First toll free helpline for smoking cessation--analysis of results after one year of operation

The aim of the study was to prove that there is a strong need among the smoking population for the antismoking telephone helpline, and to describe the structure and dynamics of calls to the Call-center. Basic data on socio-demographic characteristics, smoking habits, and reasons for calling the Center were collected during telephone conversations with smokers. The data were entered into previously prepared tables. Statistical analysis included 7,452 telephone calls; most calls were received from persons aged 26-45 years (34%), followed by 19-24 (24%) and 45-60 (19%) age groups. There was no statistically significant difference in the number of calls between men and women (54% vs. 46%, respectively). Most callers consumed on average 20 cigarettes per day. The most frequent reason for calling was to get on how to stop smoking, whereas seeking information on professional literature was the least frequent reason for calling among our respondents. Four-fifths of persons making a call to the Center started smoking when they were between 16 and 20 years of age. We can conclude that there was a need for this type of intervention due to its accessibility and potentially wide coverage of interested users.     

Controlled trial of three different antismoking interventions in general practice.

Of 6052 adult patients who consulted their doctors in six Oxfordshire general practices between October 1980 and February 1981, 2110 (35%) were smokers. The smokers were allocated to one of four study groups--a control (non-intervention) group; a group that received verbal and written antismoking advice from the general practitioner; a group that received this advice and also a demonstration of exhaled carbon monoxide; and a group that received the advice plus the offer of further help from a health visitor. After one year 72% of smokers replied to a postal follow up questionnaire: 11% of the control group claimed to have stopped smoking compared with 15% in the group that received advice alone, 17% in the exhaled carbon monoxide group, and 13% in the health visitor group. Validation of these findings by assays of urinary concentrations of cotinine showed that between 24% and 40% of subjects may have misreported their smoking habits, but there was no indication that the rate of misreporting was higher in the intervention groups than in the control group. Giving advice routinely against smoking has a useful effect, and showing an immediate, personal, and potentially harmful consequence of smoking using a CO-oximeter may improve this, particularly in lower socioeconomic groups.     

Life expectancy in men who have never smoked and those who have smoked continuously: 15 year follow up of large cohort of middle aged British men.

OBJECTIVE: To estimate the life expectancy in a representative sample of men who have never smoked and of those who have smoked all their adult lives. DESIGN: 15 year follow up of a large representative cohort of British men in the British regional heart study and use of national mortality statistics for 1992. SUBJECTS: 7735 middle aged British men aged 40-59 at the time of screening (between 1978 and 1980). MAIN OUTCOME MEASURES: Mortality from all causes and from smoking related causes. RESULTS: 1624 men had never smoked at the time of screening and did not take up smoking during the study. 127 of them died during follow up. 3151 men began smoking before they were 30 and were still smoking at the time of screening. Of these, 751 had stopped smoking five years after screening; they were excluded from the analysis five years after the date they had stopped. 560 of the lifelong smokers died during follow up. When study estimates were combined with those from national mortality statistics for men aged 20-40, only an estimated 42% (95% confidence interval 36% to 50%) of lifelong smokers alive at the age of 20 would be alive at 73, compared with 78% (74% to 82%) of lifelong non-smokers. CONCLUSION: These estimates present the effects of smoking on mortality in a way that is easily communicated to patients and the general public in health promotion initiatives.     

Cigarette smoking and smoking cessation in relation to risk of rheumatoid arthritis in women

Introduction

Whereas the overall association between smoking and rheumatoid arthritis (RA) must be regarded as established, considerably less is known about how much smoking is needed to increase the risk of RA, that is, the effect of smoking intensity, duration and cessation.

Methods

The Swedish Mammography Cohort, including 34,101 women aged 54 to 89 years, was followed up from January 1, 2003 through December 31, 2010 (219 RA cases identified). Relative risks (RR) and their 95% confidence intervals (CI) were estimated as rate ratios using Cox proportional hazards model.

Results

There was a statistically significant association between smoking intensity (RR comparing 1 to 7 cigarettes/day vs never smoking 2.31 (95% CI: 1.59, 3.36)) as well as duration of smoking (comparing 1 to 25 years vs never smoking RR = 1.60 (95% CI: 1.07, 2.38)) and risk of RA. Compared to never smokers, the risk was still significantly elevated 15 years after smoking cessation (RR = 1.99 (95% CI: 1.23, 3.20)). However, among former smokers, the risk of RA seemed to be decreasing over time since stopping smoking: women who stopped smoking 15 years before the start of the follow-up had 30% lower risk of RA compared to those who stopped only a year before start of the follow-up (RR = 0.70 (95% CI: 0.24,2.02)).

Conclusions

This prospective study highlights that even light cigarette smoking is associated with increased risk of RA in women and that smoking cessation may reduce, though not remove, this risk.     

Effects of stopping smoking for 48 hours on oxygen availability from the blood: a study on pregnant women.

The effects of stopping smoking for 48 hours on factors governing the availability of oxygen from the blood--that is, carboxyhaemoglobin (COHb), haemoglobin-oxygen (HbO2) affinity, and haemoglobin concentration--were measured in women in the last trimester of pregnancy. Three groups were studied: smokers, smokers who stopped smoking for 48 hours, and non-smokers. The 22 smokers had higher initial COHb values and greater HbO2 affinity than the 10 non-smokers, but their total haemoglobin concentrations were also higher, so that their oxygen availability was not significantly reduced. In the 11 smokers who stopped the reduction in COHb and decrease in HbO2 affinity led to a significant increase of 8% in "available oxygen" in 48 hours. Since even small improvements in oxygen delivery to the tissues may confer critical benefit to the fetus, particularly during labour or when exposed to general anaesthesia, smoking should be discouraged for 48 hours before elective deliveries. The same consideration might reasonably be applied to patients undergoing general anaesthesia for all elective operations.     

Prevalence of hardcore smoking in England,and associated attitudes and beliefs: cross sectional study

Objective To quantify the prevalence and characteristics of hardcore smokers in England.Design Cross sectional survey.Setting Interview in respondents'' household.Participants 7766 adult cigarette smokers.Main outcome measures Hardcore smoking defined by four criteria (less than a day without cigarettes in the past five years; no attempt to quit in the past year; no desire to quit; no intention to quit), all of which had to be satisfied.Results Some 16% of all smokers were categorised as hardcore. Hardcore smoking was associated with nicotine dependence, socioeconomic deprivation, and age, rising from 5% in young adults aged 16-24 to 30% in those aged ≥ 65 years. Hardcore smokers displayed distinctive attitudes towards and beliefs about smoking. In particular they were likely to deny that smoking affected their health or would do so in the future. Prevalence of hardcore smoking was almost four times higher than in California.Conclusion Hardcore smoking presents a serious challenge to public health efforts to reduce the prevalence of smoking, but the proportion of hardcore smokers does not necessarily increase as overall prevalence in a population declines. More hardcore smokers could be persuaded to quit, but this will require interventions that are targeted to the particular needs and perceptions of both socially disadvantaged and older smokers.     

Placebo controlled trial of nicotine chewing gum in general practice.

Of 2110 adult cigarette smokers originally recruited to a study of the effect of antismoking advice in general practice, 429 who reported at follow up after one year that they had tried unsuccessfully to stop smoking were offered "a special antismoking chewing gum," either nicotine gum or a placebo gum, in a double blind study. Of 200 who were willing to try the gum, 101 were randomly allocated to the nicotine gum and 99 to the placebo gum. They were followed up at six months by an unannounced home visit, at which they were interviewed and asked to provide a breath sample for analysis of carbon monoxide. Twenty five claimed that they had stopped smoking, but, of them, seven exhaled levels of carbon monoxide indicative of continued smoking. Of the 18 in whom giving up smoking was validated, 10 had received active gum and eight placebo gum, a difference which was not significant (odds in favour of nicotine gum = 1.25, 95% confidence limits 0.47-3.31). The value of nicotine chewing gum, if any, can be quite small when it is used in general practice.     

The Influence of Antismoking Television Advertisements on Cessation by Race/Ethnicity,Socioeconomic Status,and Mental Health Status

Disparities in tobacco use and smoking cessation by race/ethnicity, education, income, and mental health status remain despite recent successes in reducing tobacco use. It is unclear to what extent media campaigns promote cessation within these population groups. This study aims to (1) assess whether exposure to antitobacco advertising is associated with making a quit attempt within a number of population subgroups, and (2) determine whether advertisement type differentialy affects cessation behavior across subgroups. We used data from the New York Adult Tobacco Survey (NY-ATS), a cross-sectional, random-digit-dial telephone survey of adults aged 18 or older in New York State conducted quarterly from 2003 through 2011 (N = 53,706). The sample for this study consists of 9,408 current smokers from the total NY-ATS sample. Regression methods were used to examine the effect of New York State’s antismoking advertising, overall and by advertisement type (graphic and/or emotional), on making a quit attempt in the past 12 months. Exposure to antismoking advertising was measured in two ways: gross rating points (a measure of potential exposure) and self-reported confirmed recall of advertisements. This study yields three important findings. First, antismoking advertising promotes quit attempts among racial/ethnic minority smokers and smokers of lower education and income. Second, advertising effectiveness is attributable in part to advertisements with strong graphic imagery or negative emotion. Third, smokers with poor mental health do not appear to benefit from exposure to antismoking advertising of any type. This study contributes to the evidence about how cessation media campaigns can be used most effectively to increase quit attempts within vulnerable subgroups. In particular, it suggests that a general campaign can promote cessation among a range of sociodemographic groups. More research is needed to understand what message strategies might work for those with poor mental health.     

Cigarette advertising and children's smoking: why Reg was withdrawn.

OBJECTIVE--To examine the appeal of the Embassy Regal "Reg" campaign to young people. DESIGN--Three quantitative surveys and one piece of qualitative research: (a) self completion questionnaire administered in classrooms, (b) questionnaire led interviews with children, (c) questionnaire led interviews with adults, and (d) group discussions with children and adults. SETTINGS--(a) Secondary and middle schools in England; (b) north of England, Scotland, and Wales; (c) north of England, Scotland, and Wales; and (d) Glasgow. SUBJECTS--(a) 5451 schoolchildren aged 11-15 recruited by stratified random sampling; (b) 437 children aged 5-10 recruited by quota sampling; (c) 814 adults aged 15-65 recruited by quota sampling; and (d) 12 groups of children aged 10-15, three groups of adults aged 18-24, and three groups of adults aged 35-55. RESULTS--Children were familiar with cigarette advertising and in particular the Reg campaign. Although younger children struggled to understand the creative content of the adverts, older and smoking children could understand and appreciate the humour. They considered Reg to be amusing and could relate to the type of joke used in the advert. In addition Reg''s flippant attitude towards serious issues appealed to the children. While adults aged 18-24 understood the campaign they did not identify with it, and 35-55 year olds (the campaign''s supposed target) were unappreciative of the campaign. CONCLUSIONS--The Reg campaign was getting through to children more effectively than it was to adults and held most appeal for teenagers, particularly 14-15 year old smokers. It clearly contravened the code governing tobacco advertising, which states that advertising must not appeal to children more than it does to adults, and it may have had a direct impact on teenage smoking. In view of these findings the Advertising Standards Authority''s decision to withdraw the Reg campaign seems appropriate.     

Factors Associated with Tobacco Smoking and Cessation among HIV-Infected Individuals under Care in Rio de Janeiro,Brazil

Worldwide the prevalence of smoking among people living with HIV/AIDS is elevated compared to the general population. This probably reflects the cluster of individual characteristics that have shared risk factors for HIV infection and smoking. A cross-sectional study, enrolling a convenience sample from a Brazilian HIV clinical cohort was conducted to evaluate the prevalence of tobacco smoking and the factors associated with current smoking and abstinence. A total of 2,775 HIV-infected individuals were interviewed: 46.2% have never smoked, 29.9% were current smokers and 23.9% were former smokers. Current smokers had a higher prevalence of alcohol and illicit drug use when compared to the other two groups. A higher proportion of heterosexual individuals were former smokers or never smokers while among men who have sex with men (MSM) a higher proportion were current smokers. Former smokers had been more frequently diagnosed with high blood pressure, diabetes mellitus, cardiovascular diseases and depression, while for current smokers lung diseases were more frequent. Former smokers and current smokers were more likely to have had any hospital admission (42.0% and 41.2%, respectively) than participants who never smoked (33.5%) (p<0.001). Multivariate model results showed that current smokers (versus never smokers) were more likely to be less educated, to report the use of alcohol, crack and cocaine and to present clinical comorbidities. Former smokers (versus current smokers) were more likely to be older, to have smoked for a shorter amount of time and to have smoked >31 cigarettes/day. MSM (compared to heterosexuals) and cocaine users (versus non-users) had lower odds of being former smokers. Considering our results, smoking cessation interventions should be tailored to younger individuals, MSM and substance users.     

Cigarette smoking in male patients with chronic schizophrenia in a Chinese population: prevalence and relationship to clinical phenotypes

The high prevalence of smoking in schizophrenia of European background may be related to smoking's reducing clinical symptoms and medication side effects. Because smoking prevalence and its associations with clinical phenotypes are less well characterized in Chinese than European patients with schizophrenia, we assessed these smoking behaviors using clinician-administered questionnaires and the Fagerstrom Test for Nicotine Dependence (FTND) in 776 Chinese male schizophrenia and 560 control subjects. Patients also were rated on the Positive and Negative Symptom Scale (PANSS), the Simpson and Angus Extrapyramidal Symptom Rating Scale (SAES), and the Abnormal Involuntary Movement Scale (AIMS). We found that the schizophrenia patients had a higher lifetime incidence of smoking (79% vs 63%), were more likely to be heavy smokers (61% vs 31%), and had lower smoking cessation rates (4% vs 9%) (all p<0.0001) than controls. Among the schizophrenia patients smoking prevalence increased with age, with the largest difference from controls in the age cohort of 55-75 years: 75% vs 46% (p<0.0001). Among the schizophrenia smokers 73% started to smoke before the onset of their illness by an average of 7.6 years. The patients with schizophrenia who were current smokers scored significantly lower on the PANSS negative symptom subscore (p<0.005), and on the SAES symptom scale (p<0.04; Bonferroni corrected p>0.05) than the non-smoking patients. These results suggest that Chinese males with schizophrenia smoke more frequently than the general population. Further, smokers with schizophrenia may display fewer negative symptoms and possibly less parkinsonism than non-smokers with schizophrenia.     

Determination of methyl-, 2-hydroxyethyl- and 2-cyanoethylmercapturic acids as biomarkers of exposure to alkylating agents in cigarette smoke

Alkylating agents occur in the environment and are formed endogenously. Tobacco smoke contains a variety of alkylating agents or precursors including, among others, N-nitrosodimethylamine (NDMA), 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK), acrylonitrile and ethylene oxide. We developed and validated a method for the simultaneous determination of methylmercapturic acid (MMA, biomarker for methylating agents such as NDMA and NNK), 2-hydroxyethylmercapturic acid (HEMA, biomarker for ethylene oxide) and 2-cyanoethylmercapturic acid (CEMA, biomarker for acrylonitrile) in human urine using deuterated internal standards of each compound. The method involves liquid/liquid extraction of the urine sample, solid phase extraction on anion exchange cartridges, derivatization with pentafluorobenzyl bromide (PFBBr), liquid/liquid extraction of the reaction mixture and LC–MS/MS analysis with positive electrospray ionization. The method was linear in the ranges of 5.00–600, 1.00–50.0 and 1.50–900 ng/ml for MMA, HEMA and CEMA, respectively. The method was applied to two clinical studies in adult smokers of conventional cigarettes who either continued smoking conventional cigarettes, were switched to test cigarettes consisting of either an electrically heated cigarette smoking system (EHCSS) or having a highly activated carbon granule filter that were shown to have reduced exposure to specific smoke constituents, or stopped smoking. Urinary excretion of MMA was found to be unaffected by switching to the test cigarettes or stop smoking. Urinary HEMA excretion decreased by 46 to 54% after switching to test cigarettes and by approximately 74% when stopping smoking. Urinary CEMA excretion decreased by 74–77% when switching to test cigarettes and by approximately 90% when stopping smoking. This validated method for urinary alkylmercapturic acids is suitable to distinguish differences in exposure not only between smokers and nonsmokers but also between smoking of conventional and the two test cigarettes investigated in this study.     

Prospective study of factors predicting outcome of transdermal nicotine treatment in smoking cessation.

OBJECTIVE--To assess the factors associated with cessation of smoking with transdermal nicotine and brief behavioural counselling. DESIGN--Interviews, treatment, and follow up for 26 weeks. SUBJECTS--1481 subjects recruited by mass media publicity who smoked > or = 15 cigarettes a day and were motivated to stop smoking. INTERVENTIONS--Twelve weeks'' treatment with transdermal nicotine and brief behavioural counselling at monthly visits. MAIN OUTCOME MEASURE--Sustained smoking cessation for the 28 days before the visit at week 26 verified by expired carbon monoxide concentrations. The logistic regression analysis included all subjects. RESULTS--Most subjects were dependent on nicotine, and the mean (SD) number of cigarettes smoked a day was 32 (12). Overall, 316/1481 subjects (21.3%) stopped smoking. Factors associated with stopping were being male (adjusted odds ratio 2.0; 95% confidence interval 1.5 to 2.7), age > or = 40 years (1.5; 1.1 to 2.0), living with a spouse or partner (1.5; 1.1 to 2.1), motivation ("want to quit" 1.7; 1.2 to 2.3), and concern about weight gain (1.7; 1.3 to 2.2). Negative associations were smoking marijuana (0.4; 0.2 to 0.8) and the presence of other smokers in the household (0.8; 0.6 to 0.9). Almost all subjects who smoked three or more cigarettes in the first four weeks of treatment resumed smoking in the long term (525/547, 96%). CONCLUSIONS--Age, sex, marital status (living with a spouse or partner), motivation, concern about weight gain, recent marijuana smoking, and other smokers in the household were baseline factors associated with differences in outcome of smoking cessation attempts. Smoking three or more cigarettes in the first few weeks after stopping strongly predicted long term relapse.     

How effective is nicotine replacement therapy in helping people to stop smoking?

OBJECTIVE--To assess the efficacy of nicotine replacement therapy in helping people to stop smoking. DESIGN--Analysis of the results of 28 randomised trials of nicotine 2 mg chewing gum, six trials of nicotine 4 mg chewing gum, and six trials of nicotine transdermal patch. SUBJECTS AND SETTING--Subjects were self referred (responding to advertisements or attending anti-smoking clinics) in 20 trials and invited (general practice or hospital patients) in 20. Therapists in self referred trials were generally experienced in helping people stop smoking but not in invited trials. MAIN OUTCOME MEASURE--Efficacy was defined as difference in percentages of treated and control subjects who had stopped smoking at one year. RESULTS--Efficacy was highly significant (P < 0.001) for both gum and patch. Nicotine 2 mg chewing gum had an overall efficacy of 6% (95% confidence interval 4% to 8%), greater in self referred subjects than in invited subjects (11% v 3%). Efficacy depended on the extent of dependence on nicotine as assessed by a simple questionnaire; it was 16% (7% to 25%) in "high dependence" smokers, but in "low dependence" smokers there was no significant effect. The 4 mg gum was effective in about one third of "high dependence" smokers. The efficacy of the nicotine patch (9% (6% to 13%) overall) was less strongly related to nicotine dependence, perhaps because the patch cannot deliver a bolus of nicotine to satisfy craving. CONCLUSIONS--Both gum and patch are effective aids to help nicotine dependent smokers who seek help in stopping. Among the most highly nicotine dependent smokers (those craving a cigarette on waking) the 4 mg gum is the most effective form of replacement therapy; it could enable one third to stop. In less highly dependent smokers the different preparations are comparable in their efficacy but the patch offers greater convenience and minimal need for instruction in its use. Overall, nicotine replacement therapy could enable about 15% of smokers who seek help in stopping smoking to give up the habit.     

Risk factors for stroke in middle aged British men.

OBJECTIVE--To determine the risk factors for stroke in a cohort representative of middle aged British men. DESIGN--Prospective study of a cohort of men followed up for eight years. SETTING--General practices in 24 towns in England, Wales, and Scotland (the British regional heart study). SUBJECTS--7735 men aged 40-59 at screening, selected at random from one general practice in each town. MAIN OUTCOME MEASURE--Fatal and non-fatal strokes. RESULTS--110 of the men had at least one stroke; there were four times as many non-fatal as fatal strokes. The relative risk of stroke was 12.1 in men who had high blood pressure (systolic blood pressure greater than or equal to 160 mm Hg) and were current smokers compared with normotensive, non-smoking men. Diastolic blood pressure yielded no additional information, and former cigarette smokers had the same risk as men who had never smoked. Heavy alcohol intake was associated with a relative risk of stroke of 3.8 in men without previously diagnosed cardiovascular disease. Men with pre-existing ischaemic heart disease had an increased risk of stroke, but only when left ventricular hypertrophy on electrocardiography was also present. CONCLUSIONS--Systolic blood pressure, cigarette smoking, and left ventricular hypertrophy on electrocardiography in men with pre-existing ischaemic heart disease were found to be the major risk factors for stroke in middle aged British men. Heavy alcohol intake seemed to increase the risk of stroke in men without previously diagnosed cardiovascular disease. A large proportion of strokes should be preventable by controlling blood pressure and stopping smoking.     

Associations of Maternal Prenatal Smoking with Child Adiposity and Blood Pressure

Objective: To examine the extent to which maternal prenatal smoking is associated with adiposity, central adiposity, and blood pressure in 3‐year‐old children. Research Methods and Procedures: We studied 746 mother‐child pairs in Project Viva, a prospective cohort study, and categorized mothers as never, early pregnancy, or former smokers. Main outcome measures were overweight (BMI for age and sex > 85th percentile), BMI z‐score, sum of subscapular (SS) and triceps (TR) skinfolds, SS:TR skinfold ratio, and systolic blood pressure (SBP). Results: One hundred sixty‐one (22%) mothers quit smoking before pregnancy, 71 (10%) smoked in early pregnancy, and 514 (69%) never smoked. At age 3 years, 204 (27%) children were overweight. On multivariable analysis, compared with children of never smokers, children of early pregnancy smokers had an elevated risk for overweight [odds ratio (OR), 2.2; 95% confidence interval (CI), 1.2, 3.9] and higher BMI z‐score (0.30 units; 95% CI, 0.05, 0.55), SS + TR (2.0 mm; 95% CI, 0.9, 3.0), and SBP (2.4 mm Hg; 95% CI, ?0.1, 4.9). Children of former smokers were not more overweight (BMI z‐score, 0.02 units; 95% CI, ?0.15, 0.19) but had higher SBP (1.5 mm Hg; 95% CI, ?0.1, 3.2). We saw no relationship of smoking with central adiposity (SS:TR). Discussion: Former and early pregnancy smokers had children with somewhat higher SBP, but only early pregnancy smokers had children who were more overweight. Mechanisms linking smoking with child adiposity and blood pressure may differ. A long‐term impact of maternal smoking on offspring cardiovascular risk provides further reason to reduce smoking in women.     

Epidemiology and prevention of smoking in Tunisia: current situation and perspectives

This paper describes the trends in tobacco sales and smoking prevalence in the Tunisian population, estimates the consequences of smoking on mortality of this population, and discusses anti-tobacco actions: educational actions, legislative measures and price increases. Sales Data were collected from the Tunisia tobacco company. Smoking prevalence data from surveys, conducted by several institutes, and numbers of deaths by causes have been estimated from WHO for the year 1998. Tobacco sales increased from 4.96 g per adult per day in 1981, to 6.3 g, in 1993, then decreased widely. The proportion of smokers was 30% in 1996. 55% among men versus 5.6% among women. Among 17 to 24 years old young adults, the proportion of smokers was 29.2% in 1994 (50% among men versus 3.9%, among women). Mortality attributable to tobacco in Tunisia has been estimated to 6430 deaths in 1997 (5580 among men versus 850 among women). These deaths represent 22% of the total male deaths and 4% of the female ones. Anti-tobacco measures have been reinforced by the enactment of anti-tobacco law. Proportion of young smokers remaining elevated, it is expected that consequences of the tobacco addiction in Tunisia, in term of mortality, will be even heavier in the next two decades, if efficient anti-tobacco actions are not implemented.     

Comparison of four methods of smoking withdrawal in patients with smoking related diseases. Report by a subcommittee of the Research Committee of the British Thoracic Society.

Four methods of smoking withdrawal were compared in patients with smoking related diseases attending a hospital or chest clinic. Reinforcing verbal advice with a booklet or with a booklet together with nicotine or placebo chewing gum did not result in greater success than verbal advice alone. Roughly a quarter of those patients who denied smoking had carboxyhaemoglobin and plasma thiocyanate concentrations typical of smokers. At the end of a year 150 out of 1550 patients (9.7%) had successfully stopped smoking.     

Smoking cessation and subsequent risk of cancer: A pooled analysis of eight population-based cohort studies in Japan

BackgroundAlthough East Asia is one of the largest tobacco-epidemic regions in the world, only a few prospective studies from Asia have investigated the impact of smoking and cessation of smoking on cancer. We aimed to assess the effect of cessation of smoking on the risk of cancer using eight population-based cohort studies in Japan.MethodsWe analyzed pooled data from eight population-based prospective cohort studies in Japan with more than 320,000 participants to assess the effect of smoking cessation on the risk of total cancers and smoking-related cancers.ResultsAfter adjustment for potential confounders, cancer risks in men with >21 years of smoking cessation before baseline were found to decrease to the same level as never smokers for total cancer (never smokers: reference; former smokers with ≥21 years since smoking cessation: HR, 1.01; 95%CI: 0.91, 1.11). Even men who are heavy smokers (more than 20 pack-years) reported a reduced risk of total cancer (never smokers: reference; former smokers with ≥21 years since smoking cessation: HR, 1.06; 95%CI: 0.92, 1.23). In women, the risk of total cancer did not differ from that of never smokers after 11 years of smoking cessation before baseline (never smokers: reference; former smokers with ≥11 years since smoking cessation: HR, 0.96; 95%CI: 0.74, 1.23).ConclusionsOur study suggests that longer duration of smoking cessation may attenuate the risk of cancer in both men and women, and that even heavy smokers (more than 20 pack-years) were found to benefit from quitting smoking.