Indian Journal of Dental Research

: 2019  |  Volume : 30  |  Issue : 4  |  Page : 500--505

Prevalence of precancerous lesions in an adult population

Benley George1, Shibu T Sebastian1, Rino R Soman2, Vinod M Mulamoottil1, Minimol K Johny3,  
1 Department of Public Health Dentistry, Pushpagiri College of Dental Sciences, Tiruvalla, Kerala, India
2 Department of Periodontics, Pushpagiri College of Dental Sciences, Tiruvalla, Kerala, India
3 Department of Conservative Dentistry and Endodontics, Pushpagiri College of Dental Sciences, Tiruvalla, Kerala, India

Correspondence Address:
Dr. Benley George
Department of Public Health Dentistry, Pushpagiri College of Dental Sciences, Tiruvalla - 686 548, Kerala


Objectives: The present study aimed to identify the prevalence of precancerous lesions among an adult population in Kerala, India. Materials and Methods: A dental screening camp was organized in each district at two locations for two consecutive days to draw maximum participation of the community. All adult subject's attending the camp were initially screened for precancerous lesions using conventional light. An initial oral screening was done by two public health dentists and suspected cases were subjected to Identafi Oral cancer screening device and followed by histopathological evaluation. Results: The prevalence of oral precancerous lesions in the adult population of Kerala was 4.4%. Most of the lesions were associated with the use of tobacco followed by alcohol and spicy foods. Conclusion: The oral cancer detection device is an aid in detection of oral precancerous lesions.

How to cite this article:
George B, Sebastian ST, Soman RR, Mulamoottil VM, Johny MK. Prevalence of precancerous lesions in an adult population.Indian J Dent Res 2019;30:500-505

How to cite this URL:
George B, Sebastian ST, Soman RR, Mulamoottil VM, Johny MK. Prevalence of precancerous lesions in an adult population. Indian J Dent Res [serial online] 2019 [cited 2019 Dec 14 ];30:500-505
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Full Text


Oral cancer is a major dental public health problem in the Indian subcontinent where it ranks among the top three types of cancer in the country.[1] Age-adjusted rates of oral cancer in India are high that is, 20 per 100,000 population and accounts for over 30% of all cancers in the country.[2] The variation in incidence and pattern of the disease can be attributed to the combined effect of ageing of the population, as well as regional differences in the prevalence of disease-specific risk factors.[3] Oral cancer is of significant public health importance to India. First, it is diagnosed at later stages which result in low treatment outcomes and considerable costs to the patients whom typically cannot afford this type of treatment.[4] Second, rural areas in middle- and low-income countries also have inadequate access to trained providers and limited health services. As a result, delay has also been largely associated with advanced stages of oral cancer.[5] Earlier detection of oral cancer offers the best chance for long-term survival and has the potential to improve treatment outcomes and make healthcare affordable.[6] Third, oral cancer affects those from the lower socioeconomic groups, that is, people from the lower socioeconomic strata of society due to a higher exposure to risk factors such as the use of tobacco.[7] Lastly, even though clinical diagnosis occurs via examination of the oral cavity and tongue which is accessible by current diagnostic tools, the majority of cases present to a healthcare facility at later stages of cancer subtypes, thereby reducing chances of survival due to delays in diagnosis.[8] Public health officials, private hospitals, and academic medical centres within India have recognized oral cancer as a grave problem.[9] Efforts to increase the body of literature on the knowledge of the disease etiology and regional distribution of risk factors have begun gaining momentum. Oral cancer will remain a major health problem and efforts towards early detection, and prevention will reduce this burden. Currently, there is lack of literature on precancerous lesions among adult population in Kerala. Therefore, the present study aimed to identify the prevalence of precancerous lesions among an adult population in Kerala, India.

 Materials and methods

The present study included all 14 districts in the state of Kerala. There are 11912 registered dentists in the state of Kerala as on December 2014.[10] The survey was conducted from February 2016 till February 2017. A dental screening camp was organized in each district at two locations for two consecutive days to draw maximum participation of the community. All adult subject's attending the camp were initially screened for precancerous lesions/oral cancer using conventional light. An initial oral screening was done by two public health dentists and suspected cases were subjected to Identafi Oral cancer screening device. This portable tool has a light source in the form of a probe-like device that resembles a dental mirror and can, following appropriate infection control methods, be easily inserted into the mouth for oral examination. The amber light is designed to enhance the reflective properties of the oral mucosa, allowing a distinction between normal and abnormal tissue vasculature.[11]

The cases which have been reported positive after using Identafi device were referred to the institution for biopsy and thereby confirming the diagnosis. All mucosal lesions underwent histopathological evaluation by a trained oral pathologist. The dropout rate in the study was 6.8%. The participation was voluntary.

Data was collected using a pretested questionnaire which consisted of details pertaining to demography, medical history, tobacco and alcohol use, and spicy foods consumption. The study was approved by the Institutional Ethics Committee, Pushpagiri College of Dental Sciences (PCDS/IEC/K0015/5/17, 8 May 2017) and it was conducted in full accordance with the World Medical Association Declaration of Helsinki. Prior to the start of the study a written informed consent was obtained from all the participants. The two examiners were trained and calibrated prior to the start of the study and the kappa statistics was 0.82.

Identafi devise

The Identafi oral cancer screening system uses multispectral fluorescence and reflectance technology. The device has three light sources that can be used for the clinical examination: a white light for regular illumination, a violet light that excites fluorescence at 405 nm for tissue absorption, and green amber light at 545 nm for tissue reflectance. Reflectance spectroscopy uses light within the absorption spectrum of haemoglobin namely, between 400 and 600 nm to visualize the underlying vasculature.[12],[13],[14],[15]

Biopsy preparation

Specimens were placed in 4% buffered formalin solution for fixation. Paraffin embedded material was cut into 4-μm thick sections and stained with haematoxylin and eosin. After color staining, all mucosa lesions underwent a histopathological evaluation by an experienced oral pathologist.

Statistical analysis

The data collected was analyzed for statistical correlations using IBM SPSS 19 (Statistical Package for the Social Sciences, SPSS Inc., Chicago, IL, USA). The level of significance was P < 0.05.


[Table 1] presents the distribution of study subjects by gender. Among the 6966 study subjects, 2635 (37.8%) subjects were males and 4331 (62.2%) subjects were females.{Table 1}

[Table 2] shows the distribution of study subjects based on their place of residence. There was a maximum of 12.7% of study subjects in the district of Pathanamthitta and a minimum of 3.2% subjects in the district of Alappuzha when compared to the rest of the districts in Kerala.{Table 2}

[Graph 1] shows the distribution of subjects based on the use of smoked form of tobacco. Among the study subjects, 85.6% were nonsmokers. Among the smokers, 7.6% smoked cigarettes and 6.7% smoked bidis.[INLINE:1]

[Graph 2] depicts the distribution of subjects based on the use of smokeless form of tobacco. A high proportion of the study subjects were nontobacco chewers (88.3%). Among the tobacco chewers, 11.1% chewed betel nut while 0.6% used Hans.[INLINE:2]

[Table 3] depicts the distribution of study subjects based on the consumption of alcohol. Majority (97.1%) of the study subjects did not consume alcohol. Among the alcohol consumers, 1.2% consumed toddy.{Table 3}

[Graph 3] depicts the distribution of study subjects based on the consumption of spicy foods. Only 11.6% of the study subjects consumed spicy foods.[INLINE:3]

[Table 4] shows the distribution of the subjects based on the diagnosis of the lesion. Out of the total subjects, 95.6% were free of any lesions/conditions. Among the 309 patients with lesions, 21 patients did not report for biopsy. Majority of the study subjects suffered from leukoplakia followed by lichen planus and oral submucous fibrosis.{Table 4}

[Table 5] shows the distribution of study subjects based on the site of the lesions. Majority (3.8%) of the lesions were found to be present on the buccal mucosa when compared to other sites of the oral cavity.{Table 5}

[Table 6] demonstrates the association between tobacco, alcohol and spicy foods with the presence of precancerous lesions. The odds of having precancerous lesions is 18 times higher for those who use tobacco (OR = 18.28, 95% CI) as compared to those who do not. The odds of having precancerous lesions is 7 times higher for those who use alcohol (OR = 7.95, 95% CI) as compared to those who do not. The odds of having precancerous lesions is one time higher for those who consume spicy foods (OR = 1.49, 95% CI) compared to those who do not.{Table 6}


The present study was conducted with the objective of assessing the prevalence of precancerous lesions in an adult population in Kerala. This is one of the largest studies where Identafi device was used for detecting oral precancerous lesions. The results of the study shows that the overall prevalence of precancerous lesions in the study population was 4.4%, which is low compared to a study conducted in Indore [16] and similar to studies conducted in Sri Lanka,[17] Turkey,[18] Chennai,[19] Mumbai,[20] Yemen,[21] and Qatar.[22] The prevalence of leukoplakia was 1.8% which was similar compared to studies conducted in Chennai,[19] Yemen,[21] Yugoslavia,[23] Maharashtra,[24] Lucknow,[25] Bombay [26] and Kerala [27] and low compared to studies conducted in Indore,[16] Mumbai,[20] Aurangabad,[28] and Belgaum,[29] The prevalence of Lichen planus in the present study was 1.2% which is consistent to studies in Belgaum,[29] Indore,[16] Chennai,[19] Yemen,[21] Germany,[30] Turkey,[31] and Iran [32] and low when compared to studies in Aurangabad [28] and Mumbai.[33]

A study using Identafi device for screening 124 subjects demonstrated a sensitivity of 82% and a specificity of 87% in differentiating between neoplastic and non-neoplastic oral conditions.[34] In another study conducted in 5 patients with oral lesions and 11 normal volunteers it was shown that healthy tissue could be discriminated from dysplasia and invasive cancer with 95.9% sensitivity and 96.2% specificity in the training set, and with 100% sensitivity and 91.4% specificity in the validation set.[35]

Numerous studies have suggested that there is a strong association between tobacco consumption and development of precancerous lesions.[36] The present study also shows that tobacco was a strong predictor for development of precancerous lesions. Results of logistic regression analysis showed that tobacco consumption, alcohol consumption, and spicy foods were best predictors for development of precancerous lesions in the study population. The limitation of the present study was that it could not be used as a screening devise in all the patients due to the large number of patients who attended the camp. Only suspected cases as identified by the examiners were subjected to screening using the oral cancer detection devise.

The advantages of the Identafi devise is it is small, compact size coupled with an angled examination mirror which allows users to easily inspect hard-to-reach areas, such as under the tongue, hard and soft palate, and back of the pharynx.

The limitations of this devise is its field of illumination is considerably smaller than devices like velscope; thus the time required to visualize the entire oral cavity is longer. Another limitation is the batteries will eventually need to be replaced with a freshly recharged set or a set of nonrechargeable AA batteries, if used for a long period of time, such as in a community oral-cancer screening program.[37]


In the present study we could conclude that Identafi devise is a simple and noninvasive device which can aid the clinician in detecting oral precancerous lesions and determining the location for taking biopsies. Currently, the Identafi oral cancer detection device is the only available intraoral device across the globe which is very portable and convenient to use for detection of precancerous lesions in the oral cavity.

The reliability of the device would depend upon further studies which can reveal its specificity and sensitivity. The effectiveness of this devise when proved and reduction of the cost of the device would make it a popular and common screening tool among dentists and dental schools in the detection of oral cancer in the community. The overall prevalence of oral lesions in the study was 4.4%. Studies have shown a strong relationship between the use of tobacco and alcohol in the development of precancerous lesions. Treatment for oral cancer has been a costly affair for patients across the globe, especially in developing countries like India. The state government should take effective steps in providing a structured health education to the community by setting up tobacco cessation clinics in dental colleges, medical colleges and hospitals, and ban of all tobacco products within the country. The government authorities should provide training to rural health workers to enable them to screen patients for oral precancerous lesions and refer them for biopsy and further management at higher centres. The health authorities should provide regular health education on the hazards of tobacco use to school children thereby deterring them from adopting the habit of tobacco use.


The authors would like to thank Mrs Nisha Kurien, Statistician, Pushpagiri Institute of Medical Sciences for the help in completing the statistical analysis.

Financial support and sponsorship

The study was funded as a research devised by the International College of Dentists, UK. The authors would like to thank Dr Philip Dowell and Dr SM Balaji, ICD for the support extended for the project.

Conflicts of interest

There are no conflicts of interest.


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