|Year : 2022 | Volume
| Issue : 3 | Page : 253-257
|Burden of oral precancer and cancer among an indigenous tribal population of South India – An evaluative study
Sivaramakrishnan Muthanandam1, Bontha V Babu2, Jananni Muthu3, Suganya Rajaram1, B Sivapatha Sundharam4, M Kishore5
1 Department of Oral & Maxillofacial Pathology & Oral Microbiology, Indira Gandhi Institute of Dental Sciences, Sri Balaji Vidyapeeth (Deemed to be) University, Pondicherry, India
2 Socio-Behavioural and Health Systems Research (SB and HSR), Division, Indian Council of Medical Research, New Delhi, India
3 Department of Periodontology, Indira Gandhi Institute of Dental Sciences, Sri Balaji Vidyapeeth (Deemed to be) University, Pondicherry, India
4 Principal, Department of Oral Pathology, Priyadarshini Dental College, Chennai, Tamil Nadu, India
5 Research Assistant, Indira Gandhi Institute of Dental Sciences, Sri Balaji Vidyapeeth (Deemed to be) University, Pondicherry, India
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|Date of Submission||08-Jun-2021|
|Date of Decision||09-Sep-2022|
|Date of Acceptance||13-Sep-2022|
|Date of Web Publication||17-Jan-2023|
| Abstract|| |
Context: Oral cancer is of major concern in the Indian subcontinent and is found to be high among low socioeconomic groups. One such high-risk group is considered to be the tribal people, who are economically and socially marginalised. Aims: The aim of the present study is to assess the prevalence of oral cancer and precancer lesions among the Narikurava population in Puducherry state, India. Methods and Material: A total of 329 Narikurava tribal people were included in this study. Data was collected by clinical examination of the oral cavity by door-to-door screening. The oral cavity was examined for white/red lesions, ulcerative changes, leathery changes and tissue growths. Statistical Analysis Used: Prevalence was calculated in terms of percentages. Descriptive statistics included the calculation of percentages, mean, and standard deviation. Results: The prevalence of precancer in the population is 48.3%. The majority of the lesions were observed in the buccal mucosa: 41.6% had white lesions, 9.1% had red lesions, 0.3% had ulcerations or growth, and 28.3% had leathery changes followed by the labial mucosa: 0.6% had white lesions, 0.6% had red lesions, 0.3% had ulcerations or growth and 16.4% had leathery changes. Conclusions: The present study observed a high prevalence of precancerous lesions among the Narikurava tribe. The main reason for the high prevalence is attributed to tobacco and tobacco-related habits. Hence, cancer control activities should be prioritised. Designing a model to detect precancer and cancer early and to constantly monitor the detected cases in such populations is of utmost importance.
Keywords: Narikurava population, oral cancer, oral precancer, prevalence, survey, tribal population
|How to cite this article:|
Muthanandam S, Babu BV, Muthu J, Rajaram S, Sundharam B S, Kishore M. Burden of oral precancer and cancer among an indigenous tribal population of South India – An evaluative study. Indian J Dent Res 2022;33:253-7
|How to cite this URL:|
Muthanandam S, Babu BV, Muthu J, Rajaram S, Sundharam B S, Kishore M. Burden of oral precancer and cancer among an indigenous tribal population of South India – An evaluative study. Indian J Dent Res [serial online] 2022 [cited 2023 Feb 5];33:253-7. Available from: https://www.ijdr.in/text.asp?2022/33/3/253/367886
| Introduction|| |
Oral cancer is one of the most important health concerns in the Indian subcontinent, where it is reported to top the three types of cancer and accounts for almost 30% of all cancers. Regional variation in incidence and prevalence is observed which might be attributed to regional differences in disease-specific risk factors. Oral cancer is a major concern in the Indian subcontinent firstly due to its late diagnosis. Early detection will provide an opportunity for better treatment outcomes and survival. Moreover, the incidence of oral cancer is found to be high among low socioeconomic groups who do not seek or can afford treatment at the right time. These result in a delay in diagnosis and treatment, reducing the chance of survival.
Because this is a disease of greater concern, incidence and prevalence data on the same are available at various time periods in the literature. Widening inequities in oral health status and treatment needs exist among different social groupings. Groups of people, even today, live in isolation either geographically or socially with their traditional values and beliefs. They are commonly referred to as the tribal population and are considered to be the autochthonous people of the land, and the Narikurava tribal community is indigenous to Tamil Nadu. They face common but consequential issues like poverty, illiteracy, communication problems, poor healthcare and social discrimination. Due to these factors, large health inequities exist in this marginalised group.
Considering the aetiology of oral cancer and precancer, tobacco use and heavy alcohol consumption are attributed to over 90% of the cases. Among tobacco users, tribal people have been found to have high rates of using smokeless and smoking tobacco in many studies carried out in India., Reports have also found that 56.2% of these tribal people aged over 15 years were users of tobacco in smoking or smokeless form. Another recent survey reported that among the adult Narikurava population, 64.55% used tobacco, and among them, 29.1% used smoking tobacco; 63.4% used smokeless tobacco; 7.5% used both. Medium nicotine dependency was more prevalent in both smoking and smokeless tobacco users (82.75% and 53.57%).
Considering these reports, the prevalence of cancerous, or at the least precancerous lesions, is expected to be high in this group. To date, no data is available on the prevalence of oral cancer and precancer among this special population. In lieu of the above, the aim of this study is to assess and report the prevalence of oral cancer and precancer lesions among the Narikurava population in Puducherry state, India.
| Subjects and Methods|| |
This cross-sectional descriptive study on the prevalence of precancerous lesions, conditions, and oral cancer was conducted by the Department of Oral Pathology and Microbiology, Indira Gandhi Institute of Dental Sciences, Pondicherry. This project was funded by the Indian Council of Medical Research (ICMR), Government of India. The study was initiated after approval from the Ethical Committee of the Institute (IGIDSIEC2019NRP05FASMOPM), and informed consent was obtained from the participants. The study conforms to ethics as stated in the Declaration of Helsinki.
The largest settlement of the Narikurava population in Pondicherry, residing at Narikuravar colony, Lawspet, Pondicherry, was selected as the study population. Individuals of both gender >14 years of age were included. Children (<14 years of age) and subjects unwilling to participate in the survey were excluded. Immuno-compromised patients and subjects who were or are under treatment for any precancerous and cancerous lesions were also excluded.
The demographic data collection was the initial step. This was carried out by a door-to-door approach. The investigators collected the demographic data and cross-verified it with the voter's ID list. According to this, a total of 376 people were identified as residents of the settlement. At any given point in time, approximately only 50% of the population were available at the settlement. Hence, recording of complete demographic data was possible only for 358 people, and out of this, only 329 completed the entire survey and clinical examination.
This data was collected by clinical examination of the oral cavity. This was carried out by door-to-door screening. The clinical examination was performed by two trained oral pathologists with the use of mouth mirrors and diagnostic instruments. This data was based on visual inspection. The oral cavity was examined for, white/red lesions, ulcerative changes, leathery changes, and tissue growths. The clinical diagnosis of the precancerous lesions and conditions was performed as per the WHO (1997) criteria. At this stage, identified cases of potentially premalignant lesions were provided counselling to quit tobacco-related habits. The prevalence of premalignant and malignant lesions was calculated in terms of percentages. Descriptive statistics included the calculation of percentages, mean, and standard deviation. A comparison of the prevalence of lesions between males and females was performed using the Chi-square test, and the level of significance was set at P < 0.05.
| Results|| |
The final study population size was 329, with 163 (49.5%) males and 166 (50.5%) females. The mean age of males was 40.4 years and that of females was 37.2 years.
Tobacco and related habits
The overall smoking tobacco prevalence in the population was 65.23%, and smokeless tobacco was 78.85%.
Prevalence of oral cancer and precancerous lesions
The prevalence in men was 57.23% and that in women was 42.77%. This difference was not statistically significant (P = 0.08) [Table 1]a.
The prevalence of precancer and cancer in the population was 48.3%. The majority of the lesions were observed in the buccal mucosa: 41.6% were white lesions, 9.1% were red lesions, 0.3% were ulcerations or growth and 28.3% were leathery changes, followed by the labial mucosa: 0.6% had white lesions, 0.6% had red lesions, 0.3% had ulcerations or growth and 16.4% had leathery changes. Only very few lesions were evident in the tongue: 0.3% were white lesions, 0.3% were red lesions, and 1.2% showed leathery changes. No red or white lesions were found in the vestibule, gingiva and floor of the mouth, but leathery changes were evident at these sites. Leathery changes were the most prevalent among all sites [Table 1]b.
The high prevalence of oral precancer among this group is attributed to tobacco consumption habits, either in smokeless or smoking form and alcohol consumption. Lack of knowledge and awareness about oral precancer and poor oral hygiene also attributes to the prevalence.
Prevalence of oral cancer and precancerous lesions after toluidine blue staining
The application of toluidine blue will stain the dysplastic tissue and differentiate them from the normal tissue. This is the widely used technique for the preliminary identification of dysplasia. A total of 39.8% stained positive for oral precancerous or cancerous lesions in the oral cavity. Gender-wise prevalence is as follows: females, 35.6% and males, 44%. The frequency of detection of lesions was high in the buccal mucosa (36.2%) followed by the labial mucosa (6.1%). Data on the prevalence of lesions gender-wise and site-wise after toluidine blue staining is presented in [Table 2]a, [Table 2]b, [Table 2]c.
| Discussion|| |
The International Agency for Research on Cancer (IARC) stated that more than 266,000 fresh intra-oral cancer cases occurred in 2000 with a majority of 64% in males. Increased incidence of oral precancerous lesions and conditions in India, owing to changes in lifestyle, has already been reported. Moreover, low socioeconomic status (SES) was found to be associated with an increased prevalence of oral cancer. People with low SES were 1.84 times more likely to develop oral cancer.
In developing countries, the majority of the population belongs to lower SES, and among them, tribal people are socially marginalised groups. One such tribal group, indigenous to the Indian state of Tamil Nadu, is the Narikurava population. These people are known for their nomadic lifestyle and deleterious tobacco-related habits. However, to the best of our knowledge, no scientific literature is available reporting the prevalence of oral lesions in this special population.
The present study is a part of a larger project: Model for Oral Cancer Eradication (MOCE) among Narikurava population in Pondicherry funded by the ICMR, Government of India. The results of this study report the prevalence of oral precancer and cancer among this population.
With regards to tobacco and related habits, a high prevalence was found in this population. The present population practice tobacco and related habits as a part of culture and rituals during celebrations. The habits also commence at a very young age (14.7 ± 2.3 years for smoking tobacco and 16.9 ± 1.9 years for smokeless tobacco). Because they start at a young age, they sustain for life. The tobacco-related practice is imparted from generation to generation and hence appears to be a norm. A family history of tobacco use, peer pressure from friends and cultural beliefs were shown to be the prime constituting factors for the early onset of the habit. Another striking reason for tobacco use among adults, especially among men, is that they use tobacco as a means to confront poverty and hunger. One interesting finding in his group, is the oral use of snuff, especially by women. They rub snuff in the labial mucosa as a habit. However, no specific mucosal changes relating to the habit were observed.
The overall prevalence of oral cancer and precancer in the present study is 48.3% (n = 159). Among the cases, 57.23% were male and 42.77% were female. No gender-based difference in prevalence was observed statistically (P = 0.08). After the application of toluidine blue, 78 males (out of 91) and 58 females (out of 68) stained positive, indicating dysplasia. The difference in prevalence after toluidine blue application was not statistically significant (P = 0.085). Srivastava et al. reported a male predominance in the prevalence of oral precancerous lesions like OSMF and leukoplakia. Vinay et al. reported a significantly higher prevalence of precancerous lesions among males (5.5%) when compared to females among the general population in the Telangana region, India.
Pullishery reported a prevalence of 27% in the Aranadar tribal population in Kerala. Khanna et al. reported a 10.3% prevalence of leukoplakia among a total of 411 Baghi tribes. Palliyal reported that the precancerous oral lesions were found to be far more prevalent among the underprivileged Paniya tribes (42%). Palliyal recorded a prevalence of OL (12.9%) and OSF (13.2), respectively, among betel quid chewers in Paniya tribes. On the contrary, Valsan et al. reported a mere 4.2% prevalence of oral mucosal lesions among the Paniya tribes. Ramdas et al., in Thiruvananthapuram district, Kerala, showed a premalignant case detection rate of 2.5%. Francis detected 52% of oral mucosal lesions among tea plantation workers in Tamil Nadu.
Also, in the present study, the majority of the lesions were observed in the buccal mucosa. Few lesions were evident in the labial mucosa and tongue. Pullishery reported a different result: lesions in the tongue (45.5%) were the maximum followed by lesions in the buccal mucosa (39%).
In all of the above previously discussed studies, the main reason for the high prevalence was attributed to tobacco and tobacco-related habits. In the present population, wide long-term use of smokeless tobacco by both genders was observed. Considering this, the prevalence of cancerous, or at the least precancerous lesions, is naturally expected to be high. Our results also reveal the same. Almost half the population had some form of the potentially malignant disorder.
Educational status, knowledge and awareness about oral cancer also have a role to play. Awareness about oral cancer and precancer is inadequate among the Narikuravar population of Pondicherry. The majority of the population is not aware of the risks, signs, or treatment options of oral precancer and cancer. Due to poor knowledge, they were unwilling to quit the habit and continued to chew tobacco. This is an issue of significant concern.
As with any cancer, oral cancer also is preventable and treatable when detected early. The problem with obtaining a better prognosis is the 'time losses' encountered. Lack of awareness, doubts and negligence of the symptoms are considered 'First-time loss'. Compromise in the availability of accessible and affordable professional help delays the early and timely diagnosis is the 'second-time loss'. The time period from the diagnosis to the initiation of appropriate therapy is considered the 'third-time loss'. Taking care of all three will lead to a better prognosis.
In most of the marginalised tribal populations, lessening the first-time loss is the biggest challenge. Identification of cancer in the initial stage by investigations, under field conditions, particularly in tribal areas, is very essential. There is also a need to develop and implement culturally appropriate awareness-raising activities to target tobacco cessation in this group. Because of the high prevalence of habits and potentially malignant disorders in this group, cancer control activities should be prioritised. Primary healthcare physicians and general dentists should be sensitised to this issue and strengthen their abilities for systematic examination of the oral cavity for potential dysplastic changes and timely referral because they assume a frontline role in the battle against tobacco and oral cancer. The findings from this survey will prompt the designing of a cost-effective feasible model for early detection and monitoring of oral precancerous lesions in this tribe through mobile health.
Currently, there is a vast disparity in the availability of healthcare data between tribal and non-tribal populations which makes it difficult to devise specific and special policies targeting the needs. Hence this data will be presented to the Indian Council of Medical Research, Ministry of Tribal Affairs and NPCDCS, Government of India, for the implementation of oral cancer prevention programmes in such communities.
Financial support and sponsorship
This project is funded by the Indian Council of Medical Research (ICMR), Government of India.
Conflicts of interest
There are no conflicts of interest.
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Dr. Jananni Muthu
Department of Periodontology, Indira Gandhi Institute of Dental Sciences, Sri Balaji Vidyapeeth (Deemed to be) University, Pondicherry
Source of Support: None, Conflict of Interest: None
[Table 1], [Table 2]
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