Comparative cytology of the oral cavities of snuff users

Evaluation of micronuclei, cytomorphometric and cytologic changes of the oral mucosa in hookah and cigarette smokers

OBJECTIVE

To analyze the effect of hookah and cigarettes on the oral mucosa of smokers through the use of exfoliative cytology.

STUDY DESIGN

Smear samples were collected by exfoliative cytology from the tongue of 33 hookah smokers, 22 cigarette smokers, and 30 non-smokers. The selected analyses include micronuclei (MN), metanuclear anomalies, epithelial maturation, and cytomorphology (nuclear area [NA], cytoplasmic area [CA], and NA/CA ratio).

RESULTS

The largest differences observed for MN and metanuclear anomalies were between cigarette smokers and the control group (notably 1 MN P = .04; total cells with MN P = .039; total MN P = .042; karyorrhexis and binucleation, P = .0001). The hookah group, compared with the control group, showed the greatest differences for karyolysis (P = .0023), binucleation (P = .0003), and broken egg (P = .008). Significant differences were found between the smokers and the control groups regarding changes in the superficial cell without nucleus, perinuclear halo, vacuolization, color change, mucus, and keratohyalin granules. There was a significant increase in the NA and NA/CA ratio in the smoker groups.

CONCLUSION

This study showed that a combined analysis of exfoliative cytology associated with other diagnostic methods is a useful tool for studying oral carcinogenesis. Hookah and cigarettes showed similar effects in terms of displaying substantial cytogenetic and cytotoxic damage.

A comparative study for qualitative and quantitative analysis of light and fluorescence microscopy stains in oral premalignant and malignant lesions

Objectives:

The present study highlights the use and benefit of fluorescence microscopy stains in easy diagnosis of oral premalignant and malignant lesions. This study was carried out to evaluate the efficiency of light microscopy using Papanicolaou stain (PAP) and May Grunwald Giemsa (MGG) stains and fluorescence microscopy using acridine orange (AO) and 4′,6-diamidino-2-phenyl indole (DAPI) stains. All smears have been qualitatively and quantitatively analyzed in premalignant and malignant lesions using cytology and cytomorphometry.

Materials and Methods:

The subjects included in this study were selected from patients suffering from premalignant and clinically suspicious malignant lesions. Specimens were collected from the most representative site in study groups and normal buccal mucosa in the control group. The smears were evaluated under fluorescence microscopy for AO and DAPI and under light microscopy for conventional PAP and MGG. We studied 5 HPF to compare the number of normal cells to dysplastic cells. These were then subjected for cytomorphometric and statistical analysis.

Results:

Assessment of quality using quality index revealed that PAP has better diagnostic efficiency as compared to MGG because the quality index of PAP was 0.87 and that of MGG was 0.74, the quality index of AO was 0.9, and that of DAPI was found to be 0.82, hence proving AO to be better in comparison with DAPI.

Conclusion:

We found that among all the four stains used AO is reliable, has greater efficacy, and can be easily performed with less cost. Despite the difficulties mentioned in this study, the progress in the field of fluorescence microscopy is expected to be rapid in the following years.

The smokeless tobacco habit and DNA damage: A systematic review and meta-analysis

BACKGROUND

The aim of this systematic review was to evaluate the frequency of micronuclei or other DNA damage in the oral mucosa of adults that have smokeless tobacco habits compared to adults that not have these habits.

MATERIAL AND METHODS

We searched PubMed, Scopus, Web of Science, LILACS, BBO and Cochrane Library and SIGLE. We also surveyed gray literature. We included only clinical trials that compare the frequency of micronuclei or other DNA damage in the oral mucosa of adults that have smokeless tobacco habits compared to adults that not have these habits. Quality assessments of the selected trials were evaluated by two independent reviewers, using the Effective Public Health Practice Project - (EPHPP) with modifications.

RESULTS

After the database screening and removal of duplicates, 2574 studies were identified. After title screening, 172 studies remained, and this number was reduced to 25 after careful examination of the abstracts. The standardized mean difference of the frequency of micronuclei between groups was 1.88, with a 95% confidence interval of 1.40 to 2.36 (p < 0.00001). In all analyses heterogeneity was detected.

CONCLUSIONS

Despite the heterogeneity of studies, the frequency of micronuclei was significant bigger in adults who have the smokeless tobacco habit when compared to those not have this habit. The same occurred with the frequency of binucleated cells, karyolisis and karyorrhexis.

Cytogenetic abnormality in exfoliated cells of buccal mucosa in head and neck cancer patients in the Tunisian population: impact of different exposure sources

Chromosome/DNA instability could be one of the primary causes of malignant cell transformation. The objective of the present study was to evaluate the spontaneous genetic damages in exfoliated cells of buccal mucosa of head and neck cancer (HNC) by counting micronucleus (MN) and binucleated (BN) cells frequencies. MN and BN frequencies were significantly increased in HNC patients compared with controls (5.53 ± 3.09/1000 cells, 5.63 ± 2.99/1000 cells versus 2.36 ± 2.11/1000 cells, 3.09 ± 1.82/1000 cells, P < 0.001). Regarding the gender and the age, the frequencies of the MN and BN were significantly higher than those of controls (P < 0.01). The evaluation of the MN and BN frequencies revealed a significant increase (P < 0.001) in the cases in relation to the control group after controlling the risk factors (tobacco smoking and chewing and occupational exposure) of HNC. Moreover, MN and BN frequencies were significantly increased in smokers and chewers compared with nonsmokers and nonchewers among patients (P < 0.05). MN frequency was significantly (P = 0.014) different between patients occupationally exposed (6.99 ± 3.40/1000 cells) and nonexposed (4.70 ± 2.48/1000 cells) among HNC group. The logistic regression model illustrated that HNC was significantly associated with frequencies of MN (OR = 8.63, P < 0.0001) and BN (OR = 5.62, P = 0.001). Our results suggest that increased chromosome/DNA instabilities may be associated with HNC.

Micronucleus investigation in human buccal epithelial cells of gutkha users

BACKGROUND

Gutkha is a cheap and convenient betel quid substitute, which is popular among all age groups. Various studies reveal its carcinogenic nature that leads to oral submucosus fibrosis and increases the chances of oral cancer. The micronucleus (MN) assay in exfoliated mucosal cells is a useful method for observing genetic damage in humans.

AIM

To observe the genotoxic effect of gutkha on human buccal epithelial cells.

MATERIALS AND METHODS

The MN assay was performed to assess the frequency of MN in human buccal epithelial cells. The study comprises 60 individuals of which 30 individuals were gutkha chewers and another 30 were nonusers (control). The MN frequency was scored to estimate the genotoxic damage.

RESULTS

In gutkha users, the frequency of MN was highly significant (17.4 ± 0.944) as compared with nonusers (control) groups (4.53 ± 0.331) (P < 0.001).

CONCLUSIONS

The MN assay in human buccal epithelial cells is a useful and minimally invasive method for monitoring genetic damage in humans. Asignificantly higher frequency of micronucleated cells are found among gutkha users.

Effect of nickel and chromium exposure on buccal cells of electroplaters

The electroplating industry commonly involves the use of nickel and chromium. An assessment of the genotoxic effects of these metals can be carried out by micronucleus (MN) test in buccal cells. Other nuclear anomalies (NA) observed in buccal cells viz., karyorrhexis, pyknosis and karyolysis are also the indicators of genotoxicity. The current study aims at determining the extent of genotoxic damage in relation to the duration of exposure to nickel and hexavalent chromium via micronuclei induction and other nuclear anomalies. The present investigation included 150 subjects of which 50 individuals with no history of nickel/chromium exposure (Group I) were taken as control, 50 electroplaters exposed to nickel and hexavalent chromium for duration of less than 10 years (Group II) and 50 electroplaters exposed for ≥10 years (Group III) were included. Slides of buccal cells were prepared and the frequency of MN (‰) and NA (‰) were calculated. ANOVA was applied to test significance. Results were considered significant at p < 0.05 and p < 0.001. Group III showed the highest MN frequency (1.08 ± 0.54‰, p < 0.05), karyorrhexis (20.75 ± 6.29, p < 0.05), karyolysis (3.50 ± 1.91, p < 0.001), binucleate (4.75 ± 2.75, p < 0.05) and enucleated cells (5.75 ± 1.70, p < 0.05). Significant increase in frequencies between Group II and III was found as duration of exposure increased. Plasma nickel and chromium levels were also determined which showed a positive correlation with frequency MN and other nuclear abnormalities (p < 0.01).

Actinic lesions in fishermen's lower lip: clinical, cytopathological and histopathologic analysis

INTRODUCTION

Actinic cheilitis (AC) is considered to be a pre-malignant lesion or an incipient and superficial form of lip squamous cell carcinoma. It is commonly found in individuals whose occupational activities are related to chronic sun exposure and the definitive diagnosis is performed with biopsy. Although Exfoliative cytology has been used as a screening procedure to evaluate cancer of the oral cavity no studies have proposed the use of exfoliative cytologic analysis to evaluate and diagnose AC.

OBJECTIVE

The purpose of this study was to evaluate lower lip lesions on fishermen related to chronic solar exposure using clinical, cytologic and histopathologic analyses.

PATIENTS AND METHODS

Smears taken from the vermilion of the lower lips of 125 fishermen and 30 control individuals were subjected to cytologic analysis.

RESULTS

The harvested cells were sufficient for cytologic analysis in 83.2% of the samples. Sixteen fishermen exhibited prominent lower lip lesions that justified biopsy and histological studies. In total, 4 specimens were malignant (3.2%), and 12 displayed epithelial dysplasia, demonstrating that the prevalence of epithelial dysplasia and malignant lesions was high among the fishermen population. These conditions were strongly associated with infiltration and blurring of the vermilion margin of the lower lip.

CONCLUSION

The cytologic analysis was not useful for detecting epithelial dysplasia or malignant alterations.

Genotoxic effects of waterpipe smoking on the buccal mucosa cells

Waterpipe smoking is popular in many parts of the world. Micronuclei (MN) evaluation in the exfoliated oral cells of smokers is a non-invasive technique for evaluation of possible tobacco harm. We aimed to assess whether MN levels are higher in waterpipe smokers than in never smokers. We examined oral smears of 128 adult male waterpipe smokers and 78 males who never smoked tobacco in rural Egypt. The total number of MN per 1000 cells per subject, and the number of MN-containing cells per individual were compared. We observed a higher level of total MN in waterpipe smokers (10 +/- 4) than in never smokers (4 +/- 2, p < 0.001). A similar difference was found for the mean number of affected cells per individual (8 +/- 3 vs. 4 +/- 1.62, p < 0.001). MN levels were not significantly dose related. This study is among the first to assess the association between waterpipe smoking and a cytogenetic measure of tobacco harm. The twofold increase in MN level is consistent with previous reports of MN in cigarette smokers. More research is needed to determine if such MN levels are predictive of future health consequences.

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.

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.

Smoking and smokeless tobacco-associated human buccal cell mutations and their association with oral cancer--a review

Reported herein are the results of a structured literature review that was undertaken to (a) determine if human buccal (mouth) cell changes are associated with smoking and smokeless ("chewing") tobacco, (b) tabulate different buccal cell alterations that have been reported, (c) delineate buccal cell assays that have been used successfully, (d) determine whether buccal cell changes correlate with oral cancer as defined in clinicopathologic investigations, and (e) assess the feasibility of developing a high-throughput buccal cell assay for screening smokers for the early detection of oral cancer. The results of the studies reported herein have established that diverse buccal cell changes are associated with smoking and smokeless tobacco. This review documents also that buccal cells have been collected in a noninvasive manner, and repetitively for serial studies, from different sites of the mouth (e.g., cheek, gum, and tongue) and from normal tissue, preneoplastic lesions (leukoplakia), and malignant tumors. Tobacco-associated genetic mutations and nongenetic changes have been reported; a partial listing includes (a) micronuclei, (b) bacterial adherence, (c) genetic mutations, (d) DNA polymorphisms, (d) carcinogen-DNA adducts, and (e) chromosomal abnormalities. Clinical studies have correlated buccal cell changes with malignant tumors, and some oral oncologists have reported that the buccal cell changes are practical biomarkers. Summarily, the literature has established that buccal cells are useful not only for characterizing the molecular mechanisms underlying tobacco-associated oral cancers but also as exfoliative cells that express diverse changes that offer promise as candidate biomarkers for the early detection of oral cancer.

The anticarcinogenic effect of propolis in human lymphocytes culture

The in vitro anticarcinogenic potential of propolis in human lymphocytes was investigated. Blood samples were obtained from ten healthy males, non-smoking volunteers, which were incubated and exposed to increasing concentrations of propolis (0.01, 0.05, 0.1, 0.2, 0.5, 0.7 and 1.0 ml). The mean micronucleus rates were 1.47 +/- 0.38 - 4.02 +/- 0.64. Mitotic index rates were between 19.45 +/- 2.22 and 0.28 +/- 0.33. The differences between the control and exposed cells were statistically significant (p < or = 0.05). We conclude that exposure to different concentrations of propolis cannot produce a carcinogenic effect in peripheral human lymphocytes in vitro. However, increasing micronucleus (MN) rates showed that propolis could have a carcinogenic effect in high concentrations. Also chemical analysis of propolis sample was evaluated by GC/MS. Propolis sample mainly contains flavonoids, fatty and aromatic acids and their esters.

[Genotoxic effect of ethanol on oral mucosa cells]

Ethanol is one of the chemicals related to the development of oral malignant neoplasms. Micronuclei are chromatin fragments which, after aberrant mitoses, do not become included in the main nucleus. They have been used as indicators of genotoxic damage in cells exposed to carcinogens. The aim of this study was to assess the frequency of micronuclei in exfoliated cells from the tongue and buccal mucosa of alcoholic individuals. Samples were taken from the tongue and buccal mucosa of 40 alcoholic individuals who did not smoke, and from 20 alcohol and tobacco abstainers. Cells were stained with the Feulgen reaction and counterstained with Fast Green. A significant increase in the frequency of micronuclei in tongue cells was found in the group of subjects exposed to alcohol, when compared to the control group (p < 0.01). The frequency of micronuclei in buccal mucosa cells was higher in the group of alcoholic individuals, when compared to the control group, although there was no significant difference (p > 0.05). Our results indicate that excessive alcohol consumption may induce effective alterations on oral mucosa cells, even without exposure to tobacco. These alterations are more expressive in the tongue, which is a site more exposed to the action of carcinogens, when compared to the buccal mucosa.

Exfoliative cytology of normal buccal mucosa to predict the relative risk of cancer in the upper aerodigestive tract using the MN-assay

The high frequency of second or third primary tumors was first explained by Slaughter et al. with the concept of field cancerisation. Another theory postulates micrometastatic lesions as a reason for this phenomenon. The micronuclei (MN)-assay was evaluated to provide evidence for the concept of field cancerisation and to quantify the premalignant field change of normal mucosa in order to predict the individual cancer risk. MN-assay was carried out in 55 patients with squamous cell carcinoma of the head and neck, in 16 patients with a leucoplakia and in 99 healthy controls. A detailed questionnaire for population monitoring was completed. Buccal cytosmears of healthy mucosa of the study participants were examined for the MN count per 1000 cells. There was a direct correlation between tobacco abuse and increasing MN count as a sign of a cytogenetic damage of buccal mucosa cells. Alcohol did not influence the formation of MN. Both buccal sites were damaged in the same degree as proof of field cancerisation. The relative cancer risk (odds ratio) for smoking healthy controls with a definite MN frequency was estimated. Our study underscores the importance of the MN-assay as a biomarker to predict the relative cancer risk in the upper aerodigestive tract under suspicion of the individual susceptibility and the exposition to known carcinogenic agents such as tobacco and alcohol. The concept of field cancerisation was confirmed.

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.