Mentholated cigarette smoking and lung-cancer risk

Menthol: An underestimated anticancer agent

Menthol, a widely used natural, active compound, has recently been shown to have anticancer activity. Moreover, it has been found to have a promising future in the treatment of various solid tumors. Therefore, using literature from PubMed, EMBASE, Web of Science, Ovid, ScienceDirect, and China National Knowledge Infrastructure databases, the present study reviewed the anticancer activity of menthol and the underlying mechanism. Menthol has a good safety profile and exerts its anticancer activity via multiple pathways and targets. As a result, it has gained popularity for significantly inhibiting different types of cancer cells by various mechanisms such as induction of apoptosis, cell cycle arrest, disruption of tubulin polymerization, and inhibition of tumor angiogenesis. Owing to the excellent anticancer activity menthol has demonstrated, further research is warranted for developing it as a novel anticancer agent. However, there are limitations and gaps in the current research on menthol, and its antitumor mechanism has not been completely elucidated. It is expected that more basic experimental and clinical studies focusing on menthol and its derivatives will eventually help in its clinical application as a novel anticancer agent.

Comparison of Carcinogen Biomarkers in Smokers of Menthol and Nonmenthol Cigarettes: The 2015-2016 National Health and Nutrition Examination Survey Special Sample

BACKGROUND

The US FDA announced its commitment to prohibiting menthol as a characterizing flavor in tobacco. The relationship between cigarette menthol and exposure to toxic substances in mainstream tobacco smoke is not well characterized.

METHODS

Data from the National Health and Nutrition Examination Survey (NHANES) 2015 to 2016 special sample were used to study markers of 26 harmful and potentially harmful constituents (HPHC) in tobacco smoke. These include urine metabolites of polycyclic aromatic hydrocarbons (PAH), volatile organic compounds (VOC), and heavy metals in exclusive menthol (n = 162) and nonmenthol (n = 189) cigarette smokers. Urine metabolites of 7 PAHs, 15 VOCs, and 4 heavy metal biomarkers were compared by menthol status. Multivariable analyses were conducted on creatinine-adjusted concentrations.

RESULTS

There were no significant differences in cotinine levels or in 22 of 26 HPHCs. Among the urine metabolites of PAHs, the levels of 1-hydroxyphenanthrene were about 16% lower in menthol smokers. Among the urine metabolites of VOCs, menthol cigarette smokers presented significantly lower concentrations of acrylamide, N,N-dimethylformamide, and acrylonitrile. Menthol and nonmenthol smokers presented similar levels of heavy metals. Menthol did not affect the levels of cotinine and the nicotine metabolite ratio in urine.

CONCLUSIONS

Menthol and nonmenthol cigarettes deliver similar levels of most HPHCs.

IMPACT

Findings on toxicity are similar for menthol and nonmenthol cigarettes.

Measuring young adult appeal for menthol and non-menthol cigarettes: protocol of a clinical trial using both laboratory and intensive longitudinal methods (PRISM)

INTRODUCTION

Although the Food and Drug Administration banned other characterising flavours in cigarettes, menthol cigarettes are still available to consumers. Young adult new smokers are initiating with menthol cigarettes, such that the prevalence of young adults menthol versus non-menthol smokers is increasing. Experimentation with menthol cigarettes is associated with progression to regular smoking and nicotine dependence. This ongoing clinical trial in young adult smokers measures appeal and the reinforcing value of smoking menthol versus non-menthol cigarettes and the impact of these variables on changes in smoking behaviour at a 6-month follow-up.

METHODS AND ANALYSIS

Reinforcement for menthol smoking is assessed in the laboratory using a validated behavioural economic choice task, and appeal is measured in the natural environment using ecological momentary assessment (EMA). Analyses will examine differences between menthol and non-menthol cigarette smoking on measures of subjective response in the laboratory and via EMA, and how subjective response mediates the association between menthol preference at baseline and smoking outcomes at follow-up.

ETHICS AND DISSEMINATION

This protocol was approved by the University of Oklahoma Health Sciences Center Institutional Review Board (#10581). The findings will isolate the unique effects of menthol in smoking and will help inform regulatory decisions about the abuse liability of menthol cigarettes. Findings will be disseminated through peer-reviewed journal articles and presentations at national and international conferences.

TRIAL REGISTRATION NUMBER

NCT03953508.

Smoking Quit Rates Among Menthol vs Non-Menthol Smokers: Implications Regarding a US Ban on the Sale of Menthol Cigarettes

BACKGROUND

A ban on the sale of menthol cigarettes in the United States is currently under consideration. A justification is that menthol cigarettes are harder to quit, particularly for African American smokers who use menthols much more frequently than White smokers, but epidemiologic data are limited.

METHODS

In a cohort of 16,425 mostly low income African American and White current cigarette smokers enrolled during 2002-2009, we computed smoking quit and re-uptake rates at three follow ups conducted means of 4.6, 7.7 and 11 years after entry. Generalized estimation equations were used to compute odds ratios (OR) and 95% confidence intervals (CI) for quitting and resuming smoking for menthol vs non-menthol smokers adjusted for race, age, education, income, and smoking pack years.

RESULTS

Crude annual quit rates among current smokers were 4.3% for menthol and 4.5% for non-menthol smokers, with adjusted ORs of quitting for menthol vs non-menthol smokers of 1.01 (95% CI = 0.91-1.11) overall, 0.99 (95% CI = 0.87-1.12) among African American and 1.02 (95% CI = 0.88-1.20) among White smokers. Crude annual smoking re-uptake rates were somewhat higher among menthol (8.4%) than non-menthol smokers (7.1%), with an adjusted OR of 1.19 (95% CI = 0.97-1.47), but net quit rates remained similar (OR = 1.01 [95% CI = 0.90-1.13] overall; OR = 1.00 [95% CI = 0.86-1.15] among African American participants; and OR = 1.04 [95% CI = 0.87-1.24] among White participants).

CONCLUSIONS

This large-scale prospective survey revealed similar quit rates among menthol and non-menthol smokers. Results contribute to policy discussions, especially if, as a meta analysis suggests, lung cancer risk is higher for non-menthol smokers and a ban leads menthol smokers to switch to non-menthol cigarettes.

Role of l- and d-Menthol in the Glucuronidation and Detoxification of the Major Lung Carcinogen, NNAL

Menthol, which creates mint flavor and scent, is often added to tobacco in both menthol and nonmenthol cigarettes. A potent tobacco carcinogen, 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK), is extensively metabolized to its equally carcinogenic metabolite 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL) as (R)- or (S)-NNAL enantiomers. NNAL is detoxified by UDP-glucuronosyltransferase (UGT) enzymes, with glucuronidation occurring on either NNAL's pyridine ring nitrogen (NNAL-N-Gluc) or the chiral alcohol [(R)- or (S)-NNAL-O-Gluc]. To characterize a potential effect by menthol on NNAL glucuronidation, in vitro menthol glucuronidation assays and menthol inhibition of NNAL-Gluc formation assays were performed. Additionally, NNAL and menthol glucuronides (MG) were measured in the urine of smokers (n = 100) from the Southern Community Cohort Study. UGTs 1A9, 1A10, 2A1, 2A2, 2A3, 2B4, 2B7, and 2B17 all exhibited glucuronidating activity against both l- and d-menthol. In human liver microsomes, both l- and d-menthol inhibited the formation of each NNAL-Gluc, with a stereospecific difference observed between the formation of (R)-NNAL-O-Gluc and (S)-NNAL-O-Gluc in the presence of d-menthol but not l-menthol. With the exception of three nonmenthol cigarette smokers, urinary MG was detected in all menthol and nonmenthol smokers, with l-MG comprising >98% of total urinary MG. Levels of urinary NNAL-N-Gluc were significantly (P < 0.05) lower among subjects with high levels of total urinary MG; no significant changes in free NNAL were observed. These data suggest that the presence of menthol could lead to increases in alternative, activating metabolic pathways of NNAL in tobacco target tissues, increasing the opportunity for NNAL to damage DNA and lead to the development of tobacco-related cancers. SIGNIFICANCE STATEMENT: High levels of the major menthol metabolite, menthol-glucuronide, was observed in the urine of smokers of either menthol or nonmenthol cigarettes. The fact that a significant inverse correlation was observed between the levels of urinary menthol-glucuronide and NNAL-N-glucuronide, a major detoxification metabolite of the tobacco carcinogen, NNK, suggests that menthol may inhibit clearance of this important tobacco carcinogen.

Lung cancer health disparities

Compared with all other racial and ethnic groups in the United States, African Americans are disproportionally affected by lung cancer, both in terms of incidence and survival. It is likely that smoking, as the main etiological factor associated with lung cancer, contributes to these disparities, but the precise mechanism is still unclear. This paper seeks to explore the history of lung cancer disparities and review to the literature regarding the various factors that contribute to them.

Tobacco biomarkers and genetic/epigenetic analysis to investigate ethnic/racial differences in lung cancer risk among smokers

The Multiethnic Cohort Study has demonstrated that African Americans and Native Hawaiians have a higher risk for lung cancer due to cigarette smoking than Whites while Latinos and Japanese Americans have a lower risk. These findings are consistent with other epidemiologic studies in the literature. In this review, we summarize tobacco carcinogen and toxicant biomarker studies and genetic analyses which partially explain these differences. As determined by measurement of total nicotine equivalents in urine, which account for about 85% of the nicotine dose, African Americans take up greater amounts of nicotine than Whites per cigarette while Japanese Americans take up less. There are corresponding differences in the uptake of tobacco smoke carcinogens such as tobacco-specific nitrosamines, polycyclic aromatic hydrocarbons, 1,3-butadiene, and other toxic volatiles. The lower nicotine uptake of Japanese Americans is clearly linked to the preponderance of low activity forms of the primary nicotine metabolizing enzyme CYP2A6 in this ethnic group, leading to more unchanged nicotine in the body and thus lower smoking intensity. But the relatively high risk of Native Hawaiians and the low risk of Latino smokers for lung cancer are not explained by these factors. The possible role of epigenetics in modifying lung cancer risk among smokers is also discussed here. The results of these published studies may lead to a better understanding of susceptibility factors for lung cancer in cigarette smokers thus potentially identifying biomarkers that can detect those individuals at highest risk so that preventive approaches can be initiated at an early stage of the lung cancer development process.

Histologic Lung Cancer Incidence Rates and Trends Vary by Race/Ethnicity and Residential County

INTRODUCTION

Lung cancer incidence is higher among non-Hispanic (NH) blacks than among the NH white and Hispanic populations in the United States. However, national cancer estimates may not always reflect the cancer burden in terms of disparities and incidence in small geographic areas, especially urban-rural disparities. Moreover, there is a gap in the literature regarding rural-urban disparities in terms of cancer histologic type.

METHODS

Using population-based cancer registry data-Surveillance, Epidemiology and End Results and National Program of Cancer Registries data-we present age-adjusted histologic rates and trends by race/ethnicity and residential county location at the time of first cancer diagnosis. Rate ratios were calculated to examine racial/ethnic differences in rates. Annual percent change was calculated to measure changes in rates over time.

RESULTS

We found that declines in squamous cell carcinoma are occurring fastest in metropolitan counties, whereas rates of adenocarcinoma increased fastest in counties nonadjacent to metropolitan areas. Further, although NH black men have increased lung cancer incidence compared with NH white and Hispanic men in all geographic locations, we found that the degree of the disparity increases with increasing rurality of residence. Finally, we discovered that among women whose lung cancer was diagnosed when they were younger than 55 years, the incidence of squamous cell carcinoma and adenocarcinoma was higher for NH blacks than for NH whites.

CONCLUSIONS

Our results highlight disparities among NH blacks in nonadjacent rural areas. These findings may have significant impact for the implementation of smoking cessation and lung cancer screening programs.

Activation of the cold-receptor TRPM8 by low levels of menthol in tobacco products

Activation of the cold-receptor TRPM8 by menthol or other tobacco additives can suppress natural defense reactions such as coughing that usually would become effective as involuntary resistance against the inhalation of fumes. In Europe menthol is only regulated as flavor, but can be used as additive as long as no characteristic mint-like aroma will become noticeable in the end-product tobacco. The question needs to be addressed of whether such comparatively minor contents would be sufficient to trigger a measurable activation of TRPM8. In this study, we have analyzed both the contents of menthol and other natural TRPM8 agonists in tobacco products and developed a bioassay to determine the minimum concentrations of selected agonists to activate the TRPM8 receptor in cultured cells. The data confirm menthol as strongest natural agonist investigated. Based on these experiments and previously published data, we have estimated both the minimum menthol concentrations in cigarette smoke and in tobacco that are expected to trigger measurable physiological effects. According to our assessments, TRPM8 activation is likely to occur when cigarettes contain more than 50 micrograms of menthol. Importantly, menthol contents in cigarettes far below the typical levels that require declaration as "mentholated" would be sufficient to activate sensory receptors.

Menthol Smokers: Metabolomic Profiling and Smoking Behavior

BACKGROUND

The use of menthol in cigarettes and marketing is under consideration for regulation by the FDA. However, the effects of menthol on smoking behavior and carcinogen exposure have been inconclusive. We previously reported metabolomic profiling for cigarette smokers, and novelly identified a menthol-glucuronide (MG) as the most significant metabolite directly related to smoking. Here, MG is studied in relation to smoking behavior and metabolomic profiles.

METHODS

This is a cross-sectional study of 105 smokers who smoked two cigarettes in the laboratory one hour apart. Blood nicotine, MG, and exhaled carbon monoxide (CO) boosts were determined (the difference before and after smoking). Spearman correlation, χ2, and ANCOVA adjusted for gender, race, and cotinine levels for menthol smokers assessed the relationship of MG boost, smoking behavior, and metabolic profiles. Multivariate metabolite characterization using supervised partial least squares-discriminant analysis (PLS-DA) was carried out for the classification of metabolomics profiles.

RESULTS

MG boost was positively correlated with CO boost, nicotine boost, average puff volume, puff duration, and total smoke exposure. Classification using PLS-DA, MG was the top metabolite discriminating metabolome of menthol versus nonmenthol smokers. Among menthol smokers, 42 metabolites were significantly correlated with MG boost, which linked to cellular functions, such as of cell death, survival, and movement.

CONCLUSIONS

Plasma MG boost is a new smoking behavior biomarker that may provide novel information over self-reported use of menthol cigarettes by integrating different smoking measures for understanding smoking behavior and harm of menthol cigarettes.

IMPACT

These results provide insight into the biological effect of menthol smoking. Cancer Epidemiol Biomarkers Prev; 26(1); 51-60. ©2016 AACR.

Quantitative analysis of menthol in human urine using solid phase microextraction and stable isotope dilution gas chromatography-mass spectrometry

To accurately measure menthol levels in human urine, we developed a method using gas chromatography/electron ionization mass spectrometry with menthol-d₄ stable isotope internal standardization. We used solid phase microextraction (SPME) headspace sampling for collection, preconcentration and automation. Conjugated forms of menthol were released using β-glucuronidase/sulfatase to allow for measuring total menthol. Additionally, we processed the specimens without using β-glucuronidase/sulfatase to quantify the levels of unconjugated (free) menthol in urine. This method was developed to verify mentholated cigarette smoking status to study the influence of menthol on smoking behaviour and exposure. This objective was accomplished with this method, which has no carryover or memory from the SPME fiber assembly, a method detection limit of 0.0017μg/mL, a broad linear range of 0.002-0.5μg/mL for free menthol and 0.01-10μg/mL for total menthol, a 7.6% precision and 88.5% accuracy, and an analysis runtime of 17min. We applied this method in analysis of urine specimens collected from cigarette smokers who smoke either mentholated or non-mentholated cigarettes. Among these smokers, the average total urinary menthol levels was three-fold higher (p<0.001) among mentholated cigarette smokers compared with non-mentholated cigarette smokers.

The International Epidemiology of Lung Cancer: Latest Trends, Disparities, and Tumor Characteristics

INTRODUCTION

Our aim was to update global lung cancer epidemiology and describe changing trends and disparities.

METHODS

We presented country-specific incidence and mortality from GLOBOCAN 2012 by region and socioeconomic factors via the Human Development Index (HDI). Between- and within-country incidence by histological type was analyzed by using International Agency for Research on Cancer data on cancer incidence on five continents. Trend analyses including data from the International Agency for Research on Cancer, cancer registries, and the WHO mortality database were conducted using joinpoint regression. Survival was compared between and within countries and by histological type.

RESULTS

In 2012, there were 1.82 and 1.59 million new lung cancer cases and deaths worldwide, respectively. Incidence was highest in countries with a very high HDI and lowest in countries with a low HDI (42.2 versus 7.9 in 100,000 for males and 21.8 versus 3.1 in 100,000 for females, respectively). In most countries with a very high HDI, as incidence in males decreased gradually (ranging from -0.3% in Spain to -2.5% in the United States each year), incidence in females continued to increase (with the increase ranging from 1.4% each year in Australia to 6.1% in recent years in Spain). Although histological type varied between countries, adenocarcinoma was more common than squamous cell carcinoma, particularly among females (e.g., in Chinese females, the adenocarcinoma-to-squamous cell carcinoma ratio was 6.6). Five-year relative survival varied from 2% (Libya) to 30% (Japan), with substantial within-country differences.

CONCLUSIONS

Lung cancer will continue to be a major health problem well through the first half of this century. Preventive strategies, particularly tobacco control, tailored to populations at highest risk are key to reducing the global burden of lung cancer.

Racial differences in heritability of cigarette smoking in adolescents and young adults

INTRODUCTION

Although epidemiologic studies suggest low levels of cigarette use among African American adolescents relative to White U.S. adolescents, it is not known whether this may be due to racial differences in the relative contribution of genes and environment to cigarette use initiation and progression to regular use.

METHODS

Using data from White (n=2665) and African American (n=809) twins and full siblings sampled in the National Longitudinal Study of Adolescents, we fitted age-, sex- and race-specific variance decomposition models to estimate the magnitude of genetic and environmental effects on cigarette use initiation and cigarette use quantity in Whites and African Americans across adolescence and adulthood. We employ a causal-contingent-common pathway model to estimate the amount of variance explained in quantity of cigarettes smoked contingent on cigarette use initiation.

RESULTS

African Americans had lower cigarette use prevalence from adolescence through adulthood, and used cigarettes less heavily than Whites. Race-specific causal-contingent-common pathway models indicate that racial differences in genetic and environmental contributions to cigarette use initiation and cigarette use quantities are not present in adolescence but appear in young adulthood. Additive genetic factors were an important risk factor for cigarette use initiation for White but not African American young adults and adults.

CONCLUSIONS

Genetic and environmental contributions for cigarette use are similar by race in adolescence. In adulthood, genes have a stronger influence for cigarette use among White adolescents while the influence of the environment is minimal. For African Americans, both genetic and environmental influences are important in young adulthood and adulthood.

Smoking, menthol cigarettes and all-cause, cancer and cardiovascular mortality: evidence from the National Health and Nutrition Examination Survey (NHANES) and a meta-analysis

Background

The U.S. Food and Drug Administration has the authority to regulate tobacco product constituents, including menthol, if the scientific evidence indicates harm. Few studies, however, have evaluated the health effects of menthol cigarette use.

Objective

To investigate associations of cigarette smoking and menthol cigarette use with all-cause, cancer and cardiovascular risk in U.S. adults.

Methods

We studied 10,289 adults ≥ 20 years of age who participated in the National Health and Nutrition Examination Survey from 1999-2004 and were followed through December 2006. We also identified studies comparing risk of all-cause mortality, cardiovascular disease and cancer for menthol and nonmenthol cigarette smokers and estimates were pooled using random-effects models.

Results

Fifty-five percent of participants were never smokers compared to 23%, 17% and 5% of former, current nonmenthol and current menthol cigarette smokers, respectively. The adjusted hazard ratios (95% CI) for former, current nonmenthol and current menthol cigarette smokers compared to never smokers were 1.24 (0.96, 1.62), 2.40 (1.56, 3.71) and 2.07 (1.20, 3.58), respectively, for all-cause mortality; 0.92 (0.62, 1.37), 2.10 (1.02, 4.31) and 3.48 (1.52, 7.99) for cardiovascular mortality; and 1.91 (1.21, 3.00), 3.82 (2.19, 6.68) and 2.03 (1.00, 4.13) for cancer mortality. Using data from 3 studies of all-cause mortality, 5 of cardiovascular disease and 13 of cancer, the pooled relative risks (95% CI) comparing menthol cigarette smokers to nonmenthol cigarette smokers was 0.94 (0.85, 1.05) for all-cause mortality, 1.28 (0.91, 1.80) for cardiovascular disease and 0.84 (0.76, 0.92) for any cancer.

Conclusions

In a representative sample of U.S. adults, menthol cigarette smoking was associated with increased all-cause, cardiovascular and cancer mortality with no differences compared to nonmenthol cigarettes. In the systematic review, menthol cigarette use was associated with inverse risk of cancer compared to nonmenthol cigarette use with some evidence of an increased risk for cardiovascular disease.

Epidemiology of lung cancer: Diagnosis and management of lung cancer, 3rd ed: American College of Chest Physicians evidence-based clinical practice guidelines

BACKGROUND

Ever since a lung cancer epidemic emerged in the mid-1900 s, the epidemiology of lung cancer has been intensively investigated to characterize its causes and patterns of occurrence. This report summarizes the key findings of this research.

METHODS

A detailed literature search provided the basis for a narrative review, identifying and summarizing key reports on population patterns and factors that affect lung cancer risk.

RESULTS

Established environmental risk factors for lung cancer include smoking cigarettes and other tobacco products and exposure to secondhand tobacco smoke, occupational lung carcinogens, radiation, and indoor and outdoor air pollution. Cigarette smoking is the predominant cause of lung cancer and the leading worldwide cause of cancer death. Smoking prevalence in developing nations has increased, starting new lung cancer epidemics in these nations. A positive family history and acquired lung disease are examples of host factors that are clinically useful risk indicators. Risk prediction models based on lung cancer risk factors have been developed, but further refinement is needed to provide clinically useful risk stratification. Promising biomarkers of lung cancer risk and early detection have been identified, but none are ready for broad clinical application.

CONCLUSIONS

Almost all lung cancer deaths are caused by cigarette smoking, underscoring the need for ongoing efforts at tobacco control throughout the world. Further research is needed into the reasons underlying lung cancer disparities, the causes of lung cancer in never smokers, the potential role of HIV in lung carcinogenesis, and the development of biomarkers.

Body mass index, lifetime smoking intensity and lung cancer risk

There is as yet no generally accepted explanation for the common finding that low body mass index (BMI) is associated with an increased risk of lung cancer. We investigated this association in a Canadian population-based case-control study (1996-2002) with a particular view to assessing the hypothesis that the observed association was due to residual confounding by smoking. Analyses were based on 1,076 cases and 1,439 controls who provided their height at enrollment and their weight at two points in time, at age 20 and 2 years before enrollment. BMI, in kg/m(2) , was classified into underweight (<18.5), normal (18.5-24.9), overweight (25.0-29.9), and obese (≥30). Smoking history was synthesized into a comprehensive smoking index (CSI) that integrated duration, intensity and time since quitting. Odds ratios (ORs) and 95% confidence intervals (CIs) for BMI-lung cancer associations were estimated, adjusting for CSI as well as several sociodemographic, lifestyle and occupational factors. The normal BMI category was used as the reference. Among those who were underweight at age 20, there was a lower risk of lung cancer (OR = 0.69, 95% CI: 0.50-0.95). Conversely, lung cancer risk was increased among those who were underweight 2 years before enrollment (OR = 2.30, 95% CI: 1.30-4.10). The results were almost identical when stratifying analyses based on smoking history into never/lighter and heavier smokers. The inverse association between recent BMI and lung cancer is unlikely to be largely attributable to residual confounding by smoking. Reverse causality or a true relationship between BMI and lung cancer remain plausible.

The effect of menthol on cigarette smoking behaviors, biomarkers and subjective responses

BACKGROUND

As part of the Family Smoking Prevention and Tobacco Control Act, the U.S. Food and Drug Administration charged the Tobacco Products Scientific Advisory Committee with developing a report and recommendations about the effect of menthol in cigarettes on the public health. The purpose of this study was to examine smoking behaviors, biomarkers of exposure, and subjective responses when switching from a novel menthol cigarette to a non-menthol cigarette to isolate the effect of menthol and to approximate the effect a menthol ban might have on smokers.

METHODS

Thirty-two adult smokers completed this 35-day randomized, open-label, laboratory study. After a 5-day baseline period, participants were randomized to the experimental group (n = 22) where they would smoke menthol Camel crush for 15 days followed by 15 days of non-menthol Camel crush, or the control group (n = 10) where they smoked their own brand cigarette across all periods. Participants attended study visits every 5 days and completed measures of smoking rate, smoking topography, biomarkers of exposure, and subjective responses.

RESULTS

Although total puff volume tended to increase when the experimental group switched from menthol to non-menthol (P = 0.06), there were no corresponding increases in cigarette consumption or biomarkers of exposure (P > 0.1). Subjective ratings related to taste and smell decreased during the non-menthol period (P < 0.01), compared with the menthol.

CONCLUSIONS

Results suggest menthol has minimal impact on smoking behaviors, biomarkers of exposure, and subjective ratings.

IMPACT

When controlling for all other cigarette design features, menthol in cigarettes had minimal effect on outcome measures.

Menthol cigarettes, race/ethnicity, and biomarkers of tobacco use in U.S. adults: the 1999-2010 National Health and Nutrition Examination Survey (NHANES)

BACKGROUND

In the United States, cigarette flavorings are banned, with the exception of menthol. The cooling effects of menthol could facilitate the absorption of tobacco toxicants. We examined levels of biomarkers of tobacco exposure among U.S. smokers of menthol and nonmenthol cigarettes.

METHODS

We studied 4,603 White, African-American, and Mexican-American current smokers 20 years of age or older who participated in the National Health and Nutrition Examination Survey (NHANES) from 1999 through 2010 and had data on cigarette type and serum cotinine, blood cadmium, and blood lead concentrations. Urinary total 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol) (NNAL) was studied in 1,607 participants with available measures.

RESULTS

A total of 3,210 (74.3%) participants smoked nonmenthol cigarettes compared with 1,393 (25.7%) participants who smoked menthol cigarettes. The geometric mean concentrations comparing smokers of nonmenthol with menthol cigarettes were 163.1 versus 175.9 ng/mL for serum cotinine; 0.95 versus 1.02 μg/L for blood cadmium; 1.87 versus 1.75 μg/dL for blood lead; and 0.27 versus 0.23 ng/mL for urine NNAL. After multivariable adjustment, the ratios [95% confidence interval (CI)] comparing smokers of menthol with nonmenthol cigarettes were 1.03 (0.95-1.11) for cotinine, 1.10 (1.04-1.16) for cadmium, 0.95 (0.90-1.01) for lead, and 0.81 (0.65-1.01) for NNAL.

CONCLUSIONS

In a representative sample of U.S. adult smokers, current menthol cigarette use was associated with increased concentration of blood cadmium, an established carcinogen and highly toxic metal, but not with other biomarkers.

IMPACT

These findings provide information regarding possible differences in exposure to toxic constituents among menthol cigarette smokers compared with nonmenthol cigarette smokers.

Smoking, menthol cigarettes, and peripheral artery disease in U.S. adults

INTRODUCTION

Cigarette flavorings, with the exception of menthol, have been banned in the United States under the Family Smoking Prevention and Tobacco Control Act. Given the large number of menthol cigarette smokers in the United States, we investigated whether cigarette type (nonmenthol or menthol) is associated with peripheral artery disease (PAD).

METHODS

The authors studied 5,973 adults, 40 years of age and older, who participated in the National Health and Nutrition Examination Survey (NHANES) from 1999 to 2004. Smoking status and cigarette type were derived from self-reported questionnaires. PAD was defined as an ankle-brachial blood pressure index <0.9 in at least 1 leg.

RESULTS

Fifty percent of participants were never-smokers compared to 31%, 14%, and 5% of former, current nonmenthol, and current menthol cigarette smokers, respectively. The weighted prevalence of PAD in the study population was 5%. After multivariable adjustment, the odds ratios for PAD were 1.44 (95% CI: 0.97, 2.15), 3.65 (95% CI: 1.57, 8.50), and 2.51 (95% CI: 1.09, 5.80) comparing former, current nonmenthol cigarette smokers, and current menthol cigarette smokers to never-smokers. The associations between smoking and PAD were similar for smokers of nonmenthol and menthol cigarettes (p value for heterogeneity = .59).

CONCLUSIONS

In a representative sample of the U.S. population, current use of both menthol and nonmenthol cigarettes was associated with increased prevalence of PAD, with no difference in risk between cigarette types.

Systematic review with meta-analysis of the epidemiological evidence in the 1900s relating smoking to lung cancer

BACKGROUND

Smoking is a known lung cancer cause, but no detailed quantitative systematic review exists. We summarize evidence for various indices.

METHODS

Papers published before 2000 describing epidemiological studies involving 100+ lung cancer cases were obtained from Medline and other sources. Studies were classified as principal, or subsidiary where cases overlapped with principal studies. Data were extracted on design, exposures, histological types and confounder adjustment. RRs/ORs and 95% CIs were extracted for ever, current and ex smoking of cigarettes, pipes and cigars and indices of cigarette type and dose-response. Meta-analyses and meta-regressions investigated how relationships varied by study and RR characteristics, mainly for outcomes exactly or closely equivalent to all lung cancer, squamous cell carcinoma ("squamous") and adenocarcinoma ("adeno").

RESULTS

287 studies (20 subsidiary) were identified. Although RR estimates were markedly heterogeneous, the meta-analyses demonstrated a relationship of smoking with lung cancer risk, clearly seen for ever smoking (random-effects RR 5.50, CI 5.07-5.96) current smoking (8.43, 7.63-9.31), ex smoking (4.30, 3.93-4.71) and pipe/cigar only smoking (2.92, 2.38-3.57). It was stronger for squamous (current smoking RR 16.91, 13.14-21.76) than adeno (4.21, 3.32-5.34), and evident in both sexes (RRs somewhat higher in males), all continents (RRs highest for North America and lowest for Asia, particularly China), and both study types (RRs higher for prospective studies). Relationships were somewhat stronger in later starting and larger studies. RR estimates were similar in cigarette only and mixed smokers, and similar in smokers of pipes/cigars only, pipes only and cigars only. Exceptionally no increase in adeno risk was seen for pipe/cigar only smokers (0.93, 0.62-1.40). RRs were unrelated to mentholation, and higher for non-filter and handrolled cigarettes. RRs increased with amount smoked, duration, earlier starting age, tar level and fraction smoked and decreased with time quit. Relationships were strongest for small and squamous cell, intermediate for large cell and weakest for adenocarcinoma. Covariate-adjustment little affected RR estimates.

CONCLUSIONS

The association of lung cancer with smoking is strong, evident for all lung cancer types, dose-related and insensitive to covariate-adjustment. This emphasises the causal nature of the relationship. Our results quantify the relationships more precisely than previously.

Mentholated cigarettes and smoking-related cancers revisited: an ecologic examination

The US Food and Drug Administration is assessing whether menthol should be banned as an additive to cigarettes. An important part of this determination concerns the health effects of mentholated relative to non-mentholated cigarettes. We examined the ecologic association between sales of mentholated cigarettes for the period 1950-2007, menthol preference by race and sex, and incidence rates of four tobacco-related cancers during 1973-2007. Total sales of mentholated cigarettes (market share) increased from about 3% in 1950 to slightly less than 30% in 1980 and remained fairly stable thereafter. Additional data show consistently that, compared to White smokers, Black smokers favor mentholated cigarettes by roughly a 3-fold margin. Differences in the incidence of lung cancer, squamous cell cancer of the esophagus, oropharyngeal cancer, and laryngeal cancer by race and sex and trends over a 35-year period, during which menthol sales were relatively stable and during which Black smokers were much more likely to smoke mentholated cigarettes compared to Whites, are not consistent with a large contribution of menthol, over and above the effect of smoking per se.

Lung cancer mortality risk for U.S. menthol cigarette smokers

INTRODUCTION

The U.S. Food and Drug Administration is currently assessing the public health impact of menthol cigarettes. Results from a recent U.S. cohort study, composed largely of Blacks and limited to 12 Southern states, found that menthol cigarette smokers had lower risks of lung cancer incidence and mortality than nonmenthol smokers.

METHODS

We conducted a survival analysis of current smokers from the 1987 National Health Interview Survey Cancer Control Supplement (n = 4,832), followed for mortality through linkage with the National Death Index. We estimated mortality hazard ratios (HRs) for menthol smokers compared with nonmenthol smokers, adjusting for a full set of demographic and smoking characteristics.

RESULTS

The overall HR for lung cancer mortality for menthol smokers was 0.69 (95% CI = 0.45-1.06). The HR for lung cancer mortality for menthol smokers at ages 50 and over was 0.59 (95% CI = 0.37-0.95). All-cause mortality net of lung cancer mortality did not differ for menthol and nonmenthol smokers.

CONCLUSION

We found evidence of lower lung cancer mortality risk among menthol smokers compared with nonmenthol smokers at ages 50 and over in the U.S. population. It is not known, however, if these differences are due to the impact of menthol on cigarette smoking or long-term differences in cigarette design between menthol and nonmenthol cigarettes.

Menthol should not be given a free pass based on studies of biomarkers of toxicity

Exposure and toxicity studies comparing menthol and nonmenthol cigarettes have resulted in mixed results. On the basis of those results, cigarette manufacturers have concluded that there is no increased harm from the addition of menthol to cigarettes. We propose that such a narrow definition of harm is not appropriate in dealing with the issue of menthol, and its broader negative public health impact.

Modeling the future effects of a menthol ban on smoking prevalence and smoking-attributable deaths in the United States

We used a validated smoking simulation model and data from the 2003 Tobacco Use Supplement to the Current Population Survey to project the impact that a US menthol ban would have on smoking prevalence and smoking-attributable deaths. In a scenario in which 30% of menthol smokers quit and 30% of those who would have initiated as menthol smokers do not initiate, by 2050 the relative reduction in smoking prevalence would be 9.7% overall and 24.8% for Blacks; deaths averted would be 633,252 overall and 237,317 for Blacks.

The health effects of menthol cigarettes as compared to non-menthol cigarettes

Since the 1920s, menthol has been added to cigarettes and used as a characterizing flavor. The health effects of cigarette smoking are well documented, however the health effects of menthol cigarettes as compared to non-menthol cigarettes is less well studied. This review discusses menthol’s effects on 1) biomarkers of tobacco smoke exposure, 2) toxicity and cellular effects, 3) lung function and respiration, 4) pulmonary and/or vascular function, 5) allergic reactions and inflammation, and 6) tobacco-related diseases. It is concluded that menthol is a biologically active compound that has effects by itself and in conjunction with nicotine, however much of the data on the other areas of interest are inconclusive and firm conclusions cannot be drawn.

Systematic review of the epidemiological evidence comparing lung cancer risk in smokers of mentholated and unmentholated cigarettes

BACKGROUND

US mentholated cigarette sales have increased considerably over 50 years. Preference for mentholated cigarettes is markedly higher in Black people. While menthol itself is not genotoxic or carcinogenic, its acute respiratory effects might affect inhalation of cigarette smoke. This possibility seems consistent with the higher lung cancer risk in Black men, despite Black people smoking less and starting smoking later than White people. Despite experimental data suggesting similar carcinogenicity of mentholated and non-mentholated cigarettes, the lack of convincing evidence that mentholation increases puffing, inhalation or smoke uptake, and the similarity of lung cancer rates in Black and White females, a review of cigarette mentholation and lung cancer is timely given current regulatory interest in the topic.

METHODS

Epidemiological studies comparing lung cancer risk in mentholated and non-mentholated cigarette smokers were identified from MedLine and other sources. Study details were extracted and strengths and weaknesses assessed. Relative risk estimates were extracted, or derived, for ever mentholated use and for long-term use, overall and by gender, race, and current/ever smoking, and meta-analyses conducted.

RESULTS

Eight generally good quality studies were identified, with valid cases and controls, and appropriate adjustment for age, gender, race and smoking. The studies afforded good power to detect possible effects. However, only one study presented results by histological type, none adjusted for occupation or diet, and some provided no results by length of mentholated cigarette use.The data do not suggest any effect of mentholation on lung cancer risk. Adjusted relative risk estimates for ever use vary from 0.81 to 1.12, giving a combined estimate of 0.93 (95% confidence interval 0.84-1.02, n = 8), with no increase in males (1.01, 0.84-1.22, n = 5), females (0.80, 0.67-0.95, n = 5), White people (0.87, 0.75-1.03, n = 4) or Black people (0.90, 0.73-1.10, n = 4). Estimates for current and ever smokers are similar. The combined estimate for long-term use (0.95, 0.80-1.13, n = 4) again suggests no effect of mentholation.

CONCLUSION

Higher lung cancer rates in Black males cannot be due to their greater preference for mentholated cigarettes. While some study weaknesses exist, the epidemiological evidence is consistent with mentholation having no effect on the lung carcinogenicity of cigarettes.

Menthol cigarettes: moving toward a broader definition of harm

RATIONALE

The current practice of the tobacco industry of primarily focusing on the extent that menthol cigarettes contribute or do not contribute to excess morbidity and mortality in various diseases does not, in and of itself, fully illuminate the harm caused by these products. In fact, this practice actually masks and obscures the public health harm associated with menthol cigarettes. Given this, this commentary develops and presents a broader definition of harm in which to view menthol cigarettes and as the necessary and underlying rationale of why this candy-flavored ingredient should be removed from all tobacco products.

METHODS

This paper relies on the scientific presentations of the 2nd Conference on Menthol Cigarettes, and the peer-reviewed literature on menthol cigarettes.

OUTCOMES

A broader definition of harm from menthol cigarettes must be analyzed from a broad public health perspective and take into account youth uptake and initiation, menthol's ability to augment addiction through unique sensory properties, spurious health messages associated with these products, menthol's role in cessation inhibition and relapse promotion, and the blatant predatory marketing of these products to the most vulnerable sectors of society.

CONCLUSIONS

The Food and Drug Administration (FDA) should apply the same logic that outlawed other candy flavorings and apply it to menthol cigarettes; in the end, all candy flavorings, including menthol, only serve to make the poisons inherent in tobacco smoke go down easier. Additionally, the mobilization of communities most affected by the menthol cigarettes, the FDA, and candy flavorings and the tobacco industry's machinations will be discussed.

Lung cancer risk among smokers of menthol cigarettes

BACKGROUND

Menthol cigarettes, preferred by African American smokers, have been conjectured to be harder to quit and to contribute to the excess lung cancer burden among black men in the Unites States. However, data showing an association between smoking menthol cigarettes and increased lung cancer risk compared with smoking nonmenthol cigarettes are limited. The Food and Drug Administration is currently considering whether to ban the sale of menthol cigarettes in the United States.

METHODS

We conducted a prospective study among 85,806 racially diverse adults enrolled in the Southern Community Cohort Study during March 2002 to September 2009 according to cigarette smoking status, with smokers classified by preference for menthol vs nonmenthol cigarettes. Among 12,373 smokers who responded to a follow-up questionnaire, we compared rates of quitting between menthol and nonmenthol smokers. In a nested case-control analysis of 440 incident lung cancer case patients and 2213 matched control subjects, using logistic regression modeling we computed odds ratios (ORs) and accompanying 95% confidence intervals (CIs) of lung cancer incidence, and applied Cox proportional hazards modeling to estimate hazard ratios (HRs) of lung cancer mortality, according to menthol preference.

RESULTS

Among both blacks and whites, menthol smokers reported smoking fewer cigarettes per day; an average of 1.6 (95% CI = 1.3 to 2.0) fewer for blacks and 1.8 (95% CI = 1.3 to 2.3) fewer for whites, compared with nonmenthol smokers. During an average of 4.3 years of follow-up, 21% of participants smoking at baseline had quit, with menthol and nonmenthol smokers having equal odds of quitting (OR = 1.02, 95% CI = 0.89 to 1.16). A lower lung cancer incidence was noted in menthol vs nonmenthol smokers (for smokers of <10, 10-19, and ≥ 20 cigarettes per day, compared with never smokers, OR = 5.0 vs 10.3, 8.7 vs 12.9, and 12.2 vs 21.1, respectively). These trends were mirrored for lung cancer mortality. In multivariable analyses adjusted for pack-years of smoking, menthol cigarettes were associated with a lower lung cancer incidence (OR = 0.65, 95% CI = 0.47 to 0.90) and mortality (hazard ratio of mortality = 0.69, 95% CI = 0.49 to 0.95) than nonmenthol cigarettes.

CONCLUSIONS

The findings suggest that menthol cigarettes are no more, and perhaps less, harmful than nonmenthol cigarettes.

Menthol cigarettes and smoking cessation among racial/ethnic groups in the United States

AIM

To examine the association between smoking mentholated cigarettes and smoking cessation, separately for different racial/ethnic groups.

DESIGN

Secondary data analysis of the 2003 and 2006-07 Tobacco Use Supplements to the Current Population Survey.

SETTING

United States.

PARTICIPANTS

African American, Asian American/Pacific Islander, Hispanic/Latino, Native American, non-Hispanic white adults.

MEASUREMENTS

Examined relations between the use of mentholated cigarettes and measures of smoking cessation.

FINDINGS

Among African Americans (ORadj = 1.62, 95% CI: 1.35-1.95) and Hispanics/Latinos (ORadj = 1.21, 95% CI: 1.00-1.47), those who currently smoked mentholated cigarettes were more likely be seriously considering quitting in the next six months than were non-menthol smokers, after adjusting for sociodemographic factors. African Americans (ORadj = 1.87, 95% CI: 1.60-2.19) and Hispanics/Latinos (ORadj = 1.34, 95% CI: 1.11-1.62) who smoked mentholated cigarettes were also significantly more likely to have a positive estimation of successfully quitting in the next six months compared to non-menthol smokers. These associations were not found among Asian Americans/Pacific Islanders, Native Americans/Alaska Natives and Non-Hispanic Whites. Among former smokers, across racial/ethnic groups, those who smoked mentholated cigarettes (vs. non-menthols) were significantly less likely to have successfully quit for at least six months: African Americans (ORadj = 0.23, 95% CI: 0.17-0.31), Asian Americans/Pacific Islanders (ORadj = 0.22, 95% CI: 0.11-0.45), Hispanics/Latinos (ORadj = 0.48, 95% CI: 0.34-0.69) and Non-Hispanic Whites (ORadj = 0.28, 95% CI: 0.25-0.33).

CONCLUSION

Across race/ethnic groups, those who used to regularly smoke mentholated cigarettes were less likely to have experienced long-term quitting success. Cessation programs should consider the type of cigarette typically smoked by participants, particularly menthols.

The intersection of gender and race/ethnicity in smoking behaviors among menthol and non-menthol smokers in the United States

AIMS

To determine whether menthol is related to initiation, quantity or quitting, we examined differences in smoking behaviors among menthol and non-menthol smokers, stratified by gender and race/ethnicity, and adjusting for age, income and educational attainment.

DESIGN

Cross-sectional, using data from the 2005 National Health Interview Survey and Cancer Control Supplement.

SETTING

United States.

PARTICIPANTS

Black, Hispanic and white women and men aged 25-64 years.

MEASUREMENTS

For each group, we examined (i) proportion of menthol smokers (comparing current and former smokers); (ii) age of initiation, cigarettes smoked per day and quit attempt in the past year (comparing menthol and non-menthol current smokers); and (iii) time since quitting (comparing menthol and non-menthol former smokers). We calculated predicted values for each demographic group, adjusting for age, income and educational attainment.

FINDINGS

After adjusting for age, income and education, black (compared with Hispanic and white) and female (compared with male) smokers were more likely to choose menthol cigarettes. There was only one statistically significant difference in age of initiation, cigarettes smoked per day, quit attempts or time since quitting between menthol and non-menthol smokers: white women who smoked menthol cigarettes reported longer cessation compared with those who smoked non-menthol cigarettes.

CONCLUSIONS

The results do not support the hypothesis that menthol smokers initiate earlier, smoke more or have a harder time quitting compared with non-menthol smokers. A menthol additive and the marketing of it, given the clear demographic preferences demonstrated here, however, may be responsible for enticing the groups least likely to smoke into this addictive behavior.

Health profile differences for menthol and non-menthol smokers: findings from the National Health Interview Survey

AIMS

Although the adverse effects of smoking are well known, limited information exists about the overall health profiles of menthol smokers when compared to their non-menthol smoking counterparts. Using a well-known nationally representative survey, this study examines differences between self-reported health characteristics for menthol and non-menthol smokers.

DESIGN

Cross-sectional data from the 2005 National Health Interview Survey and its cancer control supplement were used to analyze responses for current and former smokers (n = 12,004) independently. All analyses were conducted using SAS version 9.2 and SAS callable SUDAAN version 9.0.3. Multiple logistic regression analysis was used to model menthol smoking.

FINDINGS

After controlling for sex, age and race, we found that in current smokers the mean number of cigarettes smoked per day is significantly lower for menthol smokers when compared to non-menthol smokers [odds ratio (OR): 0.99; 95% confidence interval (CI): 0.98, 1.00]. Also, we found that former menthol smokers had higher body mass indices (BMIs) (OR: 1.01; 95% CI: 1.00, 1.02) and were more likely to have visited the emergency room due to asthma (OR: 2.30, 95% CI: 1.04, 5.09).

CONCLUSIONS

Overall, current menthol and non-menthol smokers have similar health profiles. However, menthol smokers reported smoking fewer cigarettes per day than their non-menthol counterparts. While these findings are supportive of other published data, future studies may need to tease out the health-related significance of smoking fewer menthol cigarettes per day but having similar health outcomes to those who smoke more non-menthol cigarettes per day. Additionally, our findings suggest that there may be some differences between the former menthol and non-menthol smoker.

Nicotine dependence and quitting behaviors among menthol and non-menthol smokers with similar consumptive patterns

AIMS

This study examines the associations between usual cigarette brand (i.e. menthol, non-menthol) and markers for nicotine dependence and quitting behaviors.

DESIGN

The 2003 and 2006/07 Tobacco Use Supplements to the Current Population Surveys were pooled to conduct secondary data analysis.

SETTING

National data were collected using in-person and telephone computer-assisted interviews by the United States Census Bureau among civilian, non-institutionalized people aged 15 years and older.

PARTICIPANTS

Data were analyzed among daily current smokers aged 18+ (n = 46,273).

MEASUREMENTS

The associations between usual cigarette brand and time to first cigarette within 5 and 30 minutes after waking, quit attempts in the past 12 months and length of smoking abstinence in the past 12 months were examined. Bivariate and multivariate logistic regression models were stratified by smoking intensity: ≤5, 6-10, 11-19 and 20+ cigarettes per day.

FINDINGS

Menthol smokers reported a mean of 13.05 compared with 15.01 cigarettes per day among non-menthol smokers (P < 0.001). Multivariate results showed that among smokers consuming 6-10 cigarettes per day, menthol smokers were significantly more likely than non-menthol smokers to consume their first cigarette within 5 minutes after waking (odds ratio = 1.22, 95% confidence interval = 1.05,1.43). The multivariate models did not show significant associations between usual cigarette brand and quit attempts in past 12 months or duration of smoking abstinence >2 weeks in the past 12 months.

CONCLUSIONS

Findings from this national survey of daily smokers demonstrate that menthol smokers in the United States who report consuming 6-10 cigarettes per day show greater signs of nicotine dependence than comparable non-menthol smokers.

National patterns and correlates of mentholated cigarette use in the United States

AIM

To examine the patterns and correlates of mentholated cigarette smoking among adult smokers in the United States.

DESIGN

Cross-sectional data on adult current smokers (n = 63,193) were pooled from the 2003 and 2006/07 Tobacco Use Supplements to the Current Population Survey.

MEASUREMENTS

The associations between socio-demographic and smoking variables were examined with gender- and race/ethnicity-stratified multivariate logistic regression models predicting current use of mentholated cigarettes.

FINDINGS

Multivariate logistic regression analyses demonstrated that black smokers were 10-11 times more likely to smoke mentholated cigarettes than white smokers men: odds ratio (OR): 11.59, 99% confidence interval (CI): 9.79-13.72; women: OR: 10.12, 99% CI: 8.45-12.11). With the exception of American Indian/Aleut/Eskimo smokers, non-white smokers were significantly more likely to smoke mentholated cigarettes than were white smokers. Additional significant factors associated with mentholated cigarette smoking included being unmarried (never married: OR: 1.21, 99% CI: 1.09-1.34; divorced/separated: OR: 1.13, 99% CI: 1.03-1.23), being born in a US territory (OR: 2.01, 99% CI: 1.35-3.01), living in a non-metropolitan area (OR: 0.87, 99% CI: 0.80-0.96), being unemployed (OR: 1.24, 99% CI: 1.06-1.44) and lower levels of education. Race/ethnicity-stratified analyses showed that women were more likely than men to smoke mentholated cigarettes. Among black smokers, young adults (aged 18-24 years) were four times more likely to smoke mentholated cigarettes compared with individuals aged 65+.

CONCLUSIONS

Race/ethnicity, gender and age are significant correlates of mentholated cigarette smoking among current smokers. Given the importance of menthol in the cigarette market and the potential untoward health effects of this additive, continued surveillance of the prevalence and correlates of mentholated cigarette use among diverse socio-demographic groups is warranted to inform appropriate interventions.

The effect of menthol containing cigarettes on adult smokers' exposure to nicotine and carbon monoxide

There is limited information comparing biomarkers of exposure (BOE) to cigarette smoke in menthol (MS) and non-menthol cigarette smokers (NMS).

OBJECTIVE

To compare BOE to nicotine and carbon monoxide in MS and NMS.

METHODS

Cross-sectional, observational, ambulatory, multi-centre study in 3341 adult cigarette smokers. Nicotine equivalents (NE) in 24h urine, NE/cigarette, COHb and serum cotinine were measured. Statistical analyses included analysis of variance and Wilcoxon test.

RESULTS

Analyses of variance revealed no statistically significant effects of mentholated cigarettes on NE/24h, COHb, serum cotinine and NE/cigarette. On average MS smoked 15.0 and NMS 16.8 cigarettes/day. The unadjusted mean differences were as follows: MS had lower NE/24h (5.4%) and COHb (3.2%), higher serum cotinine (3.0%) and NE/cigarette (5.7%) than NMS. African-Americans MS smoked 40% fewer cigarettes, showed lower NE/24h (24%) and COHb (10%) and higher NE/cig (29%) and serum cotinine (8%) levels than their White counterparts.

CONCLUSIONS

Smoking mentholated cigarettes does not increase daily exposure to smoke constituents as measured by NE and COHb. These findings are consistent with the majority of epidemiological studies indicating no difference in smoking related risks between MS and NMS.

A review and assessment of menthol employed as a cigarette flavoring ingredient

Cigarette smoking is established as a substantial contributor to risks for cancer, cardiovascular and respiratory diseases. Less is known about the potential of cigarette composition to affect smoking risks. The use of cigarette flavoring ingredients such as menthol is currently of worldwide public health and regulatory interest. The unique conditions of menthol inhalation exposure that occur coincident with that of the complex cigarette smoke aerosol require specialized studies to support an assessment of its safety in cigarette flavoring applications. The present state of knowledge is sufficient to support an assessment of the safety of the use of menthol in cigarettes. Scientific, smoking behavioral and epidemiological data available through mid-2009 is critically reviewed and a broad convergence of findings supports a judgment that menthol employed as a cigarette tobacco flavoring ingredient does not meaningfully affect the inherent toxicity of cigarette smoke or the human risks that attend smoking. There remains a need for well-designed studies of the potential of menthol to affect smoking initiation, cessation and addiction in order to differentiate any independent effects of menthol in cigarettes from those imposed by socioeconomic, environmental and peer influences on these complex human behaviors.

Development and validation of a lung cancer risk prediction model for African-Americans

Because existing risk prediction models for lung cancer were developed in white populations, they may not be appropriate for predicting risk among African-Americans. Therefore, a need exists to construct and validate a risk prediction model for lung cancer that is specific to African-Americans. We analyzed data from 491 African-Americans with lung cancer and 497 matched African-American controls to identify specific risks and incorporate them into a multivariable risk model for lung cancer and estimate the 5-year absolute risk of lung cancer. We performed internal and external validations of the risk model using data on additional cases and controls from the same ongoing multiracial/ethnic lung cancer case-control study from which the model-building data were obtained as well as data from two different lung cancer studies in metropolitan Detroit, respectively. We also compared our African-American model with our previously developed risk prediction model for whites. The final risk model included smoking-related variables [smoking status, pack-years smoked, age at smoking cessation (former smokers), and number of years since smoking cessation (former smokers)], self-reported physician diagnoses of chronic obstructive pulmonary disease or hay fever, and exposures to asbestos or wood dusts. Our risk prediction model for African-Americans exhibited good discrimination [75% (95% confidence interval, 0.67-0.82)] for our internal data and moderate discrimination [63% (95% confidence interval, 0.57-0.69)] for the external data group, which is an improvement over the Spitz model for white subjects. Existing lung cancer prediction models may not be appropriate for predicting risk for African-Americans because (a) they were developed using white populations, (b) level of risk is different for risk factors that African-American share with whites, and (c) unique group-specific risk factors exist for African-Americans. This study developed and validated a risk prediction model for lung cancer that is specific to African-Americans and thus more precise in predicting their risks. These findings highlight the importance of conducting further ethnic-specific analyses of disease risk.

Effects of menthol on tobacco smoke exposure, nicotine dependence, and NNAL glucuronidation

Menthol is a controversial cigarette additive because its physiologic or pharmacologic effects may possibly increase the risk for cancer and its targeted market is the Black community. In a community-based cross-sectional study on 525 Black and White volunteers, we compared levels of urinary and plasma cotinine, plasma thiocyanate, urinary 4-(N-nitrosomethylamino)-1-(3-pyridyl)-1-butanol (NNAL), and its detoxified form (NNAL-Gluc) between menthol and nonmenthol smokers. In regression models that adjusted for daily cigarette intake, no significant differences were observed in the concentration of these biomarkers by menthol status in both races. There was no significant association between high Fagerstrom nicotine dependence scores and the use of menthol cigarettes (odds ratio, 1.1; 95% confidence interval, 0.6-2.0), but an increased risk was observed with smoking a cigarette soon (<or=30 minutes) after waking (odds ratio, 2.1; 95% confidence interval, 1.0-3.8). The ratio of NNAL-Gluc to NNAL, a possible indicator of lung cancer risk, was significantly lower in menthol versus nonmenthol smokers. The NNAL-Gluc/NNAL ratio was 34% lower in Whites (P < 0.01) and 22% lower in Blacks. In subsequent human liver microsome studies, menthol inhibited the rate of NNAL-O-glucuronidation and NNAL-N-glucuronidation. Collectively, these results show that menthol does not affect biological exposure to tobacco smoke constituents but indicates that menthol might inhibit the detoxification of the potent lung carcinogen NNAL.

Smokers of menthol and nonmenthol cigarettes exhibit similar levels of biomarkers of smoke exposure

There has been speculation that the addition of menthol to cigarettes may affect the manner in which cigarettes are smoked, potentially influencing smokers' exposures to smoke constituents that have been associated with smoking-related diseases. One hundred twelve male and female smokers participated in a parallel-arm study to determine whether the ad libitum smoking of menthol cigarettes results in differences in smoke constituent exposure biomarkers in blood and urine relative to those smoking nonmenthol cigarettes having similar machine-measured (Federal Trade Commission) yields of approximately 9 to 10 mg "tar." The study subjects were provided cigarettes of their preferred menthol or nonmenthol types prior to two 24-hour study intervals spaced one week apart. Carboxyhemoglobin levels were measured in blood samples drawn at midafternoon following the two 24-hour urine collection periods. Six urinary nicotine metabolites (nicotine, cotinine, trans-3'-hydroxycotinine and respective glucuronides) were determined as measures of nicotine intake, and urinary 4-(N-nitrosomethylamino)-1-(3-pyridyl)-1-butanol (NNAL) and its glucuronide were determined to assess exposure to the tobacco-specific nitrosamine 4-(N-nitrosomethylamino)-1-(3-pyridinyl)-1-butanone. Subjects' median blood carboxyhemoglobin values did not differ significantly between the cigarette types. Neither total urinary NNAL nor urinary nicotine equivalents exhibited statistically significant differences between the menthol and nonmenthol cigarette smokers. The present findings indicate that moderately heavy smokers of menthol and nonmenthol cigarettes of similar machine-generated smoke yield exhibit essentially identical levels of biomarkers of smoke constituent exposure. These results are consistent with the substantial majority of epidemiology studies to date that suggest the risks attending the smoking of menthol and nonmenthol cigarettes are similar.

Dietary isothiocyanates, glutathione S-transferase M1 (GSTM1), and lung cancer risk in African Americans and Caucasians from Los Angeles County, California

Isothiocyanates, found in cruciferous vegetables, are anticarcinogenic. Racial differences in smoking do not fully account for the African-American excess lung cancer incidence. African Americans consume more cruciferous vegetables than U.S. Whites. Impact on lung cancer risk is unknown. The glutathione S transferase M1 (GSTM1) gene promotes urinary isothiocyanate excretion. We evaluated dietary isothiocyanates and lung cancer using a population-based case-control study of 933 African Americans and Caucasians (non-Hispanic U.S. White) from Los Angeles County, California (311 cases; 622 controls). Broccoli, cauliflower, greens, and cabbage food-frequency variables represented isothiocyanates. Isothiocyanates were protective for lung cancer risk. Adjusted odds ratio (OR) for the uppermost quartile > 80 micro mol isothiocyanates/wk, compared to lowest, was 0.65 [95% confidence interval (CI) = 0.41-1.00, trend P = 0.02]. Association was stronger among subjects with homozygous deletion of GSTM1 (OR = 0.52, 95% CI = 0.31-0.86) than subjects with at least one GSTM1 copy (OR = 0.77, 95% CI = 0.49-1.21). The difference was not statistically significant (P = 0.16). Despite African Americans consuming more cruciferous vegetables, the isothiocyanate association did not vary by race (P = 0.52). Reduced lung cancer risk with higher isothiocyanate intake may be slightly stronger among subjects with deletion of GSTM1.

Relationship between menthol cigarettes and smoking cessation among African American light smokers

AIMS

To determine whether African American light smokers who smoked menthol cigarettes had lower cessation when treated with nicotine replacement therapy and counseling.

DESIGN

Data were derived from a clinical trial that assessed the efficacy of 2 mg nicotine gum (versus placebo) and counseling (motivational interviewing counseling versus Health Education) for smoking cessation among African American light smokers (smoked < or = 10 cigarettes per day).

PARTICIPANTS

The sample consisted of 755 African American light smokers.

MEASUREMENTS

The primary outcome variable was verified 7-day point-prevalence smoking cessation at 26 weeks follow-up. Verification was by salivary cotinine.

FINDINGS

Compared to non-menthol smokers, menthol smokers were younger and less confident to quit smoking (P = 0.023). At 26 weeks post-randomization, 7-day verified abstinence rate was significantly lower for menthol smokers (11.2% versus 18.8% for non-menthol, P = 0.015).

CONCLUSIONS

Among African American light smokers, use of menthol cigarettes is associated with lower smoking cessation rates. Because the majority of African American smokers use menthol cigarettes, a better understanding of the mechanism for this lower quit rate is needed.

Epidemiology of lung cancer: ACCP evidence-based clinical practice guidelines (2nd edition)

BACKGROUND

The objective of this study was to summarize the published literature concerning the epidemiology of lung cancer.

METHODS

A narrative review of published evidence was conducted, identifying and summarizing key reports that describe the occurrence of lung cancer in populations and factors that affect lung cancer risk.

RESULTS

In the United States, lung cancer remains the leading cause of cancer death in both men and women, even though an extensive list of modifiable risk factors has long been identified. The predominant cause of lung cancer is exposure to tobacco smoke, with active smoking causing most cases but passive smoking also contributing to the lung cancer burden.

CONCLUSIONS

The reductions in smoking prevalence in men that occurred in the late 1960s through the 1980s will continue to drive lung cancer mortality rates downward in men during the first portion of this century, but rates in women have not yet begun to decrease. Fortunately, exposures to major occupational respiratory carcinogens have largely been controlled, but the population is still exposed to environmental causes of lung cancer, including radon, the second leading cause of lung cancer death.

Identifying health disparities across the tobacco continuum

AIMS

Few frameworks have addressed work-force diversity, inequities and inequalities as part of a comprehensive approach to eliminating tobacco-related health disparities. This paper summarizes the literature and describes the known disparities that exist along the tobacco disease continuum for minority racial and ethnic groups, those living in poverty, those with low education and blue-collar and service workers. The paper also discusses how work-force diversity, inequities in research practice and knowledge allocation and inequalities in access to and quality of health care are fundamental to addressing disparities in health.

METHODS

We examined the available scientific literature and existing public health reports to identify disparities across the tobacco disease continuum by minority racial/ethnic group, poverty status, education level and occupation.

FINDINGS

Results indicate that differences in risk indicators along the tobacco disease continuum do not explain fully tobacco-related cancer consequences among some minority racial/ethnic groups, particularly among the aggregate groups, blacks/African Americans and American Indians/Alaska Natives. The lack of within-race/ethnic group data and its interactions with socio-economic factors across the life-span contribute to the inconsistency we observe in the disease causal paradigm.

CONCLUSIONS

More comprehensive models are needed to understand the relationships among disparities, social context, diversity, inequalities and inequities. A systematic approach will also help researchers, practitioners, advocates and policy makers determine critical points for interventions, the types of studies and programs needed and integrative approaches needed to eliminate tobacco-related disparities.

Possible effects on smokers of cigarette mentholation: a review of the evidence relating to key research questions

Menthol (2-isopropyl-5-methyl-cyclohexan-1-ol) is used in food, pharmaceutical, and tobacco products. Despite its long usage history and GRAS status, scientific literature on effects of cigarette mentholation is limited. Because African-American men have high lung cancer rates and predominantly smoke mentholated cigarettes, and because menthol's cooling effect might affect puffing and smoke inhalation, possible adverse effects of cigarette mentholation have been suggested. We review the evidence on the effects of mentholation on smokers, and we also identify areas for further study. Five large epidemiological studies provide no evidence that cigarette mentholation increases lung cancer risk. Mentholation cannot explain the higher risk for lung cancer in African-American male smokers, who also predominantly smoke mentholated cigarettes. Limited data on other cancers also suggest no risk from mentholation. The scientific literature suggests that cigarette mentholation does not increase puff number or puff volume of smoked cigarettes, and has little or no effect on heart rate, blood pressure, uptake of carbon monoxide, tar intake or retention, or blood cotinine concentration. Mentholation has little effect on other smoke constituents, and no apparent effect on nicotine absorption, airway patency and smoking initiation, dependency or cessation. Any toxicological effects of cigarette mentholation on adult smokers are probably quite limited.

Lung cancer disparities in African Americans: health versus health care

African Americans with lung cancer have disproportionately worse outcomes than other ethnic groups. The incidence of lung cancer in blacks has remained well above the rates seen for the general population and the 5-year and overall survival rates for blacks with lung cancer are among the lowest of all racial groups. Many studies have focused on socioeconomic status of African Americans as the sole cause of these disparities. Other stu-dies, however, have identified additional factors related to risks for poor outcomes in blacks with lung cancer. This article reviews data on these risks and their relationships to the health and health care of African Americans with lung cancer.

Ethnic and racial differences in the smoking-related risk of lung cancer

BACKGROUND

There is remarkable variation in the incidence of lung cancer among ethnic and racial groups in the United States.

METHODS

We investigated differences in the risk of lung cancer associated with cigarette smoking among 183,813 African-American, Japanese-American, Latino, Native Hawaiian, and white men and women in the Multiethnic Cohort Study. Our analysis included 1979 cases of incident lung cancer identified prospectively over an eight-year period, between baseline (1993 through 1996) and 2001.

RESULTS

The risk of lung cancer among ethnic and racial groups was modified by the number of cigarettes smoked per day. Among participants who smoked no more than 30 cigarettes per day, African Americans and Native Hawaiians had significantly greater risks of lung cancer than did the other groups. Among those who smoked no more than 10 and those who smoked 11 to 20 cigarettes per day, relative risks ranged from 0.21 to 0.39 (P<0.001) among Japanese Americans and Latinos and from 0.45 to 0.57 (P<0.001) among whites, as compared with African Americans. However, at levels exceeding 30 cigarettes per day, these differences were not significant. Differences in risk associated with smoking were observed among both men and women and for all histologic types of lung cancer.

CONCLUSIONS

Among cigarette smokers, African Americans and Native Hawaiians are more susceptible to lung cancer than whites, Japanese Americans, and Latinos.