUSIONS: This study's results showed that smokers exhibited a greater chance of developing oral lesions compared to non-smokers.

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.

Progression to malignancy in oral potentially malignant disorders: a retrospective study of 5,036 patients in Ontario, Canada.

OBJECTIVES: Determine the rate of malignant transformation (MT) of oral potentially malignant disorders (OPMDs) and risk factors for transformation. STUDY DESIGN: The OPMD database (2001-2015) from 2 biopsy services in Ontario, Canada, was linked to the Ontario Cancer Registry to determine the rate of progression to oral squamous cell carcinoma (OSCC). Clinical and histologic features of progressed and non-progressed cases were compared to determine risk factors for progression. RESULTS: The MT rate was 6.4% (322/5,036 cases). The mean time for cancer development was 51.2 months. 33.6% of cases (107/322) progressed after over 60 months. The risk of cancer increased with age and was higher in non-smokers. The MT rate was highest in the tongue (11.4%), followed by the floor of mouth (7.1%) and gingiva (6.5%). Histologic grade was associated with progression to cancer (P < .0001). Atypical verrucous-papillary lesions with no or mild dysplasia predominantly affected older patients' gingiva, and the progression rate was significantly higher than conventional mild dysplasia (9.2% vs 3.2%, P = .0002). CONCLUSIONS: Our population-based retrospective study showed that <10% of OPMDs progressed to cancer, which could take many years. Atypical papillary-verrucous proliferation without high-grade dysplasia is a subtype of OPMD requiring further study.

Malignant transformation rate of oral leukoplakia in the past 20 years: A systematic review and meta-analysis.

BACKGROUND: This meta-analysis aimed to assess the rate of malignant transformation (MT) of oral leukoplakia (OL) and to study potential risk factors for the MT of OL into oral squamous cell carcinoma (OSCC). METHOD: We performed a bibliographic search on nine electronic databases, including PubMed, MEDLINE, and Wanfang Data, for data on the MT rate of OL. Possible risk factors were calculated using Comprehensive Meta-Analysis and Open Meta [Analyst] software. RESULTS: The pooled proportion of OL MT for the total population described in the 26 selected studies was 7.20% (95% confidence interval: 5.40-9.10%). Nonhomogeneous type lesions, higher grades of dysplasia, the location of the lesion (tongue and multifocal), and female sex had significant effects on the MT of OL. CONCLUSION: OL tended to develop into OSCC (7.2%), and those with significant MT risk factors should be subjected to regular follow-up and observation. However, we require large-scale prospective studies to validate these results, together with unified clinicopathological diagnostic criteria, standardized risk factor recording/assessment methods, and long-term follow-up guidelines.

Follow-up study of veterans with white and red oral mucosal lesions at Veterans Affairs Dental Clinics.

OBJECTIVES: This analysis examined the clinical and histopathological characteristics of white and red oral mucosal lesions and patient lifestyle behaviors to understand how the lesions changed over 19-23 years, including among patients who developed oral and pharyngeal cancer. MATERIALS AND METHODS: Seventy-five individuals with red and/or white oral mucosal lesions with clinical diagnoses of smokeless tobacco lesions, leukoplakia, erythroplakia, lichen planus, ulcer, and virus-associated lesions were identified in six Veterans Affairs Medical Center Dental Clinics (VAMC) from 1996 to 2001. Biopsy results and patients' sociodemographic, medical, and tobacco/alcohol use characteristics were obtained. Study dentists used standardized forms to capture information about the lesions. Study participants were re-examined at intervals through January 2002. In 2020, a retrospective review of VAMC and public records ascertained whether participants developed oral cancer or died. RESULTS: The most common red or white oral mucosal lesions among the 75 study participants were leukoplakia (36.0%), smokeless tobacco lesions (26.7%), virus-associated lesions (18.7%), and lichen planus (16.0%). Lesions in 11% of participants with leukoplakia and one-third of participants with lichen planus persisted for 5 years or more. Dysplasia was present in four participants with leukoplakia. Seventeen percent of participants developed a new white or red oral mucosal lesion. Five patients (6.1%) developed oral or pharyngeal cancer, four among participants with leukoplakia (one with prior dysplasia) and one among participants with lichen planus. Four of the cancers developed 6-20 years after enrollment, and only one was at the original lesion site. CONCLUSIONS: The occurrence of oral and pharyngeal cancers in some study participants with white and red oral mucosal lesions many years after enrollment reinforces the need for patients, dentists, and health care systems to have better methods to identify and assess the malignant potential of oral lesions, monitor patients over time, and intercept high-risk oral lesions before they become cancerous.

Recurrence of premalignant oral cavity and oropharynx lesions after pulsed diode laser treatment.

PURPOSE: Leukoplakia is common with a 1 % incidence in the population and may harbor preneoplastic changes. Diode lasers provide both precision and coagulation for excision of superficial lesions in clinical and operative settings with little damage to deeper tissue. We aim to determine the rate of oral and oropharyngeal hyperkeratosis and dysplasia recurrence after treatment with diode laser. MATERIALS AND METHODS: Patients with oral or oropharyngeal hyperkeratotic or mild dysplastic lesions treated with pulsed diode laser between 2013 and 2020 at a tertiary academic institution were analyzed. The main outcome measure was recurrence of hyperkeratosis and dysplasia after treatment. RESULTS: Fourteen patients received diode laser treatment for hyperkeratotic or mild dysplastic lesions of the oral cavity or oropharynx. Demographic features included 9 (64.3 %) females and mean age of 66.6 years. In these 14 patients, 18 distinct lesions were identified. Eleven (61.1 %) lesions were located on the oral tongue, 4 (22.2 %) on the buccal mucosa, 2 (11.1 %) on the hard palate, and 1 (5.6 %) on the soft palate. Average time from lesion clinical diagnosis to the first diode laser treatment was 8.3 months with an average number of 1.4 treatments per lesion. Three (16.7 %) lesions experienced recurrence after the most recent treatment. None of the lesions underwent malignant transformation. None of the patients experienced bleeding, tethering, or dysarthria after treatment. One patient developed pyogenic granuloma and reported chronic tongue pain. CONCLUSIONS: Pulsed diode laser treatment of leukoplakia was well tolerated with low complication rates and reasonable control of precancerous lesions.

Clinicopathological Evaluation of Tobacco-related Oral Mucosal Lesions.

AIM: To clinically evaluate the nature of precancerous and cancerous lesions associated with tobacco consumption habit and to correlate clinical profile with the histopathological findings of clinically suspected precancerous and cancerous lesions. MATERIALS AND METHODS: These included the examination of patients who visited the outpatient department (OPD) of the institute that includes 1,500 patients who had tobacco chewing habits were classified into the following two groups according to their characteristics. The study group comprised 270 patients, of which 170 gave consent for biopsy and 100 patients who not gave consent were counseled for tobacco cessation. RESULTS: Among 270 patients, the highest number of patients, 146 (54.07%) patients, were found to be smokeless tobacco consumers followed by 65 (24.07%) patients who were smoked tobacco consumers while 59 (21.85%) patients were found to have both the habits. Wide variation was noted in duration and frequency of habit. Most prevalent site was the buccal mucosa affected in 138 (51.11%) patients who consumed both smoked as well as smokeless tobacco. And on clinical examination, 138 (51%) patients had leukoplakia followed by 54 (20%) patients with oral squamous cell carcinoma and 40 (15%) patients with oral submucous fibrosis (OSMF). Other patients were tobacco pouch keratosis 17 (6%), smoker's melanosis 8 (3%), smoker's palate 7 (3%), and erythroplakia 6 (2%). The patients who gave consent (170 patients) were evaluated histopathologically to correlate with clinical findings. CONCLUSION: Tobacco-related oral lesions are also high, which brings an alarming signal toward the development of cancer. Our contribution as healthcare providers can be made by conducting more oral health education programs and educating the general population about the adverse effects of tobacco. The appropriate clinical assessment and categorization of all these lesions aided us in motivating patients to undergo necessary treatments and also to discontinue their habits in order to prevent deterioration of their conditions. CLINICAL SIGNIFICANCE: Set up de-addiction centers in dental colleges and help tobacco users in discontinuing their habits. Interestingly, this study also served as a mirror for those patients who were unaware of the lesions they were giving abode to in their oral cavities.

BUCCAL CELL MICRONUCLEI AMONG PATIENTS WITH ORAL LEUKOPLAKIA.

OBJECTIVE: The aim: The purpose of research was to evaluate the efficiency of micronucleus test in buccal cells for the diagnosis of oral leukoplakia. PATIENTS AND METHODS: Materials and methods: We have conducted a comprehensive clinical and laboratory examination of 155 patients with oral leukoplakia. It was conducted histological examination leukoplakia mucosal sites, to assess the buccal epithelium cell micronucleus test was carried out. RESULTS: Results: Histological evaluation of the material was made according to the classification of leukoplakia WHO (2005). They are established 10 (14%) sites unmodified mucosa, 10 (14%) of the samples hyperkeratosis without atypia, 14 (19%) biopsies hyperkeratosis SIN1, 15 (21%) of hyperkeratosis SIN2, 10 (14%) -- SIN3 and 13 (18 %) of the cases of squamous cell carcinoma. Micronuclei, whose appearance is caused by violation of differentiation of epithelial cells, were found in patients with leukoplakia, the detection of micronuclei almost equally high as in patients with leukoplakia SIN2, and with SIN3 (a difference of 1.3 times (p <0,05, rxy = + 0.271)), and consequently the probability of occurrence of tumoral diseases of the oral mucosa or malignancy existing large. CONCLUSION: Conclusions: Thus, on the background of the general increase in proliferative activity of epithelial cells with increasing SIN, for each treatment group revealed the appearance of micronuclei in buccal cells. And the frequency of micronuclei and the fourth type of increases with hyperplasia, indicating an increase in the likelihood of malignancy and cancer of the oral mucosa in patients with leukoplakia SIN3.

Prevalence of recurrent aphthous stomatitis, oral submucosal fibrosis and oral leukoplakia in doctor/nurse and police officer population.

BACKGROUND: The doctor/nurse and police officer population have some common typical characteristics of great professional pressure and night shift and past studies indicated oral mucosa lesions were closely associated with psychological factors and health-risking behaviors, however the prevalence of recurrent aphthous stomatitis (RAS) and the two commonly seen oral potentially malignant disorders of oral submucosal fibrosis (OSF) and oral leukoplakia in doctor/nurse and police officer in the Betel quid chewing city of Mainland China is unknown The cross-sectional study was to determine the prevalence differences of RAS, oral leukoplakia and OSF among doctor/nurse, police officer and non-doctor/nurse and non-police officer population aged 20-59 years. METHODS: RAS, OSF and oral leukoplakia were examined in doctor/nurse group (male: 659, female: 2439), police officer group (male: 839, female: 262) and non-doctor/nurse and non-police officer group (male: 7576, female: 8129) from 2020-11-01 to 2021-08-31 in Health Management Center, Xiangya Hospital in Changsha city, Hunan province. RESULTS: The prevalence rates of RAS, OSF, oral leukoplakia and oral leukoplakia combined with OSF in male and female non-doctor/nurse and non-police officer group are 8.32‰ and 10.83‰, 58.08‰ and 1.23‰, 11.75‰ and 0.25‰, 7.66‰ and 0.12‰ respectively. Compared with the non-doctor/nurse and non-police officer population, prevalence rates of RAS in male (24.27‰) and female (20.50‰) doctor/nurse population were significantly higher. Prevalence rates of OSF (21.24‰) and oral leukoplakia (3.03‰) in male doctor/nurse population were significantly less but prevalence rates of OSF (93.71‰), oral leukoplakia (20.17‰) and oral leukoplakia combined with OSF (15.42‰) for male police officer were significantly greater in comparison with male non-doctor/nurse and non-police officer group. OSF and oral leukoplakia prevalence rates were obvious lower for the female than the counterpart male group, but there were no significant differences of OSF and oral leukoplakia prevalence rates between the female non-doctor/nurse and non-police officer and female doctor/nurse group. Oral leukoplakia was not found in the female police officers. CONCLUSIONS: Doctor/nurse population have higher prevalence of RAS. Male doctors/nurses have lower prevalence of OSF and oral leukoplakia, while male police officers have higher prevalence of OSF, oral leukoplakia and oral leukoplakia combined with OSF.

EPIDEMIOLOGICAL SITUATION OF PRE-CANCER DISEASES OF THE ORAL MUCOUS IN UKRAINE.

OBJECTIVE: The aim: To conduct a prospective clinical study to assess the prevalence, structure, risk factors and features of clinical manifestations of precancerous diseases of oral mucosa and red lip in Kyiv residents and to analyze opportunities to improve the quality of their primary diagnosis. PATIENTS AND METHODS: Materials and methods: The examination of 423 patients with precancerous diseases of oral mucosa and red lip included clarification of the main complaints and anamnesis of the disease, objective assessment of the state of oral mucosa and red border of the lips according to visual, stomatoscopic, luminescent analysis, cyto-, histological studies. RESULTS: Results: Attention is drawn to the prevalence among precancerous diseases of patients with leukoplakia - 41.37% and lichen planus - 44.21%. The levels of detection of precancerous diseases of the oral mucosa due to the current and preliminary history for individual nosological forms are almost identical, which indicates the reliability of the above indicators. CONCLUSION: Conclusions: Promotion between the people about timely dental treatment for precancerous diseases of the oral mocosa and the use of radical technologies in their treatment will not only increase the effectiveness of treatment, but significantly limit the malignancy of these diseases.

Effect of clinical and histologic features on time to malignancy in 224 cases of oral leukoplakia treated by surgery.

OBJECTIVES: Our main purpose and research question were to analyze and quantify whether there were significant differences in the time to develop cancer among patients with oral leukoplakia (OL), comparing the more susceptible cases to those with the least susceptibility to malignancy. MATERIALS AND METHODS: We followed 224 cases of OL after surgical or CO2 laser treatment for a mean time of 6.4 years. A Bayesian mixture cure model based on the Weibull distribution was used to model the relationship between our variables and cancer risk. In this model type, the population is considered a mixture of individuals who are susceptible or non-susceptible to developing cancer. The statistical model estimates the probability of cure (incidence model) and then infers the time to malignancy. The model was adjusted using the R-package INLA using default priors. RESULTS: Histology type (moderate or severe dysplasia) and tongue location showed hazard ratios (HR) of 3.19 (95% CI [1.05-8.59]) and 4.78 (95% CI [1.6-16.61]), respectively. Both variables increased the risk of malignant transformation, thus identifying a susceptible subpopulation with reduced time required to develop cancer, as with non-homogeneous leukoplakias. The median time for cancer development was 4 years and 5 months, with a minimum of 9 months after the diagnosis of OL and a maximum of 15 years and 2 months. CONCLUSIONS: Susceptible patients with non-homogeneous leukoplakia, dysplasia, or leukoplakia in the tongue develop cancer earlier than those with homogeneous OL and those without dysplasia. CLINICAL RELEVANCE: The novel contribution of this research is that, until now, the time it took for oral leukoplakias to develop cancer based on whether they were homogeneous or non-homogeneous, and if they have or not epithelial dysplasia, had not been comparatively described and quantified. As a final result, the time to malignant transformation in non-homogeneous and dysplastic leukoplakias is significantly shorter.

Analysis of false-negatives in exfoliative cytology in oral potentially malignant disorders: A retrospective cohort study.

INTRODUCTION: Keratinized lesions have been a conceivable false-negative (FN) factor in oral exfoliative cytology (OEC); however, other factors are poorly analyzed. In this study, we aimed to identify the factors influencing the accuracy of OEC and FNs focusing on the lesion characteristics, patient background, and surgeon factors in oral potentially malignant disorders (OPMD). MATERIAL AND METHODS: We retrospectively studied 44 patients who underwent both OEC and histopathological diagnosis. Sensitivity, specificity, FN rate, false-positive (FP) rate, and prevalence of both methods were compared. Similarly, accuracy indices were compared among clinical diagnosis groups (leukoplakia vs. other diagnosis). The association between patient and surgeon-related factors influencing FN OEC results were investigated using Fisher's exact test and a multiple logistic regression analysis. RESULTS: Overall, the sensitivity; specificity; and FN, FP, and prevalence rates of OEC were 31.8%, 82.1%, and 68.8%, 17.9%, and 36.4%, respectively. Leukoplakia was significantly more common in clinical diagnosis (P = 0.007) with sensitivity, specificity, and FN rates of 20.0%, 95.2%, and 80.0%, respectively. Contrarily, non-keratinized lesions had sensitivity, specificity, and FN of 83.3%, 85.7%, and 16.7%, respectively. In the prevalent group, leukoplakia and anucleate squamous cells were significantly associated with FN cases (P = 0.013, P = 0.050). On multivariate analysis in OEC negative patients, age ≤64 (P = 0.050) and location on the tongue (P = 0.047) was independently associated with FNs. CONCLUSION: FN of OEC was conceivable to be due to poor deep-seated cell sampling, which was associated with leukoplakia, age, and location. Therefore, these factors may be considered in the evaluation of OEC results.

A Retrospective Cohort Study of Oral Leukoplakia in Female Patients-Analysis of Risk Factors Related to Treatment Outcomes.

BACKGROUND: The aim of this study was to make a comparison of clinicopathological characteristics of oral leukoplakia between male and female patients following carbon dioxide laser excision for oral leukoplakia and analyze the factors associated with the treatment outcomes in female patients. METHODS: Medical records of patients with oral leukoplakia receiving laser surgery from 2002 to 2020 were retrospectively reviewed and analyzed statistically. RESULTS: A total of 485 patients were enrolled, including 412 male (84.95%) and 73 female (15.05%). Regarding the locations, the predilection site of oral leukoplakia in male patients was buccal mucosa (p = 0.0001) and that for women patients was tongue (p = 0.033). The differences of recurrence and malignant transformation between both sexes were not significant (p > 0.05). Among female patients, area of oral leukoplakia was the risk factor related to recurrence (p < 0.05). Clinical morphology and postoperative recurrence were the risk factors related to malignant transformation (p < 0.05). CONCLUSIONS: In comparison with male patients, there was no significant difference of the postoperative recurrence and malignant transformation of oral leukoplakia in female patients. Among the female patients, clinicians should pay more attention to large-sized and non-homogeneous leukoplakia, and postoperative recurrent lesions.

High Prevalence of Human Papillomavirus Type 18 in Oral Potentially Malignant Disorders in Thailand.

OBJECTIVES: The main objectives of this study were to investigate the detection rate of high-risk human papillomavirus types 16 and 18 (high-risk HPV16/18) in oral potentially malignant disorders (OPMDs) including oral leukoplakia (OL) and oral lichen planus (OLP) in a Thai population and their associations with demographic, risk habits, and clinicopathologic features. METHODS: Paraffin-embedded formalin-fixed specimens from 101 OL and 59 OLP patients with patients' demographic, risk habits, and clinicopathologic data were collected. Conventional qualitative polymerase chain reaction was used to detect high-risk HPV16/18 DNA. Associations between high-risk HPV type 16/18 and demographic, clinicopathologic, risk factors (tobacco and alcohol uses) of OPMDs were analysed by Chi-square or Fisher's exact test. The results with p value less than 0.05 were considered statistically significant. RESULTS: HPV16/18 DNA was found in both OL and OLP groups with the detection rate of 19.8% and 18.6%, respectively. Approximately 90% of high-risk HPV were HPV18 subtype. Additionally, in OL group, high-risk HPV was found more frequently in patients with moderate/severe dysplasia than that in mild dysplasia. Interestingly, in OLP group, high-risk HPV was only detected in atrophic/ulcerative subtypes. None of risk factors was associated with high-risk HPV. CONCLUSIONS: Approximately 19% of OPMDs were HPV16/18-positive. HPV18 DNA was predominantly detected in both OL and OLP patients (90%). Additionally, the detection rate of high-risk HPV was higher in more severe dysplastic cases of OL and more clinically severe cases of OLP.

Higher serum homocysteine level and frequency of hyperhomocysteinemia in carcinoembryonic antigen-positive or squamous cell carcinoma-antigen-positive oral leukoplakia patients.

BACKGROUND/PURPOSE: Our previous study found significantly lower serum hematinic levels and higher serum homocysteine level as well as higher frequencies of serum hematinic deficiencies and hyperhomocysteinemia in oral leukoplakia (OL) patients than in healthy control subjects. This study evaluated whether carcinoembryonic antigen (CEA)-positive or squamous cell carcinoma-antigen (SCC-Ag)-positive OL patients had significantly lower serum hematinic levels and higher serum homocysteine level as well as significantly higher frequencies of hematinic deficiencies and hyperhomocysteinemia than CEA-negative or SCC-Ag-negative OL patients or healthy control subjects. METHODS: The complete blood count, serum iron, vitamin B12, folic acid, and homocysteine levels in 184 OL patients including 85 CEA-positive, 99 CEA-negative, 25 SCC-Ag-positive, and 159 SCC-Ag-negative OL patients and in 184 age- and sex-matched healthy control subjects were measured and compared. RESULTS: We found that the 85 CEA-positive or 25 SCC-Ag-positive OL patients had a significantly lower mean serum folic acid level and a significantly higher mean serum homocysteine level as well as significantly higher frequencies of serum folic acid deficiency and hyperhomocysteinemia than 184 healthy control subjects. Moreover, the 25 SCC-Ag-positive OL patients had a significantly higher mean serum homocysteine level than the 159 SCC-Ag-negative OL patients. The 85 CEA-positive OL patients had a higher mean serum homocysteine level and a higher frequency of hyperhomocysteinemia than 99 CEA-negative OL patients (marginally significant, P = 0.060). CONCLUSION: CEA-positive or SCC-Ag-positive OL patients tend to have a higher mean serum homocysteine level and a higher frequency of hyperhomocysteinemia than CEA-negative or SCC-Ag-negative OL patients, respectively.

Malignant transformation of oral proliferative verrucous leukoplakia: A systematic review and meta-analysis.

OBJECTIVES: To investigate the available evidence on the malignant transformation (MT) of oral proliferative verrucous leukoplakia (PVL). MATERIAL AND METHODS: We searched six main electronic and three grey literature databases in a two-phase process. Cohort studies investigating MT of PVL were eligible for inclusion. The risk of bias (RoB) was assessed using a specific tool developed by the Joanna Briggs Institute. Proportion meta-analyses were performed using a random-effects model. RESULTS: Study selection resulted in the inclusion of 17 studies. The pooled proportion of MT was 43.87% (95% CI = 31.93-56.13). Females (64.02%, 95% CI = 54.87-72.75) were more affected by PVL than males (35.98%, 95% CI = 27.25-45.13). Gingiva (39.6%) and buccal mucosa (21.6%) were the most frequent PVL sites. No conclusive results were found between MT and sex or age distribution, tobacco, or alcohol consumption. Gingiva was the most common site for MT (39.9%), and the most frequent histopathological subtype was conventional squamous cell carcinoma (62.1%). Four studies were classified as low, nine as moderate, and four as high RoB. CONCLUSION: The MT pooled proportion was 43.87%. Among OPMDs, PVL has the highest risk to transform to malignancy. Development and agreement on diagnostic criteria for PVL would reduce the heterogeneity among future studies.

Identification of clinically useful predictive genetic variants in pachyonychia congenita.

BACKGROUND: Pachyonychia congenita (PC) refers to a group of autosomal dominant disorders caused by mutations in five keratin genes (KRT16,KRT6A,KRT17,KRT6B or KRT6C). Current disease classification is based on the gene harbouring disease-causing variants. AIMS: We harnessed the International Pachyonychia Congenita Research Registry (IPCRR) containing both clinical and molecular data on patients with PC worldwide, to identify genetic variants predicting disease severity. METHODS: We ascertained 815 individuals harbouring keratin mutations registered in the IPCRR. We looked for statistically significant associations between genetic variants and clinical manifestations in a subgroup of patients carrying mutations found in at least 10% of the cohort. Data were analysed using χ2 and Kruskal-Wallis tests. RESULTS: We identified five mutations occurring in at least 10% of the patients registered in the IPCRR. The KRT16 p.L132P mutation was significantly associated with younger age of onset, presence of palmar keratoderma oral leucokeratosis and a higher number of involved nails. By contrast, the KRT16 p.N125S and p.R127C mutations resulted in a milder phenotype featuring a decreased number of involved nails and older age of onset. Patients carrying the p.N125S mutation were less likely to develop palmar keratoderma while p.R127C was associated with an older age of palmoplantar keratoderma onset. Moreover, the KRT17 p.L99P mutation resulted in an increased number of involved fingernails and patients demonstrating 20-nail dystrophy, while the opposite findings were observed with KRT17 p.N92S mutation. CONCLUSIONS: We have identified novel and clinically useful genetic predictive variants in the largest cohort of patients with PC described to date.

Human papillomavirus prevalence in oral potentially malignant disorders: Systematic review and meta-analysis.

OBJECTIVES: We aimed to provide pooled estimates of human papillomavirus (HPV) prevalence in oral potentially malignant disorders (OPMD) and evaluate the impact of presence of epithelial dysplasia. METHODS: We searched PubMed, Embase, and Cochrane Library databases for studies that examined the prevalence of HPV DNA in OPMD tested by polymerase chain reaction (PCR). RESULTS: Across 52 eligible studies (2,677 cases), we found an overall pooled HPV prevalence of 22.5% (95% confidence interval [CI] 16.6-29.0). Between-study heterogeneity was 93%. When stratified by subgroup, the pooled HPV prevalence in leukoplakia (1,232 cases) was 20.2% (95% CI 11.2-31.1), lichen planus (767 cases) 23.0% (95% CI 15.0-32.2), oral submucous fibrosis (238 cases) 28.6% (95% CI 23.0-34.5), proliferative verrucous leukoplakia (60 cases) 24.7% (95% CI 1.8-62.0), and OPMD unspecified (377 cases) 25.4% (95% CI 16.2-35.8). Information on presence of epithelial dysplasia was available in 19 studies, and the results did not vary substantially between non-dysplastic and dysplastic samples. HPV16 was the predominant genotype among HPV-positive OPMD cases (48.2%, 95% CI 31.4-65.2). CONCLUSION: We found a pooled HPV DNA prevalence of 22.5% in OPMD cases with great between-study heterogeneity. The HPV prevalence appeared to be comparable across subgroups and independent of epithelial dysplasia.

High-risk human papillomavirus in patients with oral leukoplakia and oral squamous cell carcinoma-A multi-centre study in Sweden, Brazil and Romania.

OBJECTIVES: Although causal associations between oral leukoplakia (OL), oral squamous cell carcinoma (OSCC) and high-risk human papillomavirus (HR-HPV) have been speculated upon in several reports, conclusive evidence has not been presented. This study investigates whether the number of cases of HR-HPV in OL has increased over time and whether the prevalence of HR-HPV-positive OL differs in various parts of the world. PATIENTS AND METHODS: A total of 432 patients with OL from Sweden, Brazil and Romania were analysed. Patients were divided into historical (1992-2002) and contemporary (2011-2017) cohorts from the respective countries. Seventeen patients with OL developed oral squamous cell carcinoma (OSCC). A real-time PCR assay, targeting HPV sub-types 6,11,16,18,31,33,35,39,45,52,56,58 and 59, was performed to detect HR-HPV in patients with OL. RESULTS: In the Swedish and Romanian cohorts, none of the investigated HPV sub-types were detected. In the Brazilian cohorts, five patients with OL (3%) were positive for HR-HPV, including four patients from the contemporary cohort (HPV 16, 31, 33) and one from the historical cohort (HPV 11). All the cases of OL that transformed into OSCC were HR-HPV-negative, as were the corresponding tumours. CONCLUSIONS: In summary, the prevalence of HR-HPV in OL is low in all the tested countries, and the incidence has not changed over time. HR-HPV in OL does not seem to be a driver of oncogenesis.

Oral leukoplakia-epidemiological survey and histochemical analysis of 107 cases in Brazil.

OBJECTIVE: To perform an epidemiological survey comparing the cell proliferative activity of 107 cases of oral leukoplakia with their clinical and histopathological characteristics. MATERIALS AND METHODS: A cross-sectional, observational, and histological-histochemical study. The cases came from the Histopathological Diagnostic Service of UPF/RS and the School of Dentistry of Araçatuba FOA/UNESP/SP (1986-2016). The histopathological sections were stained using the silver staining (AgNOR) technique and the nuclei of 100 epithelial cells selected randomly were recorded to count the number of nucleolar organizer regions (NORs). The mean NORs per lesion were correlated to clinical and histological characteristics using ANOVA, at 5% significance. RESULTS: Most of the cases included men (62.62%), white (64.49%), and with an average age of 53.94 years. The most probable etiological factors were smoking (44.7%) and alcohol consumption (9.85%). The evolution time of most lesions was fast (33.65%), manifesting mainly in the form of plaques (70.37%) and without symptoms (58.88%). They were located mainly in the cheek mucosa (26.62%) and presented white color (66.35%), well-defined edges (59.81%), firm consistency (47.5%), and keratinized surface (49.53%). Etiological factor (p = 0.003), evolution time (p = 0.006), symptoms (p = 0.029), location (p = 0.020), consistency (p = 0.047), histopathological characteristics (p = 0.004), and superficial keratinization (p = 0.001) were statistically significant regarding the mean NORs of the leukoplakias studied. CLINICAL RELEVANCE: Oral leukoplakias caused by alcohol consumption and/or tobacco use, considering an evolution time of fewer than 12 months, asymptomatic, located in the lower lip or tongue, and with a firm consistency and increased superficial keratinization should be treated more aggressively by the clinician to avoid cancerization.