Prevalence and Correlation of Oral Lesions among Tobacco Smokers , Tobacco Chewers , Areca Nut and Alcohol Users

INTRODUCTION
The incidence of oral premalignant and malignant lesions is on the rise due to an increased number of people taking in tobacco and alcohol related habits.


MATERIAL AND METHODS
1028 patients with tobacco, alcohol and areca nut habits attending our Department of Oral Medicine and Radiology formed the study sample. An interviewer based questionnaire was used to record the habit details. All the patients were then examined clinically for the presence of lesions. Chi square and Fisher exact tests were used to assess the statistical significance of the study parameters.


RESULTS
Males had a higher prevalence and comprised 87.9% of the sample. The commonest habit in this study sample was smoking (39.2%) followed by smokeless tobacco use (28.1%). Out of the 1028 patients with habits 40% had no clinically detectable changes in their mucosa. Of the mucosal changes leukoplakia (14%) was the commonest.


CONCLUSIONS
This study provided information about the habit trends in the patients visiting this institution. The study may serve as a useful tool in educating the patients about the deleterious effects of oral tobacco, alcohol and betel exposure.


Introduction
The concept of certain precancerous lesions proceeding into oral cancer has long been accepted (Gupta et al., 1989;Yen et al., 2007).According to a workshop co-ordinated by WHO in May 2005 at London the use of the term 'Potentially malignant disorders' was recommended.The usage of this terminology conveys that not all lesions and conditions described under this term may transform to cancer, instead there is a family of morphological alterations amongst which some may have an increased potential for malignant transformation (Warnakulasuriya et al., 2007;Chong et al., 2011).
Tobacco and alcohol have been established as risk factors for the development of such potentially malignant and malignant disorders of the oral mucosa (Jaber et al., 1999;Moreno-Lopez et al., 2000;Lee et al., 2003;Znaor et al., 2003;Saraswathi et al., 2006;Yen et al., 2007;Cebeci et al., 2009;Javed et al., 2010).In South India chewing betel quid/ paan (betel leaf enclosing sliced areca nut, catechu, lime and various other spices which may or may not contain tobacco) (Warnakulasuriya et al., 2002;Rani et al., 2003;Aruna et al., 2011) is a common habit but the evidence for cancer occurrence due to this habit without tobacco is limited (Znaor et al., 2003;Lee et al., 2005).'Quid' has been defined as ' a substance or mixture of substances, placed in the mouth or chewed and remaining in contact with the mucosa usually containing one or both of the two basic ingredients, tobacco and/or areca nut, in raw or any manufactured of processed form (Mehta  et al., 1993;Jacob et al., 2004;Lee et al., 2005).Gutka is a mixture of powdered tobacco, areca nut, and slaked lime (aqueous calcium hydroxide).Some other forms of smokeless tobacco products commonly used in the Indian subcontinent are khaini, zarda which are mixtures of powdered tobacco and slaked lime and mishri a powdered form of tobacco which is rubbed on the gums (Rani et al., 2003;Javed et al., 2010).According to a re-evaluation in 2004 by the International Agency for Research of Cancer both betel quid and areca nut have been considered to be Group 1 or 'carcinogenic to humans' (Jacob et al., 2004;Lee et al., 2005).In India tobacco is most commonly smoked in the form of cigarettes or bidis.A bidi is a crude form of smoked tobacco which is 4-8 cm in length containing 0.25-0.50g of coarse ground tobacco, rolled into a cone in a dried piece of temburni leaf (Mehta et al., 1993;Znaor et al., 2003).Patients with a combination of these above mentioned habits are frequently found in the Indian population and are considered to be at a higher risk of developing oral lesions due to the added and prolonged exposure to carcinogens (Aruna et al., 2011).
There is a dearth epidemiologic studies which provide important information to understand the incidence, prevalence, and severity of oral disease in a specific population (Cebeci et al., 2009;Aruna et al., 2011;Goodson et al., 2011;Kumar et al., 2011).Especially little data has been published on dose-response relationships of oral habits and pre-malignancy.Establishing doseresponse relationships is important because such information provides evidence to educate users about the deleterious effects of such habits and to reduce the quantity or completely stop such habits.The purpose of the present study was to know the prevalence of tobacco, areca nut, betel quid and alcohol associated lesions only among patients with these habits and to correlate the dose response relationship of oral habits with potentially malignant oral lesions among this subset of the population.

Study population
All individuals who had the habit of using tobacco (chewed or smoked forms), alcohol and areca nut and betel quid were included in the study.Patients who were unwilling to give the complete habit details were excluded.1028 patients attending the Department of Oral Medicine and Radiology with alcohol, betel quid or tobacco associated habits formed the cohort of our study.An ethical clearance was obtained from the institutional review board and the study was carried out from July 2010 to March 2011.

Screening programme
All the patients were informed regarding the study and an informed consent was obtained.Following which they were interviewed for their adverse habits and examined by the same researcher for the presence of any oral lesions.
Along with patient's demographic details, information regarding the type of habit, duration, frequency, site of placement, period of contact with the mucosa and history of discontinuation of habit were recorded using the standardized interviewer based questionnaire.All the patients were then clinically examined using mouth mirrors under artificial illumination.If a lesion was clinically judged as suspicious for malignancy punch biopsy was performed.
Leukoplakia was defined as a raised white patch of the oral mucosa measuring 5mm or more, which could not be scraped off and could not be attributed to any other diagnosable disease.The diagnosis of leukoplakia was a provisional clinical diagnosis with a certainty factor C1 ( Van der Waal et al., 2002).Oral lichen planus was diagnosed on the basis of presence of Wickham's striae and oral submucous fibrosis on the basis of presence of blanching and palpable fibrous bands.Betel chewers mucosa is a condition caused by direct chemical or indirect traumatic effects of quid leading to a desquamated or peeled mucosa which may have a wrinkled appearance.Quid-induced lichenoid oral lesion is an entity that resembles oral lichen planus.It is characterized by the presence of wavy white lines that radiate from a central erythematous area and occurs at the site of betel quid placement (Avon, 2004).All the lesions were diagnosed in accordance with international recommendations (World Health Organization, 1977;Axell et al., 1984;Gupta et al., 1989;Mehta et al., 1993;Zain et al., 1996;Rajalalitha et al., 2005).

Statistical analysis
Descriptive statistical analysis was carried out in the present study.Significance was assessed at 5 % level of

Demographic data
The total sample size of 1028 patients consisted of 904 (87.9%) males and 124 (12.1%) females aged between 14 -80 years.In males maximum of 41.6% (n=428) belonged to the 21-30 years age group and in females 27.4% (n=34) belonged to the 51-60 age group.Figure 1 shows declining number of male patients with habits as the age increased whereas a reverse was observed in females with increase in number as age progressed.
Based on education, 449 (49.7%) of the males had  an education till high school level whereas in females 93 (75%) of them were uneducated.According to occupation 572 (63.3%) men were unskilled and 289 (39.1%) were skilled, while in women the highest number were housewives 73 (58.9%) and 47 (37.9%) unskilled workers.Distribution of habits: Table 1 depicts the habits included in this study were smoked tobacco (cigarette and beedis), smokeless tobacco (betel quid with tobacco and refined tobacco products like gutkha, zarda and khaini), alcohol, areca nut habit (betel quid without tobacco, powdered areca nut like supari).More than 1 habit group included patients with combination of two habits both smoking and drinking, smoking and chewed tobacco or chewed tobacco and drinking alcohol.More than 2 habits group included patients with three habits like smoking, chewed tobacco and drinking alcohol.
Of the 226 patients with a combination of two habits only 31% (n=70) had no detectable changes and the commonest lesions in the decreasing order of frequency were leukoplakia 17.7%, leukedema 12.4%, smoker's melanosis 10.2%, OSMF at 8.8% and 6.2% cases of smoker's palate and tobacco induced keratosis.Also 2 out of 8 cases of malignancy occurred in patients with more than 1 habit.Among the 1028 study population 19 patients had a combination of three habits.In these 19 patients 12 (52.6%)had no detectable lesions Smoker's melanosis at 26.3% was the commonest lesion among these patients followed by 10.5% leukedema 5.3% leukoplakia.
Table 5 depicts a significant correlation of occurrence of lesions with the duration of habit.All the 8 cases of malignancy were found in patients with duration of habits of more than 15yrs.A significantly high number of leukoplakias were also found as the duration of habits increased with 23 cases in 10 to 15yr duration and 50 cases in more than 15yrs group.Lesions like lichenoid reaction and OSMF showed a trend of early occurrence and were not associated with the duration of habit.

Discussion
Three routes for progression to cancer have been proposed: oral leukoplakia/ erythroplakia-cancer, oral submucous fibrosis -cancer sequence and oral lichen planus -cancer.(Yen et al., 2007).Hence knowing the prevalence of these precursor lesions and treating them before they progress to malignancy should be the goal of preventive oral health care workers (Van der Waal et al., 2011).
The prevalence of adverse oral habits was found to be much higher in males as compared to females in this study and is in accordance with the other studies (Jaber et al., 1999;Rani et al., 2003;Saraswathi et al., 2006;).The consumption of alcohol was 1.3% which was the lowest compared to other habits and coincides with a study performed in Hubli India (Aruna et al., 2011).In this study population the overall education of 45.8% was till high school level while around 18% of patients were degree or diploma holders which is slightly lower when compared to a study conducted in 2004 at Chennai (Saraswathi et al., 2006).75% of the female patients in this study were illiterate and the remaining with only school level education.The lack of awareness of the harmful effects of consumption of tobacco products is reflected by this low level of education.
Based on occupation the largest numbers of patients (60.2%) were unskilled which included people with occupations like laborers, daily wagers, cleaners, maids, drivers, farmers etc.Most of these occupations require a substantial amount of physical energy and a high level of concentration in case of drivers with odd work timings.This can be stressful which in combination of peer pressure can lead to the initiation of deleterious oral habits.
As this study population included only those patients with habits and not all the routine patients attending the department the prevalence of oral lesions is much higher than those recorded by most prevalence studies.The duration and frequency of habits has a significant effect on the development of oral lesions which can be noted in the findings of the present study as well as in another previous study (Yen et al., 2007;Aruna et al., 2011).Patients with the habit frequency of 5 to 10 times in a day had the maximum number of lesions.Patients with a combination of habits had fewer lesions, the possible reason being reduced time of contact or exposure to each individual habit.
In conclusion, the results of the present study throw some light on the habit trends in the institution where this study has been conducted.As parameters like education, occupation have been combined with the age and gender of the patients more meaningful information is obtained regarding the prevalence of deleterious habits.The limitations of this study include potential information bias as self reporting by the patient was used to collect the information hence underreporting of habits could have taken place.Another possible flaw could be detection bias as the researcher was aware of the habit history of the patient prior to oral examination.In future research the examiner can be blinded to the habit details and should examine the oral cavity first to prevent such bias.
Further studies including comparisons of demographic data as well as dose response relationship with oral lesions with larger sample size and in the general population need to be performed.Studies observing the effects of cessation of oral habits are sparse (Martin et al., 1999;Lodi et al., 2008) hence there is no evidence regarding the chances of reversal of altered mucosa and studies need to be performed in this regard.The results of such studies can be a great tool in educating patients regarding the adverse effects of tobacco, alcohol and betel quid habits.

Figure 1 .
Figure 1.Depicting the Age and Gender Distribution of the Study Population significance.Chi-square/ Fisher Exact test was used to find the significance of study parameters on categorical scale between two or more groups.The Statistical software namely SAS 9.2, SPSS 15.0, Stata 10.1, MedCalc 9.0.1 ,Systat 12.0 and R environment ver.2.11.1 were used for the analysis of the data.