Smokeless Tobacco Use and the Risk of Head and Neck Cancer: Pooled Analysis of US Studies in the INHANCE Consortium

Assessing survival outcomes of patients with oral tongue squamous cell carcinoma: Focus on age, sex, and stage

BACKGROUND

The purpose of this study was to provide further insights into whether age and/or sex are associated with prognosis in oral tongue squamous cell carcinoma.

METHODS

This was a retrospective cohort study utilizing hospital registry data from 2006 to 2016 obtained from the National Cancer Database. Identified patients were divided into various cohorts based on age, sex, and staging. A descriptive analysis was performed using chi-square tests and overall survival rates were estimated using Kaplan-Meier method.

RESULTS

A total of 17 642 patients were included in the study. The 5-year overall survival rates were 82.0% (95% CI: 79.8%-84.0%) in younger patients versus 67.5% (95% CI: 66.7%-68.3%, p-value <0.0001) older patients. The median overall survival for females was 143.4 months (95% CI: 133.2-NA) versus 129.8 (95% CI: 125.4-138.7, p-value <0.0001) in males.

CONCLUSIONS

Our analysis suggests that younger age and female sex are both predictors of improved survival in oral tongue squamous cell carcinoma.

Novel vaccination strategies based on optimal stimulation of CD4+ T helper cells for the treatment of oral squamous cell carcinoma

Oral Squamous Cell Carcinoma (OSCC) is the most common malignant tumor of the oral cavity. Despite recent advances in the field of oral cancer therapy, including the introduction of immunotherapeutic approaches, the 5-year survival rate remains steadily assessed around 50%. Thus, there is an urgent need for new therapeutic strategies. After the characterization of the immune phenotype of three human OSCC cell lines (CAL-27, SCC-25, and SCC-4) and one mouse OSCC cell line (MOC2) showing their similarities to resected patient tumors, we explored for the first time an experimental preclinical model of therapeutic vaccination with mouse OSCC MOC2 cell line stably expressing MHC class II antigens after CIITA gene transfection (MOC2-CIITA). Mice injected with MOC2-CIITA reject or strongly retard tumor growth; more importantly, vaccinated animals that fully reject MOC2-CIITA tumors display anti-tumor immunological memory protective against challenge with parental MOC2 tumor cells. Further experiments of adoptive cell transfer or in vivo cell depletion show that both CD4+ and CD8+ T lymphocytes prove fundamental in tumor rejection. This unprecedented approach for oral cancer opens the way for possible future translation of novel immunotherapeutic strategies to the human setting for the treatment of this tumor.

Matricellular proteins: Potential biomarkers in head and neck cancer

The extracellular matrix (ECM) is a complex network of diverse multidomain macromolecules, including collagen, proteoglycans, and fibronectin, that significantly contribute to the mechanical properties of tissues. Matricellular proteins (MCPs), as a family of non-structural proteins, play a crucial role in regulating various ECM functions. They exert their biological effects by interacting with matrix proteins, cell surface receptors, cytokines, and proteases. These interactions govern essential cellular processes such as differentiation, proliferation, adhesion, migration as well as multiple signal transduction pathways. Consequently, MCPs are pivotal in maintaining tissue homeostasis while orchestrating intricate molecular mechanisms within the ECM framework. The expression level of MCPs in adult steady-state tissues is significantly low; however, under pathological conditions such as inflammation and cancer, there is a substantial increase in their expression. In recent years, an increasing number of studies have focused on elucidating the role and significance of MCPs in the development and progression of head and neck cancer (HNC). During HNC progression, there is a remarkable upregulation in MCP expression. Through their distinctive structure and function, they actively promote tumor growth, invasion, epithelial-mesenchymal transition, and lymphatic metastasis of HNC cells. Moreover, by binding to integrins and modulating various signaling pathways, they effectively execute their biological functions. Furthermore, MCPs also hold potential as prognostic indicators. Although the star proteins of various MCPs have been extensively investigated, there remains a plethora of MCP family members that necessitate further scrutiny. This article comprehensively examines the functionalities of each MCP and highlights the research advancements in the context of HNC, with an aim to identify novel biomarkers for HNC and propose promising avenues for future investigations.

Health effects associated with chewing tobacco: a Burden of Proof study

Chewing tobacco use poses serious health risks; yet it has not received as much attention as other tobacco-related products. This study synthesizes existing evidence regarding the health impacts of chewing tobacco while accounting for various sources of uncertainty. We conducted a systematic review and meta-analysis of chewing tobacco and seven health outcomes, drawing on 103 studies published from 1970 to 2023. We use a Burden of Proof meta-analysis to generate conservative risk estimates and find weak-to-moderate evidence that tobacco chewers have an increased risk of stroke, lip and oral cavity cancer, esophageal cancer, nasopharynx cancer, other pharynx cancer, and laryngeal cancer. We additionally find insufficient evidence of an association between chewing tobacco and ischemic heart disease. Our findings highlight a need for policy makers, researchers, and communities at risk to devote greater attention to chewing tobacco by both advancing tobacco control efforts and investing in strengthening the existing evidence base.

From cultivation to cancer: formation of N-nitrosamines and other carcinogens in smokeless tobacco and their mutagenic implications

Tobacco use is a major cause of preventable morbidity and mortality globally. Tobacco products, including smokeless tobacco (ST), generally contain tobacco-specific N-nitrosamines (TSNAs), such as N'-nitrosonornicotine (NNN) and 4-(methylnitrosamino)-1-(3-pyridyl)-butanone (NNK), which are potent carcinogens that cause mutations in critical genes in human DNA. This review covers the series of biochemical and chemical transformations, related to TSNAs, leading from tobacco cultivation to cancer initiation. A key aim of this review is to provide a greater understanding of TSNAs: their precursors, the microbial and chemical mechanisms that contribute to their formation in ST, their mutagenicity leading to cancer due to ST use, and potential means of lowering TSNA levels in tobacco products. TSNAs are not present in harvested tobacco but can form due to nitrosating agents reacting with tobacco alkaloids present in tobacco during certain types of curing. TSNAs can also form during or following ST production when certain microorganisms perform nitrate metabolism, with dissimilatory nitrate reductases converting nitrate to nitrite that is then released into tobacco and reacts chemically with tobacco alkaloids. When ST usage occurs, TSNAs are absorbed and metabolized to reactive compounds that form DNA adducts leading to mutations in critical target genes, including the RAS oncogenes and the p53 tumor suppressor gene. DNA repair mechanisms remove most adducts induced by carcinogens, thus preventing many but not all mutations. Lastly, because TSNAs and other agents cause cancer, previously documented strategies for lowering their levels in ST products are discussed, including using tobacco with lower nornicotine levels, pasteurization and other means of eliminating microorganisms, omitting fermentation and fire-curing, refrigerating ST products, and including nitrite scavenging chemicals as ST ingredients.

Pan-American prevalence of smokeless tobacco use and association with oral potentially malignant disorders and head and neck cancer: a systematic review and meta-analysis

OBJECTIVES

To determine the prevalence of smokeless tobacco (SLT) use and its association with oral potentially malignant disorders (OPMDs) and head and neck cancer (HNC) in the Pan-American Health Organization (PAHO) region.

STUDY DESIGN

A literature search was conducted across 9 databases and other sources. The eligibility criteria were pediatric (0-18 years old) and adult (19 years and older) populations consuming any type of SLT. Meta-analysis was performed to determine the prevalence of SLT and the association between its use and OPMDs/HNC in the PAHO region; the Grading of Recommendations Assessment, Development, and Evaluation tool was used to verify the certainty of evidence.

RESULTS

Fifty-nine studies from 6 PAHO countries were included, of which 51 were also subjected to quantitative analysis. The pooled SLT prevalence of use was 15% (95%CI: 11.93-18.69) overall, 17% (95%CI: 13.25-22.65) in adults, and 11% (95%CI: 8.54-14.78) in the pediatric population. The highest reported SLT prevalence of use was 33.4% (95%CI: 27.17-39.93) in Venezuela. HNC was positively associated with SLT use (OR = 1.98, 95%CI: 1.54-2.55), with a moderate certainty of evidence. Among OPMDs, only leukoplakia reported a positive association with SLT use (OR = 8.38; 95%CI: 1.05-67.25). However, the quality of the evidence was very low.

CONCLUSION

A high consumption of SLT use, chewing tobacco and snuff, is reported among the adult population residing in the PAHO region with a positive association with the development of oral leukoplakia and HNC.

Effects of a Reduced Risk Claim on Adolescents' Smokeless Tobacco Perceptions and Willingness to Use

PURPOSE

United States Smokeless Tobacco Company LLC submitted a modified risk tobacco product application to the US Food and Drug Administration, proposing a claim that switching to Copenhagen snuff fine cut from cigarettes reduces lung cancer risk. This claim could affect adolescents' smokeless tobacco perceptions and its use.

METHODS

Students (N = 592; mean age: 15.3 years; 46% male; 32% nonHispanic White; 8% smokeless tobacco ever-users) at seven California high schools were randomized within a survey to view a Copenhagen snuff image, either with or without the proposed reduced risk claim. Participants were then asked about the harm of smokeless tobacco and their willingness to try Copenhagen snuff if a friend offered. Postimage harm rating and willingness were compared between image groups overall, stratified by past 30-day tobacco use (87% of tobacco users were e-cigarette users), and adjusted for participant characteristics using multivariable regression.

RESULTS

Participants who viewed the claim were less likely to perceive smokeless tobacco to cause "a lot" of harm (56% vs. 64%; p = .03), including after statistical adjustment (risk ratio [RR]: 0.84; 95% confidence interval [CI]: 0.75, 0.94), and with a numerically stronger effect among tobacco users (RR: 0.65; 95% CI: 0.48, 0.86). The claim did not increase willingness overall (17% vs. 20%; p = .41) but did increase willingness among tobacco users (RR: 1.67; 95% CI: 1.05, 2.67).

DISCUSSION

Brief exposure to a reduced-risk claim decreased adolescents' smokeless tobacco harm perceptions and increased willingness to try among tobacco users. The Food and Drug Administration order permitting this claim could increase some adolescents' susceptibility to smokeless tobacco, particularly those already using other tobacco products like e-cigarettes.

Estimated projection of oral squamous cell carcinoma annual incidence from twenty years registry data: a retrospective cross-sectional study in Indonesia

Background

The incidence of oral squamous cell carcinoma (OSCC) has not been well documented in Indonesia. Thus, we aimed to analyze trends and clinicopathological profiles of OSCC cases in Indonesia, focusing on differences between age and sex groups.

Methods

A cross-sectional study was conducted in Indonesia's main referral hospital, analyzing 1,093 registered OSCC cases from 2001 to 2020. Trend analysis was performed using Joinpoint regression analysis to determine the annual percentage change (APC) for overall cases and each case group based on age, sex, and anatomical subsites. APC significance was assessed using a Monte Carlo permutation test. The projection of case numbers for the following 5 years (2021-2025) was estimated using linear/non-linear regression analysis and presented as a mathematical function. The significance of the trend slope was measured using an ANOVA test. Demographic and clinicopathological characteristics of OSCC were analyzed according to age and sex, and their comparative analysis was assessed using Chi-square and its alternatives.

Results

The incidence of OSCC in female patients and in the tongue and buccal mucosa showed a positive trend (APC 2.06%; 3.48%; 8.62%, respectively). Moreover, the incidence of OSCC overall, and in women with OSCC, is projected to increase significantly in the next 5 years following the quadratic model. The mean age of patients was 51.09 ± 14.36 years, with male patients being younger than female patients. The male-to-female ratio was 1.15, and 36.5% of these patients were categorized as young (≤45 years old). The tongue was the predominantly affected site. Prominent pathologic characteristics included well-differentiation, keratinization, and grade I of Bryne's (1992) cellular differentiation stage. Most patients presented with advanced staging, lymphovascular invasion, and uninvaded margins. Tumor sites and staging varied according to age, while age and tumor sites differed between sexes.

Conclusion

The rising incidence trends of OSCC among Indonesian patients, both in the past and projected future, are concerning and warrant attention. Further research into risk factors should be conducted as preventive measures.

Put Down the Tin: Chewing Tobacco Use Is Associated With Worse Outcomes After Primary Lumbar Fusion

STUDY DESIGN

Retrospective study.

OBJECTIVE

This study evaluated the impact of chewing tobacco on both medical and spine-related complication rates after spinal lumbar fusions in comparison to both a control cohort and a smoking cohort.

SUMMARY OF BACKGROUND DATA

Smoking is a prevalent modifiable risk factor that has been demonstrated to be associated with increased complications after lumbar fusion. Although smoking rates have decreased in the United States, chewing tobacco use has not similarly reduced. Despite chewing tobacco delivering up to 4 times the dose of smoking, the impact of chewing tobacco is incompletely understood.

METHODS

A retrospective cohort study was conducted using the PearlDiver database. Patients who underwent lumbar spine fusion and used chewing tobacco were matched with a control cohort and a smoking cohort. Medical complications within 90 days after primary lumbar fusion were evaluated, including deep venous thrombosis, acute kidney injury, pulmonary embolism, transfusion, acute myocardial infarction, and inpatient readmission. Spine-related complications were evaluated at 2 years postoperatively, including pseudoarthrosis, incision and drainage (I&D), instrument failure, revision, and infection.

RESULTS

After primary lumbar fusion, the chewing tobacco cohort demonstrated significantly higher rates of pseudoarthrosis [odds ratio (OR): 1.41], revision (OR: 1.57), and any spine-related complication (OR: 1.32) compared with controls. The smoking cohort demonstrated significantly higher rates of pseudoarthrosis (OR: 1.88), I&D (OR: 1.27), instrument failure (OR: 1.39), revision (OR: 1.54), infection (OR: 1.34), and any spine-related complication (OR: 1.77) compared with controls. The chewing tobacco cohort demonstrated significantly lower rates of pseudoarthrosis (OR: 0.84), I&D (OR: 0.49), infection (OR: 0.70), and any spine-related complication (OR: 0.81) compared with the smoking cohort.

CONCLUSIONS

This study demonstrated that chewing tobacco is associated with higher rates of both spine-related and medical complications after primary lumbar fusion. However, chewing tobacco use is associated with less risk of complications compared with smoking.

LEVEL OF EVIDENCE

Level III.

Phase Angle in Head and Neck Cancer: A Sex-Differential Analysis from Biological and Clinical Behavior to Health-Related Quality of Life

Head and neck cancer (H&NC) is a diverse category of tumors related to malignancies in the common aerodigestive pathway, with high metabolic rate, poor nutritional and treatment outcomes, and elevated mortality despite the best standard treatment. Herein, we focus on determining how the phase angle (PA) differs across sex as a predictor of poor prognosis, low quality-of-life (QoL) scores, and mortality in patients with head and neck cancer. This follow-up study presents a sex-differential analysis in a prospective cohort of 139 head and neck cancer patients categorized by sex as male (n = 107) and female (n = 32). Patients were compared in terms of nutritional, biochemical, and quality-of-life indicators between low and normal PA in women (<3.9° (n = 14, 43.75%) and ≥3.9°) and men (<4.5° (n = 62, 57.9%) and ≥4.5°). Our results show that most patients were in locally advanced clinical stages (women: n = 21 (65.7%); men: n = 67 (62.6%)) and that patients with low PA had a lower punctuation in parameters such as handgrip strength, four-meter walking speed, albumin, C-reactive protein (CRP), and CRP/albumin ratio (CAR), as well as the worst QoL scores in functional and symptomatic scales in both the male and female groups. A comparison between sexes revealed significant disparities; malnourishment and tumor cachexia related to an inflammatory state was more evident in the women's group.

Risk factors for head and neck cancer in more and less developed countries: Analysis from the INHANCE consortium

OBJECTIVE

We analyzed the pooled case-control data from the International Head and Neck Cancer Epidemiology (INHANCE) consortium to compare cigarette smoking and alcohol consumption risk factors for head and neck cancer between less developed and more developed countries.

SUBJECTS AND METHODS

The location of each study was categorized as either a less developed or more developed country. We compared the risk of overall head and neck cancer and cancer of specific anatomic subsites associated with cigarette smoking and alcohol consumption. Additionally, age and sex distribution between categories was compared.

RESULTS

The odds ratios for head and neck cancer sites associated with smoking duration differed between less developed and more developed countries. Smoking greater than 20 years conferred a higher risk for oral cavity and laryngeal cancer in more developed countries, whereas the risk was greater for oropharynx and hypopharynx cancer in less developed countries. Alcohol consumed for more than 20 years conferred a higher risk for oropharynx, hypopharynx, and larynx cancer in less developed countries. The proportion of cases that were young (<45 years) or female differed by country type for some HNC subsites.

CONCLUSION

These findings suggest the degree of industrialization and economic development affects the relationship between smoking and alcohol with head and neck cancer.

Exclusive use of different types of tobacco products, exposure to secondhand tobacco smoke and risk of subtypes of head and neck cancer among Indian males

Tobacco products are used in vary many forms in India. Although the risk of tobacco uses in developing head and neck cancer (HNC) is known, risk by exclusive use of different tobacco products on HNC and its subtypes is poorly understood. A case-control study was conducted at a tertiary cancer hospital, which receives cases from different geographical regions of India with use of different types of tobacco products. The study included 824 oral cavity (OC), 149 oropharynx (OPX) 104 hypopharyngeal (HPX) and 81 larynx (LX) cancer cases and 1206 visitor controls. Information on 11 different types of tobacco products and exposure to secondhand smoke was collected through structured questionnaires. Odds ratios (OR) and 95% confidence intervals (CI), for the association of various HNC subtypes with exclusive use of each tobacco product compared to nonusers of tobacco were estimated using logistic regression models, after adjusting for potential confounders. Exclusive use of any type of smokeless tobacco product was strongly associated with all subtypes of HNC. Gutka chewing (only) had highest risk (OR = 33.67; 95% CI = 19.8-57.0) while exclusive users of betel quid with tobacco (BQ + T), tobacco quid, Khaini, Mawa and Mishri users had a OR of 14.77, 24.20, 5.33, 2.96 and 3.32, respectively, for development of OC. Bidi smoking and secondhand smoke was independently associated with increased risk of HNC. Our study indicates that tobacco control policies should focus on product specific awareness messaging that switching between tobacco product types is not a safe alternative to complete cessation.

Reviewing the epidemiology of head and neck cancer: definitions, trends and risk factors

Introduction Head and neck cancer appears to be increasing in incidence, with potential changes in aetiology proposed. This paper aims to provide a narrative overview of the epidemiological literature to describe the disease burden and trends in terms of incidence and mortality both in the UK and globally and to review the evidence on current risk factors.

Methods A search was performed on multiple databases (PubMed and Epistemonikos), applying filters to identify systematic reviews and meta-analyses which investigated head and neck cancer incidence, mortality and risk factors. International and UK cancer registries and sources were searched for incidence and mortality data.

Results Multiple definitions of head and neck cancer are employed in epidemiology. Globally, incidence rates have increased in recent decades, largely driven by oropharyngeal cancer. Mortality rates over the last decade have also started to rise, reflecting the disease incidence and static survival rates. Major risk factors include tobacco smoking alone and in combination with alcohol consumption, betel chewing (particularly in Southeast Asian populations) and the human papillomavirus in oropharyngeal cancer.

Conclusions These epidemiological data can inform clinical and preventive service planning for head and neck cancer.

Head and neck cancer incidence is increasing and is projected to continue to rise, largely driven by increases in oropharyngeal cancer.

Mortality rates have started to increase within the last decade, reflecting a rising incidence and static survival rates.

Major risk factors that are associated with the risk of head and neck cancer are tobacco smoking and tobacco used in combination with alcohol consumption. Human papillomavirus is an additional major risk factor for oropharyngeal cancer. Cancers of the head and neck are clearly socioeconomically patterned but this socioeconomic risk is not entirely explained by smoking and alcohol behaviours.

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.

Interaction of cytochrome P450s with environmental risk factors increases their expression and risk to head and neck cancer

To investigate the role of interaction of tobacco metabolizing polymorphic cytochrome P450s (CYPs) and glutathione S-transferase M1 (GSTM1) with environmental risk factors in modifying the susceptibility to head and neck squamous cell carcinoma (HNSCC), a case-control study with 1250 proven cases of HNSCC and equal number of healthy controls was planned. A small but significant increase in the risk to HNSCC (1-2 fold) in the cases with variant genotypes of CYPs (1A1 or 1B1 or 2E1) increased several folds (up to 13 fold) in regular tobacco or alcohol users. This several fold increase in risk could be due to more than multiplicative interaction observed between the risk genotypes of CYPs and tobacco or alcohol. A synergistic effect was also observed between tobacco as well as alcohol users among cases with risk genotypes of CYPs and GSTM1 that resulted in a further increase in risk (up to 29 fold) to HNSCC. Interestingly, the increase in the risk in tobacco users among cases with variant genotypes of CYPs or a combination of CYPs & GSTM1 (-) was associated with a higher mRNA expression of CYPs when compared to nontobacco users in controls with wild type of genotypes of CYPs & GSTM1. The data suggest that the interaction of genetic and environmental risk factors leads to increased expression of CYPs which may increase the levels of tobacco-derived carcinogens thereby modifying the risk to HNSCC.

Age of initiation of smokeless tobacco use among young adults: Findings from the population assessment of tobacco and health (PATH) study, 2013–2017

INTRODUCTION

Smokeless tobacco (SLT) use, across all age groups, is most prevalent among young adults in the US. A study estimating the age of initiation of SLT use among young adults is needed amid the changing landscape of tobacco products.

METHODS

Secondary analyses of PATH young adults across waves 1–4 were conducted. A total of 10595 young adults who were never SLT users at their first wave of adult participation in PATH (waves 1–3) were included in the analysis. Age of initiation outcomes of ever, past 30-day, and fairly regular SLT use, were assessed prospectively in waves 2–4. Interval censoring Cox regression models were used to assess differences in the age of initiation of each outcome by sex and race/ethnicity, adjusting for other tobacco product use.

RESULTS

By the age of 27 years, 4.9%, 3.0%, and 1.9% of young adults reported initiating ever, past 30-day, and fairly regular SLT use, respectively. After controlling for demographic factors and other tobacco use, males initiated each of the SLT outcomes at earlier ages than females; non-Hispanic Blacks initiated each of the SLT use at later ages than non-Hispanic Whites; and Hispanic and non-Hispanic others initiated ever use at later ages than non-Hispanic Whites.

CONCLUSIONS

These data suggest that three young adult groups are more likely to initiate use of SLT at earlier ages: males, non-Hispanic Whites, and poly-tobacco users. Knowing the age of SLT initiation outcomes among young adults will educate the public domain, inform SLT use prevention campaigns, and provide a baseline to measure the success of the Tobacco 21 legislation from December 2019.

Smokeless tobacco and cigarette smoking: chemical mechanisms and cancer prevention

Tobacco products present a deadly combination of nicotine addiction and carcinogen exposure resulting in millions of cancer deaths per year worldwide. A plethora of smokeless tobacco products lead to unacceptable exposure to multiple carcinogens, including the tobacco-specific nitrosamine N'-nitrosonornicotine, a likely cause of the commonly occurring oral cavity cancers observed particularly in South-East Asian countries. Cigarettes continue to deliver a large number of carcinogens, including tobacco-specific nitrosamines, polycyclic aromatic hydrocarbons and volatile organic compounds. The multiple carcinogens in cigarette smoke are responsible for the complex mutations observed in critical cancer genes. The exposure of smokeless tobacco users and smokers to carcinogens and toxicants can now be monitored by urinary and DNA adduct biomarkers that may be able to identify those individuals at highest risk of cancer so that effective cancer prevention interventions can be initiated. Regulation of the levels of carcinogens, toxicants and nicotine in tobacco products and evidence-based tobacco control efforts are now recognized as established pathways to preventing tobacco related cancer.

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.

A real-world evaluation of a smokeless tobacco cessation text message program for veterans: Outcomes and comparison to cigarette smokers

INTRODUCTION

Smokeless tobacco (ST) use and cessation rates have remained unchanged while cigarette smoking has declined, and cessation rates have increased. Text message programs have proved effective for cigarette smokers but have not been evaluated for ST users. The Veterans Health Administration (VHA) created a ST-specific arm of its SmokefreeVET automated text message program to help veteran ST users quit.

METHODS

A retrospective evaluation was conducted on a real-world sample of veteran ST users (n=1,139) who subscribed to SmokefreeVET between 2017 and 2020. Time in program, abstinence, and nicotine replacement therapy (NRT) use were evaluated and compared to 9,764 cigarette smokers who subscribed to SmokefreeVET.

RESULTS

Younger subscribers were more likely to opt out early; 54% of ST users and 60% of cigarette smokers completed the 6-week program. ST users were more likely to report abstinence than cigarette smokers at all time points: the primary outcome, 30-day abstinence at 6 months, was 3.9% in ST users and 2.6% in cigarette smokers (p=.05) and the secondary outcome, abstinence at 3 months, was 5.3% in ST users and 3.4% in cigarette smokers (p=.03). NRT was used by 17% of ST users and was associated with a trend toward higher abstinence compared to ST users who did not use NRT.

CONCLUSION

A real-world sample of ST users were more likely to report abstinence after using the SmokefreeVET text program than cigarette smokers. Automated text message programs may be effective for increasing cessation among ST users and warrant further investigation.

IMPLICATIONS

Smokeless tobacco (ST) cessation is an important public health priority and of importance for veteran and military populations that have higher rates of ST use. There have been relatively few studies conducted investigating the effectiveness of text message interventions for ST cessation, despite the proven efficacy for cigarette smokers. This study provides evidence from a large, real-world sample that text message programs may be effective for ST users and suggests that further research into this treatment modality for ST users is needed.

Chemopreventive and Anti-tumor Potential of Natural Products in Oral Cancer

Oral cancer (OC) is a multifactorial disease caused by isolated or combined risk factors related to tobacco, alcohol consumption, and human papillomavirus infection. It is an aggressive pathology with a low five-year survival rate after surgery, chemotherapy, and/or radiotherapy, frequently associated with severe side effects. Drugs with the highest anti-tumor effect are obtained from natural products with diverse biological and molecular activities and potential chemopreventive and anticancer properties. This review summarizes the natural products reported to have the chemopreventive and anti-tumor potential for OC treatment, showing that several of these compounds are promising candidates as chemopreventive agents, and those with the highest anti-tumor potential induce apoptosis and inhibit proliferation and metastasis-related processes. For this reason, natural products have the potential to be important preventive and therapeutic options for OC in the future.

The Burden of Head and Neck Cancer in the United States, 1990 - 2017

PURPOSE

Head and neck cancers (HNC) are among the most common malignancies in the United States and are a significant cause of morbidity and mortality. Traditional risk factors for HNC include tobacco, alcohol, and Human Papilloma Virus (HPV) infection. Geographic location has also been shown to play a role, whether directly or indirectly. The purpose of this study was to describe the incidence, mortality and geographic variability of HNC within the United States between 1990 and 2017.

MATERIALS AND METHODS

The Global Burden of Diseases Study 2017, which models incidence and mortality, was used to obtain incidence and mortality data for "lip and oral cavity cancer", "nasopharynx cancer", "other pharynx cancer" (tonsil, oropharynx, and hypopharynx) and "larynx cancer" for the United States between 1990 and 2017.

RESULTS

The overall incidence rate of HNC increased (annual percent change (APC) = 0.23. 95% CI: 0.1-0.3) from 1990 through 2017 while overall mortality decreased (APC = -0.37. 95% CI: -0.4 to -0.3). The anatomic sub-site which saw the largest increase in incidence was "other pharynx" (APC=1.07. 95% CI: 0.9-1.2). In 2017, those in the West had the lowest incidence while those in the South had the highest (15.7 and 20.8 per 100,000 individuals, respectively).

CONCLUSIONS

The incidence of HNC in the United States increased between 1990 and 2017. This was driven by larger increases in those sites more prone to HPV-related HNC. While there exists geographic variability in the burden of this disease, additional studies are needed to further understand the impact of patient-specific factors.

A qualitative study to assess perceptions, barriers, and motivators supporting smokeless tobacco cessation in the US fire service

While firefighters currently have low smoking rates, rates of smokeless tobacco (SLT) use among this population are remarkably high and substantially greater than similar occupational groups, and the general population. This study explored determinants associated with SLT use, barriers to cessation, and motivators for SLT cessation in the fire service. Key informant interviews were conducted in 23 career firefighters who were current (n = 14) and former (n = 9) SLT users from across the U.S. Discussions were recorded and independently coded according to questions and themes. Major themes that developed among firefighters regarding SLT use determinants included positive perceptions of SLT products, social influences from their peers and family members, acceptability of SLT use in the fire service, and a coping resource for job stress. Firefighters discussed several barriers to SLT cessation, including intrapersonal barriers such as SLT use habits and its dependency, concerns about withdrawal symptoms; and social-environmental barriers including lack of support from health and other services providers, and lack of enforcement of existing tobacco policies regarding SLT use. Firefighters also mentioned both internal and external motivators for cessation. Internal motivators included self-motivation and their health concerns while external motivators included friends and family support, incentives or rewards, and price of SLT products. Findings provide unique perspectives from firefighters on factors that influence SLT use and barriers and motivators to SLT cessation. These are insufficiently assessed and considered by the fire service organizations and their health care providers. Thus, the organizations must understand these issues in order to mitigate barriers and motivate the personnel to quit using SLT. Information gained from firefighters who were current and former SLT users can be used to develop an effective, culturally-tailored intervention that is acceptable to fire service personnel.

Best Practices: Application of NI-RADS for Posttreatment Surveillance Imaging of Head and Neck Cancer

Imaging surveillance is an important component of posttreatment management of head and neck cancers. There is variability in the surveillance regimen used by various practitioners and institutions, with no official National Comprehensive Cancer Network guidelines for patients showing no symptoms beyond 6 months posttreatment. Moreover, imaging of the neck after treatment is a complex examination with significant interreader heterogeneity, particularly in terms of the manner in which degree of suspicion for disease recurrence is expressed. The Neck Imaging Reporting and Data System (NI-RADS) was introduced by the American College of Radiology (ACR) in 2018 as a practical guide for the interpreting radiologist. NI-RADS is a proposed interpretive framework that can be applied to any standardized or institutional surveillance imaging protocol. NI-RADS simplifies communication between radiologists and referring clinicians and provides management guidance linked to specific levels of suspicion. The ACR NI-RADS Committee also provided general best practice recommendations for imaging surveillance modality and timing in the 2018 white paper. This article will review existing literature regarding choice of modality and timeline for surveillance in treated cancer of the head and neck. NI-RADS will then be presented as an approach to imaging reporting, interpretation, and design of next steps in management.

1, 6-O, O-Diacetylbritannilactone from Inula britannica Induces Anti-Tumor Effect on Oral Squamous Cell Carcinoma via miR-1247-3p/LXRα/ABCA1 Signaling

Introduction

Oral squamous cell carcinoma (OSCC) is the most prevalent malignancy affecting the oral cavity and is associated with severe morbidity and high mortality. 1, 6-O, O-Diacetylbritannilactone (OODBL) isolated from the medicinal herb of Inula britannica has various biological activities such as anti-inflammation and anti-cancer. However, the effect of OODBL on OSCC progression remains unclear. Here, we were interested in the function of OODBL in the development of OSCC.

Methods

The effect of OODBL on OSCC progression was analyzed by MTT assays, colony formation assays, transwell assays, apoptosis analysis, cell cycle analysis, and in vivo tumorigenicity analysis. The mechanism investigation was performed by qPCR assays, Western blot analysis, and luciferase reporter gene assays.

Results

We found that OODBL inhibits the proliferation of OSCC cells in vitro. Moreover, the migration and invasion were attenuated by OODBL treatment in the OSCC cells. OODBL arrested cells at the G0/G1 phase and induced cell apoptosis. OODBL was able to up-regulate the expression of LXRα, ABCA1, and ABCG1 in the system. In addition, OODBL activated LXRα/ABCA1 signaling by targeting miR-1247-3p. Furthermore, the expression levels of cytochrome c in the cytoplasm, cleaved caspase-9, and cleaved caspase-3 were dose-dependently reduced by OODBL. Besides, OODBL increased the expression ratio of Bax to Bcl-2. Moreover, OODBL repressed tumor growth of OSCC cells in vivo.

Discussion

Thus, we conclude that OODBL inhibits OSCC progression by modulating miR-1247-3p/LXRα/ABCA1 signaling. Our finding provides new insights into the mechanism by which OODBL exerts potent anti-tumor activity against OSCC. OODBL may be a potential anti-tumor candidate, providing a novel clinical treatment strategy of OSCC.

Exposure to a Tobacco-Specific Carcinogen Among Adolescent Smokeless Tobacco Users in Rural California, United States

INTRODUCTION

Approximately the same percentage of male high school students in the United States currently uses conventional smokeless tobacco as smokes cigarettes, resulting in toxin exposure.

METHODS

This study assessed tobacco product use (smokeless, combustible, and electronic cigarettes) and nicotine and carcinogen exposures in a sample of 594 male rural high school baseball players-a population traditionally at risk for smokeless tobacco use. Salivary specimens were assayed for cotinine (a biomarker of nicotine exposure) and urine specimens for 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL, a biomarker of the carcinogen 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) using liquid chromatography-tandem mass spectrometry.

RESULTS

The prevalence of past 30-day use of any tobacco product was 29%. Past 7-day smokeless tobacco use (prevalence: 13%) was associated with the highest levels of cotinine and NNAL observed in the sample, whether smokeless tobacco was used exclusively (geometric means: cotinine 11.1 ng/mL; NNAL 31.9 pg/mg-creatinine) or in combination with combustible products (geometric means: cotinine 31.6 ng/mL; NNAL 50.0 pg/mg creatinine). Cotinine and NNAL levels were incrementally higher in each increasing category of smokeless tobacco use frequency. However, observed levels were lower than previously reported for adults, likely reflecting less smokeless use per day among adolescents.

CONCLUSIONS

Based on these biomarker observations, adolescents who use conventional smokeless tobacco products are exposed to substantial levels of nicotine and NNK. Although exposed to lower levels than adult smokeless users, the findings are concerning given the young age of the sample and tendency for smokeless tobacco users to increase use intensity over time.

IMPLICATIONS

This study demonstrates that adolescents using smokeless tobacco are exposed to levels of nicotine and NNK that increase with use frequency and that exceed exposures among peers using other tobacco products. Youth smokeless tobacco use in the United States has not declined along with youth smoking prevalence, giving greater importance to this health concern. To reduce youth (and adult) exposures, needed actions include effective smokeless tobacco use prevention, potentially in combination with reducing the levels of harmful and potentially harmful chemicals in smokeless tobacco products currently popular among adolescents.

Epidemiology of head and neck cancers: an update

PURPOSE OF REVIEW

This review attempts to give an update of epidemiological knowledge on head and neck cancers (HNC).

RECENT FINDINGS

Worldwide, from 1990 to 2017, incidence rates for larynx and nasopharyngeal cancers decreased, whereas they increased for oro/hypopharyngeal cancers and lip/oral cavity cancers. They are still markedly higher among men than women. South Asia has the highest HNC incidence rate, followed by Europe, North America, and Australasia.Tobacco and alcohol remain the major risk factors. Rate of cancers attributable to human papillomavirus (HPV) among HNCs is highly depending on world region and tobacco use prevalence. It increases in high-income countries. In the US population, the number of HPV-attributable oropharyngeal cancers now exceeds the number of cervix cancers. HPV vaccination for boys is recommended in an increasing number of countries. Many occupations are associated with an increased HNC risk. Fruits and vegetables intake have a protective effect against HNC.

SUMMARY

To decrease HNC incidence, measures to reduce tobacco use and alcohol consumption remain essential. Improvement of HPV vaccination coverage is also a major objective. Reduction of carcinogens at occupation, protection of workers from carcinogen exposures, education for better diet, and easy and affordable access to fruits and vegetables can contribute to incidence decrease.

Disparate survival of late-stage male oropharyngeal cancer in Appalachia

The United States Appalachian region harbors a higher cancer burden than the rest of the nation, with disparate incidence of head and neck squamous cell carcinomas (HNSCC), including oral cavity and pharynx (OC/P) cancers. Whether elevated HNSCC incidence generates survival disparities within Appalachia is unknown. To address this, HNSCC survival data for 259,737 tumors from the North American Association for Central Cancer Registries 2007-2013 cohort were evaluated, with age-adjusted relative survival (RS) calculated based on staging, race, sex, and Appalachian residence. Tobacco use, a primary HNSCC risk factor, was evaluated through the Behavioral Risk Factor Surveillance System from Appalachian states. Decreased OC/P RS was found in stage IV Appalachian white males within a subset of states. The survival disparity was confined to human papillomavirus (HPV)-associated oropharyngeal cancers, specifically the oropharynx subsite. This correlated with significantly higher smoking and male smokeless tobacco use in most Appalachian disparity states. Lower survival of Appalachian males with advanced-stage HPV-associated oropharyngeal cancers suggests pervasive tobacco consumption likely generates more aggressive tumors at HPV-associated oropharynx subsites than national averages. Comprehensive tobacco and HPV status should therefore be evaluated prior to considering treatment de-intensification regimens for HPV-associated oropharyngeal cancers in populations with high tobacco consumption.

Risk factors of head and neck cancer mortality compared with those of all-cause and all-cancer mortalities

This study aimed to clarify the risk factors of head and neck cancer (HNC) mortality, relative to those of all-cause and all-cancer mortalities, using the Korean National Health Insurance Service-Health Screening Cohort (NHIS-HEALS) data set. Data from 238 HNC deaths, 14,769 all-cancer deaths, and 38,086 all-cause deaths were extracted during a median follow-up period of 9.5 years. Baseline characteristics were assessed via chi-square tests, t tests, and multivariable logistic regression. HNC mortality was found to be positively associated with male sex, past and current smoking habits, moderate-to-heavy alcohol consumption, and being underweight. In addition, serum gamma-glutamyltransferase level was found to be significantly elevated in cases of HNC mortality. In contrast, obesity, a history of diabetes, and fasting blood glucose levels were found to be inversely associated with overall HNC mortality. Among the HNC subtypes, mortality due to laryngeal cancer was most strongly associated with past and heavy cigarette smoking, and mortality due to oro-/hypopharyngeal cancer was most strongly associated with heavy alcohol consumption. The present study demonstrates that this nationwide, population-based NHIS-HEALS data set can provide useful information for health research and policy development.

Characterisation of a subpopulation of CD133+ cancer stem cells from Chinese patients with oral squamous cell carcinoma

Cancer stem cells (CSCs) play a critical role in cancer development and growth. The aim of this study was to identify and isolate CSCs from populations of primary oral squamous cell carcinoma (OSCC) cells, which were obtained from OSCC specimens and identified by cell morphology and immunohistochemical staining for keratin. CD133⁺ cells detected by flow cytometry comprised 0.41 ± 0.06% of primary OSCC cells and were isolated from primary OSCC cell populations using magnetic-activated cell sorting, revealing that 93.39% of high-purity CD133⁺ cells were in the G0/G1 phase of the cell cycle. Additionally, the growth rate of CD133⁺ cells was higher than that of CD133⁻ cells, and in vivo tumourigenesis experiments showed that the tumourigenic ability of CD133⁺ cells was markedly stronger than that of CD133⁻ cells. Moreover, CD133⁺ cells showed increased chemotherapeutic resistance to cisplatin and higher self-renewal ability according to sphere-formation assay, as well as higher mRNA levels of stemness-associated genes, including NANOG, SOX2, ALDH1A1, and OCT4. These results indicated that OSCC cells, which share certain characteristics of CSCs, harbour CD133⁺ cells potentially responsible for OSCC aggressiveness, suggesting CD133 as a potential prognostic marker and therapeutic target.

Comparison of tobacco-specific nitrosamine levels in smokeless tobacco products: High levels in products from Bangladesh

Bangladesh exhibits the second highest rate of smokeless tobacco (SLT) product usage in the world, and this has been associated with the high upper aerodigestive tract cancer incidence in this country. The goal of the present study was to examine the levels of the highly carcinogenic tobacco-specific nitrosamines (TSNAs) in Bangladeshi SLT products and compare these levels to that observed in SLT brands from southeast Asia and the USA. The levels of TSNAs and nicotine were determined by LC-MS/MS in twenty-eight SLT brands and several tobacco additives from Bangladesh, as well as several SLT brands from India, Pakistan and the USA. The levels of N-nitrosonornicotine (NNN), 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK), N-nitrosoanatabine (NAT) and N-nitrosoanabasine (NAB) in Bangladeshi SLT brands ranged from 1.1-59, 0.15-34, 0.79-45, and 0.037-13 μg/g SLT powder, respectively. The mean levels of the highly carcinogenic TSNAs (NNN+NNK) were 7.4-, 2.4-, and 63-fold higher in Bangladeshi SLT products as compared to SLT brands from the USA, India and Pakistan, respectively; these trends were also observed for NAT and NAB. Similar mean levels of nicotine were observed in the Bangladeshi brands (31 mg/g powder) versus brands from the USA (25 mg/g powder) and India (20 mg/g powder); they were 3-fold higher than brands from Pakistan (10 mg/g powder). Gul SLT brands exhibited the highest pH and the highest levels of unprotonated nicotine. The high levels of TSNAs in Bangladeshi SLT brands may be an important factor contributing to the high rates of upper aerodigestive tract cancer in Bangladesh.

Cancer Perceptions Among Smokeless Tobacco Users: A Qualitative Study of US Firefighters

Background

Prevalence rates of smokeless tobacco (SLT) use among firefighters are remarkably high and substantially higher than similar occupational groups and the general U.S. population. The purpose of this study was to explore the perspectives of fire service personnel regarding cancer and its associations with tobacco and SLT use.

Methods

This descriptive study used a qualitative approach. Key informant interviews were conducted in 39 career firefighters and fire service administration from across the U.S. Discussion were recorded, transcribed verbatim and transferred to NVivo software for narrative analysis. Topics explored included cancer perceptions, attitudes and beliefs, and cultural factors related to SLT use behaviors. Results: Major themes that emerged among fire service personnel included concerns about cancer and its risk factors including firefighting tasks, such as fire overhaul operations, and from their lifestyle behaviors, such as alcohol and tobacco use. Firefighters also suggested a number of reasons for their increased SLT use, such as fire department tobacco-free policy and fire service culture.

Conclusion

The current study provides a rich foundation for future research, prevention, and intervention efforts for the fire service and research communities regarding tobacco and SLT use and cancer risk. Additional research on firefighters' cancer beliefs deserves future research in order to improve messaging about the risks of cancer due to firefighting.

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.

Prevalence and Correlates of Snuff Use, and its Association With Tuberculosis, Among Women Living With HIV in South Africa

INTRODUCTION

A higher proportion of people living with HIV (PLWH) smoke compared to the general population, but little information exists about the prevalence and correlates of smokeless tobacco use among PLWH. In South Africa, dry powdered tobacco is inhaled nasally as snuff.

METHODS

A cross-sectional survey among PLWH attending three HIV clinics was conducted. Snuff use was assessed via self-report and urine cotinine.

RESULTS

Given the low (3%) prevalence of snuff use among men, analysis was restricted to n = 606 nonsmoking women living with HIV. Half (n = 298, 49%) were snuff users, the majority of whom (n = 244, 84%) had a positive urine cotinine test. In adjusted analysis, snuff use was negatively associated with higher education (relative risk [RR] 0.55; 95% confidence interval [CI]: 0.39, 0.77) and mobile phone ownership (RR 0.83; 95% CI: 0.71, 0.98), and positively associated with ever having tuberculosis (TB) (RR 1.22; 95% CI: 1.03, 1.45). In adjusted analysis, with current TB as the outcome, snuff use was marginally statistically significantly associated with a twofold increase in odds of a current TB diagnosis (odds ratio [OR] 1.99; 95% CI: 0.98, 4.15).

DISCUSSION

A high proportion of nonsmoking South African women living with HIV use snuff, which was a risk factor for TB. Additional research is needed to understand the relationship between snuff, TB, and other potential health risks.

IMPLICATIONS

PLWH have a higher prevalence of smoking than their seronegative peers, but there is a paucity of research on smokeless tobacco use in this population, especially in low-resource settings. TB is the leading cause of death among PLWH, and with improvements to HIV treatment and care, PLWH are at greater risk of tobacco-related diseases. We report an extremely high prevalence of snuff use among women living with HIV in South Africa. Further, in this population snuff use is positively associated with ever having a TB diagnosis, as well as currently having TB.

Smokeless tobacco use and risk of oral cavity cancer

Background/aim

Smokeless tobacco has been associated with oral cavity cancer for several decades. The incidence of oral cavity cancer is higher in some parts of the world especially South and South-East Asia including Pakistan. The aim of current study was to evaluate the risk of oral cavity cancer among smokeless tobacco users in our country.

Materials and methods

A case-control study was conducted between November 2016 and September 2017. Patients diagnosed with oral cavity cancer receiving treatment were included as cases and the attendants of various cancer patients visiting the hospital during the study period were included in the study as controls. Odds ratios (OR) and 95% confidence intervals (CI) were calculated and all reported P-values were considered significant at < 0.05.

Results

The crude OR for the “ever smokeless tobacco users” among cases and controls came out to be 4.98 (95%CI; 2.76–9.01). The OR for snuff users among cases and controls was 4.82 (95%CI; 2.37–9.80) and that for betel leaf users was 4.42 (95%CI; 1.66–11.91) after adjusting for smoking and age.

Conclusion

Our study provided strong evidence for snuff and betel leaf to be independent risk factors for oral cavity cancer.

Tobacco smoking, chewing habits, alcohol drinking and the risk of head and neck cancer in Nepal

Although tobacco smoking, pan chewing and alcohol drinking are important risk factors for head and neck cancer (HNC), the HNC risks conferred by products available in Nepal for these habits are unknown. We assessed the associations of tobacco smoking, chewing habits, and alcohol drinking with HNC risk in Nepal. A case-control study was conducted in Nepal with 549 incident HNC cases and 601 controls. Odds ratios (OR) and 95% confidence intervals (CI) were estimated using unconditional logistic regression adjusting for potential confounders. We observed increased HNC risk for tobacco smoking (OR: 1.54; 95% CI: 1.14, 2.06), chewing habits (OR: 2.39; 95% CI: 1.77, 3.23), and alcohol drinking (OR: 1.57; 95% CI: 1.14, 2.18). The population attributable fraction (PAF) was 24.3% for tobacco smoking, 39.9% for chewing habits and 23.0% for alcohol drinking. Tobacco smoking, chewing habits, and alcohol drinking might be responsible for 85.3% of HNC cases. Individuals who smoked tobacco, chewed products and drank alcohol had a 13-fold increase in HNC risk (OR: 12.83; 95% CI: 6.91, 23.81) compared to individuals who did not have any of these habits. Both high frequency and long duration of these habits were strong risk factors for HNC among the Nepalese with clear dose-response trends. Preventive strategies against starting these habits and support for quitting these habits are necessary to decrease the incidence of HNC in Nepal.

Tobacco use and nicotine dependence among people living with HIV who drink heavily in South Africa: a cross-sectional baseline study

Background

People living with HIV (PLWH) who drink alcohol and use tobacco are particularly vulnerable to tobacco-induced diseases due to an already compromised immune system. This study investigated the prevalence and factors associated with tobacco use (cigarette and snuff) among PLWH who drink heavily.

Methods

Participants (n = 623) on antiretroviral therapy for HIV who reported heavy drinking using the Alcohol Use Disorders Identification Test (AUDIT) and AUDIT-C were recruited from six hospitals in Gauteng Province, South Africa. The Fagerström test was used to assess nicotine dependence. Chi Square tests and modified Poisson regression analyses were conducted to identify factors associated with tobacco use.

Results

Almost half of the participants reported ever smoking (44.0%; CI: 40.1–47.9) and about a quarter reported ever using snuff (25.5%; CI: 22.2–29.1). Current smokers and current snuff users comprised 27.3% (CI: 23.9–30.9) and 19.1% (CI: 16.2–22.3) of all participants respectively. Among current smokers, 37.9% (CI: 30.8–45.3) were moderately/highly dependent on nicotine. Current ‘any tobacco product users’ (ATPU: use cigarettes or snuff) were 45.4% (CI: 41.5–49.3) while 1.0% (CI: 0.4–2.0) currently used cigarettes and snuff. Adjusted regression analyses showed that, compared to males, females were less at risk of being: ever smokers (Relative Risk Ratio [RRR] = 0.33; CI: 0.27–0.41), current smokers (RRR = 0.18; CI: 0.12–0.25), and ATPU (RRR = 0.75; CI: 0.63–0.89) but were more at risk of ever snuff use (RRR = 5.23; CI: 3.31–8.25), or current snuff use (RRR = 26.19; CI: 8.32–82.40) than males. Ever snuff users (RRR = 1.32; CI: 1.03–1.70), current snuff users (RRR = 1.40; CI: 1.03–1.89) and ATPU (RRR = 1.27; CI: 1.07–1.51) were more at risk of reporting significant depressive symptoms. We found no significant associations between smoking status and years on ART and viral load.

Conclusion

There is a high prevalence of cigarette and snuff use among PLWH who drink heavily. Tobacco use cessation interventions tailored specifically for this population and according to their tobacco product of choice are urgently needed given their vulnerability to ill-health.

Age at start of using tobacco on the risk of head and neck cancer: Pooled analysis in the International Head and Neck Cancer Epidemiology Consortium (INHANCE)

BACKGROUND

Tobacco use is a well-established risk factor for head and neck cancer (HNC). However, less is known about the potential impact of exposure to tobacco at an early age on HNC risk.

METHODS

We analyzed individual-level data on ever tobacco smokers from 27 case-control studies (17,146 HNC cases and 17,449 controls) in the International Head and Neck Cancer Epidemiology (INHANCE) consortium. Adjusted odds ratios (ORs) and 95% confidence intervals (CIs) were estimated using random-effects logistic regression models.

RESULTS

Without adjusting for tobacco packyears, we observed that younger age at starting tobacco use was associated with an increased HNC risk for ever smokers (OR<10 years vs. ≥30 years: 1.64, 95% CI: 1.35, 1.97). However, the observed association between age at starting tobacco use and HNC risk became null after adjusting for tobacco packyears (OR<10 years vs. ≥30 years: 0.97, 95% CI: 0.80, 1.19). In the stratified analyses on HNC subsites by tobacco packyears or years since quitting, no difference in the association between age at start and HNC risk was observed.

CONCLUSIONS

Results from this pooled analysis suggest that increased HNC risks observed with earlier age at starting tobacco smoking are largely due to longer duration and higher cumulative tobacco exposures.

Rhinologic signs associated with snuff taking

OBJECTIVE

To study rhinologic signs associated with nasal tobacco (snuff) intake in Parakou, northern Benin.

MATERIALS AND METHODS

A cross-sectional descriptive comparative study included 300 tobacco snuff takers and 300 subjects who did not use tobacco at all. The sampling technique was a stratified 4-stage random sample for non-users and a convenience non-random sample for snuff takers.

RESULTS

The sex-ratio was 0.92 in non-users and 41.9 in snuff takers. Duration of snuff taking was more than 20 years in 24.3% of cases. The symptoms studied were significantly more frequent in snuff takers than non-users (P<0.05). Snoring was reported by 58.3% of snuff takers, versus 5.7% of non-users (P=0.000). Nasal obstruction and rhinorrhea were reported by respectively 26.3% and 22.7% of snuff takers, versus 6.3% and 5.3% of non-users (P=0.000). Hyposmia was reported by 14% of snuff takers, versus 1.3% of non-users (P=0.000). Anterior rhinoscopy found abnormalities in 81.7% of snuff takers, compared to 10.67% of non-users. Nasal hypertrichosis was more frequent in snuff takers than non-users: 40% versus 5% (P=0.000).

CONCLUSION

Nasal intake of tobacco is responsible for morbidity in snuff takers compared to non-users of tobacco.

The changing epidemiology of oral cancer: definitions, trends, and risk factors

Objective

This review has three objectives, namely: (i) to discuss how oral cancer is and ought to be defined and recorded; (ii) to present up-to-date data on the incidence burden of the disease in the four countries of the UK, and review recent analyses of trends in the disease; and (iii) to summarise recent evidence on risk factors of the disease.

Methods

Cancer definitions were clarified by the International Classification of Diseases accounting for anatomical and aetiological differences; descriptive epidemiology included international / UK literature review and information requests for incidence data from the UK cancer registries (2000-2016); analytical epidemiology focused on reviewing the findings of the International Head and Neck Cancer Epidemiology (INHANCE) consortium, which has pooled data from multiple case-control studies providing the best estimates of risk factors.

Results

Emerging evidence of the role played by risk factors in different anatomical sites means that oral cavity cancer and oropharynx cancer should be considered distinct disease entities – and a standardised attribution of anatomical subsites will be helpful in ensuring consistency in how data are presented. In 2016, over 3,700 people were diagnosed with oral cavity cancer and over 3,500 people were diagnosed with oropharyngeal cancer in the UK. Incidence of oropharyngeal cancer is rapidly rising across the UK. Rates of oral cavity cancer are higher in Northern Ireland and higher still (and relatively stable) in Scotland, but rising in England and Wales. INHANCE data show that while the consumption of alcohol and tobacco are the prime risk factors for oral cavity and oropharyngeal cancers, they provide greater certainty in the preventive benefits of reducing these risk factors. The role played by other factors such as low socioeconomic status, genetics, oral health, and human papillomavirus (only for oropharyngeal cancer) have become clearer.

Conclusions

This epidemiology provides a strong foundation for designing and managing both population and individual oral cavity and oropharyngeal cancer control strategies.

Addiction of tobacco chewing and smoking in the patients of head and neck squamous cell carcinoma: A descriptive epidemiological study in Pakistan

Objective:

The associated risk factors for the majority of patients with head and neck squamous cell carcinoma (HNSCC) are tobacco and betel nut abuse, while there also seems to be a rising proportion of patients who report no history of tobacco or betel nut usage. Therefore, objective of the study was to find out potential risk factors and demographics of HNSCC patients addicted to tobacco and/or betel nut, as well as non-addicted patients.

Methods:

This epidemiological study was conducted in Karachi Institute of Biotechnology and Genetic Engineering (KIBGE), University of Karachi, and Jinnah Postgraduate Medical Centre (JPMC) from January to December 2016. All subjects were participants in an epidemiological study of HNSCC. Demographics and clinical characteristics were obtained for 185 addicted and 26 non-addicted patients.

Results:

Non-addicted patients were more likely to be females (χ2=19.0, p<0.001) and were significantly younger than addicted patients (χ2=21.0, p<0.001). Addicted patients more likely belonged to a lower income group (χ2=14.4, p=0.006) and had a higher proportion of oral cancers (χ2=30.0, p<0.001). Almost all addicted females had oral cancers (97%), whereas more than half of the non-addicted females had oral cancers (53%).

Conclusions:

Addicted patients commonly have oral cavity cancers. This might be due to the habit of chewing tobacco and/or betel nut that addicted patients have. Non-addicted patients are commonly young females. It is likely that no single known factor is responsible for HNSCC in non-addicted patients, and several occupational exposure studies in future may be important to the etiology of non-addicted patients.

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.

A review of the effects of tobacco smoking on cancer treatment: smoking cessation intervention should be integrated into the cancer care continuum

Background:

The adverse health effects associated with smoking tobacco have been well investigated, and its detrimental effects on cancer treatment outcomes, efficacy and quality of life (QOL) for cancer patients have also been well documented. Tobacco smoke contains many thousands of chemicals, including a plethora of carcinogens, and the exposure of human cells to these carcinogens, and their metabolic activation, is the main mechanism by which smoking-related cancer is initiated.

Materials and Methods:

This paper reports on a narrative review of recent studies in the field of effects of tobacco smoking on cancer treatment, including the effects of carcinogens in smoke on carcinogenesis, cell mutations and the immune system. The health effects of smokeless tobacco, effects of tobacco smoking on cancer treatment, and its impact on surgery, radiation therapy and chemotherapy are reported. The potential risks of second primary cancers or recurrence from tobacco use, the effects of second-hand smoking and cancer treatment, the impact of smoking on the QOL after cancer treatment and the need to integrate smoking cessation programs into the cancer care continuum are also reported.

Conclusions:

Tobacco use has a direct impact on cellular function by inhibiting apoptosis, stimulating proliferation and decreasing the efficacy of cancer treatment; therefore, quitting its use has the potential to improve treatment response rates and survival, as well as reduces the risk of developing second cancers and potentially improves the QOL after treatment. Smoking cessation is one of the most important interventions to prevent cancer and is also essential after the diagnosis of cancer to improve clinical outcomes. Due to the numerous benefits of smoking cessation, it should become a critical component of the cancer care continuum in all oncology programs – from prevention of cancer through diagnosis, treatment, survivorship and palliative care. Evidence-based smoking cessation intervention should be sustainably integrated into any comprehensive cancer program, and the information should be targeted to the specific benefits of cessation in cancer patients.

Contemporary Associations of Exclusive Cigarette, Cigar, Pipe, and Smokeless Tobacco Use With Overall and Cause-Specific Mortality in the United States

Background

A growing proportion of tobacco users in the United States use non-cigarette products including cigars, pipes, and smokeless tobacco. Studies examining the disease and mortality risks of these products are urgently needed.

Methods

We harmonized tobacco use data from 165 335 adults in the 1991, 1992, 1998, 2000, 2005, and 2010 National Health Interview Surveys. Hazard ratios (HRs) and 95% confidence intervals (CIs) for overall and cause-specific mortality occurring through December 31, 2015, were estimated by exclusive use of cigarettes, cigars, pipes, or smokeless tobacco using Cox proportional hazards regression with age as the underlying time metric and never tobacco users as the referent group.

Results

Current use of cigarettes (HR = 2.23, 95% CI = 2.13 to 2.33) and smokeless tobacco (HR = 1.36, 95% CI = 1.17 to 1.59) were each associated with overall mortality. Relative to never tobacco users, higher risks were observed both in daily (HR = 2.34, 95% CI = 2.24 to 2.44) and nondaily (HR = 1.69, 95% CI = 1.54 to 1.86) cigarette smokers, with associations also observed across major smoking-related causes of death. Daily use of smokeless tobacco was also associated with overall mortality (HR = 1.41, 95% CI = 1.20 to 1.66) as was daily use of cigars (HR = 1.52, 95% CI = 1.12 to 2.08). Current smokeless tobacco use was associated with a higher risk of mortality from heart disease and smoking-related cancer, with strong associations observed for cancers of the oral cavity and bladder.

Conclusions

Exclusive daily use of cigarettes, cigars, and smokeless tobacco was associated with higher mortality risk. Tobacco control efforts should include cigars and smokeless tobacco.

Epidemiology of Head and Neck Squamous Cell Carcinomas: Impact on Staging and Prevention Strategies

OPINION STATEMENT

The epidemiology of head and neck squamous cell carcinoma (HNSCC) has shifted dramatically over the last 50 years, as smoking-related HNSCCs decrease in incidence while human papillomavirus (HPV)-related cancers rise. The shift in HNSCC risk factors has changed patient demographics, the distribution of affected anatomical subsites, and prognosis of this illness. As such, the medical community has responded by devising novel staging systems and prevention strategies. The medical community will require continued vigilance in reducing HNSCC traditional risks factors for HNSCC, such as cigarette use, and emerging risk like HPV infection.

Smokers' perceptions of risks and harm from snus relative to cigarettes: A latent profile analysis study

INTRODUCTION

Certain types of smokeless tobacco (SLT) products, particularly snus, carry fewer health risks than cigarette smoking and might be able to serve as harm-reduction products for smokers. However, studies frequently find that smokers misperceive SLT and snus to be as or more harmful than smoking. This perception is often measured with a single general harm question, and research on underlying risk perceptions is limited.

METHODS

Using a sample of 256 current smokers, we utilized Latent Profile Analysis to examine response profiles to items that assessed perceived risk of specific health outcomes (lung cancer, heart disease, oral cancer) from snus relative to cigarettes, along with the typical single item measure of overall harm from snus compared to cigarettes.

RESULTS

Three smoker response profiles emerged. Almost half (44.9%) of smokers perceived snus to be as or more risky than cigarettes for all three specific health outcomes (group 1), while over one third (38.3%) had an elevated perceived risk for oral cancer only (group 2). About 17% of smokers perceived snus to have lower risks for lung cancer only (group 3). Across each profile, perceived risk was highest for oral cancer.

CONCLUSIONS

If smokers are to consider snus for harm-reduction, efforts may be needed to better inform smokers about their lower relative risks, including for particular health outcomes of interest. This study also suggests that smokers may vary in their level of need for information to correct their relative risk misperceptions.

Predictors of Smokeless Tobacco Susceptibility, Initiation, and Progression Over Time Among Adolescents in a Rural Cohort

BACKGROUND

Use of smokeless tobacco (ST, moist snuff and chewing tobacco) is elevated among male rural youth, particularly participants in certain sports, including baseball.

OBJECTIVES

This study aimed to assess factors associated with adolescent male athletes' ST-related behaviors over time, including: baseline use, initiation, and progression in use intensity in a school-based longitudinal cohort.

METHODS

Baseline and one-year follow-up questionnaires assessed sociodemographic characteristics, environmental factors, and tobacco-related perceptions and behaviors among 9- to12th-grade interscholastic baseball players in 36 rural California schools. Population characteristics were compared among ST use categories (never, experimental, and experienced users). Multivariable models using generalized estimating equations were estimated for outcomes among baseline ST never-users (ST susceptibility and future initiation) and experimenters (ST expectations and progression in ST use).

RESULTS

Of 594 participants, over half (57%) had ever tried a tobacco product and the most common products tried were ST (36%) and electronic cigarettes (36%). Being older, perceiving less ST harm, being Non-Hispanic White, using alcohol or other tobacco products, having family or friends who use ST, and being receptive to advertising were associated with greater baseline ST use. Baseline alcohol consumption, lower perceived ST harm, peer use, and susceptibility and expectations were predictive of ST initiation and/or progression at one-year follow-up. Conclusion/Importance: Certain environmental, socio-demographic, cognitive, and behavioral factors predict ST susceptibility and later initiation and progression in use. Interventions addressing these factors have potential to prevent ST uptake and continued use within this high-risk adolescent population.

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.