Smokeless tobacco-associated cancers: A systematic review and meta-analysis of Indian studies

Uncovering Risks Associated with Smoking Types and Intensities in Esophageal Cancer within High-Prevalence Regions in Africa: A Comprehensive Meta-analysis

Tobacco is usually cited among the well-known risk factors of esophageal cancer; nevertheless, the extent of the contribution of the type of smoking and its intensity to the disease has not been comprehensively elucidated in Africa. We searched MEDLINE/PubMed, Excerpta Medica Database, Web of Science, Scopus, Cochrane Library, and African Journals Online studies published before September 2023. The quality of the studies was assessed using the Newcastle-Ottawa scale, and the funnel plot was used for assessing potential publication bias. Meta-analyses were conducted to estimate summary effects using random-effects models. This study included 22,319 participants from 27 studies. The results strongly indicate a significant association between tobacco use and a higher risk of esophageal cancer. The risk of esophageal cancer is notably higher among pipe smokers [OR = 4.68; 95% confidence interval (CI), 3.38-6.48], followed by hand-rolled cigarette smokers (OR = 3.79; 95% CI, 2.68-5.35), in comparison with those who smoked commercially manufactured cigarettes (OR = 2.46; 95% CI, 1.69-3.60). Our findings also showed that the risk of esophageal cancer is highest in people smoking >183 packs per year (OR = 5.47; 95% CI, 3.93-7.62), followed by those smoking 93 to 183 packs per year (OR = 3.90; 95% CI, 3.13-4.86), in comparison with those smoking ≤92 packs per year (OR = 2.90; 95% CI, 2.19-3.84). Our findings strongly show that among the different types of tobacco use in Africa, pipe and hand-roller smokers face a higher risk of esophageal cancer.

Microbial community and functions involved in smokeless tobacco product: a metagenomic approach

Smokeless tobacco products (STPs) are attributed to oral cancer and oral pathologies in their users. STP-associated cancer induction is driven by carcinogenic compounds including tobacco-specific nitrosamines (TSNAs). The TSNAs synthesis could enhanced due to the metabolic activity (nitrate metabolism) of the microbial populations residing in STPs, but identifying microbial functions linked to the TSNAs synthesis remains unexplored. Here, we rendered the first report of shotgun metagenomic sequencing to comprehensively determine the genes of all microorganisms residing in the Indian STPs belonging to two commercial (Moist-snuff and Qiwam) and three loose (Mainpuri Kapoori, Dohra, and Gudakhu) STPs, specifically consumed in India. Further, the level of nicotine, TSNAs, mycotoxins, and toxic metals were determined to relate their presence with microbial activity. The microbial population majorly belongs to bacteria with three dominant phyla including Actinobacteria, Proteobacteria, and Firmicutes. Furthermore, the STP-linked microbiome displayed several functional genes associated with nitrogen metabolism and antibiotic resistance. The chemical analysis revealed that the Mainpuri Kapoori product contained a high concentration of ochratoxins-A whereas TSNAs and Zink (Zn) quantities were high in the Moist-snuff, Mainpuri Kapoori, and Gudakhu products. Hence, our observations will help in attributing the functional potential of STP-associated microbiome and in the implementation of cessation strategies against STPs. KEY POINTS: •Smokeless tobacco contains microbes that can assist TSNA synthesis. •Antibiotic resistance genes present in smokeless tobacco-associated bacteria. •Pathogens in STPs can cause infections in smokeless tobacco users.

The contribution of smoking and smokeless tobacco to oesophageal squamous cell carcinoma risk in the African oesophageal cancer corridor: Results from the ESCCAPE multicentre case-control studies

Tobacco use is a well-established risk factor for oesophageal squamous cell carcinoma (ESCC) but the extent of its contribution to the disease burden in the African oesophageal cancer corridor has not been comprehensively elucidated, including by type of tobacco use. We investigated the contribution of tobacco use (smoking and smokeless) to ESCC in Tanzania, Malawi and Kenya. Hospital-based ESCC case-control studies were conducted in the three countries. Incident cases and controls were interviewed using a comprehensive questionnaire which included questions on tobacco smoking and smokeless tobacco use. Logistic regression models were used to estimate odds ratios (OR) and their 95% confidence intervals (CI) of ESCC associated with tobacco, adjusted for age, sex, alcohol use, religion, education and area of residence. One thousand two hundred seventy-nine cases and 1345 controls were recruited between August 5, 2013, and May 24, 2020. Ever-tobacco use was associated with increased ESCC risk in all countries: Tanzania (OR 3.09, 95%CI 1.83-5.23), and in Malawi (OR 2.45, 95%CI 1.80-3.33) and lesser in Kenya (OR 1.37, 95%CI 0.94-2.00). Exclusive smokeless tobacco use was positively associated with ESCC risk, in Tanzania, Malawi and Kenya combined (OR 1.92, 95%CI 1.26-2.92). ESCC risk increased with tobacco smoking intensity and duration of smoking. Tobacco use is an important risk factor of ESCC in Tanzania, Malawi and Kenya. Our study provides evidence that smoking and smokeless tobacco cessation are imperative in reducing ESCC risk.

An Insight into Survivin in Relevance to Hematological, Biochemical and Genetic Characteristics in Tobacco Chewers with Oral Squamous Cell Carcinoma

BACKGROUND

Survivin is an inhibitor of apoptosis protein (IAP), encoded by the Baculoviral IAP Repeat Containing 5 (BIRC5) gene located on q arm (25.3) on chromosome 17. It is expressed in various human cancers and involved in tumor resistance to radiation and chemotherapy. The genetic analysis of the BIRC5 gene and its protein survivin levels in buccal tissue related to oral squamous cell carcinoma (OSCC) in South Indian tobacco chewers has not been studied. Hence, the study was designed to quantify survivin in buccal tissue and its association with pretreatment hematological parameters and to analyze the BIRC5 gene sequence.

METHOD

In a single centric case control study, buccal tissue survivin levels were measured by ELISA. A total of 189 study subjects were categorized into Group 1 (n = 63) habitual tobacco chewers with OSCC, Group 2 (n = 63) habitual tobacco chewers without OSCC, and Group 3 (n = 63) healthy subjects as control. Retrospective hematological data were collected from Group 1 subjects and statistically analyzed. The BIRC5 gene was sequenced and data were analyzed using a bioinformatics tool.

RESULTS

Survivin protein mean ± SD in Group 1 was (1670.9 ± 796.21 pg/mL), in Group 2 it was (1096.02 ± 346.17 pg/mL), and in Group 3 it was (397.5 ± 96.1 pg/mL) with significance (p < 0.001). Survivin levels showed significance with cut-off levels of absolute monocyte count (AMC), neutrophil/lymphocyte ratio (NLR), and lymphocyte/monocyte ratio (LMR) at (p = 0.001). The unique variants found only in OSCC patients were T → G in the promoter region, G → C in exon 3, C → A, A → G, G → T, T → G, A → C, G → A in exon 4, C → A, G → T, G → C in the exon 5 region.

CONCLUSIONS

The tissue survivin level increased in OSCC patients compared to controls; pretreatment AMC, LMR, and NLR may serve as add-on markers along with survivin to measure the progression of OSCC. Unique mutations in the promoter and exons 3-5 were observed in sequence analysis and were associated with survivin concentrations.

Mass Spectrometry-Based Metabolic Profiling of Urinary Metabolites of N'-Nitrosonornicotine (NNN) in the Rat

The tobacco-specific nitrosamine N'-nitrosonornicotine (NNN) and its close analogue 4-(N-nitrosomethylamino)-1-(3-pyridyl)-1-butanone (NNK) are classified as "carcinogenic to humans" (Group 1) by the International Agency for Research on Cancer. The currently used biomarker to monitor NNN exposure is urinary total NNN (free NNN plus its N-glucuronide). However, total NNN does not provide information about the extent of metabolic activation of NNN as related to its carcinogenicity. Targeted analysis of the major metabolites of NNN in laboratory animals recently led to the identification of N'-nitrosonornicotine-1N-oxide (NNN-N-oxide), a unique metabolite detected in human urine that is specifically formed from NNN. To further investigate NNN urinary metabolites that hold promise as new biomarkers for monitoring NNN exposure, uptake, and/or metabolic activation, we conducted a comprehensive profiling of NNN metabolites in the urine of F344 rats treated with NNN or [pyridine-d4]NNN. Using our optimized high-resolution mass spectrometry (HRMS)-based isotope-labeling method, 46 putative metabolites were identified with robust MS evidence. Out of the 46 candidates, all known major NNN metabolites were identified and structurally confirmed by comparing them to their isotopically labeled standards. More importantly, putative metabolites considered to be exclusively formed from NNN were also identified. The two new representative metabolites─4-(methylthio)-4-(pyridin-3-yl)butanoic acid (23, MPBA) and N-acetyl-S-(5-(pyridin-3-yl)-1H-pyrrol-2-yl)-l-cysteine (24, Py-Pyrrole-Cys-NHAc) ─were identified by comparing them to synthetic standards that were fully characterized by nuclear magnetic resonance and HRMS. They are hypothesized to be formed by NNN α-hydroxylation pathways and thus represent the first potential biomarkers to specifically monitor the uptake plus metabolic activation of NNN in tobacco users.

Smokeless tobacco utilization among tribal communities in India: A population-based cross-sectional analysis of the Global Adult Tobacco Survey, 2016–2017

Introduction

Evidence on smokeless tobacco use is scarce among indigenous communities, with the available literature based either on a specific tribe or on a particular region. Therefore, we aimed to estimate the prevalence of smokeless tobacco and assess its correlation among tribal communities in India.

Methods

We utilized data from the Global Adult Tobacco Survey-2 conducted in 2016–2017. A total of 12,854 tribal people aged &gt;15 years were included in this study. The utilization of smokeless tobacco was estimated using the weighted proportion, and its correlates were assessed by multivariable logistic regression reported as an adjusted odds ratio (AOR) with a 95% confidence interval.

Results

The prevalence of smokeless tobacco use was 32%. Participants aged 31–45 years [AOR: 1.66 (1.37–2.00)], who were men [AOR: 2.37 (1.94–1.90)], and who were daily wage/casual laborers [AOR: 5.32 (3.39–8.34)] were observed to have a significant association with smokeless tobacco. Willingness and attempt to quit smokeless tobacco were higher in Eastern India (31.2%) and central India (33.6%), respectively.

Discussion

We observed one-third of the tribal individuals used smokeless tobacco in India. Tobacco control policies should prioritize men, rural residents, and individuals with fewer years of schooling. Culturally appropriate and linguistically tailored messages are required for behavioral change communication.

Current Status and Future Prospects for Esophageal Cancer

Esophageal cancer (EC) is the ninth most common cancer and the sixth leading cause of cancer deaths worldwide. Esophageal squamous cell carcinoma (ESCC) and esophageal adenocarcinoma (EAC) are the two main histological subtypes with distinct epidemiological and clinical features. While the global incidence of ESCC is declining, the incidence of EAC is increasing in many countries. Decades of epidemiologic research have identified distinct environmental exposures for ESCC and EAC subtypes. Recent advances in understanding the genomic aspects of EC have advanced our understanding of EC causes and led to using specific genomic alterations in EC tumors as biomarkers for early diagnosis, treatment, and prognosis of this cancer. Nevertheless, the prognosis of EC is still poor, with a five-year survival rate of less than 20%. Currently, there are significant challenges for early detection and secondary prevention for both ESCC and EAC subtypes, but Cytosponge™ is shifting this position for EAC. Primary prevention remains the preferred strategy for reducing the global burden of EC. In this review, we will summarize recent advances, current status, and future prospects of the studies related to epidemiology, time trends, environmental risk factors, prevention, early diagnosis, and treatment for both EC subtypes.

Common assumptions in tobacco control that may not hold true for South-East Asia

Tobacco is a threat to public health in South-East Asia and its control should be a priority. However, many common assumptions about tobacco control may not hold true for the region and can misdirect policy. The substantial health risks associated with smokeless tobacco have been largely misunderstood and neglected. The syndemic association between tuberculosis and tobacco has also been overlooked. Similarly, less attention has been paid to address second-hand smoke exposure of pregnant women to indoor smoking (caused predominantly by men). On the other hand, our poor understanding of the diverse tobacco supply chain has been blocking progress in tobacco control. Finally, the rising popularity of electronic cigarettes has thrown new challenges; many governments, concerned for its youth, have banned such products. We argue for a nuanced approach to tobacco control in South-East Asia. We also encourage a wider debate in public health, where other established assumptions may be hampering progress.

Oral Cancer Risk Assessment for Different Types of Smokeless Tobacco Products Sold Worldwide: A Review of Reviews and Meta-analyses

Smokeless tobacco (SLT) use is a significant cause of lip and oral cavity cancers. Globally, oral cancer prevalence is strongly linked to the types of tobacco products used, their chemical composition, and their pattern of use. Except snus, all SLT products sold in different World Health Organization regions are strongly associated with oral cancer incidence. Shammah showed the highest association OR with 95% confidence intervals (CI; OR, 38.74; 95% CI, 19.50-76.96), followed by oral snuff (OR, 11.80; 95% CI, 8.45-16.49), gutkha (OR, 8.67; 95% CI, 3.59-20.93), tobacco with betel quid (OR, 7.74; 95% CI, 5.38-11.13), toombak (OR, 4.72; 95% CI, 2.88-7.73), and unspecified chewing tobacco (OR, 4.72; 95% CI, 3.13-7.11). Most SLT products containing high levels of carcinogenic tobacco-specific nitrosamines (TSNA) exhibit a high risk of oral cancer. There is an urgent need to frame and implement international policies for oral cancer prevention through legal control of the TSNA levels in all SLT product types.

PREVENTION RELEVANCE

Most smokeless tobacco products sold worldwide, mainly shammah, toombak, gutkha, betel quid with tobacco, and dry snuff, are associated with a high risk of oral cancer. A high concentration of tobacco-specific nitrosamines in smokeless tobacco products is the major causative factor for oral cancer development.

Health Effects of Tobacco at the Global, Regional, and National Levels: Results From the 2019 Global Burden of Disease Study

INTRODUCTION

The purpose was to quantify the health effects of tobacco using data from the 2019 Global Burden of Disease study.

AIMS AND METHODS

We collected detailed information on tobacco consumption overall as well as its individual aspects (smoking, secondhand smoke, and chewing tobacco) for the deaths and disability-adjusted life years (DALYs) for all-cause disease, cardiovascular disease, neoplasms, and chronic respiratory diseases, and their age-standardized rates (ASRs).

RESULTS

Tobacco was responsible for 8.71 million deaths and 229.77 million DALYs globally in 2019. The ASRs of all tobacco-related deaths and DALYs declined from 1990 to 2019, to 108.55 deaths per 100 000 population and 2791.04 DALYs per 100 000 population in 2019. During any year the ASRs of all tobacco-related deaths and DALYs were higher in males than in females. The ASRs of all tobacco-related deaths and DALYs were highest in countries with a low-middle sociodemographic index (SDI) and lowest in high-SDI countries in 2019. Cardiovascular disease, neoplasms, and chronic respiratory diseases were the three leading causes of tobacco-related mortality.

CONCLUSIONS

Although the ASRs of deaths and DALYs related to tobacco have declined, the absolute number remain high. Tobacco control policies need to be strengthened further in order to reduce the heavy health burden of tobacco.

IMPLICATIONS

This study provides a detailed description on the health effects of tobacco, including maps of the current global burden of tobacco-related disease. Although the ASRs of tobacco-related deaths and DALYs have declined, the absolute numbers remain high-tobacco was responsible for 8.71 million deaths and 229.77 million DALYs globally in 2019. The findings may have implications for tobacco control. Countries where progress has been slower in reducing tobacco-related disease burden should study and consider implementing policies and strategies that have been applied in countries like Singapore which show the greatest declines for recent decades.

Influence of Oral Dipping Tombak Smokeless Tobacco on Coagulation Profile and Platelet Counts

The goal of this paper is to investigate the influence of oral dipping of Tombak Smokeless Tobacco (SLT) on prothrombin time (PT), activated partial thromboplastin time (APTT), international normalized ratio(INR) values, and platelet counts (PLTs), in Sudanese Tombak users. An analytical cross-sectional study was conducted at Kosti health insurance hospital, Sudan, in 2019. According to the inclusion and exclusion criteria, 100 adult users of oral Tombak for three or more years were chosen randomly as a study group. Another 100 matched healthy individuals who never used Tombak were randomly selected as a comparative group. Venous blood specimens were collected in ethylene diamine tetra-acetic acid (EDTA) containers for the PLT counts using the automated haematology analyser (Sysmex, Tokyo, Japan XK-21SYSMEX) and in trisodium citrate anti-coagulant containers for coagulation tests using a co-agulometer machine analyser. Our findings show a significant decrease in PLT count mean values in the Tombak users group (212.1 × 103/mm3 ± 74.3 × 103/mm3) compared with the non-taking Tombak group mean values (243.2 × 103/mm3 ± 83.0 × 103/mm3), (p < 0.006). Both PT and APTT were significantly prolonged in Tombak users (16.03 ± 1.22 s vs. 14.44 ± 0.557 s), p < 0.001 for PT, and (41.62 ± 7.28 s vs. 34.99 ± 4.02 s), (p < 0.001) for APTT. INR mean values were significantly longer in Tombak users (1.11 ± 0.096) vs. (1.07 ± 0.66; p < 0.001). Multiple linear regression analysis findings show a significant impact of the four investigated variables, including duration of taking Tombak, age, and frequency of taking Tombak per day (p < 0.001). In conclusion, using Tombak a Smokeless Tobacco (SLT) for a long period significantly affect Platelet counts and coagulation profile.

Protocol for a feasibility study of longitudinal surveys to assess the impact of policies on tobacco use among school-going adolescents in South Asia

Background: Smokeless tobacco (ST) use is common among youth in South Asia where 85% of the world’s 300 million ST users live and use the most lethal ST forms. Little is known about the impact of tobacco control policies on the youth ST uptake in those countries. We planned to conduct longitudinal surveys among school going adolescents to evaluate existing tobacco control policies on tobacco uptake and use, and a feasibility study for that prospective, observational cohort study.

Study objectives: (1) To demonstrate the feasibility of selection, recruitment and retention of schools and of study participants; (2) To assess the feasibility and acceptability of the study procedure and study tool (questionnaire); (3) To evaluate if the questionnaire can assess tobacco uptake and use, and their potential predictors.

Methods and analysis: The feasibility study will be conducted in two administrative areas within each of three South Asian countries: Bangladesh, India and Pakistan. We will use both quantitative and qualitative data collection methods. Eight eligible schools will be randomly selected within purposively selected sub-districts from each country. We plan to conduct one baseline and one follow up survey among students of grade 6-8, one year apart. At each time point, data on tobacco uptake and potential predictors will be collected from students via self-administered questionnaires that were designed for the longitudinal study. The qualitative component will be embedded into the study with each round of data collection to assess the acceptability of the study instrument (questionnaire) and data collection methods, via focus group discussions with students and semi-structured interviews with schoolteachers.

Recruitment and retention rates, completeness of the questionnaires, frequencies and associations of tobacco use and explanatory variables will be reported. Data gathered from the focus group and interviews will be analysed using the framework approach.

Hoarseness: its spectrum, associations and management in a tertiary care centre in India

Objective

To determine the demographic, aetiopathological and diagnostic profiles of patients presenting with hoarseness to a laryngology unit of a tertiary care centre in India.

Methods

A retrospective observational study was conducted.

Results

The 1033 patients who presented with dysphonia showed a male predominance (70 per cent), high rates of malignancy (18 per cent), late presentation (mean, 24 months) and poor follow-up trends (53 per cent with 3 months’ follow up), which contrasts with data from developed countries. The patient population hailed from different states in India and neighbouring countries around India, serving as a good sample for the subcontinent. The majority (67 per cent) were managed conservatively; however, surgical management was the preferred choice for those who presented with airway stenosis (91 per cent) and laryngeal trauma (75 per cent). Significant associations between vocal professionalism level and co-morbidities and dysphonia aetiopathologies are discussed.

Conclusion

These findings give insight into the trends of hoarseness in the developing Indian subcontinent, which can aid understanding and management.

The health impact of smokeless tobacco products: a systematic review

INTRODUCTION

The objective was to systematically review studies on health outcomes from smokeless tobacco (SLT) products.

METHODS

We analysed published literature on the health outcomes from SLT use between 01/01/2015 to 01/02/2020, following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) protocol using PubMed, Embase, Scopus, and Google Scholar.

RESULTS

Of 53 studies included, six were global, 32 from Asia, Middle East and Africa (AMEA), nine from USA and six from Europe. 'Poor'-rated studies predominated (23;43%), in particular, for global (4;66%) and AMEA (16;50%). Health outcomes differed between SLT-products and regions; those in AMEA were associated with higher mortality (overall, cancer, Coronary heart disease (CHD), respiratory but not cardiovascular disease (CVD)), and morbidity (CVD, oral and head and neck cancers), with odds ratios up to 38.7. European studies showed no excess mortality (overall, CVD, from cancers) or morbidity (ischemic heart disease (IHD), stroke, oral, head and neck, pancreatic or colon cancers) from several meta-analyses; single studies reported elevated risk of rectal cancer and respiratory disorders. Pooled study data showed protection against developing Parkinson's disease. US studies showed mixed results for mortality (raised overall, CHD, cancer and smoking-related cancer mortality; no excess risk of respiratory or CVD mortality). Morbidity outcomes were also mixed, with some evidence of increased IHD, stroke and cancer risk (oral, head and neck). No studies reported on switching from cigarettes to SLT-products.

CONCLUSION

Our review demonstrates stark differences between different SLT-products in different regions, ranging from zero harm from European snus to greatly increased health risks in AMEA. The literature on the safety profile for SLT-products for harm reduction is incomplete and potentially misinforming policy and regulation.

Co-producing an intervention for tobacco cessation and improvement of oral health among diabetic patients in Bangladesh

BACKGROUND

Tobacco consumption is a major risk factor for many diseases including diabetes and has deleterious effects on oral health. Diabetic patients are vulnerable to developing certain oral conditions. So far, no studies have attempted to co-develop a tobacco cessation intervention to be delivered in dental clinics for people with diabetes in Bangladesh.

AIM

To co-produce a tobacco cessation intervention for people with diabetes for use in dental clinics in Bangladesh.

OBJECTIVES

To assess: (1) tobacco use (patterns) and perceptions about receiving tobacco cessation support from dentists among people with diabetes attending the dental department of Bangladesh Institute of Research and Rehabilitation in Diabetes, Endocrine and Metabolic Disorders (BIRDEM) who smoke or use smokeless tobacco (ST) (2) current tobacco cessation support provision by the dentists of the dental department of BIRDEM (3) barriers and facilitators of delivering a tobacco cessation intervention at a dental clinic, and (4) to co-produce a tobacco cessation intervention with people with diabetes, and dentists to be used in the proposed context.

METHODS

The study was undertaken in two stages in the dental department of BIRDEM, which is the largest diabetic hospital in Bangladesh. Stage 1 (July-August 2019) consisted of a cross-sectional survey among people with diabetes who use tobacco to address objective 1, and a survey and workshop with dentists working in BIRDEM, and consultations with patients to address objectives 2 and 3. Stage 2 (January 2020) consisted of consultations with patients attending BIRDEM, and a workshop with dentists to co-produce the intervention.

RESULT

All survey participants (n = 35) were interested in receiving tobacco cessation support from their dentist. We identified important barriers and facilitators to deliver tobacco cessation intervention within dental services. Barriers reported by dentists included lack of a structured support system and lack of training. As a facilitator, we identified that dentists were willing to provide support and it would be feasible to deliver tobacco cessation intervention if properly designed and embedded in the routine functioning of the dental department of BIRDEM. Through the workshops and consultations at stage 2, a tobacco cessation intervention was co-developed. The intervention included elements of brief cessation advice (using a flipbook and a short video on the harmful effects of tobacco) and pharmacotherapy.

CONCLUSION

Incorporation of tobacco cessation within dental care for people with diabetes was considered feasible and would provide a valuable opportunity to support this vulnerable group in quitting tobacco.

Association between smokeless tobacco use and oral cavity cancer risk in women compared with men: a systematic review and meta-analysis

BACKGROUND

The impact of smokeless tobacco (SLT) use on the risk of oral cavity cancer (OCC) has been confirmed; however, the sex-based difference in this association remains inconclusive. Therefore, this study aimed to estimate the association between SLT use and OCC risk in women and compared it to that in men.

METHODS

PubMed, Embase, and Cochrane Library databases were systematically searched for eligible studies from their inception up to August 2020. Studies reporting the effect estimates of SLT use on OCC risk in men and women, were eligible for inclusion. The relative risk ratio (RRR) was applied to calculate the sex-based difference in the relationship between SLT use and OCC risk, and pooled analysis was conducted using a random-effects model with inverse variance weighting.

RESULTS

Nineteen studies reporting a total of 6593 OCC cases were included in the final meta-analysis. The pooled relative risk (RR) suggested that SLT use was associated with an increased risk of OCC in both men (RR, 2.94; 95% confidence interval [CI], 2.05-4.20; P < 0.001) and women (RR, 6.39; 95%CI, 3.16-12.93; P < 0.001). Moreover, the SLT-use-related risk of OCC was higher in women than that in men (RRR,1.79; 95%C, 1.21-2.64; P = 0.003). The risk of OCC related to SLT use in women was still significantly higher than that in men (RRR, 1.75; 95%CI, 1.15-2.66; P = 0.008) after excluding indirect comparison results. Finally, a subgroup analysis suggested significant sex-based differences only in individuals who received chewed smokeless products, regardless of the control definition. Pooled analysis of studies with high design quality confirmed the notably higher risk of OCC in women than in men.

CONCLUSIONS

This study found that SLT use was associated with a higher risk of OCC in women than in men. Further large-scale prospective cohort studies should be conducted to verify sex-based differences in the association between use of specific smokeless products and OCC risk.

Novel Pathways and Mechanism of Nicotine-Induced Oral Carcinogenesis

BACKGROUND

Smokeless Tobacco (SLT) contains 9 times more nicotine than Smoked Tobacco (SMT). The carcinogenic effect of nicotine is intensified by converting nicotine-to-nicotine-derived Nitrosamines (NDNs).

METHODS

A review of the literature was conducted with a tailored search strategy to unravel the novel pathways and mechanisms of nicotine-induced oral carcinogenesis.

RESULTS

Nicotine and NDNs act on nicotinic Acetylcholine Receptors (nAChRs) as agonists. Nicotine facilitates cravings through α4β2nAChR and α7nAChR, via enhanced brain dopamine release. Nicotine binding to nAChR promotes proliferation, migration, invasion, chemoresistance, radioresistance, and metastasis of oral cancer cells. Nicotine binding to α7nAChR on keratinocytes triggers Ras/Raf-1/MEK1/ERK cascade promoting anti-apoptosis and pro-proliferative effects. Furthermore, the nicotine-enhanced metastasis is subdued on nAChR blockade through reduced nuclear localization of p-EGFR.

CONCLUSION

Protracted exposure to nicotine/NDN augments cancer-stimulatory α7nAChR and desensitizes cancer inhibitory α4β2nAChR. Since nAChRs dictate both addictive and carcinogenic effects of nicotine, it seems counterintuitive to designate nicotine just as an addictive agent devoid of any carcinogenicity.

Periodontal status associated with dual habits of smoking and smokeless tobacco use: A cross-sectional study in young adults

Background. Tobacco smoke is an established risk factor for periodontitis. However, few studies have evaluated the periodontal status of smokeless tobacco (SLT) users, while that of individuals with dual habits has largely been unexplored. Therefore, the current study aimed to find if the periodontal status in individuals with dual habits of smoking and SLT use is different from those with any single habit.Methods. Four groups (A: exclusive smokers, B: exclusive tobacco chewers, C: individuals with dual habits, and D: non-users of tobacco), each comprising 75 males in the age group of 20 to 35 years, were selected. Along with the history of tobacco use, a modified oral hygiene index (OHI), gingival index (GI), probing depth (PD), and the number of teeth with gingival recession (GR) were recorded. The data were assessed using the Chi-squared test, one-way ANOVA, and logistic regression. Statistical significance was set at P<0.05.Results. Group C exhibited the highest mean OHI scores, with 94.66% of participants having poor oral hygiene (OHI>3.0). The prevalence of severe gingivitis (GI>2.0) was significantly lower among exclusive smokers (group A) and those with dual habits (group C) compared to the other two groups. As much as 60% of group C participants had average PD in the range of 4-6 mm, while deeper average PD (>6 mm) was most common among smokers. The highest risk of having a tooth with GR was also associated with the dual habit (OR = 4.33, 95% CI = 3.24 - 5.76) compared with the non-users.Conclusion. While both forms of tobacco were associated with poor periodontal status, the additive effect of smoking and SLT use was evident in almost all the parameters, more so with poor oral hygiene and the prevalence of gingival recession. These findings emphasize that individuals with dual habits have an additional risk for periodontal destruction.

Cancer epidemiology literature from India: Does it reflect the reality?

BACKGROUND

The alarming escalation of cancers over infectious diseases in the lower and middle-income countries warrants a better understanding of this epidemiological transition. The epidemiology of cancers in India is sparsely addressed in the literature. Hence, in this manuscript, we present the review done, on research manuscripts, addressing cancer incidence, trends and risk factors from India over the last 12 years. Studies addressing screening, treatment and clinical trials were excluded.

METHODS

We evaluated the studies for the theme addressed, study design, sample size, the region of origin and whether it was population or hospital-based study.

RESULTS

The studies highlighted a significant shortage of multicenter population-based data in the incidence and risk factors associated with various malignancies in India. Further, we also observed that there was a relative lack of information from the northern and northeastern parts of India. The reviewed articles also indicated the need for a robust design for the studies, large sample size and uniformity in reporting incidence for appropriately drawing conclusions from a study. Reporting of country-specific risk factors with their geographical variations was also sparse.

CONCLUSION

Overall, the cancer epidemiology literature from India is sparse. More studies with robust designs representing all parts of the country are currently needed.

Epidemiology of Barrett's Esophagus and Esophageal Carcinoma

To care and treat patients with esophageal cancer, one must first understand the epidemiology of Barrett's esophagus (BE). BE is defined as the intestinal metaplasia occurring within the esophagus from normal squamous epithelium to abnormal specialized columnar epithelium. BE, while first described by Allison in 1948, was attributed to Norman Barrett in 1950, who reported a case of chronic peptic ulcer in the lower esophagus that was covered by columnar epithelium.

Microbiology of the American Smokeless Tobacco

Smokeless tobacco products (STP) contain diverse microbial communities that contribute to the formation of harmful chemical byproducts. This is concerning since 300 million individuals around the globe are users of smokeless tobacco. Significant evidence has shown that microbial metabolic activities mediate the formation of carcinogens during manufacturing. In recent years, studies have revealed a series of additional health impacts that include lesions and inflammation of the oral mucosa and the gastrointestinal tract, as well as alterations of the endogenous microbiota. These findings are due to recent developments in molecular technologies that allowed researchers to better examine the microbial component of these products. This new information illustrates the scale of the STP microbiota and its diversity in the finished product that is sold for consumption. Additionally, the application of metagenomics and metatranscriptomics has provided the tools to look at phylogenies across bacterial, viral, and eukaryotic groups, their functional capacities, and viability. Here we present key examples of tobacco microbiology research that utilizes newer approaches and strategies to define the microbial component of smokeless tobacco products. We also highlight challenges in these approaches, the knowledge gaps being filled, and those gaps that warrant further study. A better understanding of the microbiology of STP brings vast public health benefits. It will provide important information for the product consumer, impact manufacturing practices, and provide support for the development of attainable and more meaningful regulatory goals. KEY POINTS: Newer technologies allowed quicker and more comprehensive identification of microbes in tobacco samples, encapsulating microorganisms difficult or impossible to culture. Current research in smokeless tobacco microbiology is filling knowledge gaps previously unfilled due to the lack of suitable approaches. The microbial ecology of smokeless tobacco presents a clearer picture of diversity and variability not considered before.

Investigation of 2'-Deoxyadenosine-Derived Adducts Specifically Formed in Rat Liver and Lung DNA by N'-Nitrosonornicotine Metabolism

The International Agency for Research on Cancer has classified the tobacco-specific nitrosamines N'-nitrosonornicotine (NNN) and 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) as "carcinogenic to humans" (Group 1). To exert its carcinogenicity, NNN requires metabolic activation to form reactive intermediates which alkylate DNA. Previous studies have identified cytochrome P450-catalyzed 2'-hydroxylation and 5'-hydroxylation of NNN as major metabolic pathways, with preferential activation through the 5'-hydroxylation pathway in some cultured human tissues and patas monkeys. So far, the only DNA adducts identified from NNN 5'-hydroxylation in rat tissues are 2-[2-(3-pyridyl)-N-pyrrolidinyl]-2'-deoxyinosine (Py-Py-dI), 6-[2-(3-pyridyl)-N-pyrrolidinyl]-2'-deoxynebularine (Py-Py-dN), and N⁶-[4-hydroxy-1-(pyridine-3-yl)butyl]-2'-deoxyadenosine (N⁶-HPB-dAdo) after reduction. To expand the DNA adduct panel formed by NNN 5'-hydroxylation and identify possible activation biomarkers of NNN metabolism, we investigated the formation of dAdo-derived adducts using a new highly sensitive and specific liquid chromatography-nanoelectrospray ionization-high-resolution tandem mass spectrometry method. Two types of NNN-specific dAdo-derived adducts, N⁶-[5-(3-pyridyl)tetrahydrofuran-2-yl]-2'-deoxyadenosine (N⁶-Py-THF-dAdo) and 6-[2-(3-pyridyl)-N-pyrrolidinyl-5-hydroxy]-2'-deoxynebularine (Py-Py(OH)-dN), were observed for the first time in calf thymus DNA incubated with 5'-acetoxyNNN. More importantly, Py-Py(OH)-dN was also observed in relatively high abundance in the liver and lung DNA of rats treated with racemic NNN in the drinking water for 3 weeks. These new adducts were characterized using authentic synthesized standards. Both NMR and MS data agreed well with the proposed structures of N⁶-Py-THF-dAdo and Py-Py(OH)-dN. Reduction of Py-Py(OH)-dN by NaBH₃CN led to the formation of Py-Py-dN both in vitro and in vivo, which was confirmed by its isotopically labeled internal standard [pyridine-d₄]Py-Py-dN. The NNN-specific dAdo adducts Py-THF-dAdo and Py-Py(OH)-dN formed by NNN 5'-hydroxylation provide a more comprehensive understanding of the mechanism of DNA adduct formation by NNN.

Tobacco use and betel quid chewing among adults in Myanmar- estimates and social determinants from demographic and health survey, 2015-16

BACKGROUND

National-level prevalence of tobacco use and betel quid chewing, and associated socio-demographic factors were estimated using first-ever, Myanmar Demographic Health Survey, 2015-16.

METHODS

Questions about tobacco smoking, smokeless tobacco use, and betel quid chewing were used to create outcome variables such as tobacco smoking, smokeless tobacco use, and 'dual use' (tobacco use and betel quid chewing). Sex-stratified weighted prevalence rates, distribution by socio-demographic factors were presented. Association of demographic factors with tobacco and/or betel quid chewing was assessed by multinomial logistic regression.

RESULTS

Among men, prevalence (%) of tobacco use and betel quid chewing was 40.9 (95% CI 38.1, 42.1) and 58.9 (95% CI 56.3, 61.6) respectively. Among women tobacco use was 3.7 (95% CI 2.0, 4.3) and betel quid chewing 18.2 (95% CI 16.4, 20.0). Among men prevalence of either tobacco or betel quid and 'dual use' was 50.4 (95% CI 48.5, 52.3) and 25.0 (95% CI 23.1, 26.8) respectively, whereas among women the corresponding rates were 17.9 (95% CI 16.2, 19.6) and 2.0 (95% CI 1.6, 2.9). Smokeless tobacco use was low (< 5%) in both sexes. Tobacco use and/or betel quid chewing was associated with age, wealth, marital status, and occupation in both sexes. However, the effect sizes were much larger among women for wealth groups. People of older age and lower wealth had a higher odds of being a tobacco user and/or betel quid chewer.

CONCLUSIONS

In Myanmar, prevalence of both tobacco use and betel quid chewing was high particularly among men. Tobacco control interventions should be strictly implemented and 'dual use' of both tobacco and betel quid should also be urgently addressed.

Addictions Causing Head-and-Neck Cancers

Head-and-neck cancers pose a serious economic burden, with most countries investing significant resources to reduce the incidence, primarily focusing on understanding addictive etiologies. The traditional literature focused on tobacco and alcohol use, with few studies on contemporary factors such as e-cigarette, waterpipe smoking, and human papillomavirus. This article attempts to collate and present an update on the globally identified etiologic factors.

The aim of this study was to identify and review the addictive etiologic factors causing head-and-neck cancers.

An electronic search was performed on Medline, Embase, and Google Scholar to identify the etiologies causing head-and-neck cancers and narrowed down on those driven by addiction. Further, we identified their constituents, mechanism of action, and the risks attributable to various forms of products.

Substances identified included smoked and chewed tobacco, alcohol, mate, marijuana, areca nut and betel quid, and viruses. An alarming majority of youth are now utilizing these substances. Furthermore, migrant movements have led to the spread of traditional practices across the regions, especially from the Asian subcontinent.

Ironically, despite modern advances and technology, we still see that a large proportion of population succumb to these cancers, emphasizing the need for more effective and targeted policies to combat this menace at the grassroots level.

Compliance of smokeless tobacco supply chain actors and products with tobacco control laws in Bangladesh, India and Pakistan: protocol for a multicentre sequential mixed-methods study

INTRODUCTION

South Asia is home to more than 300 million smokeless tobacco (ST) users. Bangladesh, India and Pakistan as signatories to the Framework Convention for Tobacco Control (FCTC) have developed policies aimed at curbing the use of tobacco. The objective of this study is to assess the compliance of ST point-of-sale (POS) vendors and the supply chain with the articles of the FCTC and specifically with national tobacco control laws. We also aim to assess disparities in compliance with tobacco control laws between ST and smoked tobacco products.

METHODS AND ANALYSIS

The study will be carried out at two sites each in Bangladesh, India and Pakistan. We will conduct a sequential mixed-methods study with five components: (1) mapping of ST POS, (2) analyses of ST samples packaging, (3) observation, (4) survey interviews of POS and (5) in-depth interviews with wholesale dealers/suppliers/manufacturers of ST. We aim to conduct at least 300 POS survey interviews and observations, and 6-10 in-depth interviews in each of the three countries. Data collection will be done by trained data collectors. The main statistical analysis will report the frequencies and proportions of shops that comply with the FCTC and local tobacco control policies, and provide a 95% CI of these estimates. The qualitative in-depth interview data will be analysed using the framework approach. The findings will be connected, each component informing the focus and/or design of the next component.

ETHICS AND DISSEMINATION

Ethical approvals for the study have been received from the Health Sciences Research Governance Committee at the University of York, UK. In-country approvals were taken from the National Bioethics Committee in Pakistan, the Bangladesh Medical Research Council and the Indian Medical Research Council. Our results will be disseminated via scientific conferences, peer-reviewed research publications and press releases.

Association of Smokeless Tobacco Use and Oral Cancer: A Systematic Global Review and Meta-Analysis

INTRODUCTION

Smokeless tobacco products have been linked to precancerous and cancers of oral cavity for long. Evidence was available on the association between smokeless tobacco (SLT) products and oral cancers at regional but not at global level. Present meta-analysis is aimed to evaluate the risk of oral cancer with the use of SLT products among "ever" versus "never" users.

METHOD

Studies published for the period (1960-2016) are retrieved using Pubmed, Indmed, EMBASE, and Google Scholar search engines for the subject "ever" versus "never" users of SLT products and estimated the risk association with oral cancer. Summary odds ratios (relative risk) are estimated and meta-analysis was performed using random-effects model.

RESULTS

Thirty-seven studies from four of six WHO regions, Southeast Asia region (SEAR), the Eastern Mediterranean Region (EMR), Europe, and region of Americas (North and South) are included in the analysis. Significant risk with SLT products with oral cancer was found for SEAR (4.44, 95% CI = 3.51 to 5.61) and for EMR (1.28, 95% CI = 1.04 to 1.56). Significantly higher risk (p < .001) was found for females (5.83, 95% CI = 2.93 to 11.58). Product wise analysis for different SLT products revealed various levels of risk viz. gutkha (8.67, 95% CI = 3.59 to 20.93), pan tobacco / betel liquid (7.18, 95% CI = 5.48 to 9.41), oral snuff (4.18, 50% CI = 2.37 to 7.38), Mainpuri tobacco (3.32, 95% CI = 1.32 to 8.36), and snus (0.86, 95% CI = 0.58 to 1.29).

CONCLUSION

A significant positive association was observed between SLT use and the risk of oral cancer, in SEAR, EMRs, and among women users.

IMPLICATIONS

The present meta-analysis demonstrates SLT product use and the risk of oral cancer at global level. Moreover, the present analysis provided data on the risk associated with individual SLT product. The results fulfil the gap in the data on independent effect of individual SLT product use on the outcome of oral cancer at global level, conclusively. Chewing SLT products was associated with higher risk of oral cancer than other types of SLT. This can serve as a useful tool for policy makers in forming strict policies in controlling SLT menace. Hence, we propose that in addition to smoking, efforts should be directed towards SLT product cessation as well in reducing oral cancer incidence.

Smokeless Tobacco Use, Cigarette Smoking, and Upper Aerodigestive Tract Cancers: A Case-Control Study in the Batna Region, Algeria, 2008-2011

BACKGROUND

A significant proportion of the Algerian population uses tobacco products and is at risk of developing tobacco-associated cancers.

AIMS

This case-control study reports on the association between tobacco use and the occurrence of upper aerodigestive tract (UADT) cancers in Batna, Algeria.

METHODS

Incident primary UADT cancer cases in residents of Batna in 2008-2011 were identified using the regional tumor registry. One hospital and 1 population control were matched to each case by sex, year of birth, and residence. Information on tobacco use was collected, and odds ratios (ORs) were obtained using conditional logistic regression also after sex stratification.

RESULTS

The study included 192 cases (80%) of the 241 primary UADT cancer cases identified and 384 controls. Males represented 76.6% of cancer cases. Cancers of the nasopharynx (48%) and the larynx (26%) were the most common types. Ever use of smokeless tobacco (ST) (OR = 1.0; 95% confidence interval [CI]: 0.6-1.5) or current ST use (OR = 1.1; 95% CI: 0.6-1.7) was not associated with overall risk of UADT cancers. Associations with cancers of the nasopharynx (OR = 1.5; 95% CI: 0.5-4.6) and oral cavity/oropharynx (OR = 3.0; 95% CI: 0.8-11.8) were found when comparing use of ST only to no consumption of any tobacco. Cigarette smoking was associated with an increase in the overall risk of UADT cancers, with a 3-fold increase in the risk of laryngeal cancer when comparing smoking only to no consumption of any tobacco (OR = 3.3; 95% CI: 1.0-11.5). Associations for smokers who also consumed ST differed by cancer site.

CONCLUSION

In this study from Algeria dominated by male cases and by cancer in the nasopharynx, cigarette smoking but not ST was associated with UADT cancer. Analyses by anatomical site and using as reference never use of any type of tobacco suggested few associations with ST but of lower precision.

Naswar (Smokeless Tobacco) Use and the Risk of Oral Cancer in Pakistan: A Systematic Review With Meta-Analysis

Introduction

With an annual increase of 16000 new cases each year, oral cancer is the second most common cancer in Pakistan. There is conflicting evidence regarding the carcinogenicity of different forms of smokeless tobacco (SLT) from different countries. This difference in evidence may be attributed to the varied composition of SLT products used around the world, necessitating the establishment of individual risks related to each SLT product.

Methods

An electronic search in relevant databases yielded 119 publications, out of which six were included in this review. Effect estimates (odds ratios (ORs)) were abstracted or calculated from the given data. A fixed effects meta-analysis was performed to assess the risk of oral cancer with the use of Naswar. Population attributable fractions (PAF) were also calculated.

Results

The Meta Odds Ratio (mOR) for oral cancer associated with the "ever use" of Naswar compared to "never use" was 11.8 (95% CI = 8.4-16.4), I2 = 67%. The pooled estimate for oral cancer in "Ever-users" of Naswar compared to "Never-users," in the Khyber Pakhtunkhwa province was 18.3 (95% CI = 8.7-38.5), I2 = 0%. The PAF for oral cancer associated with the use of Naswar in Pakistan was 44% (95% CI = 35-53).

Discussion

This review highlights a strong relationship between oral cancer incidence and the use of Naswar in Pakistan and adds to the evidence base on the carcinogenicity of SLT products in humans. Although the synthesized evidence may not be of a high quality, it represents the "best available evidence" which can be used to inform policy.

Implications

The carcinogenicity of Naswar, a form of smokeless tobacco used extensively in Pakistan, Afghanistan, and Central Asia, has yet to be recognized by the International Agency for Research on Cancer (IARC), partly due to the lack of evidence on the association of Naswar use and cancer. Additionally, Naswar is yet un-regulated in Pakistan and evades the tax net, resulting in it being freely available to both adults and children at very cheap prices compared to cigarettes, which has been the main focus of tobacco control in Pakistan. This review provides ample evidence for the IARC to declare Naswar as carcinogenic, as well as the Government of Pakistan to regulate the production and sale of Naswar.

Smokeless Tobacco Use is "Replacing" the Smoking Epidemic in the South-East Asia Region

Background

The sustained anti-tobacco campaign initiated in response to the mounting evidence against tobacco smoking has driven tobacco companies and smokers to look for alternative choices, such as smokeless tobacco (SLT) products. If this strategy advances, it could undermine several gains made by the campaign over the years. Our objective was to examine the trends in the prevalence of different tobacco types in three countries (Bangladesh, India, and Nepal) of South-East Asia.

Methods

Data from national surveys were used to estimate the trends of weighted and age-standardized prevalence (along with 95% CI) of different tobacco products. The share of each tobacco type was then calculated as a percentage of total tobacco use for each time point and country.

Results

In all the three countries, smoking prevalence declined (by 6% in Bangladesh, 3% in India, and 7% in Nepal) but SLT use increased (by 3% in Bangladesh, 6% in India, and 4% in Nepal) over the study period. SLT use increased irrespective of whether the total tobacco use increased or decreased. The share of SLT as a percentage of total tobacco use increased from 15% to 19% among Bangladeshi men, from 46% to 61% in India, and from 29% to 41% in Nepal.

Conclusions

In South-East Asia, a clear shift in the product preference from smoking to SLT was noted. Misleading advertising by tobacco companies may be responsible for the increase in the SLT prevalence, which is as harmful as smoking. Countries should strengthen policies to restrict SLT usage and prevent the rise of its use.

Implications

It has been documented that the smoking prevalence has been declining in most countries of the South-East Asia region where effective anti-tobacco laws have been implemented. But, due to a number of factors, the prevalence of smokeless tobacco has been increasing steadily, making the entire anti-tobacco movement less effective in terms of reducing the tobacco-attributable disease burden. In this context, this study has provided a detailed comparative analysis of the prevalence of smokeless tobacco use and smoking in three countries of the SEAR where such data were available. It can be clearly seen that the preference for smoking has shifted towards the smokeless tobacco in all the three study countries. This study recommends that tobacco control interventions should be aligned with the changing dynamics of the tobacco epidemic, and the need of the hour is placing restrictions of smokeless tobacco use so as to drive forward the gains of the anti-tobacco movement.

Cancer incidence in Madras Presidency in 1892-1901: William Niblock's commentary of 1902

William J. Niblock (WJN), an Assistant Surgeon at the Madras General Hospital (MGH), published a paper 'Cancer in India' (2 pages of text and 3 pages of tables) in the Indian Medical Gazette in 1902. He appears to have been a popular surgeon in Madras who surgically treated mouth cancers, testicular filariasis, and calcareous stones in the liver, gall bladder, and kidney. His 'Cancer in India' article is a compilation of numerical data of different cancers recorded in MGH from 1892 to 1901 mostly, and from 1896 to 1901 occasionally. In this article, WJN refers to cancers of different internal organs and external parts. He attributes the mouth cancers to constant chewing of 'betel' (the betel quid), which he explains as giving rise to leukoplakia, forerunner of buccal carcinoma. He supplies many, easily comparable, paired tables. These tables are made of raw numbers about the diverse human populations living in Madras, such as the Indians (Hindus and Muslims), Europeans, and Eurasians (Anglo-Indians) extracted from the 10-year records of MGH. None of the tables has been analyzed statistically. Nevertheless, he supplies the total numbers of admissions into MGH, which serve usefully as denominators in this study; occasionally, he presents data as percentages. Despite the lack of parametric statistical analysis, WJN's article, written in 1902, impresses as a useful contribution, because it provides a cross-sectional view of cancer incidence in Madras, particularly in defiance of Saldanha's supposition that cancers do not manifest in dark-skinned people, such as Indians.

Autophagy modulators for the treatment of oral and esophageal squamous cell carcinomas

Oral squamous cell carcinomas (OSCC) and esophageal squamous cell carcinomas (ESCC) exhibit a survival rate of less than 60% and 40%, respectively. Late-stage diagnosis and lack of effective treatment strategies make both OSCC and ESCC a significant health burden. Autophagy, a lysosome-dependent catabolic process, involves the degradation of intracellular components to maintain cell homeostasis. Targeting autophagy has been highlighted as a feasible therapeutic strategy with clinical utility in cancer treatment, although its associated regulatory mechanisms remain elusive. The detection of relevant biomarkers in biological fluids has been anticipated to facilitate early diagnosis and/or prognosis for these tumors. In this context, recent studies have indicated the presence of specific proteins and small RNAs, detectable in circulating plasma and serum, as biomarkers. Interestingly, the interplay between biomarkers (eg, exosomal microRNAs) and autophagic processes could be exploited in the quest for targeted and more effective therapies for OSCC and ESCC. In this review, we give an overview of the available biomarkers and innovative targeted therapeutic strategies, including the application of autophagy modulators in OSCC and ESCC. Additionally, we provide a viewpoint on the state of the art and on future therapeutic perspectives combining the early detection of relevant biomarkers with drug discovery for the treatment of OSCC and ESCC.

Trauma-informed interventions versus control for cancer-risk behaviours among adults: rationale and design for a randomized trial

Background

Tobacco use, alcohol use, and sugar-sweetened beverage consumption are each associated with increased cancer-risk. Psychological trauma is a common experience and a key driver of these behaviours among adults. The primary aim of this study is to evaluate the effect of trauma-informed yoga, drumming, and psychoeducation compared to control on tobacco use, alcohol use, and sugar-sweetened beverage consumption among community-based adults. Secondary aims are to evaluate the effect of these interventions compared to control on psychological and physiological stress symptomology, social connection, and coping behaviour.

Methods

Recruitment for this single-blinded randomized trial began in April 2019 in the Faculty of Health Sciences at the University of Lethbridge. Adults who consumed tobacco, alcohol, or sugar-sweetened beverages in the past month and live in Lethbridge, Alberta are being recruited using ads placed in public spaces. Participants are randomly allocated to a 12-session group yoga class, 12-session group drumming class, a 12-session psychoeducation class, or control. Participants attend an appointment in-person to fill out an online questionnaire package, provide a saliva sample, and complete physical measures pre-intervention, and 1-month and 6-months post-intervention.

Discussion

This study provides a unique opportunity to compare the impacts of two trauma-informed body-based interventions to psychoeducation and control for cancer-risk behaviour among community-based adults. The findings can be used to develop trauma-informed group interventions to reduce cancer-risk behaviour in general populations. Results are expected in 2022.

Trial registration

This trial was registered with ClinicalTrials.govISRCTN15583681 on 22 August 2019 (retrospectively registered).

Association of smokeless tobacco with oral cancer: A review of systematic reviews

INTRODUCTION

Various primary studies and systematic reviews have been conducted to explain the association between smokeless tobacco and oral cancer. This study aims to consolidate and summarize the risk estimates from various systematic reviews with or without meta-analysis to provide the spectrum of estimates on the association between smokeless tobacco use and oral cancer.

METHODS

A comprehensive literature search was done on various databases (PubMed, Google Scholar, IndMED, and TOXLINE) by two of the authors independently. Both qualitative and quantitative data extraction and analysis were performed for the included systematic reviews. Range of risk estimates was obtained and analyzed as quantitative findings due to the limitation of an overview of reviews for the pooled estimates. CASP (Critical Appraisals Skills Programme) and AMSTAR 2 (A Measurement Tool to Assess Systematic Reviews) tools were used for the quality assessment of the studies included.

RESULTS

In total, 12 systematic reviews with or without meta-analysis were included in the review. There was a positive and strong association of Smokeless Tobacco (SLT) use with oral cancer irrespective of gender, region, and type of smokeless tobacco. The risk estimate for the South–East Asia Region (SEAR) ranged 4.44–7.90, for Gutkha it was 8.67, while for Paan it ranged 6.3–7.90 and for overall SLT it ranged 1.36–7.90. Risk estimate for females ranged 5.83–14.56.

CONCLUSIONS

The study confirmed the association between SLT use and oral cancer. These findings are of high importance, especially to the South-East Asia Region.

Improving Utility of Data on Cancer Mortality Risk Associated with Smokeless Tobacco: Recommendations for Future Research

Background:

We analyzed in detail the studies utilized in most recent global systematic review of risk of cancer mortality with smokeless tobacco (SLT) use to report challenges in the available data that limit the understanding of association between SLT use and cancer mortality.

Methods:

For each study, we documented study design, reporting of mortality risk by type of SLT variant, SLT use frequency, and sex of SLT user for oral, oesophageal, pharyngeal, laryngeal and orolaryngeal cancers. These findings are discussed within the context of prevalence of SLT use by geographic regions and sex.

Results:

Majority of studies reported mortality risk for oral (70.6%) followed by oesophageal cancer (38.2%). The availability of population-based evidence was low (35.3%). The geographic distribution of studies did not reflect the geographic distribution of countries with high SLT consumption; 61.8% of the studies were from India followed by Sweden (20.6%). Hospital-based (84.2%) studies reported risk with chewing tobacco and the population-based studies (61.5%) with non-chewing tobacco. Hardly any study reported on a particular type of SLT. Definition of SLT use as current, ever or former was limited without consideration of the wide variations in frequency and duration of use within these patterns. Mortality risk reporting for males dominated all cancers other than oral (50% males).

Conclusions:

Unless the methodological and generalizability challenges identified in this review are addressed in future research to develop a stronger scientific basis of the association of SLT use and cancer mortality, we would continue to face significant challenges in monitoring the health effects of SLT.

Permanence of Modifications in Oral Microcirculation in Ex-Smokers

Background

The aim of this study was to assess the long-term effects of smoking and to investigate the permanence of this damage to the oral microcirculation.

Material/Methods

We recruited 75 patients and divided them into 3 groups: group 1 was composed of 25 healthy non-smokers, group 2 was composed of 25 healthy current smokers, and group 3 was composed of 25 healthy ex-smokers. Video-capillaroscopic examination was performed on all patients.

The video-capillaroscopic investigation was performed on patients in sitting position, always with the same light source, at the same room temperature (23°C), in the morning, with the same operator (GAS), and was repeated many times for every area under investigation. An enlargement of 200× allowed us to explore point-by-point all the morpho-structural characteristics of the capillaroscopic field. For non-parametric data, we evaluated the visibility of the loops and their position in relation to the surface of the mucosa. The evaluated parametric data were length of capillary loop, diameter of the loop, capillary tortuosity, and capillary density.

Results

Our study clearly shows there was no remission of vascular damage, even 13 years after smoking cessation.

Conclusions

Our research shows that that the effects of smoking are still visible in ex-smokers, even at 13 years after cessation and also that ex-smokers are still subject to the risk of oral pathologies in the interval of time that we considered.

Relationship between type of smokeless tobacco & risk of cancer: A systematic review

Background & objectives:

Causative linkages of smokeless tobacco (SLT) use with oral potentially malignant disorders and cancers of oral cavity, oesophagus and pancreas have been reported. Published meta-analyses have provided pooled risk estimates for major cancers caused by SLT, both on global and regional levels. This systematic review was aimed at summarizing the available studies on occurrence and mortality risk of common cancers due to various SLT products.

Methods:

PubMed and Google Scholar databases were systematically searched from 1985 till January 2018 for observational studies on SLT and cancer. The included studies were evaluated and data were extracted and reviewed.

Results:

The review included 80 studies providing 121 risk estimates for various cancers. Majority of the studies from South-East Asian Region (SEAR) and Eastern Mediterranean Region (EMR) showed a significant positive association of SLT use with oral [odds ratio (OR) ranging from 1.48 to 27.4] and oesophageal cancers (OR between 2.06 and 12.8), while studies from European Region (EUR) reported a positive association with pancreatic cancer (OR between 1.6 and 2.1). Cancer-related mortality was evaluated in a few reports with higher risk of mortality for lung (OR between 2.0 and 9.1), cervical (OR 2.0) and prostate (OR 2.1) cancers. A wide variation was noted in the association of various cancers and specific SLT products based on their nature, methods of use and inherent toxicity. The majority of chewing tobacco products displayed higher risk for oral and oesophageal cancers while the same was not observed for snus.

Interpretation & conclusions:

This review emphasizes on the significantly positive association of SLT use with oral and oesophageal cancers in SEAR and EMR and pancreatic cancer in EUR. Mortality estimates for SLT-associated cancers need further analysis. Risk analysis for cancers of other sites in SLT users also requires multicentric well-designed studies.

School-based behavioral intervention to reduce the habit of smokeless tobacco and betel quid use in high-risk youth in Karachi: A randomized controlled trial

There have been recent surges in the use of smokeless tobacco (SLT) and betel quid (BQ) chew among adolescents in South East Asian countries, with an increase, on average, of 7% to 15% between 2004 and 2013, necessitating interventional investigations to modify this behavior. The current intervention was aimed towards changing adolescents' perceptions regarding the harmful effects of SLT and BQ use and encouraging them to quit. This randomized control trial involved 2140 adolescents from 26 private and public-sector schools in Karachi, Pakistan. After randomization, 1185 individuals were placed in the intervention group and administered a behavior changing intervention (BCI), while 955 individuals constituted the control group. A generalized estimating equation was employed to measure differences in repeated measures for both groups. The beta coefficients were reported after adjusting the covariates with the 95% confidence interval, and the p-value was considered significant at <0.050. Cohen's d was employed to report the effect size of the intervention. The BCI resulted in a 0.176-unit (95% CI 0.078-0.274, p-value <0.001) increase in knowledge scores regarding the health hazards of SLT and BQ, a 0.141-unit (95% CI 0.090-0.192, p-value <0.001) increase in use perception scores, and a 0.067-unit (95% CI 0.006-0.129, p-value 0.031) increase in quit perception scores in the intervention group compared with those in the control group. A knowledge related module (p-value 0.024) and quit preparation module (p-value 0.005) were found to be helpful by adolescents in either changing their perceptions regarding SLT and/or BQ chew use or in quitting. The role of BCI is promising in improving adolescents' knowledge and changing their perceptions in a positive manner regarding their harmful SLT and BQ use. Convincing results may be achieved if interventions are tailored, with an emphasis on the identification of the products that are used by adolescents in addition to highlighting their ill effects and how students may manage to quit them. If included in the schools' curricula, this BCI method may help in developing schools that are free of SLT and BQ use. Trial registration: ClinicalTrials.gov NCT03488095.

Betel Quid Dependency and Associated Intrapersonal, Interpersonal, and Environmental Factors among Adolescents: A School-Based Cross-Sectional Survey

BACKGROUND

Betel quid (BQ) is one of the fourth most commonly used substance globally. Though BQ is a psycho-active substance, yet little has been explored regarding dependency on it particularly among adolescents.

OBJECTIVES

Therefore, in this study, we aimed to determine adolescents' dependency on BQ, along with their intrapersonal, interpersonal and environmental determinants of dependency.

METHODS

This cross-sectional study focused on 2200 school-going adolescents of Karachi, Pakistan in 2016. Primary outcome was dependency on BQ among adolescents. Both univariate and multivariate regressions were used to estimate crude and adjusted odds ratios (after adjustments for all intrapersonal, interpersonal, and environmental factors) with 95% confidence level.

RESULTS

Out of 2200 students, 874 (39.7%) were found to be BQ users amongst whom 69 (7.9%) were dependent on BQ. Comparing the groups with only areca nut users as reference category, betel quid with tobacco additives chewers were considerably dependent (OR = 14.08, 95% CI 3.64-54.16). The individuals who chewed >5 chews per day (OR = 1.87, 95% CI 1.08-3.29) and chronic users (>1year) (OR = 2.02, 95% CI 1.09-3.74) were more likely to be dependent. Older students (>12 years) (OR = 2.12, 95% CI 1.06-4.23), and who studied in government schools were significantly dependent (OR = 3.32, 95% CI 1.80-6.10) than those who studied in private schools.

CONCLUSIONS

In conclusion, intrapersonal characteristics like more than 5 chews per day, chronic chewers of more than a year, BQ with tobacco chewers, older adolescents and children studying in government schools were significantly associated with BQ dependency.

The cigarette smoke components induced the cell proliferation and epithelial to mesenchymal transition via production of reactive oxygen species in endometrial adenocarcinoma cells

Cigarette smoke (CS) causes about 480,000 deaths each year worldwide and is well-known to have harmful effects on the human body, leading to heart disease, stroke, lung cancer, and cardiovascular problems. In the present study, the effects of acrylonitrile (AN), benzo(a)pyrene (B(a)P), formaldehyde (FOR), isoprene (ISO), nicotine-derived nitrosamine ketone (NNK), which are the main components of CS, on the proliferation, invasion, and the epithelial-mesenchymal transition (EMT) process of human Ishikawa endometrial adenocarcinoma cells were investigated. Treating Ishikawa cells with CS components resulted in increased cell growth and altered expression of cell cycle-related genes: the protein expression of cyclin D & E increased, while the levels of p21 & p27 were reduced following treatment of these five CS components. In addition, CS components increased the invasion capacity of Ishikawa cells. The expression of the epithelial markers, E-cadherin and occludin, were significantly decreased, while the expression of the mesenchymal marker, N-cadherin, was significantly increased by CS components. In dichloro-dihydro-fluorescein diacetate (H2DCF-DA) assay, ROS production increased by treatment of CS components. The CS components activated the ROS-p38 MAPK-EMT pathway by increasing the level of phosphorylated p38 MAPK and p44/42 (ERK1/2), and by up-regulating Snail and Slug, the transcription factors for EMT. Taken together, these results indicate that CS components can promote progression of endometrial adenocarcinoma via increasing cell proliferation and the ROS-mediated EMT process.

Smokeless Tobacco and Cigar and/or Pipe Are Risk Factors for Barrett Esophagus in Male Patients With Gastroesophageal Reflux Disease

OBJECTIVE

To investigate the effect of smokeless tobacco (ST), cigar and/or pipe smoking (CP) on the development of Barrett esophagus (BE) in white male patients with gastroesophageal reflux disease (GERD).

PATIENTS AND METHODS

A total of 1015 records of white male adults with BE (cases; n=508) or GERD (controls, n=507) were reviewed for lifestyle factors. Logistic regression analyses were performed after adjusting for lifestyle factors to assess the effects of ST and CP on the risk of developing BE. Differences between patients with BE and those with GERD were compared using chi-square and t tests.

RESULTS

Patients with BE were significantly older than patients with GERD (mean age, 66±12 years for patients with BE and 55±15 years for patients with GERD; P<.001). The odds of developing BE in patients who used CS were 1.7 times higher than that in patients who never smoked cigarettes (odds ratio [OR], 1.7; 95% CI, 1.3-2.2). It was observed that when CS use was combined with either ST or CP use, the odds of having BE significantly increased (OR, 2.5; 95% CI, 1.2-5.2; P=.01 and OR, 1.9; 95% CI, 1.03-3.58; P=.04) in comparison to CS alone. There were no significant differences in body mass index and alcohol consumption between BE and GERD groups.

CONCLUSION

This study suggests that there is indeed an association between CS and BE. We believe that this is the first time that ST and CP were associated with an even higher odds of developing BE. Further studies are needed to investigate whether the use of ST and CP is also associated with an increased risk of developing BE-associated adenocarcinoma.

Feedback from vendors on gutka ban in two States of India

BACKGROUND & OBJECTIVES

Beginning in 2012, all States in India eventually banned the sale of gutka. This study was conducted to investigate gutka vendors' knowledge on gutka ban, products covered under ban, penalties for non-compliance and action for enforcement by government agencies.

METHODS

Twenty vendors were interviewed, 10 each in Mumbai (Maharashtra) and Indore (Madhya Pradesh) during May - June, 2013, one year after ban was imposed. Interviewers used a standardized questionnaire to assess vendors' knowledge of gutka ban, their attitude towards it and compliance to it in practice.

RESULTS

All 20 vendors were aware that gutka sale was banned. However, despite ban, eight of the 10 vendors in Mumbai perceived sale of pan masala as legal. In Indore, all 10 vendors perceived sale of Indori Tambakoo, a local gutka variant, as legal. No vendor was sure about the quantum of fine applicable on being caught selling the banned product. Two vendors in Mumbai and nine in Indore admitted selling gutka. Five vendors in Mumbai and four in Indore supported an existing ban on gutka.

INTERPRETATION & CONCLUSIONS

All vendors were aware of the ban on gutka and reason for it. Many vendors supported the ban. However, awareness of other products covered under ban and on fines in case of non-compliance was low. Law enforcement system needs to be intensified to implement ban. Notification of ban needs to be further strengthened and made unambiguous to explicitly include all smokeless tobacco products.

Implementation of Article 20 of the World Health Organization Framework Convention on Tobacco Control

BACKGROUND & OBJECTIVES

Article 20 of the World Health Organization (WHO) Framework Convention on Tobacco Control (FCTC) deals with surveillance and research on all tobacco products including smokeless tobacco (SLT). Here we describe the availability of indicators related to SLT among 180 Parties to the convention (countries ratifying the WHO FCTC are referred as Parties to the Convention).

METHODS

Data on SLT use among adults and adolescents and SLT-related economic and health indicators among Parties were obtained through rigorous literature search. Data analysis for high-burden parties was done using SPSS.

RESULTS

Nearly 92 per cent (166) of the Parties reported SLT use prevalence among adults or adolescents at national or subnational level, of these nearly one-fifth of the Parties (20.5%) were high-burden Parties. Comparable SLT tax incidence rate was available for 19.4 per cent (n=35) Parties, and SLT attributable morbidity and mortality risks of major diseases were available for only five per cent (n=10) of Parties.

INTERPRETATION & CONCLUSIONS

SLT use is a global epidemic widespread among Parties to the Convention. There are a data gap and dearth of research on SLT-related issues. Parties need to monitor SLT use and related health and economic indicators regularly at periodic intervals.

Regulation of toxic contents of smokeless tobacco products

Effective regulation of contents of tobacco products is one of the primary milestones to reduce negative health effects associated with the use of smokeless tobacco (SLT) products. As per the available sources, testing of some SLT products has been done on ad hoc basis, but there is a lack of comprehensive and periodic analysis of these products. In addition, the available results indicate huge variations among the levels of pH, 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone, N-nitrosonornicotine, benzo[a]pyrene, heavy metals and nicotine within different products as well as within different brands of the same product. This review was aimed to throw light on the variations and gaps in testing of SLT products and emphasize the need for strong policy regulation for monitoring the chemical constituents of these products.

Challenges in Indian Women’s Readiness to Quit Smokeless Tobacco Use

Introduction: In India, there are few cessation programs for women smokeless tobacco (SLT) users who want to quit. This paper uses Fishbein’s IM model to identify women SLT users’ challenges to quitting and multilevel correlates of “readiness to quit”. Methods: A survey of SLT use among women of reproductive age was conducted in 2010-13 in an urban slum community of Mumbai with a representative sample of 409 married women aged 18 to 40 years using at least one type of SLT daily. Data were analyzed using frequencies, bivariate statistics and logistic regression. Results: Social influences to continue SLT use included husband’s use (71%), family influence and positive beliefs and norms about use. Pressure to quit from significant others influenced past quit attempts but media had no effect on reported behavior. Four groups represented different readiness to quit statues based on intention to quit and past quit/reduce attempts. Seventeen percent had no intention of quitting or reducing; their husbands were more likely to be tobacco users. Half of (52%) the sample had attempted to quit/reduce tobacco and intended to do so in the future. These women were depressed. Fifteen percent had tried to quit but did not intend to again. Correlates were positive beliefs and norms about SLT and withdrawal symptoms. Conclusions: Cessation programs should be made available to women, addressing correlates of women’s readiness to quit statuses. Results suggest the need for more complex social/contextual approaches to sustained cessation of SLT use including addressing depression and withdrawal, improved media messages and campaigns tailored to women, and support from family members.

Risk factors and etiopathogenesis of potentially premalignant oral epithelial lesions

Potentially malignant oral mucosal disease has some ability to give rise to malignancy of the oral epithelium, that is, oral squamous cell carcinoma (OSCC). The present article provides a succinct review of the possible or probable causes of potentially premalignant oral epithelial lesions. There is a focus upon studies that examined the causes or etiologic associations with clinically likely or histopathologically detectable oral epithelial dysplasia.