Oral potentially malignant disorders (OPMDs) are associated with an increased risk of occurrence of cancers of the lip or oral cavity. This paper presents an updated report on the nomenclature and the classification of OPMDs, based predominantly on their clinical features, following discussions by an expert group at a workshop held by the World Health Organization (WHO) Collaborating Centre for Oral Cancer in the UK. The first workshop held in London in 2005 considered a wide spectrum of disorders under the term "potentially malignant disorders of the oral mucosa" (PMD) (now referred to as oral potentially malignant disorders: OPMD) including leukoplakia, erythroplakia, proliferative verrucous leukoplakia, oral lichen planus, oral submucous fibrosis, palatal lesions in reverse smokers, lupus erythematosus, epidermolysis bullosa, and dyskeratosis congenita. Any new evidence published in the intervening Medical Sciences,

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.

No abstract

Extracellular vesicles (EVs) play a key role in the communication between cancer cells and stromal components of the tumor microenvironment (TME). In this context, cancer cell-derived EVs can regulate the activation of a CAF phenotype in TME cells, which can be mediated by several EV cargos (e.g., miRNA, proteins, mRNA and lncRNAs). On the other hand, CAF-derived EVs can mediate several processes during tumorigenesis, including tumor growth, invasion, metastasis, and therapy resistance. This review aimed to discuss the molecular aspects of EV-based cross-talk between CAFs and cancer cells during tumorigenesis, in addition to assessing the roles of EV cargo in therapy resistance and pre-metastatic niche formation.

No abstract

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.

Objectives: This systematic review and meta-analysis aimed to determine the proportion of patients who develop oral carcinomas following a diagnosis of oral submucous fibrosis (OSF) in reported longitudinal studies. We also aimed to evaluate the demographic and clinicopathological factors contributing to the progression of OSF to cancer.Methods: Individual search strategies were applied for the following bibliographic databases: MEDLINE by PubMed, Scopus, Embase, Web of Science, and Grey literature databases until August 30, 2020. Methodological assessment of the risk of bias of the included studies was undertaken using the modified Newcastle-Ottawa scale.Meta-analyses were conducted using a random-effects (DerSimonian and Liard) method to calculate the pooled proportion of the malignant transformation (MT) in OSF patients.Results: Out of 585 records screened, a total of 9 observational studies were included with a total number of 6,337 patients; of these, 292 OSF cases developed carcinomas. The pooled proportion of the MT was 4.2% (95% CI: 2.7%-5.6%) with an annual transformation rate of 0.73%. Subgroup analysis revealed that the pooled MT proportion was significantly higher among population-based studies in comparison with hospital-based ones (p < .005). Most of the studies showed a high risk of bias. In several studies, there was a lack of information about the demographic and clinicopathological characteristics of OSF patients and associated risk indicators; this insufficiency in details hindered the ability to conduct further subgroup analyses.Conclusions: Despite the poorly reported and the limited number of studies, our analysis confirms that close to 4% of patients diagnosed with OSF may develop oral cancer. Cases with oral epithelial dysplasia had a higher potential for malignant transformation.

BackgroundTo investigate the prevalence of malignant and potentially malignant lesions of the lip in an oral pathology service and to compare these data with a literature review.Material and MethodsA total of 3173 biopsy reports and histopathological records were analyzed. Cases with a histological diagnosis of actinic cheilitis (AC) with or without epithelial dysplasia, in situ carcinoma, or lip squamous cell carcinoma (LSCC) were included. A comprehensive literature review was conducted to investigate the prevalence of AC and/or LSCC.Results124 cases (3.91%) were included, 75 (60.5%) had some degree of epithelial dysplasia and 31 (25.0%) were LSCC. Clinically, most of the lesions were diagnosed as AC (50.8%); however, eight cases clinically reported as AC were histologically diagnosed as LSCC. Regarding clinical characteristics, most individuals were fair-skinned male, with mean age of 54.3±12.3 years, and with a history of long-term solar exposure. Furthermore, 18 articles were selected from the literature, showing that the lower lip was predominantly affected and that most individuals were males, fair-skinned, and older than 40 years.ConclusionsSince most of the cases diagnosed clinically as AC presented some degree of epithelial dysplasia, it is important to emphasize the value of biopsy and the histological evaluation of this lesion. Key words:Actinic cheilitis, Precancerous conditions, In situ carcinoma, Oral diagnosis, Mouth neoplasms.