Oral potentially malignant disorders (OPMD) are chronic conditions, which have a higher risk of transformation to oral squamous cell carcinoma. The aim of this systematic review and meta-analysis was to answer the question: "What is the prevalence of oral potentially malignant disorders among adults?" Studies reporting the prevalence of these conditions (leukoplakia, erythroplakia, oral submucous fibrosis [OSMF], and actinic cheilitis) were selected, only studies in which a clinical assessment and histopathological confirmation were performed were included. Of the 5513 studies, 22 met the inclusion criteria for qualitative and quantitative analyses. The risk of bias (RoB) of the selected studies was assessed using the Joanna Briggs Institute Critical Appraisal Checklist for Studies Reporting Prevalence Data. Seven studies were classified as high risk, 12 as moderate risk, and 3 as low RoB. The meta-analysis showed that the prevalence of OPMD was 4.47% (95% CI = 2.43-7.08). The most prevalent OPMDs were OSMF (4.96%; 95% CI = 2.28-8.62) and leukoplakia (4.11%; 95% CI = 1.98-6.97). OPMDs were identified more commonly in males (59.99%; 95% CI = 41.27-77.30). Asian and South American/Caribbean populations had the highest prevalence rates of 10.54% (95% CI = 4.60-18.55) and 3.93% (95% CI = 2.43-5.77), respectively. The overall prevalence of OPMD worldwide was 4.47%, and males were more frequently affected by these disorders. The prevalence of OPMD differs between populations; therefore, further population-based studies may contribute to the better understanding of these differences.

Prevalence of oral potentially malignant disorders: A systematic review and meta-analysis

Oral microbiota are among the most diverse in the human body. More than 700 species have been identified in the mouth, and new sequencing methods are allowing us to discover even more species. The anatomy of the oral cavity is different from that of other body sites. The oral cavity has mucosal surfaces (the tongue, the buccal mucosa, the gingiva, and the palate), hard tissues (the teeth), and exocrine gland tissue (major and minor salivary glands), all of which present unique features for microbiota composition. The connection between oral microbiota and diseases of the human body has been under intensive research in the past years. Furthermore, oral microbiota have been associated with cancer development. Patients suffering from periodontitis, a common advanced gingival disease caused by bacterial dysbiosis, have a 2-5 times higher risk of acquiring any cancer compared to healthy individuals. Some oral taxa, especially Porphyromonas gingivalis and Fusobacterium nucleatum, have been shown to have carcinogenic potential by several different mechanisms. They can inhibit apoptosis, activate cell proliferation, promote cellular invasion, induce chronic inflammation, and directly produce carcinogens. These microbiota changes can already be seen with potentially malignant lesions of the oral cavity. The causal relationship between microbiota and cancer is complex. It is difficult to accurately study the impact of specific bacteria on carcinoma development in humans. This review focuses on the elucidating the interactions between oral cavity bacterial microbiota and cancer. We gather literature on the current knowledge of the bacterial contribution to cancer development and the mechanisms behind it.

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Oral Microbiota and Cancer Development.

Anti-PD-L1-modified and ATRA-loaded nanoparticles for immuno-treatment of oral dysplasia and oral squamous cell carcinoma

Background A retrospective clinical-histopathological study was made of the evolution of oral leukoplakia over time, staging the disease according to the classification of van der Waal. Material and methods A study was made of 412 patients with oral leukoplakia, analyzing the corresponding clinical factors and histopathological findings; assessing associations between the different clinical presentations and epithelial dysplasia; and evaluating the factors influencing malignant transformation of the lesions. Results Clinically, homogeneous presentations were seen to predominate (n = 336, 81.6%), while histologically most of the lesions exhibited no dysplastic changes (n = 271; 65.7%). Stage 1 of the van der Waal classification was the most common presentation (n = 214; 51.9%). The lesion malignization rate was 8.3%, and the factors associated to a significantly increased malignization risk were non-homogeneous OL lesions (p=0.00), lesion location in the tongue (p=0.00), and the presence of epithelial dysplasia (p=0.00). Conclusions In our series of patients with oral leukoplakia, malignization was associated to the less common clinical presentations of the disease, i.e., non-homogeneous lesions, and the latter tended to exhibit high grade epithelial dysplasia. Key words:Oral leukoplakia, potentially malignant disorders, malignant transformation.

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Oral leukoplakia, a clinical-histopathological study in 412 patients.

Introduction: Oral leukoplakia (OL) is the most common potentially malignant lesion of the oral cavity. Aim: The purpose of the study was clinical and epidemiological analysis of patients with OL diagnosed and treated in the Department of Maxillofacial and Oral Surgery, Medical University of Gdansk, comparison of effectiveness of treatment methods, defining whether van der Waal level of OL influences treatment effectiveness, correlation between localization of OL and treatment effectiveness, and defining the optimal OL therapeutic method. Material and methods: Among 55 911 patients diagnosed and treated in the Department in the years 1999-2009, 204 people with OL were selected (104 women, 100 men, average age: 58.1 years). Treatment and observation period of 6 months was completed by 178 (87.25%) patients. Seventy-four patients were treated with cream containing 0.05% tretinoin. Sixty-three patients underwent cryosurgery, and 41 surgery. Control visits were made in week 2, 4, 6 and 8 and 6 months after completed treatment. Results: Three hundred and twenty lesions of OL were diagnosed. According to van der Waal classification, the largest group of patients was classified into stage I and II. The percentage of totally cured patients was 90.07%. There were no statistic differences in effectiveness between surgical and cryosurgical treatment. Conclusions: Evaluation of OL treatment methods depends on localization of the lesions and its stage of pro- gression. The effectiveness of treatment with locally applied tretinoin is smaller in comparison to surgery and cryosurgery. It allows to reduce the number and size of OL lesions, what makes it possible to reduce the number of ablative procedures.

/pdf/estimation-of-oral-leukoplakia-treatment-records-in-the-116tpeqx1n.pdf

Estimation of oral leukoplakia treatment records in the research of the Department of Maxillofacial and Oral Surgery, Medical University of Gdansk.

Introduction: Leukoplakia is the most common potentially malignant condition of the oral cavity. Aim: Epidemiological and clinical analysis of patients with oral leukoplakia (OL) diagnosed and treated in the Department of Maxillofacial and Oral Surgery, Medical University of Gdansk. Material and methods: The study was retrospective and prospective. Among 55 911 patients diagnosed and treated in the Department in 1999–2009, 204 people with OL were selected. The material includes 104 women and 100 men with an average age of 58.1. Most of the patients were in the age group of 50–70 years, average age was 58.1. Results: The most common concomitant disease was diabetes. More than 88% of the patients declared occurrence of OL predisposing development factors (50.49% – cigarette smoking). Three hundred and twenty foci of OL were found among patients. Homogeneous OL dominated (72.05%). Multifocal OL was diagnosed in 58.3% of patients. The most common location of lesions was buccal mucosa (52.2%). Cancers developed on the basis of OL in 7 patients (3.43%). The percentage of malignant transformation was 12.19% for untreated patients and 1.41% for treated patients. The floor of the oral cavity was proven to be the location of the highest risk of oral squamous cell carcinoma. Patients with diabetes may be more likely to develop OL. The risk of malignant transformation is relatively high. In our material it was equal to 3.43%. Conclusions: Cigarette smoking is the most important factor, which can influence the effectiveness of treatment.

https://www.termedia.pl/Journal/-7/pdf-22338-10?filename=Oral premalignant.pdf

Dorota Renkielska

Papers

Oral premalignant lesions: epidemiological and clinical analysis in the northern Polish population.

Estimation of oral leukoplakia treatment records in the research of the Department of Maxillofacial and Oral Surgery, Medical University of Gdansk.