Molecular mechanisms of tobacco induced oral and oropharyngeal cancer: Results of a tissue microarray and immunohistochemistry-based study from a tertiary cancer center in India

Background: It is well established that chronic exposure to tobacco induces head and neck cancers but the exact etiopathogenesis is not known. Though studies have shown expression of TIMP1, EPS8 and AXL in cancers, their role in tobacco-induced cancers is not known. We aimed this study to evaluate the role of these molecules in oral and oropharyngeal squamous cell cancers (SCC). Materials and Methods: In this single institutional study, 31 patients of oral and oropharyngeal SCC with history of chewing tobacco were included. Smokers were excluded from the study. After informed consent biopsies were taken from affected and contralateral normal mucosa. Paraffin blocks were made and tissue microarray (TMA) were constructed using these blocks. Immunohistochemistry (IHC) for TIMP1, EPS8, AXL kinase was carried out on these tissue microarrays. The intensity of staining was scored from 0 to 3+, related to expression of each of the three molecules. Results: The expression of TIMP1, EPS8 and AXL kinase was significantly more in the cancerous mucosa versus non-cancerous mucosa (P = 0.000 in all three) in oral and oropharyngeal SCC exposed to chewing tobacco. Conclusion: Immunohistochemical expression of these molecular markers in oral and oropharyngeal SCC correlated with their molecular based studies. Significant IHC expression of TIMP1, EPS8 and AXL establishes their role in the pathogenesis of oral and oropharyngeal squamous cell carcinomas. Novel targeted therapies may be researched that can detect and target these molecules at an earlier stage of pathogenesis of these tumors.

Smokeless tobacco taxation: Lessons from Southeast Asia

Southeast Asia accounts for nearly 86 per cent of the smokeless tobacco (SLT) consumers in the world. The heterogeneous nature of SLT is a major impediment to using taxation as a tool to regulate SLT. This study was aimed to review issues around fiscal policies on SLT with the objective of providing clarity on the use of taxation as an effective policy instrument to regulate SLT use. Descriptive statistics and graphical representations were used to analyze published data from different sources. An analysis of prices and tax between smoke and SLT products was done to understand the impact of tax policies on SLT consumption. India, Bangladesh and Myanmar together account for 71 per cent of the world SLT users. The retail prices (PPP$) and tax were lower for SLT in low- and lower-middle-income countries and higher in high-income countries, on an average, suggesting a direct relationship between the two. Evidence from India and Bangladesh suggested that taxation had significantly reduced SLT use among adults. The compounded levy scheme used in India to tax SLT was found effective after incorporating speed of packing machines into the assessment of deemed production and tax on SLT products. The current analysis shows that taxation can be an effective instrument to regulate SLT consumption if tax rates are harmonized across SLT products and in a manner not to encourage substitution with other tobacco products. It is also imperative to set a minimum floor price on all tobacco products including SLT.

Oral health consequences of smokeless tobacco use

Smokeless tobacco (SLT) use has many oral effects including oral cancer, leukoplakia and erythroplakia, oral submucous fibrosis (if mixed with areca nut), loss of periodontal support (recession) and staining of teeth and composite restorations. This review was aimed to provide information to identify oral lesions that occur due to the use of smokeless tobacco so that effective interventions can be undertaken to reduce morbidity and mortality from the use of SLT.

Prevalence of oral mucosal lesions among chewing tobacco users: A cross‑sectional study.

Context: The increasing use of chewing tobacco (CT) in the last 10–12 years has led to an increased incidence of potentially malignant oral disorders and frank oral malignancies. Aim: To determine the frequency of oral mucosal lesions and to correlate the dose‑response relationship among CT users of Bengaluru North province. Settings and Design: This population‑based cross‑sectional study was conducted among a randomized cluster sample of adults in low‑income group (slums), of Bengaluru North, Karnataka state, India. Materials and Methods: Nine hundred and one subjects, all CT users were surveyed in this cross‑sectional study. A prestructured questionnaire which included information on type and amount of CT used, duration and frequency of use, and location of placement of tobacco in the oral cavity was used for assessment, which was followed by oral examination for the presence of lesions. Statistical Analysis Used: Chi‑square and Fisher’s exact tests were used to assess the statistical significance. Results: Of the 901 subjects with CT habits, 55.8% revealed no clinically detectable oral mucosal changes and 44.1% showed mucosal changes of which 63.8% were males and 36.1% were females. The most common finding was chewers mucositis (59.5%) followed by submucous fibrosis (22.8%), leukoplakia (8%), lichenoid reaction (6.5%), oral cancer (2.7%), and lichen planus (0.5%). Conclusion: This study provides information about different CT habits and associated mucosal lesions among this population.

Prevalence of Smokeless Tobacco Use and Number of Users in 121 Countries.

Background: In 2010, a study estimated the number of smokeless tobacco (SLT) users in 70 countries at 302.4 million. These countries represented 70% of the global population. We aimed to update this information and widen the scope to estimate the global prevalence of SLT use by including a larger number of countries. Methods: Data on the prevalence of current SLT use in 121 countries were obtained from various sources. Country-wise and gender-wise breakdown of the adult population in these countries was derived from the UN World Population for 2015. To translate prevalence rates into an estimate of the number of adult SLT users, we multiplied the adult male and female SLT prevalence rates by the corresponding male and female adult population in the respective countries. We then added the estimated number of male and female SLT users to get an overall estimate of SLT use. Results: There were 352 million SLT users (351.9 million) in 121 countries. Of these, 67% were men (232.7 million) and 33% were women (119.2 million). Nearly 95% (333.1 million) of global SLT users lived in developing countries and only 5% (918.8 million) lived in developed countries; 82.7% of global SLT users lived in the World Health Organization (WHO) South-East Asia Region. Globally, 90.4% of SLT users live in 11 countries of the world: India (237.4 million, 67.5%), Bangladesh (30.9 million), Myanmar (12.6 million), Pakistan (10.1 million), USA (9.6 million), China (4.1 million), Indonesia (3.2 million), Nepal (2.7 million), Madagascar (2.6 million), Germany and Uzbekistan (2.4 million each). Conclusion: Smokeless tobacco use is a global epidemic affecting 121 countries. All 180 countries that have ratified the WHO Framework Convention on Tobacco Control (WHO FCTC) are obliged to monitor SLT use. Parties to the Convention should collect information periodically using standard protocols for national and international comparability. To prevent health and economic losses attributable to SLT use, countries, especially developing countries, should formulate strategies specific to SLT control.

Prevalence of Tobacco Habits Among Health Care Students in Jaipur.

A questionnaire based study to assess the prevalence of tobacco use among undergraduate health care students of Maharaja Vinayak Health Care campus in Jaipur was done on 219 students of dental, nursing, physiotherapy and occupational therapy students. Global Health professional students survey (GHPSS), survey questionnaire given by (CDC) centre for disease control Athlanta which is a standard pre-tested questionnaire for assessing prevalence of tobacco use among health care professionals around the world was used. The present study showed 25.11% prevalence of smoking and 13.70% prevalence of chewing tobacco.This reflect alarming situation and demands urgent anti tobacco & tobacco cessation measures to be adopted by health professionals, who happens to be health promoters & health role models for society.