[Precancers of the oral mucosa: clinic, diagnostics]. / Predraki slizistoi obolochki rta: klinika i diagnostika.

OBJECTIVE: The aim of the study. Improving the efficiency of diagnosis and detailing the features of the clinic of «potentially malignant¼ diseases of the oral mucosa. MATERIALS AND METHODS: Clinical and laboratory examination of 124 patients of the department of oral mucosa diseases aged 35 to 80 years, among whom there were 75 women and 49 men, with diseases such as erythroplakia - 12 patients, verrucous leukoplakia - 52 patients, erosive form of leukoplakia - 35 patients, cheilitis Manganotti - 25 patients. Histological and immunohistochemical methods of investigation were used as diagnostics. To assess the proliferative activity of epithelial cells, the determination of the Ki-67 index was used. The synthesis of keratin 15 (K15) in epithelial layers was determined as a diagnostic criterion for the severity of neoplasia. The expression of human papillomavirus type 16 (HPV 16) antigens and p16INK4a protein in epithelial cells was studied, as well as the expression of p53 protein. RESULTS: A high prevalence of p53 mutations was observed in patients with erythroplakia. In leukoplakia, the expression of the Ki-67 protein was detected in the cell nuclei in both the basal and parabasal layers of the multilayer squamous epithelium, in 77% of cases, the expression of the p16INK4a protein in the epithelial nuclei with varying degrees of dysplastic changes was noted, and a positive reaction to HPV16 was also observed in the cell nuclei and cytoplasm of epithelial cells in the basal, parabasal and spiny epithelial layers. The appearance of K15 in the cytoplasm of cells above the basal layer with abrasive precancerous cheilitis was found in 48% of cases. CONCLUSION: To diagnose early manifestations of neoplastic processes in «potentially malignant¼ diseases of the oral mucosa, it is necessary to use both classical histological and immunohistochemical methods of investigation with various markers.

Treating erythroplasia of Queyrat with photodynamic therapy following circumcision and dermabrasion.

We describe a case of a patient with erythroplasia of Queyrat located on the whole glans and end of the prepuce that was successfully treated with three courses of photodynamic therapy after the completion of circumcision and dermabrasion. Skin lesions disappeared after receiving this combination of treatments and have not recurred during the past 6 months of follow-up.

Oral erythroplakia and oral erythroplakia-like oral squamous cell carcinoma - what's the difference?

BACKGROUND: Oral erythroplakia (OE) is a rare oral potentially malignant disorder, that has a high rate of malignant transformation. The definition of OE still lacks uniformity. In particular, lesions that look clinically like erythroplakias, but are histopathologically diagnosed as squamous cell carcinomas are still sometimes called erythroplakias. The purpose of this study is to present demographic and clinicopathologic features of a series of OEs and clinically oral erythroplakia -like squamous cell carcinomas (OELSCC), to study their differences and to discuss the definition of OE. METHODS: A multicenter retrospective case series of OEs and OELSCCs. Descriptive statistics were used to analyze the data. RESULTS: 11 cases of OEs and 9 cases of OELSCCs were identified. The mean age of the OE patients was 71 years and 72.7% were female, while the mean age of the OELSCC patients was 69 years, and all were female. 9% of the OE and 22% of the OELSCC patients had smoked or were current smokers. 72.7% of the OEs and 55.5% of OELSCCs were uniformly red lesions. 63.6% of the OE and 22% of the OELSCC patients had a previous diagnosis of oral lichenoid disease (OLD). The malignant transformation rate of OE was 9% in a mean of 73 months. CONCLUSIONS: OE and OELSCC may arise de novo or in association with OLD. Tobacco and alcohol use were not prevalent in the present cases. The clinical features of OEs and OELSCC are similar, but symptoms, uneven surface and ulceration may be more common in OELSCCs than in OEs. Clinical recognition of OE is important since it may mimic other, more innocuous red lesions of the oral mucosa. The diagnosis of OE requires biopsy and preferably an excision. Clarification of the definition of OE would aid in clinical diagnostics.

Critical update, systematic review, and meta-analysis of oral erythroplakia as an oral potentially malignant disorder.

BACKGROUND: Oral erythroplakia has been classically considered as the potentially malignant disorder with the highest rate of malignant development into squamous cell carcinoma. This critical systematic review and meta-analysis aim to estimate the malignant development rate of oral erythroplakia and identify the associated risk factors. METHODS: We performed a bibliographic search in PubMed, Scopus, Web of Science, Embase, and LILACS, with keywords "erythroplakia," "erythroplasia," "malignant transformation," "malignant development," "malignization," "carcinogenesis," "oral cancer," "oral squamous cell carcinoma," "mouth neoplasm," and "prognosis." Meta-analysis was conducted using a random-effects model. RESULTS: Ten observational studies with 441 patients met the inclusion criteria, whose mean malignant development rate was 12.7% and with a mean follow-up period of patients of 6.66 years. In the initial biopsy, 42.8% of oral erythroplakia were already squamous cell carcinoma. The buccal mucosa was the most frequent location of oral erythroplakia, but the floor of the mouth was the most common site of malignant development. All patients who underwent malignant development showed epithelial dysplasia on the initial diagnostic biopsy. CONCLUSION: Overall malignant development rate of OE in the meta-analysis was 19.9%. We could not associate any specific clinicopathological feature with the malignant development. The presence of epithelial dysplasia in the initial biopsy remains the worst prognostic factor. Further observational studies on OE are needed, with well-established diagnostic criteria and good clinical follow-up, in order to identify the true risk of malignant development of oral erythroplakia and the related risk factors.

Oral leukoplakia, leukoerythroplakia, erythroplakia and actinic cheilitis: Analysis of 953 patients focusing on oral epithelial dysplasia.

BACKGROUND: To analyse the clinical and histological characteristics from a series of oral leukoplakias, leukoerythroplakias, erythroplakias and actinic cheilitis diagnosed in a 14-year period. METHODS: The files were reviewed and all cases diagnosed as leukoplakia, leukoerythroplakia, erythroplakia and actinic cheilitis were selected. Clinical information was obtained from the biopsy submission forms, and histological review was performed in all cases. RESULTS: Final sample included 953 lesions, mostly affecting females (534, 56%), and 87.5% of the patients were 41 to 80 years old. The most commonly affected regions were the lower lip (20.1%), tongue (18.1%) and buccal mucosa (16.9%). Leukoplakias, actinic cheilitis, leukoerythroplakias and erythroplakias represented, respectively, 74.6%, 15.2%, 9.3% and 0.8% of the sample. Most cases presented no dysplasia (42.1%) or mild dysplasia (33.5%). Lesions in the tongue, floor of mouth and lower lip, as well as lesions that presented hyperparakeratosis, showed higher frequencies of moderate dysplasia and severe dysplasia/carcinoma in situ. The most common histological criteria were the increase in number and size of nucleoli, loss of polarity of the basal cells and variations in cellular size and shape. Classification by the binary system showed that 7% were high-risk lesions. CONCLUSION: All histological criteria for classification of oral epithelial dysplasia recommended by the World Health Organization showed increased frequency as grading increased. Additional criteria seem to be useful in grading oral epithelial dysplasia, such as the presence of normal and abnormal superficial mitotic figures and endophytic epithelial proliferation.

Evaluation of P53 gene expression by immunohistochemistry to diagnosis oral precancerous lesions.

Oral Precancerous lesions include leukoplakia, erythroplakia, and mucosa palate changes due to reverse smoking. Assessing the prevalence of these lesions in a cross-sectional study can be effective in the timely prevention and treatment of lesions, in any community. Hence, in the present study, evaluation of P53 gene expression was done by immunohistochemistry method to diagnosis oral precancerous lesions. For this purpose, 111 Chinese patients (54 women and 57 men) were selected for examination. The age range of these patients was 22 to 69 years, and their average age was 32.6 years. All patients were examined by one physician. Oral mucosa was used for immunohistochemical evaluations. All samples taken from patients' mucosa were evaluated by one pathologist under a light microscope. 80 cases of the 111 patients were smokers and 27 were non-smokers. Among the 80 smokers, 56.25% had leukoplakia, 3.75% had erythroplakia, and 40% had mucosa palate changes. Regarding non-smokers, 74.07% had leukoplakia and 25.93% had erythroplakia. None of the non-smokers had mucosa palate changes. In terms of the lesion location, in patients with leukoplakia 89.23%, and patients with erythroplakia 90% of the lesion was located in the cheek mucosa and buccal vestibule. Also, in patients with leukoplakia 9.23%, and patients with erythroplakia 10% of the lesion was located in the lips vestibular mucosa. Only 1.54% of leukoplakia had a lesion in the vermilion border, and none of the erythroplakia patients had a lesion on the vermilion border. 76 patients (68.46%) showed positive expression of the P53 gene. The expression level of the P53 gene did not show a significant relationship with age, and the genders did not have a statistically significant difference in terms of gene expression. The expression level of the P53 gene was 59.8% in leukoplakia, 70% in erythroplakia, and 40% in Mucosa palate changes. The present study showed that the evaluation of P53 gene expression was well able to detect oral precancerous lesions and their severity by increasing their expression rate.

Diabetes mellitus and oral cancer/oral potentially malignant disorders: A systematic review and meta-analysis.

The objective was to evaluate current evidence on the prevalence and risk of oral cancer and potentially malignant oral disorders among patients with diabetes mellitus. We searched PubMed, Embase, Web of Science, and Scopus for observational studies published before November 2019. We evaluated the study quality using GRADE, QUIPS, and a specific method for systematic reviews addressing prevalence questions. Meta-analyses were conducted, and heterogeneity and publication bias were examined. A total of 1,489 studies were found, 116 analyzed in full text, 52 included in qualitative synthesis and 49 meta-analyzed. Pooled prevalence (PP) of oral cancer in patients with diabetic was 0.25% (95% CI = 0.15-0.39)-250 per 100,000 patients with diabetes mellitus -with a greater chance of oral cancer among patients with diabetes mellitus (OR = 1.41 [95% CI = 1.10-1.81], p = .007). Patients with oral cancer and diabetes mellitus had a higher mortality than controls (HR = 2.09 [95%CI = 1.36-3.22], p = .001). Leukoplakia had a PP = 2.49% (95% CI = 1.14-4.29)-2,490 per 100,000 patients with diabetes mellitus -(OR = 4.34 [95% CI = 1.14-16.55], p = .03). A PP of 2.72 (95% CI = 1.64-4.02) was obtained for oral lichen planus among patients with diabetic -2,720 per 100,000 patients with diabetes mellitus (OR = 1.87 [95% CI = 1.37-2.57], p < .001). A low PP was estimated for erythroplakia (0.02%[95%CI = 0.00-0.12]-20 per 100,000 patients with diabetes mellitus. In conclusion, patients with diabetes mellitus have a higher prevalence and greater chance of oral cancer and OPMD development in comparison with non-diabetic patients. In addition, patients with oral cancer suffering from diabetes mellitus have a higher mortality compared to non-diabetic patients with oral cancer.

[Optimization of the diagnosis of precancerous diseases of the oral mucosa and lips (Manganotti's abrasive precancerous cheilitis and erythroplakia)]. / Optimizatsiya diagnostiki predrakovykh zabolevanii slizistoi obolochki rta i krasnoi kaimy gub (abrazivnyi prekantseroznyi kheilit Manganotti i eritroplakiya).

OBJECTIVE: To optimize the identification of precancerous diseases of the oral mucosa, such as Manganotti's abrasive precancerous cheilitis and erythroplakia of the oral mucosa using markers Ki-67 and keratin 15. MATERIAL AND METHODS: The study group included 17 patients with Manganotti's abrasive precancerous cheilitis and 8 with erythroplakia of the oral mucosa. A histological analysis was carried out to scrutinize the biopsy material of the oral mucosa of the patients. Ki-67 protein and keratin 15 were used to assess the proliferative activity of epithelial cells and the severity of neoplasia. Results. Thirteen patients with Manganotti's cheilitis had dysplasia of varying degrees, and 4 had signs of malignancy. A high proliferative activity of the Ki-67 protein was found in the stratum basal and stratum spinosum of the epithelium. In 5 patients with erythroplakia, according to histological examination, grade 2-3 intraepithelial neoplasia was revealed and 3 patients had cancer in situ. The expression of keratin 15 in all patients with Manganotti's abrasive precancerous cheilitis and erythroplakia in the basal layer tended to decrease with an increase in the degree of dysplasia, however, the appearance of keratin 15 in the cytoplasm of cells located above the basal layer was discovered. CONCLUSION: The use of Ki-67 protein and keratin 15 as immunohistochemical markers in the study of diseases such as Manganotti's abrasive precancerous cheilitis and erythroplakia of the oral mucosa makes it possible to identify the initial signs of malignancy more accurately in the epithelium.

Oral potentially malignant disorders: clinical-pathological study of 684 cases diagnosed in a Brazilian population.

BACKGROUND: The frequency and distribution of oral potentially malignant disorders (OPMD) may vary among different populations. The aim of the present study was to evaluate the clinical-pathological characteristics of OPMD diagnosed in a Brazilian oral pathology laboratory over a period of 11 years. MATERIAL AND METHODS: All cases diagnosed as leukoplakia, speckled leukoplakia, erythroplakia, and actinic cheilitis from 2005 to 2015 were analyzed. Clinical information was obtained from laboratory forms and histological information was obtained from histological slides stained with hematoxylin and eosin. RESULTS: the final sample was comprised of 684 cases, of which 292 were males and 392 were females. The mean age was 58 years. The anatomical site most often involved was the lateral border of the tongue (23%), followed by the lower lip (20%), and by the buccal mucosa/vestibule (18%). Leukoplakia accounted for 82% of the sample (564 cases). The mean size of the leukoplakia and speckled leukoplakia lesions was 13 mm (ranging from 1 to 100 mm) and 15 mm (ranging from 5 to 30 mm), respectively (p=0.460). Males reported smoking and drinking alcohol more frequently than females (p=0.001 and p<0.0001, respectively). In half of the cases, dysplasia was not histologically detected, while slight dysplasia was detected in 28% of the cases. The lesions from patients aged from 41 to 80 years presented moderate and severe dysplasia more often than lesions from patients in other age groups. CONCLUSIONS: OPMD were more common in females in their sixties. Females were more frequently affected in all anatomical sites, except for the lips. Leukoplakia lesions were the most common OPMD, followed by actinic cheilitis. The lateral border of the tongue was the most affected anatomical site. OPMD located in the floor of the mouth/sublingual mucosa and lesions from older patients presented severe epithelial dysplasia with greater frequency.

Recognition of oral potentially malignant disorders and transformation to oral cancer.

Oral potentially malignant disorders refer to oral mucosal disorders with increased risk for malignant transformation, primarily to oral squamous cell carcinoma (SCC). Leukoplakia and erythroplakia are the most common of these disorders, but others have been identified. Transformation rates to oral cancer vary based on multiple factors. Healthcare providers should be aware of risk factors and clinical manifestations of these disorders and should intervene early to monitor and/or treat them to reduce the potential for malignant transformation.

White, red, and mixed lesions of oral mucosa: A clinicopathologic approach to diagnosis.

A wide range of conditions could present as persistent white or red, or mixed white and red patches on the oral mucosa. Discussed here are some common conditions encountered in clinical practice that appear as white or red patches, together with some rare, but clinically significant, conditions. Based on pathognomonic features, major diagnostic criteria are outlined to help with the differential diagnosis, while some require further investigation (eg, biopsy and/or microbiologic or hematologic investigation) to confirm the provisional clinical diagnosis. Two conditions that require special consideration are leukoplakia and erythroplakia, as they have the potential to transform to cancer.

Smokeless tobacco use and oral neoplasia among urban Indian women.

OBJECTIVES: Oral cavity cancers are fourth most common cancers among Indian women. The objectives were to create cancer awareness (CA) and screen tobacco-using women for oral cavity cancers. MATERIALS AND METHODS: A community-based CA and screening programme was conducted among women in Mumbai, India. The tobacco-using women participated in CA and oral cavity screening by oral visual inspection (OVI). All screen-positive women were referred to nodal hospital and assisted for diagnostic confirmation and treatment completion. RESULTS: Twelve slum clusters comprising of 138,383 population and 13,492 tobacco-using women have been covered. Among them, 11,895 (88.2%) participated in CA and 11,768 (87.2%) in OVI. A total of 377 (3.2%) women were screened positive, 275 (72.9%) complied with referral and 207 oral precancers [173 leukoplakia, 9 erythroplakia, 3 erythroleukoplakia and 41 sub-mucus fibrosis (SMF) including 35 women with multiple precancers] and 7 oral cancers were diagnosed. The detection rate of oral precancerous lesions and oral cancers was 17.6 and 0.6 per 1,000 screened women. Thirty-five women had multiple oral precancerous lesions. The results of multivariate analysis indicate dose-response relationship between tobacco use and risk of oral precancers. CONCLUSION: Good participation rates (>85%) for cancer awareness and OVI were seen among urban slum women in India. Many oral precancer and cancer cases were detected and were managed at the nodal hospital.

Impact of oral potentially malignant disorder subtypes on all-cause and cause-specific mortality in males.

OBJECTIVES: To quantify the effect of oral potentially malignant disorder (OPMD) subtypes on mortality from oral cancer and type 2 diabetes among areca nut chewers and/or cigarette smokers. MATERIALS AND METHODS: A retrospective cohort design was devised to follow 14,749 men attending community-based screening program for oral cancer between 1998 and 2000 and followed until 2010. The Cox proportional hazards regression model was applied to assess the effect of OPMD on death. RESULTS: A total of 1,291(8.75%) patients were detected as OPMD. Among those free of T2DM at baseline, the elevated risk for death from T2DM was noted for OSF (aHR = 3.62, 95% CI: 1.25-10.51) and erythroplakia (aHR = 5.01, 95% CI: 1.17-21.45). The elevated risk for all-cause death for OPMD was mainly explained by deaths from oral cancer and T2DM but not other causes of death. CONCLUSIONS: Oral potentially malignant disorder, particularly OSF and erythroplakia, in male cigarette smokers and/or areca nut chewers led to an incremental elevated risk of T2DM mortality in the way of being distal to the occurrence of T2DM, implying that early detection and prevention of OPMD may not only reduce oral cancer mortality but also result in the reduction of T2DM mortality.

Accuracy of dermoscopy in distinguishing erythroplasia of Queyrat from common forms of chronic balanitis: results from a multicentric observational study.

BACKGROUND: Clinical differentiation of erythroplasia of Queyrat (EQ) and chronic forms of balanitis may be challenging, especially in early phases or in overlapping cases. Dermoscopy has been shown to be a useful supportive tool in facilitating the distinction between tumoral and inflammatory skin conditions; yet, data on EQ and balanitis are scarce or sparse. OBJECTIVES: To systematically assess the dermoscopic features of both EQ and common forms of chronic balanitis and to investigate the accuracy of dermoscopy in distinguishing these conditions. METHODS: Subjects with EQ or chronic balanitis confirmed histologically or microbiologically (for infectious forms) were recruited. A representative dermoscopic image of a target lesion was retrospectively assessed for the presence of specific morphological findings. A correlation matrix was created using Spearman's rho. Proportions of dermoscopic variables scoring among different conditions were compared with the non-parametric Pearson's chi-square test. RESULTS: A total of 81 lesions (14 EQ, 23 psoriasis, 31 Zoon plasma cell balanitis and 13 candidal balanitis) from 81 patients were included in the study. Glomerular vessels (both clustered and diffusely distributed) were highly predictive for the diagnosis of EQ, while diffuse dotted vessels were strongly associated with psoriatic balanitis. Finally, Zoon plasma cell balanitis was characterized by orange structureless areas (focal or diffuse) and focused linear curved vessels, whereas cottage cheese-like structures (sparse white coating corresponding to Candida yeast colonies growth) showed a strong correlation with candidal balanitis. CONCLUSIONS: Erythroplasia of Queyrat and balanitis may display different dermoscopic patterns, thereby bearing the usefulness of dermoscopy as a supportive non-invasive tool for the recognition and differential diagnosis of such conditions.

Dermatoscopic findings of penile intraepithelial neoplasia: Bowenoid papulosis, Bowen disease and erythroplasia of Queyrat.

BACKGROUND/OBJECTIVES: The clinical diagnosis of penile intraepithelial neoplasia is challenging. No specific dermoscopic criteria for penile intraepithelial neoplasia have been described in the literature. This study aimed to describe and evaluate the dermoscopic features of penile intraepithelial neoplasia. METHODS: Clinical and dermoscopic images of 11 patients with histopathologically confirmed penile intraepithelial neoplasia were recorded and evaluated. RESULTS: The most frequent dermoscopic features were the presence of structureless areas (100%, structureless pink 72.7%) and vascular structures (81.8%), particularly dotted vessels (72.7%). Other findings included the absence of a pigment network (100%); scale (45.5%); scar-like areas (45.5%); erosions (27.3%); and pigmentation consisting of brown-grey dots and globules (27.3%). CONCLUSIONS: The dermoscopic features that characterise penile intraepithelial neoplasia are structureless pink areas and a prominent vascular pattern (mainly clustered dotted vessels). Dermoscopy is a useful tool that can aid in the diagnosis and surveillance of penile intraepithelial neoplasia.

Bibliometric analysis of a century of research on oral erythroplakia and leukoplakia.

BACKGROUND: Oral squamous cell carcinoma is a major cause of cancer-associated morbidity and mortality and may develop from oral erythroplakia and leukoplakia (OEL), the most common oral potentially malignant lesions. Our objective was to provide a descriptive overview of the global research activity on OEL over the past decades. METHODS: We performed a systematic bibliometric analysis of articles and reviews on OEL up to December 31st 2016 using the SCOPUS database. Contribution of each country was analyzed by density-equalizing mapping (DEMP). The overall scientific productivity was analyzed for each journal and country. RESULTS: A total of 5098 published items (articles or reviews) were identified. They are expected to double by 2040, with an expected number of 400 items per year. Only 4% of all research on oral oncology is focused on OEL. Together with the increasing number of publications since 1980s, an increasing number of international collaborative studies were observed. Journal of Oral Pathology and Medicine and Oral Oncology are the leading journals in terms of number of published items. The US, India, and the UK were the most prolific countries in terms of publications overtime. CONCLUSIONS: We identified the leading journals as well as the leading authors and countries contributing to the research on OEL. International collaborative studies in the field are to be encouraged to refine strategies of oral cancer prevention.

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

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.

Oral erythroplakia-What is it?

Oral erythroplakia is a rare type of lesion, and little is known about the origin of the lesion. It has traditionally been described as the red counterpart of oral leukoplakia, which implies that it is a red lesion that cannot be characterized clinically or pathologically as any other definable lesion. A definition by exclusion is less satisfactory than a positive description to define a lesion, and as erythroplakia probably is related to lichenoid lesions, a new approach to perceive the lesion is proposed based on the clinical features of a fiery red, sharply demarcated lesion situated at a slightly lower level than the surrounding mucosa. Such a definition would probably help clinicians distinguish erythroplakia from other red lesions of the oral mucosa. Although the course of such lesions varies, a significant proportion will develop malignancy, which is why they should be followed at short intervals.

[Precancerous lesions of the buccal epithelium]. / Les lésions précancéreuses épithéliales buccales.

Squamous cell carcinomas of the oral cavity and lips consistently have a high incidence (they constitute the fifth most common form of cancer in France) and carry a heavy prognosis, particularly if diagnosed late. According to different studies, between 10 and 80% of such carcinomas occur in a pre-existing or precancerous lesion. The World Health Organisation (WHO) recommends the use of two terms for such lesions: precursor lesions, i.e. histological lesions associated with intraepithelial neoplasia (IEN) and verrucous hyperplasia (VH), frequently resulting clinically in leukoplakia or erythroplakia; "at risk" lesions, which include lichen planus, submucosal oral fibrosis and certain forms of genodermatosis.

Prevalence and factors associated with oral potentially malignant disorders in Brazil's rural workers.

OBJECTIVES: To determine the prevalence of oral potentially malignant disorders (OPMDs) in a population of rural workers in the northeast of Brazil and to investigate the association with sociodemographic, occupational, and health factors. METHODS: A total of 1385 workers answered a validated questionnaire and were examined by calibrated dentists. A descriptive analysis, chi-square homogeneity test, and binary logistic regression were performed. RESULTS: The prevalence of OPMDs was 29.6%. Actinic cheilitis was the most predominant (28.4%), followed by leukoplakia (2.3%) and erythroplakia (0.3%). Gender, type of skin, and time exposed to the sun explained the presence of OPMD (P < 0.0001). The study found increased prevalence, especially for males over the age of 60 years and being exposed to the sun for more than 45 years. CONCLUSION: Rural workers showed high vulnerability to the presence of OPMDs, as estimated prevalence exhibited was high.