Epidemiology of oral cancer in South and South-East Asia: Incidence and mortality.

INTRODUCTION: This study provides an epidemiological description of cancer in the lip, oral cavity, and oropharynx in the South and South-East Asia region. METHODS: The number of new cases and deaths was extracted from the GLOBOCAN 2020 and the CI5 series. We present age-standardized incidence and mortality rates per 100,000 inhabitants. To assess temporal trends, we estimated the annual percent change. RESULTS: The incidence rates (ASR) for lip and oral cavity cancer in South and South-East Asia were highest in Taiwan (30.2), Sri Lanka (16.5), India (14.8), and Pakistan (13.2) among males. For oropharyngeal cancer, the highest rates were found in Taiwan (4.7), Bangladesh, Sri Lanka, and India (4.3, 2.9, and 2.6, respectively). Incidence rates were consistently higher in males compared to females. Overall, trends in lip and oral cavity cancer incidence were either stable or decreasing in most of the populations evaluated. In India, an increase in rates among males contrasted with a decline among females over the study period. CONCLUSION: Incidence and mortality rates of oral cavity cancer in South and South-East Asia are among the highest globally. Our results suggest an optimistic trend of reduction in oral cavity rates in the region, despite an increase in rates among Indian males.

Natural products and diet for the prevention of oral cancer: Research from south and southeast Asia.

Medicinal plants are of prime importance in the discovery of drugs. They are an inherent source of naturally available phytochemicals that can help in the prevention and treatment of several diseases including cancer. This article reviews the experimental and clinical evidence of phytochemicals available in natural dietary products that are used in everyday life across South Asia and South-East Asia for their perceived effectiveness in the management of Potentially Malignant Disorders and prevention of Oral Cancer. The review also highlights the active phytometabolites, their in vitro anti-proliferative properties and targeted signalling pathways, biological activities in in vivo models and translative potential for clinical trials in humans.

Prevalence of human papillomavirus in oral cancer in Asia: A systematic review and meta-analysis.

OBJECTIVE: To determine the prevalence of human papillomavirus (HPV) in oral squamous cell carcinoma (OSCC) across Asian countries, focusing on South and Southeast Asia. METHODS: A systematic search of four databases-MEDLINE/PubMed, EMBASE, Scopus, and ProQuest-was conducted to identify observational studies published between January 2013 and December 2023. The pooled prevalence of HPV was estimated using random-effects models, and subgroup analysis was performed to investigate the source of heterogeneity. RESULTS: A total of 77 studies were included, comprising 7289 OSCC cases from 11 countries. The pooled HPV prevalence in OSCC was 23.1% (95% CI 17.9-28.7, I2 = 96.7%). South Asia had the highest prevalence (27.1%), followed by East Asia (19.4%), and Southeast Asia (16.7%). Two subtypes were commonly reported: HPV-16 (9.1%) and HPV-18 (5.1%). Anatomical subsites, buccal mucosa (34.0%), and floor of the mouth (33.2%) had similar ranges of HPV prevalence. All studies exhibited a high degree of heterogeneity, with the OSCC location and risk of bias identified as potential sources of heterogeneity. CONCLUSIONS: Due to the high HPV prevalence in OSCC in Asia, HPV detection in routine pathology practice is recommended. Future studies should be conducted in multicentre settings using similar HPV detection methods and reporting detailed demographic and clinical information on oral sub-sites.

Surgical protocols for oral leukoplakia and precancerous lesions across three different anatomic sites.

OBJECTIVE: This systematic review and meta-analysis aimed to compare the risk of recurrence and cancer progression after surgical treatment for oral potentially malignant disorders (OPMD) and precancerous lesions in different anatomical sites. MATERIALS AND METHODS: A comprehensive search was conducted in nine databases and grey literature. We included randomized controlled trials assessing surgical treatment efficacy for OPMD and precancerous lesions of cervical, vaginal, anal, and penile sites. Excision or ablation surgical treatments were considered. RESULTS: Overall, 12 studies met the eligibility criteria for oral leukoplakia (OL), proliferative verrucous leukoplakia, cervical intraepithelial neoplasia (CIN), vaginal intraepithelial neoplasia, and anal intraepithelial neoplasia (AIN). In qualitative analysis of surgical protocols, the lack of margin description impacts the clinical outcomes of OL and AIN, and the ablative protocols were heterogeneous in both OPMD and precancerous lesions. No significant difference in OL (risk ratio 0.82 [95% CI: 0.59-1.15]) and CIN (risk ratio 0.31 [95% CI: 0.09-1.09]) for recurrence was observed when cold-knife was compared with ablative protocols. OL exhibited higher recurrence and cancer progression rates compared to CIN and AIN. CONCLUSION: There is no difference in recurrence risk post-surgical treatment for OL and CIN. Surgical protocols for oral leukoplakia and CIN/AIN lack standardized approaches.

Barriers to early diagnosis and management of oral cancer in Latin America and the Caribbean.

OBJECTIVE: This study aimed to explore perceived barriers to early diagnosis and management of oral cancer, as well as potential pathways for improvement in Latin America and the Caribbean (LAC). METHODS: This cross-sectional study used a self-administered online questionnaire created via the Research Electronic Data Capture platform. The survey was distributed to health professionals trained in Oral Medicine, Oral Pathology, Oral and Maxillofacial Surgery, and Dentists with clinical and academic expertise in oral potentially malignant disorder (OPMD) and oral cancer. Data obtained were systematically organized and analyzed descriptively using Microsoft Excel. RESULTS: Twenty-three professionals from 21 LAC countries participated. Major barriers included the limited implementation of OPMD and oral cancer control plans (17.4%), low compulsory reporting for OPMD (8.7%) and oral cancer (34.8%), unclear referral pathways for OPMD (34.8%) and oral cancer (43.5%), and a shortage of trained professionals (8.7%). Participants endorsed the utility of online education (100%) and telemedicine (91.3%). CONCLUSION: The survey highlights major perceived barriers to early diagnosis and management of OPMD and oral cancer in LAC, as well as potential avenues for improvement.

Machine learning for detection and classification of oral potentially malignant disorders: A conceptual review.

Oral potentially malignant disorders represent precursor lesions that may undergo malignant transformation to oral cancer. There are many known risk factors associated with the development of oral potentially malignant disorders, and contribute to the risk of malignant transformation. Although many advances have been reported to understand the biological behavior of oral potentially malignant disorders, their clinical features that indicate the characteristics of malignant transformation are not well established. Early diagnosis of malignancy is the most important factor to improve patients' prognosis. The integration of machine learning into routine diagnosis has recently emerged as an adjunct to aid clinical examination. Increased performances of artificial intelligence AI-assisted medical devices are claimed to exceed the human capability in the clinical detection of early cancer. Therefore, the aim of this narrative review is to introduce artificial intelligence terminology, concepts, and models currently used in oncology to familiarize oral medicine scientists with the language skills, best research practices, and knowledge for developing machine learning models applied to the clinical detection of oral potentially malignant disorders.

Oral epithelial dysplasia grading: Comparing the binary system to the traditional 3-tier system, an actuarial study with malignant transformation as outcome.

BACKGROUND: Establishing the risk of malignant transformation (MT) in oral leukoplakia is usually based on grading oral epithelial dysplasia (OED) on biopsy tissue, for which two systems are proposed: a 3-tier and a binary system. Only very few actuarial studies have tested the accuracy of such methods in predicting MT, especially for the binary system. This study aimed to assess the accuracy of the two grading systems in predicting MT in a cohort of oral leukoplakia (OL) from Brazil, with follow-up data. METHODS: The sample comprised 878 individuals diagnosed with OL from 2005 to 2018. Follow-up data were obtained both locally and from the regional cancer registry. All lesions were graded using both the 3-tier and the binary systems. Kaplan-Meier curves (Log-rank Mantel-Cox) were used to assess risk and kappa to assess interobserver agreement. RESULTS: Thirty-five individuals underwent MT (4%). Both systems demonstrated prognostic value, though the 3-tier system proved superior, with OR 9.23 (3.42-23.69), PPV 0.152, NPV 0.98, compared to binary OR 3.49 (1.79-6.79), PPV 0.079, NPV 0.976. Interobserver agreement was also superior in the 3-tier system (0.47, p < 0.05) compared to the binary system (0.139, p = 0.39). Combining the two systems enhanced prognostic values (OR 14.28, PPV 0.217, NPV 0.981). CONCLUSION: The 3-tier system presented superior prognostic value to the binary system. Combining both systems to double-grade intermediate lesions might enhance risk assessment.

Association between autoimmune rheumatic diseases and head and neck cancer: Systematic review and meta-analysis.

BACKGROUND: Personal history of autoimmune rheumatic diseases has been implicated in the development of malignant neoplasms. Our aim was to assess the risk of head and neck (H&N) cancers in patients with autoimmune rheumatic diseases. METHODS: The articles search included PubMed, EMBASE, LILACS, The Cochrane Library, CINAHL, Scopus, Web of Science, and Google Scholar with no language restrictions for studies published from inception of the databases to August 20, 2022, assessing the risk of H&N cancer in patients with autoimmune rheumatic diseases. Studies were included if they reported the standardized incidence ratio (SIR) with corresponding 95% confidence intervals (CIs). The primary outcome was risk of H&N cancers in patients with autoimmune rheumatic diseases compared with the general population. Pooled summary estimates were calculated using a random-effects model, and subgroup analyses were done to establish whether risk of H&N cancers varied according to study site. RESULTS: Our search identified 5378 records, of which 32 cohort studies were eligible for systematic review and 24 for meta-analysis (including 273 613 patients). A significant association was found between H&N cancer and autoimmune rheumatic diseases (SIR = 2.35; 95% CI: 1.57-3.50; p < 0.01, I2  = 94%). CONCLUSION: Our study suggests that patients with autoimmune rheumatic diseases had a significantly increased risk of H&N cancer compared with the general population, including thyroid, oral, and nasopharyngeal cancers. These findings have implications for the individualized screening of these patients and the planning of oncology units. The protocol is registered with PROSPERO, number CRD42020197827.

The carcinogenicity of opium consumption: a systematic review and meta-analysis.

The carcinogenicity of opium consumption was recently evaluated by a Working Group convened by the International Agency for Research on Cancer (IARC). We supplement the recent IARC evaluation by conducting an extended systematic review as well as a quantitative meta-analytic assessment of the role of opium consumption and risk for selected cancers, evaluating in detail various aspects of study quality on meta-analytic findings. We searched the published literature to identify all relevant studies on opium consumption and risk of selected cancers in humans through 31 October, 2022. Meta-relative risks (mRRs) and associated 95% confidence intervals (CIs) were estimated using random-effects models for studies of cancer of the urinary bladder, larynx, lung, oesophagus, pancreas, and stomach. Heterogeneity among studies was assessed using the I2 statistic. We assessed study quality and conducted sensitivity analyses to evaluate the impact of potential reverse causation, protopathic bias, selection bias, information bias, and confounding. In total, 2 prospective cohort studies and 33 case-control studies were included. The overall pooled mRR estimated for 'ever or regular' versus 'never' use of opium ranged from 1.50 (95% CI 1.13-1.99, I2 = 0%, 6 studies) for oesophageal cancer to 7.97 (95% CI 4.79-13.3, I2 = 62%, 7 studies) for laryngeal cancer. Analyses of cumulative opium exposure suggested greater risk of cancer associated with higher opium consumption. Findings were robust in sensitivity analyses excluding studies prone to potential methodological sources of biases and confounding. Findings support an adverse association between opium consumption and cancers of the urinary bladder, larynx, lung, oesophagus, pancreas and stomach.

Oral leukoplakia: A clinicopathological study and malignant transformation.

OBJECTIVES: To assess the clinicopathological characteristics of a cohort of patients with oral leukoplakia (OL) managed in a Romanian dental hospital and to evaluate the risk of malignant transformation (MT). MATERIALS AND METHODS: We conducted a hospital-based retrospective study using the clinical charts of patients diagnosed with OL that had complete clinical and histopathological evaluation followed up for 1-16 years. RESULTS: From 120 included patients, 68 (56.7%) were females, and 71 (59.2%) were current smokers. The homogeneous form was present in 60% of cases; the buccal mucosa was the most frequently involved site. MT was observed in 9 cases, which was more common in females and in those with dysplastic leukoplakia. A significant statistical association was found between MT and dysplasia grade (χ2 test: p = 0.007). MT occurred during a mean interval of time 75 months in both treated and non-treated patients. CONCLUSIONS: In this leukoplakia cohort, most of the lesions encountered were in smokers, clinically homogeneous and 62.5% proved histologically benign. But despite the clinically benign appearance of leukoplakia, tissue diagnosis of some cases was carcinoma. The results of the current study advocate the necessity for biopsy even in apparently homogeneous, clinically benign lesions. The malignization rate was 7.5%; two-thirds were nonhomogeneous lesions.

Autoimmune disorders in oral lichen planus: A systematic review and meta-analysis.

OBJECTIVES: The association of OLP with other autoimmune processes points to the possibility that OLP-affected patients are actually developing an autoimmune status that predisposes them to autoaggression against different targets. This systematic review and meta-analysis aim to evaluate the current evidence on the prevalence of autoimmune disorders in patients with OLP and their magnitude of association. METHODS: We searched PubMed, Embase, Web of Science, Scopus databases for the studies published before May 2021, with no limitation in regards to their publication date or language. We evaluated the quality of studies, carried out meta-analyses and performed heterogeneity, subgroups, meta-regression, and small-study effects analyses. RESULTS: Inclusion criteria were met by 153 studies (23,327 patients). Our results indicate the existence of high prevalence and a frequent association between OLP and some autoimmune disorders, especially in regards to thyroid disease (PP = 7.96%, 95% CI = 6.32-9.75; OR = 1.99, 95% CI = 1.60-2.49, p < 0.001) and diabetes mellitus (PP = 9.41%,95% CI = 8.16-10.74; OR = 1.64, 95% CI = 1.34-2.00, p < 0.001). CONCLUSIONS: Our study demonstrates the existence of a comorbidity between autoimmune thyroid diseases as well as between diabetes mellitus and OLP respectively. Quality of evidence should be upgraded on other autoimmune diseases (fibromyalgia, gastrointestinal disorders, rheumatic diseases, Sjogren's syndrome, lupus erythematosus, and dermatological diseases) for which the current data do not allow us to know whether they are really associated with OLP.

Oral squamous cell carcinoma arising from chronic traumatic ulcers.

BACKGROUND: A proportion of oral squamous cell carcinoma (OSCC) is preceded by oral potentially malignant disorders (OPMD), and the rest might not be associated with any well-established OPMD. Chronic traumatic ulcer (CTU) has been suggested as a lesion with potential for malignant transformation, but the evidence is inconclusive. OBJECTIVE: The aim of this study was to describe clinicopathological features of non-healing CTU (NHCTU) that later developed to OSCC. MATERIALS AND METHODS: A retrospective cohort study was performed of patients attending the Facultad de Odontología Universidad Nacional de Córdoba (2013-2019). The study included patients with a provisional diagnosis of CTU. CTUs without complete healing after removal of traumatic factors-non healing CTU (NHCTU)-were investigated by biopsy. A detailed description of cases where a malignancy was diagnosed is presented. RESULTS: A total of 107 CTU were included. Of these, 32 CTUs were considered NHCTU and two cases showed histological features of OSCC in the background of NHCTU. In both cases, lesions were found on the lateral tongue. Both were non smoking, non alcohol drinking individuals. Absence of any well-known OPMD was also registered. CONCLUSIONS: The possibility of malignant transformation in a subset of tongue NHCTU should not be underestimated. CLINICAL RELEVANCE: In a subgroup of patients, NHCTU could be considered an OPMD. Although the potential malignant transformation rate is low, these conditions should be always followed up.

Immunohistochemical biomarkers in oral submucous fibrosis: A scoping review.

INTRODUCTION: This scoping review was done to study the immunohistochemical biomarkers involved in the pathogenesis and malignant transformation of oral submucous fibrosis (OSF), in literature published from 2010 to 2021. METHOD: The protocol was adapted from the Joanna Briggs Institute Reviewer's Manual (2017), and reported according to the PRISMA guidelines for Scoping Reviews. RESULTS: Eighty-six studies included in this review reported 84 immunohistochemical (IHC) biomarkers in OSF: 10 epithelial markers, 28 connective tissue markers, 22 proliferative markers, and 24 other biomarkers that are transcription factors, cancer stem cell markers, cell signaling markers, proteins, and enzymes. The commonly reported IHC biomarkers were alpha-smooth muscle actin (α-SMA) and E-cadherin (seven articles each) followed by vascular endothelial growth factor (VEGF) and CD34 (six articles each), p53, p63, and Ki67 (five articles each). α-SMA, Ki67, CD105, and hTERT were significantly increased in oral squamous cell carcinoma arising in a background of OSF (OSCC-OSF) compared with OSF and normal subjects. CONCLUSION: The identified surrogate IHC biomarkers reported in OSF in this scoping review require validation with long-term prospective studies to facilitate early diagnosis, for use in risk assessment, and plan appropriate treatment for OSF in clinical practice. Open Science Framework ID: osf.io/epwra.

Salivary gland polymorphous adenocarcinoma: Clinicopathological features and gene alterations in 36 Japanese patients.

BACKGROUND: Polymorphous adenocarcinoma is a common intraoral minor salivary gland carcinoma in Western countries but is extremely rare in Japan. The current study aimed to characterize the clinicopathological features and status of molecular alterations of polymorphous adenocarcinoma-associated genes, such as PRKD1/2/3, ARID1A, and DDX3X, in a large cohort of Japanese patients with polymorphous adenocarcinoma. METHODS: We examined the cases of 36 Japanese patients with salivary gland polymorphous adenocarcinoma and 26 cases involving histopathological mimics. To detect gene splits, fluorescence in situ hybridization was carried out for polymorphous adenocarcinoma-associated genes. Additionally, we applied a SNaPshot multiplex assay to identify PRKD1 hotspot mutations. RESULTS: This study revealed the indolent clinical course of polymorphous adenocarcinoma with a high 10-year overall survival rate (92.9%), accompanied by occasional local recurrences and cervical lymph node metastasis (23.3%). Twenty cases (55.6%) of polymorphous adenocarcinoma (but none of the mimics) exhibited alterations in at least one polymorphous adenocarcinoma-associated gene. Rearrangement of polymorphous adenocarcinoma-associated genes and PRKD1 E710D were identified in 17 (47.2%) and 4 (11.1%) cases, respectively; one case showed coexisting PRKD3 split and PRKD1 E710D. In the multivariate analysis, high clinical stage (p = 0.0005), the presence of prominent nucleoli (p = 0.0003), and ARID1A split positivity (p = 0.004) were independent risk factors for disease-free survival. CONCLUSION: Japanese patients with polymorphous adenocarcinoma showed clinicopathological features similar to those reported in Western countries. This study disclosed that polymorphous adenocarcinoma-associated genetic alterations were common and specific findings in polymorphous adenocarcinomas. The diagnostic role and possible prognostic significance of polymorphous adenocarcinoma-associated genetic alterations in polymorphous adenocarcinomas were suggested.

Secondhand smoke exposure and oral cancer risk: a systematic review and meta-analysis.

OBJECTIVES: Inhalation of secondhand smoke (SHS) causes several diseases, including lung cancer. Tobacco smoking is a known cause of oral cancer; however, it has not been established whether SHS also causes oral cancer . The aim of this study was to evaluate the potential association between SHS exposure and the risk of oral cancer. METHODS: A systematic review and meta-analysis study (following the PRISMA guidelines) was developed to examine the studies reporting on the associations of SHS and the risk of oral cancer, employing a search strategy on electronic databases (PubMed, Web of Science, Scopus, Cochrane Library, Open Grey, and ProQuest databases for dissertations) until 10 May 2020. Meta-analyses and sensitivity analyses were performed using random-effect models. The protocol was registered in PROSPERO (CRD42020189970). RESULTS: Following the application of eligibility criteria, five studies were included, comprising a total of 1179 cases and 5798 controls, with 3452 individuals exposed and 3525 individuals not exposed to SHS. An overall OR of 1.51 (95% CI 1.2o to 1.91, p=0.0004) for oral cancer was observed, without significant heterogeneity (I2=0%, p=0.41). The duration of exposure of more than 10 or 15 years increased the risk of oral cancer (OR 2.07, 95% CI 1.54 to 2.79, p<0.00001), compared with non-exposed individuals, without significant heterogeneity (I2=0%, p=0.76). CONCLUSIONS: This systematic review and meta-analysis supports a causal association between SHS exposure and oral cancer. Our results could provide guidance to public health professionals, researchers, and policymakers to further support effective SHS exposure prevention programs worldwide.

Podoplanin could be a predictive biomarker of the risk of patients with oral leukoplakia to develop oral cancer: A systematic review and meta-analysis.

OBJECTIVES: The aim of this study is to identify and analyze the existing literature on the utility of podoplanin to predict the risk of malignancy development (MD) in patients previously diagnosed with oral leukoplakia (OL). METHODS: A systematic review and meta-analysis (SRMA) was performed though a search strategy using several electronic databases and a combination of keywords related to podoplanin and MD of OL, until 15 May, 2022 (PROSPERO CRD42022329326). Evaluation of the risk of bias (ROB) was performed using the Quality in Prognosis Studies Tool. The meta-analyses were estimated using fixed-effect models. RESULTS: From 421 articles, 6 studies were finally included, that enrolled 546 patients with OL, of whom 125 presented with an oral cancer during follow-up (32 to 90 months). Some limitations regarding the ROB were identified mostly related to small sample sizes, short follow-up times, lack of information on covariables in the included studies and lack of accuracy (including sensitivity and specificity). Meta-analysis of 6 studies reveal that high expression of podoplanin carries a pooled hazard ratio (HR) of 3.72 (95% CI, 2.40-5.76; p < 0.00001) for MD without statistical heterogeneity (I2  = 0%, p = 0.53). CONCLUSION: The results of this SRMA support the role of podoplanin immunohistochemical expression as a potential predictive biomarker to assess the risk of malignancy development in oral leukoplakia.

Depression, anxiety, and stress in oral lichen planus: a systematic review and meta-analysis.

OBJECTIVES: We present this systematic review and meta-analyses to evaluate current evidence on the prevalence of depression, anxiety, and stress in patients with oral lichen planus and their magnitude of association. MATERIAL AND METHODS: We searched PubMed, Embase, Web of Science, Scopus, PsycInfo, and Google Scholar for studies published before January 2021. We evaluated the quality of studies using a specific method for systematic reviews addressing prevalence questions, designed by the Joanna Briggs Institute. We carried out meta-analyses and performed heterogeneity, subgroups, meta-regression, and small-study effects analyses. RESULTS: Fifty-one studies (which recruited 6,815 patients) met the inclusion criteria. Our results reveal a high prevalence of depression (31.19%), anxiety (54.76%), and stress (41.10%) in oral lichen planus. Furthermore, OLP patients presented a significantly higher relative frequency than control group without OLP for depression (OR = 6.15, 95% CI = 2.73-13.89, p < 0.001), anxiety (OR = 3.51, 95% CI = 2.10-5.85, p < 0.001), and stress (OR = 3.64, 95% CI = 1.48-8.94, p = 0.005), showing large effect sizes. Subgroups meta-analyses showed the relevance of the participation of psychologists and psychiatrists in the diagnosis of depression, anxiety, and stress in patients with OLP. Multivariable meta-regression analysis showed the importance of the comorbidity of depression-anxiety in patients with OLP. CONCLUSIONS: Our systematic review and meta-analysis show that patients with OLP suffer a higher prevalence of depression, anxiety, and stress, being more frequent than in general population. Clinical relevance In the dental clinic, especially dentists should be aware of depression, anxiety, and stress in OLP patients to achieve a correct referral.

Comparison of tobacco and alcohol consumption in young and older patients with oral squamous cell carcinoma: a systematic review and meta-analysis.

OBJECTIVE: To compare the proportion of young (up to 45 years of age) and older (over 45 years of age) oral squamous cell carcinoma (OSCC) patients who report tobacco and alcohol consumption. METHODS: Observational studies reporting tobacco and alcohol consumption among young and older OSCC patients were selected in a two-phase process. Search strategies were conducted on five main electronic databases and complemented by grey literature. The risk of bias was assessed using the Joanna Briggs Institute's Critical Appraisal Checklist for Studies Reporting Prevalence Data. Synthesis of results was calculated with the software R Statistics version 4.0.2 (The R Foundation). RESULTS: From 6675 records identified, 38 studies met the eligibility criteria and were selected for qualitative synthesis and meta-analysis, encompassing 2439 young and 13,393 older patients. Tobacco smoking was reported by 39.5% (confidence interval (CI) = 31.7% to 47.9%, I2 = 78%) of the young patients and 48.4% (CI = 37.8% to 59.2%, I2 = 94%) of the older patients. Alcohol consumption was reported by 30.9% (CI = 22.7% to 40.5%, I2 = 83%) of the young and 45.8% (CI = 35.6% to 56.5%, I2 = 95%) of the older patients (P < 0.05). CONCLUSION: The comparison in the proportion of individuals reporting tobacco and alcohol consumption demonstrated that these habits were more prevalent in the older group (48.4% and 45.8% respectively) than in the young group (39.5% and 30.9%, respectively). CLINICAL RELEVANCE: As a significant proportion of patients with OSCC reported no habits, novel risk factors for OSCC need to be investigated in further research.

Chronic mechanical irritation enhances the effect of tobacco and alcohol on the risk of oral squamous cell carcinoma: a case-control study in Argentina.

OBJECTIVES: Oral squamous cell carcinoma (OSCC) is a multifactorial disease. The individual effect of each risk factor for OSCC may be conditioned by the frequency of other factors. The objective of this study was to identify the association between chronic mechanical irritation (CMI) and OSCC and to analyse the influence of CMI on other important risk factors for OSCC. MATERIALS AND METHODS: A prospective and age/sex-matched case-control study was performed in two institutions from Argentina between 2009 and 2019, with consecutive and newly diagnosed OSCC. The frequencies of tobacco, alcohol, and CMI were analysed using conditional logistic regression. Cumulative tobacco consumption and the presence of CMI were analysed using the Mann-Whitney test. RESULTS: CMI and OSCC were associated with an OR of 7.02 (95% CI 3.57-13.78, p < 0.001). The combination of CMI and alcohol demonstrated the highest risk of OSCC (OR 53.83, CI 95% 8.04-360, p < 0.0001), followed by the combination of CMI, tobacco, and alcohol (OR 48.06, CI 95% 8.47-272, p < 0.0001). The combination of CMI and tobacco was also significant (OR 5.61, CI 95% 1.07-29.54, p = 0.042). Patients with CMI developed OSCC with less cumulative tobacco use compared with those without CMI. CONCLUSION: CMI is an independent risk factor for OSCC, and it could act as a risk modifier among tobacco and alcohol users having an enhancing effect. CLINICAL RELEVANCE: Elimination of CMI could decrease the risk of OSCC.

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

BACKGROUND: Recognition and differentiation of early forms of proliferative verrucous leukoplakia (PVL) could be a challenge to both clinicians and pathologists. OBJECTIVE: 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. METHODS: 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. RESULTS: Fifty-one patients (25 men and 26 women) with a mean age 51 years (men) and 53 years (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%). CONCLUSION: 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.