The epidemiology of oral and pharynx cancer in Brazil

Dietary patterns and risk of oral and pharyngeal cancer: a case-control study in Rio de Janeiro, Brazil

The study investigated the association between dietary patterns and oral cancer as part of a Latin American multicenter hospital-based case-control study, and included 210 incident cases of oral cancer and 251 controls. Dietary data were collected using a Food Frequency Questionnaire (FFQ). Factor analysis was used to define dietary patterns, which were categorized into terciles. Odds ratios (OR) with 95% confidence intervals (95%CI) were calculated using unconditional multiple logistic regression. The patterns "prudent", characterized mainly by vegetables and fruits, and "traditional", by rice, and pulses showed an inverse association with oral cancer for the higher tercile, respectively, OR = 0.44; 95%CI: 0.25-0.75, p value for trend (p tend) = 0.03; OR = 0.53; 95%CI: 0.30-0.93, p tend = 0.06. The "snacks pattern" was not associated with oral cancer. Besides the protective effect of a diet rich in vegetables and fruit, our data suggest that the traditional Brazilian diet, consisting mostly of rice and beans, may improve protection against oral cancer.

Prognostic factors in squamous cell carcinoma of the oral cavity

Researchers have been looking for factors that can influence the prognosis of oral cancer, because its outcome is highly uncertain. Aim: To evaluate variables that can impact the survival rate of patients with squamous-cell carcinoma of the oral cavity. Material and Methods: Data analysis of 45 patients from January, 2001 to January, 2006. Survival rate curves have been estimated using the Kaplan-Meier method and they have been compared through the log-rank test and the Cox regression standard. Study design: Retrospective analysis. Results: Total five-year survival rate was of 39% fpr these patients. Only the neck metastases (p=0.017), postoperative radiotherapy (p=0.056) and diseased margin(p=0.004) variables had statistic relevance. Survival rate was lower in patients with neck metastases, margins involved and those who underwent postoperative radiotherapy, in other words, those with the most aggressive tumors. After adjustment, radiotherapy did not prove to be statistically relevant. It is likely that the survival rate of 39% was due to the high number of patients with metastasis (52%) and because the samples were mostly of tongue and mouth floor diseases (82%), which are the hardest to control. Conclusion: Neck metastases and diseased margins of oral cavity carcinomas are the prognostic factors that can most impact the survival rate.

Oral carcinoma epidemiology in Paraná State, Southern Brazil

Oral carcinoma is the sixth most frequent type of cancer in the world and the seventh most common in Brazil (the country with the highest incidence in Latin America). Mean five-year survival remains one of the lowest among the main cancers, thus justifying studies that contribute to the development of preventive strategies. The aim of this study was to compare the epidemiological, clinical, and histological characteristics of 91 patients with oral carcinoma. Mean age was 58.62 +/- 10.46 years, and male-to-female ratio was 6.6:1.0 (79 men and 12 women). European descendants predominated with 79 patients (86.8%). Eighty-five individuals (93.4%) smoked and 70 (76.9%) consumed alcohol regularly. Anatomical distribution of tumors was: 27 (29.7%) tongue; 18 (19.8%) floor of mouth; 11 (12.1%) oropharynx; and 11 (12.1%) oral mucosa. Fifty-seven patients (62.6%) presented lymph node involvement and three (3.3%) had distant metastases. Surgery and radiotherapy were used in 43.2% of patients. With the exception of the male/female ratio (which was higher), our data are consistent with previous studies on oral carcinoma patients.

Sociodemographic and etiologic differences of malignant orofacial tumors in Iran

Oral malignant tumors are the sixth most common malignancy in the world, and there is a recent trend of rising incidence of these tumors in young patients. The aim of this study was to compare demographic and etiologic data from young and old patients with orofacial malignant tumors. Data were obtained by retrospective analysis of files of patients with malignant orofacial tumors, who were categorized into 2 groups: the young group (< or = 40 years old) an the older group (> 60 years old). Both younger and older groups showed male predilection (male-female ratio was 1.05:1 and 2.4:1 in the younger and older groups, respectively). Consumption of tobacco and alcohol was reported by 13 young patients (31.7%) and by 45 older patients (62.5%). Tongue was the most common site for older group (37.5%), whereas that for the younger group was the parotid (29.3%). We found that the pattern of malignant orofacial tumors in the young age group was changed, and these tumors can occur in young patients who report no tobacco or alcohol use.

[Oral cancer epidemiology in a public laboratory in Mato Grosso State, Brazil]

This study analyzed oral cancer epidemiology based on histopathology reports from a public laboratory in Mato Grosso, Brazil, after a specific policy was implemented for treating oral and facial diseases in the State. This was a cross-sectional epidemiological study, based on 1,324 histopathology reports issued from January 2005 to December 2006. The study identified 44 cases of oral cancer, or 3% of all oral lesions, and analyzed them in relation to the following variables: histological type, gender, age, and patient's place of residence (capital versus rest of State). The most common histological type was squamous cell carcinoma. Most of the diagnoses occurred in men in their 50s and 60s living in the interior of the State. During two years in operation, this public oral pathology service had recorded a considerable number of oral cancer cases.

Clinical analysis of head and neck cancer cases in south-west China 1953 - 2002

The occurrence of head and neck cancers varies worldwide. This study retrospectively analysed the incidence and types of 8646 cases of head and neck cancers in south-west China that were treated at the West China Stomatology Hospital of Sichuan University between 1953 and 2002. Overall mean patient age was 50.3 years and the overall male:female ratio was 2.38:1; mean age increased and the male:female ratio decreased over the study period. Peak incidence occurred between the ages of 40 and 60 years. Primary tumours most frequently developed in the tongue, followed by the bucca and gingiva. Histologically, squamous cell carcinomas were most frequently recorded. The parotid gland and palate were the most common locations for salivary gland tumours. Over the study period the incidence of head and neck cancers increased with time and the rate of increase was greater in females than males. The frequency of histological types and topography were similar to previous reports.

Analysis of 724 cases of primary head and neck squamous cell carcinoma (HNSCC) with a focus on young patients and p53 immunolocalization

This study evaluated 724 primary head and neck squamous cell carcinoma (HNSCC) in young and old patients, with regard to clinical profile and immunohistochemical expression of p53 protein. Associations among age, epidemiological and clinicopathological parameters, and survival analysis were evaluated. HNSCC in young people occurred in 14.5% (median age 40.7years; male-to-female ratio 5.9:1). A statistical association was demonstrated between age and family history of cancer, and between age and anatomical site. Among older patients, a higher presence of disease was noted in posterior sites. Expression of p53 was found in 71.7% of the samples and a higher expression was noted in lesions of young patients. Survival analysis showed that the age parameter is not a reliable prognostic factor for HNSCC. Among young patients, cervical metastasis was associated with worse survival. The presence of a family history of cancer in young patients could indicate genetic susceptibility and molecular disturbances in the p53 pathway in HNSCC of young and older patients seem to be distinct.

[Infant mortality from preventable causes in Brazil: an ecological study in 2000-2002]

This study aims to test the associations between infant mortality from preventable causes in Brazil and socioeconomic factors, including those pertaining to health services and investments. This was an ecological study using 296 Brazilian counties (municipalities) with more than 80,000 inhabitants each as the analytical units. Kruskall-Wallis and ANOVA tests were performed to compare independent variables according to infant mortality quartile, and Pearson and Spearman's correlation coefficients were computed to test the associations. As the infant mortality quartile from preventable causes increases, there is a gradual decrease in the municipal human development index, per capita gross domestic product, households with bathrooms and indoor plumbing, total health expenditures per inhabitant, and physicians per 1,000 inhabitants, and an increase in the Gini coefficient. Improved socioeconomic conditions and public health investments are strongly associated with reduction of infant mortality from preventable causes. This knowledge should permeate actions aimed at minimizing the number and unequal distribution of such deaths.

Changes in immunoexpression of E-cadherin and beta-catenin in oral squamous cell carcinoma with and without nodal metastasis

The aim of this study is to analyze the immunohistochemical expression of E-cadherin and beta-catenin in oral squamous cell carcinoma to better understand the biological behavior of this lesion. The sample consisted of 15 cases of the tongue and 15 of the lower lip. The pattern and intensity of the labeling and the analysis of the percentage of tumor cells immunopositive in membrane for E-cadherin and beta-catenin were related to the anatomic location of the lesion, the presence or absence of nodal metastasis, and the histological gradation of malignancy in the tumor invasion front. The presence or absence of cytoplasmic and nuclear labeling was also recorded. The membrane expression for E-cadherin and beta-catenin predominately displayed a heterogeneous pattern in the carcinomas studied. No significant difference was observed between the expression pattern and the quantity of cells immunopositive for E-cadherin and beta-catenin and the anatomic location of the lesion or the presence or absence of nodal metastasis. However, a statistically significant difference was found between the reduced expressio\n of these proteins and the high malignancy score. The reduced immunoexpression of these proteins in the membrane may be related to the high degree of cell indifferentiation in cases of oral squamous cell carcinoma with high scores.

Inequalities in mortality of men by oral and pharyngeal cancer in Barcelona, Spain and São Paulo, Brazil, 1995-2003

Background

Large inequalities of mortality by most cancers in general, by mouth and pharynx cancer in particular, have been associated to behaviour and geopolitical factors. The assessment of socioeconomic covariates of cancer mortality may be relevant to a full comprehension of distal determinants of the disease, and to appraise opportune interventions. The objective of this study was to compare socioeconomic inequalities in male mortality by oral and pharyngeal cancer in two major cities of Europe and South America.

Methods

The official system of information on mortality provided data on deaths in each city; general censuses informed population data. Age-adjusted death rates by oral and pharyngeal cancer for men were independently assessed for neighbourhoods of Barcelona, Spain, and São Paulo, Brazil, from 1995 to 2003. Uniform methodological criteria instructed the comparative assessment of magnitude, trends and spatial distribution of mortality. General linear models assessed ecologic correlations between death rates and socioeconomic indices (unemployment, schooling levels and the human development index) at the inner-city area level. Results obtained for each city were subsequently compared.

Results

Mortality of men by oral and pharyngeal cancer ranked higher in Barcelona (9.45 yearly deaths per 100,000 male inhabitants) than in Spain and Europe as a whole; rates were on decrease. São Paulo presented a poorer profile, with higher magnitude (11.86) and stationary trend. The appraisal of ecologic correlations indicated an unequal and inequitably distributed burden of disease in both cities, with poorer areas tending to present higher mortality. Barcelona had a larger gradient of mortality than São Paulo, indicating a higher inequality of cancer deaths across its neighbourhoods.

Conclusion

The quantitative monitoring of inequalities in health may contribute to the formulation of redistributive policies aimed at the concurrent promotion of wellbeing and social justice. The assessment of groups experiencing a higher burden of disease can instruct health services to provide additional resources for expanding preventive actions and facilities aimed at early diagnosis, standardized treatments and rehabilitation.

Oral health, hygiene practices and oral cancer

OBJECTIVE: To assess the association between oral health and hygiene practices and oral cancer. METHODS: Hospital-based case-control study in the metropolitan area of São Paulo, southeastern Brazil, from 1998 to 2002. A total 309 patients with squamous cell carcinoma of the mouth and the pharynx and 468 controls matched by sex and age were included in the study. Cases were recruited in seven reference hospitals and controls were selected in five out of the seven participating hospitals. Detailed information on smoking, alcohol consumption, schooling, oral health status and hygiene practices were obtained through interviews. Odds ratios (OR) and 95% confidence intervals (95% CI), adjusted by sex, age, schooling, smoking, alcohol consumption as well as the variables oral health status and hygiene practices were estimated using unconditional logistic regression analyses. RESULTS: The use of complete dental prosthesis was not associated with oral cancer but regular gum bleeding showed a strong association (OR 3.1; 95% CI 1.2-7.9). Those who never attended a dental visit were more likely to have oral cancer (OR 2.5; 95% CI 1.3-4.8). Daily mouthwash use showed a stronger association to pharynx (OR 4.7; 95% CI 1.8-12.5) than mouth cancer (OR 3.2; 95% CI 1.6-6.3). CONCLUSIONS: Gum bleeding, no dental care, and daily mouthwash use were factors associated with oral cancer regardless of tobacco and alcohol consumption.

Radiographic and histological evaluation of bisphosphonate alendronate and metotrexate effects on rat mandibles inoculated with Walker 256 carcinosarcoma

PURPOSE

To investigate the effects of bisphosphosnate alendronate (ALD) and metotrexate (MTX) on an experimental model of Walker 256 carcinosarcoma developed in the oral cavity of rats. METHODS Walker 256 carcinosarcoma cell suspension (0,1 mL) containing 10(6) cell/mL was implanted in the alveoli of the first and second molars. The animals were divided and treated with saline, MTX, ALD, and MTX plus ALD. Later, the animals were sacrificed, the tumors were measured and the mandibles were removed for radiographic and histological analysis.

RESULTS

In the control group, the radiographic images demonstrated radioluscency with poorly defined borders, and the microscopic examination revealed tumor infiltration into the peripheral and central regions of the bone. Areas of necrosis were commonly seen. In the treated groups with ALD, associated or not with MTX, the radiographic analysis revealed circumscribed tumor-induced osteolysis and various degrees of radiotransparence; while, histologically, preserved bone trabeculae with osteoid formation was observed among malignant cells.

CONCLUSION

The bisphosphonate alendronate exherted an osteoprotective effect and induced bone neoformation on the Walker 256 carcinosarcoma inoculated in rat mandibles. The combination of metotrexate with bisphosphonate alendronate is more successful than treatment with the agents alone in controlling the growth of neoplastic cells and in stimulating reactive new bone. Therefore, this may be an alternative treatment to malignant lesions of maxillaries with osteolysis.

[Dietary factors and oral cancer: a case-control study in Greater Metropolitan São Paulo, Brazil]

Dietary factors associated with oral cancer were investigated in a case-control hospital-based study in the city of São Paulo, Brazil, from 1998 to 2002. A total of 835 subjects, 366 with histologically confirmed incident cases of oral-cavity or pharyngeal cancer and 469 controls participated in the study. Dietary data were collected with a food frequency questionnaire (FFQ). Odds ratios (OR) and 95% confidence intervals (95%CI) were obtained from unconditional logistic regression, adjusted for potential confounders. Inverse associations with risk of oral cancer were found for the highest intake of beans, OR = 0.37 (95%CI: 0.22-0.64), raw vegetables, OR = 0.51 (95%CI: 0.29-0.93) and the intermediate tertile of rice and pasta intake, OR = 0.56 (95%CI: 0.38-0.83). Positive associations were observed for the highest intake of eggs, OR = 1.84 (95%CI: 1.23-2.75), potatoes, OR = 2.22 (95%CI: 1.53-3.25), and milk, OR= 1.80 (95%CI: 1.09-2.98). Some traditional Brazilian foods like rice and beans emerged as protective factors against oral cancer, independently of other risk factors.

Phenotypic heterogeneity of mutations in androgen receptor gene

Androgen receptor (AR) gene has been extensively studied in diverse clinical conditions. In addition to the point mutations, trinucleotide repeat (CAG and GGN) length polymorphisms have been an additional subject of interest and controversy among geneticists. The polymorphic variations in triplet repeats have been associated with a number of disorders, but at the same time contradictory findings have also been reported. Further, studies on the same disorder in different populations have generated different results. Therefore, combined analysis or review of the published studies has been of much value to extract information on the significance of variations in the gene in various clinical conditions. AR genetics has been reviewed extensively but until now review articles have focused on individual clinical categories such as androgen insensitivity, male infertility, prostate cancer, and so on. We have made the first effort to review most the aspects of AR genetics. The impact of androgens in various disorders and polymorphic variations in the AR gene is the main focus of this review. Additionally, the correlations observed in various studies have been discussed in the light of in vitro evidences available for the effect of AR gene variations on the action of androgens.

[Trends in oral cancer mortality in the city of São Paulo, Brazil, 1980-2002]

The current study assessed trends in oral cancer mortality in the city of São Paulo, Brazil, from 1980 to 2002. The official mortality information system supplied data on deaths whose underlying cause was classified as oral cancer, stratified by sex, age, and anatomic site. Death rates were estimated and adjusted by the direct method, using population data supplied by national censuses from 1980, 1991, and 2000 and a population count performed in 1996. There was an upward trend in overall cancer mortality, at a yearly rate of 0.72%. Accounting for more than one third of these deaths, tongue cancer was the main mortality category. Labial, gengival, and retromolar cancer showed a downward trend, while oropharyngeal cancer and cancer in unspecified parts of the mouth and oropharynx showed increasing mortality. Monitoring the magnitude and trends in cancer mortality can assist the planning of health initiatives aimed at reducing the disease burden from oral cancer in Brazil.

Dietary patterns and risk of oral cancer: a case-control study in São Paulo, Brazil

OBJECTIVE: To analyze the association between dietary patterns and oral cancer. METHODS: The study, part of a Latin American multicenter hospital-based case-control study, was conducted in São Paulo, Southeastern Brazil, between November 1998 and March 2002 and included 366 incident cases of oral cancer and 469 controls, frequency-matched with cases by sex and age. Dietary data were collected using a food frequency questionnaire. The risk associated with the intake of food groups defined a posteriori, through factor analysis (called factors), was assessed. The first factor, labeled "prudent," was characterized by the intake of vegetables, fruit, cheese, and poultry. The second factor, "traditional," consisted of the intake of rice, pasta, pulses, and meat. The third factor, "snacks," was characterized as the intake of bread, butter, salami, cheese, cakes, and desserts. The fourth, "monotonous," was inversely associated with the intake of fruit, vegetables and most other food items. Factor scores for each component retained were calculated for cases and controls. After categorization of factor scores into tertiles according to the distribution of controls, odds ratios and 95% confidence intervals were calculated using unconditional multiple logistic regression. RESULTS: "Traditional" factor showed an inverse association with cancer (OR=0.51; 95% CI: 0.32; 0.81, p-value for trend 0.14), whereas "monotonous" was positively associated with the outcome (OR=1.78; 95% CI: 1.78; 2.85, p-value for trend <0.001). CONCLUSIONS: The study data suggest that the traditional Brazilian diet, consisting of rice and beans plus moderate amounts of meat, may confer protection against oral cancer, independently of any other risk factors such as alcohol intake and smoking.

Mouthrinses containing alcohol and oral cancer: revision of epidemiological studies

The strong association between alcohol usage and the development of oral cancer (OC) has been reported in numerous papers. As some mouthrinses contain significant amounts of ethanol, a possible relationship to this pathology has been considered. The purpose of the present paper is to analyze several epidemiological studies which evaluated the association between commercial mouthrinses and the etiology of OC. Although some authors report an association, most of the studies are unclear and sometimes contradictory. The controversial aspects regarding the role of alcohol in OC may also make difficult to find a clear relationship between the use of mouthrinses containing alcohol and OC.

Evaluation of the quality of life of patients with oral cancer in Brazil

This study performed a field trial of a Portuguese version of the University of Washington quality of life questionnaire (UW-QOL, 3rd version), aiming at appraising its ability to identify different patterns of health-related quality of life of patients with oral cancer in Brazil. Patients (N = 100) were interviewed as they were undergoing treatment for oral squamous cell carcinoma at a large Brazilian hospital ("Hospital das Clínicas", School of Medicine, University of São Paulo). The results were compared based on categories of socio-demographic and clinical characteristics of the patients. At a one-year follow-up, 20 patients had died, and 24 were considered dropouts. The remaining patients accounted for the longitudinal assessment of modifications in the self report of quality of life. Patients with larger tumours and neoplasms in the posterior part of the mouth presented significantly (p < 0.05) poorer indications of quality of life. Chewing was the poorest rated domain (35.0/100.0), and presented the highest proportion of complaints both at the baseline and at the follow-up assessments. The questionnaire allowed the identification of important contrasts (while comparing clinical characteristics) and similarities (while comparing socio-demographic status) among subsets of respondents, and it can contribute to reduce the impact of treatments and improve subsequent patient management.

Relação entre o estadiamento, o tratamento e a sobrevida no câncer da faringe

OBJETIVO: Estudo da sobrevida de pacientes portadores de carcinoma epidermóide (CEC) da faringe a partir do estadiamento e tratamento isolado (cirurgia ou radioterapia) e associação terapêutica (cirurgia e radioterapia ou quimioterapia). MÉTODO: consideradas variáveis como gênero, etnia, sintomas, estadiamento, tratamento e sobrevida, foram utilizados para cálculo da sobrevida o método de Kaplan Meyer e para verificar a associação de variáveis o teste do Qui Quadrado (p<0,05). RESULTADOS: A idade média foi de 56,5 anos ( ± 11,9 anos), sendo 456 homens e 51 mulheres (relação 9:1). Quanto à etnia, a branca foi constatada em 480 pacientes (94.7%) e a negra em 27(5.3%) com relação de 19:1. Quanto à sintomatologia, ferida na garganta (13.6%), linfonodo metastático cervical (11.8%) e rouquidão (7.9%). Quanto ao estadiamento, o estádio IV predominou (60.6%), o que justificou a indicação de cirurgia isolada, em 11.0% dos casos e da radioterapia isolada em 5.7%. No que diz respeito à sobrevida, tivemos com a cirurgia isolada para a hipofaringe 62.2% e 68.0% para a orofaringe, e 38.9% para a nasofaringe com a quimioterapia associada à radioterapia. CONCLUSÕES: A sobrevida a cinco anos foi satisfatória nos estádios iniciais na oro e hipofaringe com o tratamento cirúrgico e na nasofaringe com o tratamento quimioterápico associada à radioterapia.

Alterations of the CCND1 and HER-2/neu (ERBB2) proteins in esophageal and gastric cancers

We evaluated the relationship of amplification and polysomy of both the CCND1 and the ERBB2 (alias HER-2/NEU) genes to the overexpression of their proteins in esophageal and gastric cancers and also their association with clinicopathological features. CCND1 gene amplification (45%) was more prevalent than polysomy (25%) in esophageal carcinoma, but the pattern observed was similar in gastric adenocarcinoma (10% amplification, 15% polysomy). For ERBB2, polysomy was a more frequent mechanism than amplification in both esophageal (32.5 vs. 7.5%) and gastric (15 vs. 5%) cancers. Overexpression of cyclin D1 protein was identified in 37.5% of the specimens of esophageal tumors and 35% of gastric tumors, and overexpression of Her-2/neu protein in 12.5 and 7.5%, respectively. The kappa-statistics revealed a fair agreement in both types of tumors only in overexpression and amplification of the CCND1 gene; the ERBB2 gene showed a fair agreement in amplification and polysomy and the level of protein expression in gastric adenocarcinoma. Thus, polysomy 17 could contribute to a high Her-2/neu protein level, at least in gastric cancer. Our data indicated an association with alcohol consumption and the CCND1 gene or protein levels, in both esophageal and gastric cancers.

An Overview of Epidemiology and Common Risk Factors for Oral Squamous Cell Carcinoma

Understanding the epidemiologic picture and the risk factors for oral cancer can help identify and treat patients at risk for oral cancers. Early diagnosis of an oral cancer continues to be important to achieving a favorable prognosis. Absent a diagnosis of oral/pharyngeal cancer, there clearly can-lot be an effective treatment plan. Discovering a potentially malignant or malignant lesion and through biopsy reaching a diagnosis for the lesion begins by performing an examination with the purpose of detecting oral/pharyngeal lesions. An oral cancer screening can be performed in less than five minutes without any expensive diagnostic aids. Despite the ease with which this exam can be performed and the noninvasive nature of the examination,most patients report that they have never had an oral cancer examination. Late stage diagnosis continues to be a common situation resulting in high rates of morbidity and mortality. Without early recognition it seems that the trend of late stage diagnosis will continue. Physicians, dentists, and other health care providers should be performing the oral cancer screening examination on a routine basis for all of their patients.Note: For the interested clinician, the author highly recommends an excellent comprehensive text on the subject of oral cancer. Sol Silverman's(with multiple contributors) The American Cancer Society's Atlas of Clinical Oncology Oral Cancer: Fifth Edition by BC Decker Publishers is an excellent overview of oral cancer covering in greater detail many of the subjects that could not be covered in this brief article. Additionally, there are excellent color photographs of the common presentations of oral malignancies that can be helpful in assessing oral/pharyngeal lesions.

Ocupação e câncer da cavidade oral e orofaringe

Estudo caso-controle conduzido para avaliar a associação de exposições ocupacionais e câncer oral e orofaringe na Região Metropolitana de São Paulo. Inclui 325 casos e 468 controles, recrutados por freqüência de sexo e faixa etária, entrevistados entre janeiro de 1999 e março de 2002. A análise por ramos de atividade e ocupações foi restrita aos homens (266 casos, 362 controles) e os odds ratios (OR), calculados por regressão logística não-condicional, foram controlados por idade, tabagismo e consumo de álcool. Observou-se risco em trabalhadores de oficinas mecânicas (26 casos, 12 controles) OR = 2,45 (IC95%: 1,14-5,27), que aumentou nos que estavam empregados por dez ou mais anos (OR = 7,90; IC95%: 2,03-30,72). Os mecânicos de veículos (14 casos, 7 controles) apresentaram OR = 2,10 (IC95%: 0,78-5,68), e os expostos por 10 ou mais anos OR = 26,21 (IC95%: 2,34-294,06). Outros ramos de atividade e ocupações apresentaram OR > 1,5, porém não estatisticamente significantes. Em conclusão, emprego em oficinas mecânicas e a profissão de mecânico de automóveis revelaram risco para câncer oral e orofaringe, independente da idade, tabaco e álcool. Longas exposições aumentaram o risco.

DNA methylation in the CTCF-binding site I and the expression pattern of the H19 gene: does positive expression predict poor prognosis in early stage head and neck carcinomas?

Loss of allele-specific expression by the imprinted genes IGF2 and H19 has been correlated with a differentially methylated region (DMR) upstream to the H19 gene. The H19-DMR contains seven potential CCCTC-binding factor (CTCF) binding sites. CTCF is a chromatin insulator and a multifunctional transcription factor whose binding to the H19-DMR is suppressed by DNA methylation. Our study included a group of 41 head and neck squamous cell carcinoma (HNSCC) samples. The imprinting status of the H19 gene was analyzed in 11 out of 35 positive cases for H19 gene expression, and only 1 of them showed loss of imprinting. We detected a significant correlation (P = 0.041, Fisher's exact test) between H19 expression and tumor recurrence. Among H19 positive cases, six were T2, in which five developed recurrence and/or metastasis. Inversely, in the group of tumors that showed no H19 gene expression, 5 out of 24 were T2 and only 1 presented regional recurrence. These data support the hypothesis that H19 expression could be used as a prognostic marker to indicate recurrence in early stage tumors. We also examined the methylation of the CTCF binding site 1 in a subgroup of these samples. The H19 gene silencing and loss of imprinting were not correlated with the methylation pattern of the CTCF binding site 1. However, the significant correlation between H19 expression and tumor recurrence suggest that this transcript could be a marker for the progression of HNSCC.

Oral malignant neoplasia: a survey of 428 cases in two Zimbabwean hospitals

A review of oral malignant neoplasms biopsies accessioned in the pathology services of Harare Central Hospital and Parirenyatwa Hospital, Harare, Zimbabwe, during the 10year period January 1982 to December 1991 was carried out. Clinical records of 428 patients with histologically diagnosed oral malignant neoplasms by ICD-O type and site (COO.O-CO6.9) were retrieved and analyzed for gender, age, history of tobacco and alcohol usage, neoplastic type and histologic differentiation of squamous cell carcinoma (8000/3). Oral malignant neoplasms constituted 24.8% (n = 428) of the 1723 biopsies accessioned in the department during this period. There was a male to female ratio of 1.9:1, with lesions being most common in the 41-60 year age group. Squamous cell carcinoma, (8070/3) 73.1%, was the predominant oral malignancy most common in the 61-70 year age group with 21.1% on the mandibular gingivae (CO3.1), 20.5% on the tongue (CO1.9-CO2.9), 18.5% on the floor of the mouth (CO4.9) and 10.5% each on the maxillary gingivae (CO3.O) and buccal mucosa (CO6.O). The hard palate (CO5.9) had 9% of the lesions. Lip malignancy (COO-COO.9 and C44.0), inclusive of mucosa of lip, vermilion and skin, constituted 3.3% and minor salivary gland (CO6.9) malignancy (M-8940/3) 4.9%. The remaining oral malignancies, 11%, included Burkitt's lymphoma (M-9687/3) 4.7%; Kaposi's sarcoma (M-9140/3) 3.7%; osteosarcoma (M-9180/3) 2.6% and malignant melanoma (M-8720/3) 1.9%. Fourty five percent of the patients admitted tobacco and alcohol consumption, of whom 95% were males. Oral malignant neoplasms were more common in males than females and occurred in a relatively young age group. Well-differentiated squamous cell carcinoma (M-8070/31) was the most common oral malignant neoplasm and was most frequently found on the mandibular gingivae (CO3.1), tongue (CO1.9-CO2.9) and floor of the mouth (CO4.9). The lip (COO-COO.9) was least affected with a high palatal (CO5.9) involvement.

Habitual risk factors for head and neck cancer

Chronic tobacco smoking and alcohol consumption are well-established risk factors for the development of squamous cell carcinoma (SCC) of the head and neck. There are, however, a variety of other habitual and culturally based activities that are less commonly seen in the Western world and that are also risks factors for the development of this type of cancer. In this era of globalization, many of these habits have now crossed borders and appear in various areas throughout the world. This article reviews habitual and social risk factors for cancer of the head and neck, excluding smoking and alcohol consumption. These factors include chewing tobacco and snuff, areca nut in its various forms, Khat leaves, and the drinking of Mate.

EBM RATING

D.

Fat food habitual intake and risk of oral cancer

This case-control study evaluated fat food habitual intake in the context of the Brazilian diet as a risk factor for oral cancer. A food frequency questionnaire was applied to 70 patients with oral carcinoma and an equal number of controls treated in the same hospital for acute non-neoplastic conditions. Participants were paired for age, gender and smoking status, and matched by frequency for the use of dental prostheses and length of smoking history. Conditional logistic regression for multivariate analysis indicated as risk factors the habitual intake of foods rich in animal and saturated fat: pork meat, soup, cheese, bacon and fried food. The multivariate model also indicated the protective effect of non-cooked butter or margarine, probably the most effective vehicle for vitamin A ingestion in the Brazilian diet. These findings suggest that there is a non-negligible scope for the prevention of oral cancer through the improvement of diet.

The CAG repeat polymorphism in the androgen receptor gene (AR) and its relationship to head and neck cancer

Sex hormones may play an important role in the tumorigenic process of the head and neck. The aim of our work was to investigate whether the androgen receptor (AR) CAG repeat polymorphism is associated with an increased relative risk for head and neck cancer. Genomic DNA from 103 male patients with head and neck carcinomas and 100 male controls were analyzed for the AR CAG polymorphism by PCR amplification and direct sequencing or denaturing polyacrilamide gel electrophoresis. Logistic regression analysis showed a significant association between CAG repeat length and risk of head and neck cancer in individuals with more than 20 CAG repeats [OR=2.54 (95% CI, 1.3-4.8)]. For the group of individuals with oral and laryngeal cancer the estimated relative risk was increased to 2.79 (95% CI, 1.2-6.3) and 3.06 (95% CI, 1.0-9.6), respectively, in men with CAG repeat length >20. These results suggest, for the first time, that shorter AR CAG repeat alleles have a protective effect for head and neck cancer development.