The prevalence of oral lesions in smokeless tobacco users and an evaluation of risk factors

Identificação e procedência de pacientes laringectomizados em hospitais de referência de Belo Horizonte - Minas Gerais

  Nos últimos anos, tem-se verificado uma tendência mundial na epidemiologia de diversos tipos de câncer. A introdução de novas substâncias, parte das quais oncogênicas, nos alimentos, bebidas e ambiente, e a incorporação de novos hábitos parecem influenciar o aumento da incidência de várias neoplasias malignas. O aparente hiato verificado nos últimos anos na literatura nacional em relação a esses fatores e o câncer de laringe motivou o presente estudo. Foram pesquisados 205 prontuários de pacientes com câncer de laringe e submetidos à laringectomia. Destes, 41 pacientes foram tratados entre 1979 e 1981 (Grupo 1) e 164, entre 1990 e 1992 (Grupo 2). Não se observaram diferenças entre os grupos analisados, considerando-se a idade, sexo, cor da pele, procedência e atividade profissional, o que permite concluir, de acordo com os dados ora apresentados, que não houve alteração na epidemiologia do câncer de laringe em nosso meio.

Revisão dos fatores de risco para o câncer de boca e faringe

O presente artigo realizou breve análise de perfil epidemiológico de tumores de boca e faringe no Brasil e no mundo, bem como uma revisão da literatura pertinente a seus fatores de risco. Sua incidência, geralmente, varia entre 2% a 30% do total dos novos casos de câncer no mundo, e é fortemente influenciada pela localização geográfica. No Brasil, é a sexta localização anatômica mais comum nos Registros de Base Populacional entre os homens, sendo que a localização envolvendo a língua corresponde a 40% do total de casos. Os principais fatores de risco são o tabaco, o álcool e a interação entre ambos, que exibem forte efeito multiplicativo sobre o risco. A quantidade consumida e o tempo de exposição a estes dois fatores exibem, comumente, gradiente crescente de risco para o câncer. Elementos da dieta são considerados fatores de proteção, especialmente oβ-caroteno, enquanto estados de carência nutricional são comumente percebidos entre os casos. Condições de precária saúde bucal são achados comuns entre os casos de câncer de boca e faringe. As recentes linhas de pesquisa em patogênese e prevenção do câncer de boca e faringe têm estudado a contribuição viral e genética. O comprometimento de grupos etários mais jovens e de mulheres provavelmente deve-se à universalização dos fatores de risco, levando a esta modificação do perfil epidemiológico.

Effect of Frequency and Duration of Tobacco Use on Oral Mucosal Lesions – A Cross-Sectional Study among Tobacco Users in Hyderabad, India

Purpose: Tobacco use is one of the most important risk factors for the development of oral mucosal lesions including oral pre-cancer and cancer. The type and location of the lesion varies with the type of tobacco used, the way it is used, and the frequency and duration of use. Hence, the present study aimed to determine the effect of frequency and duration of tobacco use on oral mucosal lesions among tobacco users in Hyderabad city. Materials and Methods: A cross-sectional study was carried out among 280 tobacco users who were categorized into smokers, chewers and mixed groups according to the habit. One forty subjects diagnosed with Oral Mucosal Lesions, designated as cases and One forty lesion free controls, frequency matched for age, gender, habit and family income were assessed. The study protocol included a visual oral soft tissue examination and a questionnaire-based interview. Statistical analysis was done using Chi square test and t- test. Multiple logistic regression analysis was done to assess the association of the variables with lesions. Results: Oral submucous fibrosis (18%) was the most common oral mucosal lesion followed by Leukoplakia (14%) and Smoker’s palate (12%). Dose-response relationships were observed for both duration and frequency of habits on the risk of oral mucosal lesions. However, it was significant only for frequency of the habit. A significant positive correlation was observed between occurrence of lesion and those with no education (p=0.005). Conclusion: The study revealed that frequency and duration of tobacco use was associated with the risk of oral mucosal lesions.

Clinicopathologic evaluation of lesions associated with tobacco usage

INTRODUCTION

Tobacco usage in different forms is the single most common etiological factor responsible for oral cancers. The aim of the present study was to record various mucosal lesions associated with tobacco usage and to ascertain the prevalence of dysplasia in them by histopathological evaluation and to compare the extent of dysplastic features seen among patients associated with a habit of smoked and smokeless form of tobacco.

MATERIALS AND METHODS

Seventy-six patients with the clinical diagnosis of tobacco related lesions (Leukoplakia, Erythroplakia, Nicotina stomatitis, Tobacco pouch keratosis) were selected. A detailed description of the clinical presentation of the lesion was noted and the patients were subjected to incisional biopsy followed by a histopathological evaluation.

RESULTS

Showed dysplastic changes in 50 cases (65.8%) ranging from mild dysplasia in 27 cases (35.5%), moderate dysplasia in 17 cases (22.4%) and 6 cases (7.9%) showed severe dysplasia. Moderate to severe dysplasia was 1.83 times more likely to occur with smokeless tobacco usage when compared to smoked form. Data obtained from this study reveals that patients with a duration of tobacco usage more than 10 years were 2.17 times more likely to have moderate to severe dysplasia (p = 0.154).

CONCLUSION

Thus, the study highlights the role of oral physicians in detecting oral mucosal lesions and screening high-risk patients on a regular basis and also reaffrms the importance of public education, stressing the risk factors for oral cancers.

The prevalence and determinants of tobacco use among adolescents in Saudi Arabia

BACKGROUND

Adolescent tobacco use has been a serious public health issue, resulting in longer duration of tobacco use and higher nicotine dependence in adulthood. This study identified the current status of tobacco use among middle schools students in Jeddah, Saudi Arabia and the factors leading to tobacco use, to provide information on how to effectively prevent tobacco use among adolescents.

METHODS

A cross-sectional survey was administered to measure the prevalence of tobacco use and profile tobacco users. School selection was stratified by region, gender, and type (public or private). Altogether, 1186 seventh- to ninth-grade students were selected. Of those, 1019 questionnaires were used for analysis.

RESULTS

The mean age of the participants was 14.3 years (SD = 1.2) and boys comprised 54% of the sample. The prevalence of tobacco use among students was 9.72% with a significant difference between sexes (12.43% for boys and 6.65% for girls). Bivariate and multivariate analyses results showed that students whose families had higher income, had larger daily allowances, spent less time studying, skipped class more frequently, were less religious, spent more time out of home, drank more Coca-Cola, intended to use tobacco in the next year, and were males who were more likely to use tobacco.

CONCLUSION

Prevention programs designed to reduce adolescent tobacco use need to consider these sociodemographic characteristics. Understanding the characteristics of adolescent tobacco users and the associated sociocultural context is critical for developing effective tobacco prevention programs targeted at adolescents.

Systematic review of the relation between smokeless tobacco and non-neoplastic oral diseases in Europe and the United States

Background

How smokeless tobacco contributes to non-neoplastic oral diseases is unclear. It certainly increases risk of oral mucosal lesions, but reviewers disagree as to other conditions. In some areas, especially South-East Asia, risk is difficult to quantify due to the many products, compositions (including non-tobacco ingredients), and usage practices involved. This review considers studies from Europe (in practice mainly Scandinavia) and from the USA.

Methods

Experimental and epidemiological studies published in 1963–2007 were identified that related risk of oral lesions to smokeless tobacco use. Data were assessed separately for oral mucosal lesions, periodontal and gingival diseases, dental caries and tooth loss, and oral pain.

Results

Oral mucosal lesions: Thirty-three epidemiological studies consistently show a strong dose-related effect of current snuff on oral mucosal lesion prevalence. In Scandinavia, users have a near 100% prevalence of a characteristic "snuff-induced lesion", but prevalence of the varied lesions reported in the USA is lower. Associations with chewing tobacco are weaker. The lack of clear association with former use suggests reversibility following cessation, consistent with experimental studies showing rapid lesion regression on quitting.

Periodontal and gingival diseases: Two of four studies report a significant association of snuff with attachment loss and four out of eight with gingival recession. Snuff is not clearly related to gingivitis or periodontal diseases. Limited evidence suggests chewing tobacco is unrelated to periodontal or gingival diseases.

Tooth loss: Swedish studies show no association with snuff, but one US study reported an association with snuff, and another with chewing tobacco.

Dental caries: Evidence from nine studies suggests a possible relationship with use of smokeless tobacco, particularly chewing tobacco, and the risk of dental caries.

Oral pain: Limited evidence precludes any clear conclusion.

Conclusion

This review confirms the strong association of current use of smokeless tobacco, particularly snuff, with prevalence of oral mucosal lesions. It provides suggestive evidence of an association of snuff use with gingival recession and attachment loss, and of chewing tobacco with dental caries. While smokeless tobacco clearly increases risk of oral mucosal lesions, interpretation for other endpoints is limited by study weaknesses, including poor confounding control.

Epidemiologic perspectives on smokeless tobacco marketing and population harm

Moist snuff is the most popular form of orally-used smokeless tobacco in North America and parts of Europe. Because moist snuff use conveys lower risks for morbidity or mortality than does cigarette smoking, its use has been proposed as a tobacco harm-reduction strategy. This article critically reviews new and published epidemiologic evidence on health effects of moist snuff and its patterns of use relative to smoking in the United States, Sweden, and Norway. The available evidence suggests that: (1) moist snuff is a human carcinogen and toxin, (2) increased promotion of moist snuff has led to increased sales in those countries, (3) the uptake of moist snuff in these three countries during the past several decades has occurred primarily among adolescent and young adult men, (4) increased prevalence of snuff use has not been associated consistently with a reduction in smoking initiation or prevalence, (5) moist snuff use apparently plays a very minor role in smoking cessation in the U.S. and an inconsistent role in Sweden, (6) U.S. states with the lowest smoking prevalence also tend to have the lowest prevalence of snuff use, (7) there are no data on the efficacy of snuff as a smoking-cessation method, (8) the prevalence of cigarette smoking is relatively high among people who use snuff, and (9) snuff use is more consistently associated with partial substitution for smoking than with complete substitution. The evidence base for promotion of snuff use as a public health strategy is weak and inconsistent.

Oral cancer

Five percent of all tumors occur in the head and neck, and approximately half of those occur specifically in the oral cavity. Of the 615,000 new cases of head and neck [corrected] tumors reported worldwide in 2000, 300,000 were primary oral cavity squamous cell carcinomas. Recent data from the Surveillance, Epidemiology, and End Results Program suggest that 28,900 new cases of oral cancer will be identified and 7400 deaths attributed to oral cancer each year in the United States. The sixth leading cause of cancer-related mortality, oral cancer accounts for 1 death every hour in the United States. However, despite advances in screening tools, imaging technology, and access to primary care physicians, a considerable percentage of patients present with advanced-stage disease. Clinical signs and symptoms of head and neck tumors are often nonspecific and may be mistaken for other common ailments. Primary care physicians must be aware of the possibility of oral cancer, particularly the increasing incidence in young patients without traditional risk factors of alcohol and tobacco abuse. To improve survival, all patients should be routinely and vigilantly screened for oral mucosal lesions.

Prospective study of vitamins C, E, and A and carotenoids and risk of oral premalignant lesions in men

Case-control studies indicate that vitamins C, E, A and carotenoids decrease risk of oral premalignant lesions (OPLs) and oral cancer, but clinical trials have failed to find protective effects of beta-carotene and suggest that vitamin E may increase risk. The authors prospectively evaluated the association between intake of vitamins C, E, A and carotenoids and incidence of OPL. Participants were 42,340 men in the Health Professionals Follow-up Study who provided information on supplement use and diet every 2-4 years by food frequency questionnaire. The authors confirmed 207 clinically or histopathologically diagnosed OPL events occurring between 1986 and 2002 by medical record review. Multivariate-adjusted relative risks (RR) of OPL were calculated with proportional hazards models. Total intake of vitamin C, vitamin A or carotenoids was not significantly associated with OPL risk. Dietary vitamin C was significantly associated with reduced risk (quintile 5 vs. 1, RR = 0.52, 95% CI 0.31-0.85, p(trend) = 0.04), but no association with supplemental vitamin C was observed. Inverse associations were apparent for beta-cryptoxanthin and alpha-carotene intake. No clear relationship emerged with beta-carotene, lycopene or lutein/zeaxanthin. Vitamin E was associated with increased risk (quintile 5 vs. 1, RR = 1.86, 95% CI 1.06-3.19), particularly among current smokers and with supplemental intake (current-smokers, supplement dose tertile 3 vs. 1, RR = 3.07, 95% CI 1.28-7.34, p(trend) = 0.01). For current smokers, beta-carotene also increased risk. Vitamin C from dietary sources, but not supplements, was associated with a reduced risk of OPL. The observed increased risk for current smokers with high vitamin E or beta-carotene intake should be explored further.

Clinical, pathological, cellular and molecular lesions caused by oral smokeless tobacco - a review

While carcinogenicity of smokeless tobacco (ST) to humans is well established the oral lesions that precede development of cancer are less well characterized. The clinical appearances of ST-associated lesions are variable. Epidemiological studies show a strong significant association of risk with chronic daily use but population differences are noted because of various commercial products in use. Morphological features observed are some what different to oral lesions caused by smoking and oral dysplasia in ST-associated lesions is less common. Effects of ST on oral keratinocytes observed in vitro include alterations in cell proliferation, apoptosis and activation of inflammatory markers. Genetic aberrations caused by ST include activation of ras, uncommon in smokers but mutational hot spots in p53 encountered are similar to those in smokers.

Prospective study of fruits and vegetables and risk of oral premalignant lesions in men

The authors prospectively evaluated fruit and vegetable consumption and the incidence of oral premalignant lesions among 42,311 US men in the Health Professionals Follow-up Study. Diet was assessed every 4 years by food frequency questionnaires. The authors confirmed 207 cases of clinically or histopathologically diagnosed oral premalignant lesions occurring between 1986 and 2002. Multivariate-adjusted relative risks were calculated from proportional hazards models. Significant inverse associations were observed with citrus fruits, citrus fruit juice, and vitamin-C-rich fruits and vegetables, indicating 30-40% lower risks with greater intakes (e.g., citrus fruit juice quintile 5 vs. quintile 1 relative risk = 0.65, 95% confidence interval: 0.42, 0.99). Inverse associations with fruits did not vary by smoking status and were stronger in analyses of baseline consumption, with a 10-year lag time to disease follow-up (quintile 5 vs. quintile 1 relative risk = 0.41, 95% confidence interval: 0.20, 0.82; p = 0.01). No associations were observed with total vegetables or with beta-carotene-rich or lycopene-rich fruits and vegetables. For current smokers, green leafy vegetables (ptrend = 0.05) and beta-carotene-rich fruits and vegetables (ptrend = 0.02) showed significant linear trends of increased risk (one additional serving/day relative risk = 1.7). The risk of oral premalignant lesions was significantly reduced with higher consumption of fruits, particularly citrus fruits and juices, while no consistent associations were apparent for vegetables.

Smokeless tobacco extracts modulate keratinocyte and fibroblast growth in organotypic culture

Smokeless tobacco is associated with pathologic alterations of the oral mucosa, yet its direct effects on human keratinocytes and fibroblasts in stratified squamous epithelium are not well-understood. We hypothesized that smokeless tobacco could modulate the growth of keratinocytes and fibroblasts in an in vivo-like, organotypic tissue model. To test this, we exposed organotypic cultures for 3 days to smokeless tobacco aqueous extracts and determined the changes in morphology and proliferation of human keratinocytes and fibroblasts. All smokeless tobaccos stimulated keratinocyte proliferation at low doses (0.25% w/v) and suppressed growth at higher doses (> 0.5% w/v). In contrast, smokeless tobacco extracts promoted fibroblast growth at all concentrations without inducing fibroblast turnover. Fibroblasts and keratinocytes, therefore, were differentially affected by smokeless tobacco extracts in an organotypic tissue model, suggesting incipient changes that may occur in vivo.

Sanguinaria-associated oral leukoplakia: comparison with other benign and dysplastic leukoplakic lesions

OBJECTIVE

This study was undertaken to compare and contrast biomarkers and ploidy data from maxillary gingiva leukoplakias associated with dentifrices and mouthrinses containing the herbal compound sanguinaria with other forms of oral benign and premalignant mucosal keratosis.

STUDY DESIGN

Representative archived specimens of benign keratosis, sanguinaria-associated keratosis, and keratosis with dysplasia were used for computerized image analysis and biomarker immunohistochemical assays to assess ploidy, DNA content, and p53 and proliferating cell nuclear antigen immunoreactivity of nuclei.

RESULTS

DNA content was significantly higher and higher numbers of cell populations with hyperploid nuclei were encountered in the dysplastic group than in the other two groups (P <.001). Sanguinaria-associated keratosis did not harbor significant numbers of p53-expressing nuclei, yet it showed a significant elevation in proliferating cell nuclear antigen-labeled nuclei in total, in the basal layer, and in the spinous layer in comparison with benign keratoses (P <.001). In addition, 1.5% of the sanguinaria-associated leukoplakia epithelial cell population was characterized by nuclei with a greater than 4-fold increase in DNA content.

CONCLUSIONS

Sanguinaria-associated keratoses show some marker and image analysis profiles similar to those of non-sanguinaria dysplastic lesions of the lip and mucosa. Preparations containing sanguinaria should be avoided until the risk for malignant transformation is determined.

The adverse health effects of tobacco and tobacco-related products

Tobacco use continues to occur in epidemic proportions and with it, significant morbidity and mortality. One third of smokers will die prematurely of a smoking-related disease. This article reviews the adverse health effects of tobacco use so that clinicians can be aware of the benefits patients will reap when they stop using this lethal substance.

Initial characterization of the complement activating compounds in extracts of smokeless tobacco

Aqueous extracts of smokeless tobacco (ST) have been shown to be potent activators of complement. However, the mechanisms by which smokeless tobacco activates complement are not well understood. This study was undertaken to identify the complement activating compounds in ST extracts. The approximate molecular size of the activating agent(s) in smokeless tobacco was determined by dialyzing aqueous extracts of loose leaf chewing tobacco (1S1), dry snuff (1S2), and moist snuff (1S3). Following dialysis (total dilution effect of 1:10(9)), using a membrane with a molecular weight retention limit of 12-14 kDa, all extracts retained full capacity to activate serum complement as determined by a hemolytic assay. Fractionation of the extracts by gel filtration chromatography revealed that the complement activating agents in ST were high molecular weight compounds that eluted between 400 kDa and the void volume (1500 kDa) of a Sephacryl S300 column. The high molecular weight complement-activating peak was isolated and found to be a more potent complement activator than the unfractionated extract. The chemical nature of the complement activating compounds was determined by subjecting the extracts to boiling for 30 min, an organic extraction with chloroform/methanol 2:1, or treatment with a DNAse/RNAse enzyme cocktail. None of these treatments destroyed the capacity of ST extracts to activate complement, suggesting that the activating agents may be carbohydrate-like. Finally, an extraction protocol designed to remove polyphenols significantly diminished the complement activating capacity of the ST extracts. These results clearly demonstrate that the complement activating substances in smokeless tobacco extracts may be large (>400 kDa) polyphenol-containing compounds (i.e. tannins). Identification of this agent(s) will be important for distinguishing the mechanism of smokeless tobacco-induced complement activation.

Oral leukoplakia status six weeks after cessation of smokeless tobacco use

BACKGROUND

This study evaluated the prevalence and risk of developing oral leukoplakia in smokeless tobacco, or ST, users and the response of these leukoplakic lesions after six weeks of involuntary tobacco cessation. U.S. Air Force basic military training provided an environment of a mandatorily tobacco-free setting.

METHODS

The authors designed their investigation as a case control study with a nested cohort study. The principal investigator (G.C.M.) conducted oral examinations of 3,051 male U.S. Air Force basic military trainees. Using a questionnaire, he obtained detailed information concerning subjects' ST use patterns before basic training. Clinical photos were taken of all leukoplakic lesions identified in ST users at the initial examination and again six weeks later.

RESULTS

Of the 3,051 male trainees examined (mean age = 19.5 years), 9.9 percent (302/3,051) were identified as current ST users. Among current ST users, 39.4 percent (119/302) had leukoplakia vs. 1.5 percent (42/2,749) of nonusers of ST (odds ratio = 41.9, 95 percent confidence interval = 28.1-62.6). At the end of the involuntary cessation of tobacco use, 97.5 percent of these leukoplakic lesions had complete clinical resolution. The type of ST used (snuff vs. chewing tobacco), amount used (cans or pouches per day), length of use (months), number of days since last use and brand of snuff used were significantly associated with the risk of developing leukoplakic lesions among ST users.

CONCLUSIONS

The important new finding from this investigation is that if a young, otherwise healthy man with leukoplakic lesions stops using tobacco for six weeks, most of his leukoplakic lesions will resolve clinically. Use of ST, specifically snuff, is strongly associated with development of oral leukoplakia in young adult men.

CLINICAL IMPLICATIONS

The clinician can use these findings in deciding when to perform biopsies on leukoplakic lesions associated with ST use. This information also should be used to assist ST users in quitting this addictive behavior.

Smokeless tobacco extracts activate complement in vitro: a potential pathogenic mechanism for initiating inflammation of the oral mucosa

The use of smokeless tobacco has been linked to an increased incidence of inflammation of the buccal and gingival mucosa. However, the mechanisms by which smokeless tobacco initiates inflammation are not well understood. The complement cascade is a ubiquitous source of proinflammatory molecules and can be activated rapidly by a wide variety of agents. Therefore, the effect of smokeless tobacco on complement was investigated as a potential pathogenic mechanism for triggering inflammation of the oral mucosa. Aqueous extracts of loose leaf chewing tobacco (1S1), dry snuff (1S2), and moist snuff (1S3), added to normal human serum, depleted complement hemolytic activity in a dose-dependent manner. Experiments utilizing sera deficient in one specific complement component indicated that the smokeless tobacco-induced depletion of hemolytic activity was due largely to consumption of C3. Furthermore, assays designed to test the activity of the alternative pathway of complement clearly showed that all three extracts depleted the hemolytic activity of this pathway. Finally, all three smokeless tobacco extracts activated the alternative pathway since significantly elevated levels of the cleavage fragments iC3b and Bb were detected in extract-treated serum. High quantities of the classical pathway cleavage fragment C4d also were detected in serum treated with moist snuff (1S3). The results clearly demonstrate that smokeless tobacco extracts activate the alternative pathway and also suggest some measure of classical pathway activation. Activation of complement by smokeless tobacco may be a mechanism for initiating inflammation of the oral mucosa.

Epidemiology of cancer and other systemic effects associated with the use of smokeless tobacco

Persons who use chewing tobacco and snuff experience an increased risk of oral cancer. Because of the pharmacologic properties of nicotine and other constituents of smokeless tobacco, there is also concern that smokeless tobacco products may lead to cardiovascular diseases as well. The relatively few human population studies to date conflict with respect to whether smokeless tobacco use elevates cardiovascular risk factors or leads to cardiovascular disease or death from cardiovascular causes. Hemoglobin adducts to carcinogens present in smokeless tobacco products are measurable in the blood of smokeless tobacco users, indicating that smokeless-tobacco-related carcinogens circulate throughout the body. This prompts a concern that smokeless tobacco may increase risks of other cancers as well. The evidence to date from epidemiologic studies indicates no relationship between smokeless tobacco and bladder cancer, but there is suggestive evidence linking smokeless tobacco use to prostate cancer risk. Only single studies have been conducted of some cancers, and inconsistencies among studies of the same cancer site have been reported. Molecular epidemiologic studies may help identify markers of malignant transformation in smokeless tobacco users that may help in early intervention to prevent or ameliorate the consequences of oral cancer. Further studies are needed to determine more clearly the cardiovascular and non-oral cancer risks potentially associated with smokeless tobacco use.

Oral leukoplakia: a clinicopathological review

Leukoplakia is the most common premalignant or potentially malignant lesion of the oral mucosa. It seems preferable to use the term leukoplakia as a clinical term only. When a biopsy is taken, the term leukoplakia should be replaced by the diagnosis obtained histologically. The annual percentage of malignant transformation varies in different parts of the world, probably as a result of differences in tobacco and dietary habits. Although epithelial dysplasia is an important predictive factor of malignant transformation, it should be realized that not all dysplastic lesions will become malignant. On the other hand non-dysplastic lesions may become malignant as well. In some parts of the world the tongue and the floor of the mouth can be considered to be high-risk sites with regard to malignant transformation of leukoplakia, while this does not have to be the case in other parts of the world. The cessation of tobacco habits, being the most common known aetiological factor of oral leukoplakia, has been shown to be an effective measure with regard to the incidence of leukoplakia and, thereby, the incidence of oral cancer as well. Screening for oral precancer may be indicated in individuals at risk.

Adult smokeless tobacco use and age of onset

To determine if an earlier age of onset is associated with greater levels of adult smokeless tobacco (SLT) use and to evaluate if this relationship differs by SLT type, 345 current adult SLT users were interviewed to obtain the age at first onset and current frequency of SLT use. The results indicated that more than twice as many SLT users began during adulthood than during preadolescence. Although preadolescent onset was associated with greater chewing tobacco use than adolescent onset, the greatest levels of both chewing tobacco and snuff use were associated with adult onset, suggesting an increased need for SLT prevention programs for young adults.

Oral leukoplakia

Leukoplakia has evolved as a clinico-pathologic concept over many years, with the current clinical designation being accepted worldwide. Reflective of the biology of leukoplakia is the concept of cellular atypia and epithelial dysplasia. Adding to a better understanding of leukoplakia in general has been the definition of relevant clinical subsets which, in some cases, includes etiology (snuff), while in other cases a verrucous clinical appearance will suggest a more aggressive anticipated behavior pattern. Tobacco usage, in many of its forms, remains the prime etiologic factor; however, other considerations also apply. More recently, the potential etiologic role of Candida albicans has been stressed, as well as its possible role in carcinogenesis. So-called oral hairy leukoplakia has been defined in relation to a possible Epstein-Barr viral infection, usually in the immunosuppressed patient. Other viruses, human papilloma virus in particular, have been implicated in leukoplakia, while genetic alterations involving tumor suppressor elements (p53) have also been investigated. Finally, the management of this common condition remains a variable and includes local, topical, and systemic therapies such as anti-oxidants, carotenoids, and retinoids.

Oral precancer: preventive and medical approaches to management

Leukoplakias are among the most common potentially malignant oral lesions. Some are idiopathic, others are related to habits such as tobacco and/or alcohol use. Medical management includes reducing or abandoning these habits, increasing the intake of fruit and vegetables in the diet, and possibly the use of active agents. Retinoids, carotenoids and topical cytotoxic agents show promise, and newer therapies are on the horizon.

Should physicians screen for oral disease? A physical examination study of the oral cavity

OBJECTIVE

To assess how well primary care clinicians select patients needing early referral to a dentist based on an oral cavity examination.

DESIGN

Prospective comparison of the screening oral cavity examinations performed by primary care clinicians with that performed by a dentist.

SETTING

General medicine clinic and dental clinic of a Veterans Affairs Medical Center.

PATIENTS

A sample of 86 consecutive patients attending regularly scheduled appointments in a primary care medical clinic.

MEASURES

Each patient was examined independently by two primary care clinicians and then one dentist. History and physical findings, clinical impression, and plan based on the oral cavity examination were recorded. The reference standard was the examination by a dentist blinded to the patient's history.

RESULTS

The prevalences of lesions suspicious for premalignancy, periodontal disease, calculus, and caries were 23%, 37%, 54%, and 18%, respectively. When the primary care clinicians noticed a lesion suspicious for premalignancy, the likelihood that such a lesion was present increased significantly (LR+ = 2.7 to 6.6). However, a normal examination by the primary care clinicians did not significantly lower the likelihood of a premalignant lesion (LR- = 0.7 to 0.8). The primary care clinicians were more efficient at evaluating dental and gingival conditions (LR+ = 2.7 to 5.8, LR- = 0.2 to 0.7).

CONCLUSIONS

Screening for oral disease by primary care clinicians is justified but should not replace routine screening by dentists.

Planning a spit tobacco cessation intervention: identification of beliefs associated with addiction

We examine the relationship between beliefs regarding spit tobacco (ST) use and addiction among 473 male college athletes who currently use ST. Beliefs were assessed using methods prescribed by the Theory of Reasoned Action. Independent associations between beliefs and addiction, defined by self-reported amount of ST used per week, were found via multivariate polychotomous regression modeling. We found that with increasing addiction level, athletes were significantly more likely to believe that "ST helps me relax," "ST keeps me alert," "ST tastes good," and "ST is addicting." All athletes believed that clinicians, parents, and girlfriends do not approve of their ST use, but that male peers, coaches, and professional athletes are fairly indifferent about it. To increase quit rates, highly addicted ST users may require an intensive cessation program including nicotine replacement to overcome symptoms of withdrawal, oral substitutes for the enjoyable taste of ST, and the support of male peers and athletes who influence their social norms.