A prospective study of the attributable risk of cancer due to cigarette smoking.

BACKGROUND. The goals of this study were to measure the impact of cigarette smoking on cancer incidence and to determine the attributable risk of cancer due to smoking. METHODS. A cigarette smoking history was obtained from 8006 Japanese-American men examined from 1965 through 1968. After 22 years, 1389 incident cases of cancer were identified. There were 212 men with lung cancer; 202 with oral, esophageal, laryngeal, pancreatic, renal, ureteral, or bladder (oral-bladder) cancer; and 975 with cancer at other sites. RESULTS. Current smokers at time of examination had a higher incidence than nonsmokers for each of the three cancer site categories. Eighty-five percent of lung cancer cases diagnosed among current and never smokers can be attributed to cigarette smoking. The attributable risks were 46%, 16%, and 29%, respectively, for oral-bladder cancers, other cancers, and all cancers combined. In turn, the corresponding attributable risks were 60%, 26%, 13%, and 21% in comparing current smokers with past smokers. CONCLUSIONS. Current smokers can greatly reduce their risk of cancer, especially lung cancer, if they quit smoking.     

Attributed risk to smoking for lung cancer,laryngeal cancer and esophageal cancer

OBJECTIVE: Lung, laryngeal and esophageal cancers have smoking as one of their main risk factors. The objective of this study was to evaluate the population attributed risk (PAR) of smoking for these forms of cancer. METHODS: The study was based in three case-control studies conducted in medium size cities in Brazil. Incident cases of lung cancer, laryngeal cancer and esophageal cancer seen at a hospital setting and diagnosed through biopsy were analyzed; controls were hospitalized patients with another diagnoses. Smoking was the exposure factor measured at three levels: non-smokers, former smokers and smokers, which were defined using a questionnaire applied by trained interviewers. For effect measure, odds ratio was used and the populational attributed risk for smoking was then calculated for a 95% CI. RESULTS: A total of 122 lung cancer cases and 244 controls, 50 cases of laryngeal cancer and 48 cases of esophageal cancer, and 96 controls for both of them were studied. The prevalence of smoking exposure was 34%, which is the overall prevalence of smoking in this city's adult population. Odds ratios (OR) for the PAR analysis were the adjusted OR for confounding variables from each study. Lung cancer PAR was 63% (95% IC, 0.58-0.68) for former smokers and 71% (95%IC, 0.65-0.77) for smokers. Larynx cancer PAR was 74% (95% IC, 0.70-0.78) and 86% (95%IC, 0.81-0.85) for former smokers and smokers, respectively. Esophageal cancer PAR was 54% (95%IC, 0.46-0.62) for smokers. CONCLUSION: Smoking is an avoidable risk factor and smoking cessation could be responsible for significant reductions in the incidence of these three forms of cancer.     

High cumulative risk of lung cancer death among smokers and nonsmokers in Central and Eastern Europe

The authors have calculated cumulative risks of lung cancer from a case-control study conducted between 1998 and 2002 involving 2,633 lung cancer cases and 2,884 controls in Hungary, Poland, the Czech Republic, Slovakia, Romania, and Russia. The odds ratios for smoking history were combined with national lung cancer mortality rates to obtain the cumulative risk of lung cancer. The cumulative risk of death from lung cancer by the age of 75 years among current male smokers was 14.6% in Romania and Russia and 15.8% in Poland, similar to levels reported in Western Europe, although higher risks were found in the Czech Republic (19.8%), Hungary (21.9%), and Slovakia (28.2%). Cumulative risks of lung cancer death among never smokers of over 1% were observed in Hungary among both men and women and among men in Poland. The effect of quitting smoking on the lifetime cumulative risk was substantial, with between 67% and 83% of lung cancer risk among men being avoided by quitting before the age of 50 years. This substantial reduction in risk among former smokers confirms that lung cancer mortality in Central Europe over the next three decades will be determined by the extent to which current smokers can successfully quit smoking.     

Chronic bronchitis: Prevalence, smoking habits, impact, and antismoking advice

Although the prevalence of chronic bronchitis has been measured in several populations, its impact on quality of life has not been assessed. We report the prevalence and impact of chronic bronchitis (defined as having phlegm on most days for at least 3 months during the previous year) among 4,708 adults ages 20 to 69 representative of the nonaged U.S. population. Men reported chronic bronchitis more frequently than women (12 vs 8%); smokers, regardless of age and sex, reported chronic bronchitis more frequently than former or never smokers. Among both men and women 35 years of age or older, current smokers--as opposed to ex- or never smokers--with chronic bronchitis had the poorest forced expiratory volume in 1 sec (FEV1). The most commonly reported impact of chronic bronchitis was worry, followed by pain and restricted activity days, regardless of age, sex, or smoking habits. Of those current and ex-smokers who had seen a physician about their chronic bronchitis, 65% of men and 44% of women had decreased or stopped smoking. Among those current and ex-smokers with chronic bronchitis who did not consult a physician, the proportion of those who had decreased or stopped smoking was 29% for men and 37% for women. Finally, only 43% of male current smokers and 55% of female current smokers who had chronic bronchitis reported that a physician had advised them to decrease or stop smoking.     

Cigarette smoking and breast cancer.

An epidemiological case-control study was conducted in New York State, with 1617 primary breast cancer patients and an equal number of controls, to examine the relationship between cigarette smoking and breast cancer. Results showed no overall association between ever smokers versus never smokers and breast cancer risk (odds ratio [OR] = 1.03, 95% confidence interval [CI]: 0.90-1.19), nor was there any dose response trend observed with increased levels of smoking. In addition, no association was found with risk and age started smoking, age stopped smoking, amount smoked or total years smoked. Controlling for previously identified risk factors for breast cancer in the analysis did not significantly alter these relationships. Previous studies have found a difference in menopausal age among smokers compared to nonsmokers. The mean menopausal age was only slightly lower in smokers than in never smokers for both cases and controls. Breast cancer risk was observed to be close to unity for premenopausal women (OR = 0.97, 95% CI: 0.74-1.34) and postmenopausal women (OR = 1.06, 95% CI: 0.91-1.26). A recent study suggested breast cancer risk was more strongly related to starting smoking at a young age among women who smoked at least 25 or more cigarettes per day in the most recent year of smoking. This hypothesis was not supported by these data.     

Upper aerodigestive tract cancers in former employees at an iron and steel works

Local concern about numbers of laryngeal cancer cases led to an investigation of the incidence of upper aerodigestive tract (UAT) cancer in an industrial cohort. Males (n = 11 470) who had been directly employed at an iron and steel works in northern England at any time between January 1960 and site closure in September 1983 were followed up for UAT cancers until December 1998. The incidence of UAT and laryngeal cancer was compared to the general population of the region via indirect standardization. Fifty-two members of the cohort developed a UAT cancer during 1960-1998. There were no more UAT cancers than expected [standardized incidence ratio = 97, 95% confidence interval (CI) = 72-127], but slightly more laryngeal cancers than expected (standardized incidence ratio = 118, 95% CI = 78-171), although this estimate was less precise. The lack of complete work histories meant that relationships between cancer incidence and length of service or job categories could not be explored.     

Effect of smoking cessation and tobacco type on the risk of cancers of the upper aero-digestive tract in Brazil.

Tobacco smoking has long been identified as the most important risk factor for upper aero-digestive tract cancers. To investigate the effect of different tobacco types and the benefit of smoking cessation, we analyzed data from a case-control study of 784 cases of mouth, pharynx, and larynx cancers and 1,578 non-cancer controls in three metropolitan hospital areas in Brazil. Subjects were interviewed as to their smoking and drinking habits, demographics, environmental exposures, occupational history, health characteristics, and diet. Controlling for total tobacco and alcohol consumption, risks for ex-smokers compared with current smokers decreased substantially with time since cessation of the habit. Compared with never smokers, ex-smokers of >20 years had a relative risk (RR) of 1.98 [95% confidence interval (CI) = 1.0-3.8] for all upper aerodigestive tract cancers. RRs for long-term (>20 years) ex-smokers tended to be lower for mouth (RR = 1.61) and pharynx (RR = 1.52) than for larynx (RR = 3.63) cancers. The benefit of quitting was strongest for commercial cigarettes (RR = 1.45, 95% CI = 0.7-3.0) for ex-smokers of >10 years, as compared with smoking of black tobacco (RR = 2.57, 95% CI = 1.4-4.6), cigars (RR = 2.59, 95% CI = 0.6-11.6), and pipe tobacco (RR = 3.40, 95% CI = 1.3-8.8).     

Tabakassoziierte Krebserkrankungen in Deutschland – Entwicklung der Inzidenz und Mortalität seit 1995

Background and Objectives

Tobacco consumption is the most important cancer risk factor. In Germany, about 15% of all new cancer cases can be attributed to smoking. The aim of this paper is to analyze the incidence and mortality trends in tobacco-associated cancer cases in Germany for the last two decades.

Materials and Methods

Age standardized incidence and mortality rates were calculated for tumors of the upper aerodigestive tract and lower urinary tract for the period from 1995 to 2014/2015. In addition, average annual percentage changes were calculated with joinpoint regression analysis. Regarding lung cancer, trends in incidence and mortality rates were also stratified by different age groups and trends in mortality rates were analyzed by birth cohorts.

Results

The incidence and mortality rates among men are declining for all tobacco-associated cancers except esophageal cancer. Lung cancer mortality rates showed the greatest decrease with ?1.9% on average per year. The incidence rates among women increased for all tobacco-associated cancers except lower urinary tract cancers. The increase in lung cancer incidence was greatest with 3.3% on average per year. Among men there was a continuous decline over all birth cohorts regarding the chance of dying of lung cancer at a certain age. Among women, the chance of dying of lung cancer increased for all birth cohorts until 1960.

Conclusions

The present analyses regarding tobacco-associated cancers in Germany reflect the changes in smoking prevalence with a deferment of multiple decades.

     

Pipe and cigar smoking and major cardiovascular events, cancer incidence and all-cause mortality in middle-aged British men

BACKGROUND: Pipe and cigar smoking are still regarded by many as less hazardous to health than cigarette smoking. METHODS: Prospective study of 7735 men aged 40-59 years drawn from general practices in 24 British towns with mean follow-up of 21.8 years. The outcome measures include major coronary heart disease (CHD) and stroke events, cancer incidence, and deaths from all causes. RESULTS: There were 1133 major CHD events and 440 stroke events, 919 new cancers and 1994 deaths from all causes in the 7121 men with no diagnosed CHD, stroke, diabetes, or cancer at screening. Compared with never smokers, pipe/cigar smokers (primary and secondary combined) showed significantly higher risk of major CHD events (relative risk [RR] = 1.69, 95% CI: 1.32, 2.14) and stroke events (RR = 1.62, 95% CI: 1.08, 2.41) and of cardiovascular, non-cardiovascular, and total mortality (RR = 1.49, 95% CI: 1.13, 1.96, RR = 1.40, 95% CI: 1.08, 1.83 and RR = 1.44, 95% CI: 1.19, 1.74, respectively), after adjustment for lifestyle and biological characteristics. They also showed a significantly higher incidence of smoking-related cancers (RR = 2.67, 95% CI: 1.70, 4.26), largely due to lung cancer (RR = 4.35, 95% CI: 2.05, 8.94). Overall, the effects in pipe/cigar smokers were intermediate between never-smokers and light cigarette smokers, although risks for lung cancer were similar to light cigarette smokers. CONCLUSION: Pipe and cigar smoking, whether primary or secondary, carries significant risk of smoking-related ill health.     

Contribution of tobacco and alcohol to the high rates of squamous cell carcinoma of the supraglottis and glottis in Central Europe

Incidence rates for laryngeal cancer in Central Europe are among the highest in the world. The authors recruited cases and controls between 2000 and 2002 for the Central and Eastern Europe Multicenter Study to investigate the role of tobacco and alcohol as causes of laryngeal cancer in this region. A total of 384 incident squamous cell cases were included, comprising 254 glottic and 108 supraglottic cancers. Hospital controls were chosen from within the same catchment area, from diseases unrelated to tobacco or alcohol (n = 918). Significant dose-response trends for frequency and duration of tobacco use were observed for both supraglottic and glottic cancers, with potentially a more important effect for supraglottic cancer. Quitting smoking was protective against laryngeal cancers after 5 years. Any increases in risk for alcohol drinking were generally moderate and nonsignificant. A greater than multiplicative interaction was observed between tobacco and alcohol on the risk of laryngeal cancer (p = 0.04). Approximately 87% of laryngeal cancer cases in Central Europe are attributable to tobacco use, of which 75% and 12% are due to current and past smoking, respectively. Approximately 39% are attributable to the interaction between alcohol and tobacco. Preventive efforts to encourage current smokers to quit are likely to be the most effective way to reduce the incidence of laryngeal cancer in this region.     

Effects of smoking and stopping smoking on serum high-density lipoprotein cholesterol levels in a representative population sample

Serum high-density lipoprotein (HDL) cholesterol levels were assessed in a random sample of 939 men and 853 women ages 14-65 years in eastern Finland. Amount of daily smoking measured by serum thiocyanate concentration was negatively and independently associated with serum HDL cholesterol level and HDL/total cholesterol ratio in men. This negative association seemed largely to be due to low HDL cholesterol levels in heavy smokers. Both male and female current smokers had lower HDL cholesterol levels and HDL/total cholesterol ratios than those who had never smoked. This difference was found even after adjustment for age, body mass index, and beer drinking. The reduction of HDL cholesterol level seemed to be reversible, because those who had recently stopped smoking had higher HDL cholesterol levels and higher HDL/total cholesterol ratios than current smokers.     

History of lifetime smoking, smoking cessation and cognitive function in the elderly population

To examine potential associations of the history of lifetime smoking and smoking cessation with cognitive function in the elderly. In a population-based cohort study of older adults in Saarland, Germany, a detailed lifetime history of smoking was obtained using standardised questionnaires. Cognitive function was assessed with a validated telephone-based instrument (COGTEL) at the five-year follow-up in a subsample of n = 1,697 participants with a baseline age >65 years. Multiple linear regression models were employed to predict cognitive performance, adjusting for potential confounding factors. Ever-smokers with a higher cumulative dose of smoking in pack-years scored lower in the cognitive assessment than never-smokers, with the association being more pronounced in current smokers than in former smokers. In fully adjusted models, current smokers with 21–40 pack-years scored 4.06 points lower (95 % CI ?7.18 to ?0.94) than never-smokers. In former smokers, a longer time since smoking cessation was associated with higher scores in the cognitive test with reference to current smokers, even after adjustment for pack-years. Former smokers who had quit for more than 30 years scored 4.23 points higher (95 % CI 1.75 to 6.71) than current smokers. Dose–response-relationships of cognitive function with cumulative dose of smoking as well as with time since smoking cessation were substantiated by restricted cubic splines regression. Our results support suggestions that smokers are at an increased risk for cognitive impairment in older age; that the risk increases with duration and intensity of smoking, and subsides with time after smoking cessation.     

Cessation of smoking after myocardial infarction in women. Effects on mortality and reinfarctions

Among 262 women with a first myocardial infarction discharged alive from hospital in G?teborg, Sweden between 1968 and 1977, 161 (61%) were smokers at the time of infarction. Postinfarction smoking was established after three months. In relation to smoking status three months after the infarction, subsequent survival and reinfarction rate were calculated by comparing those who smoked before infarction and later stopped (52%) with those who continued to smoke after the infarction (48%). There were no differences in preinfarction characteristics between quitters and continuing smokers. Women who stopped smoking after the infarction had higher serum enzymes during the acute phase than those who continued to smoke. The cumulative five-year survival rate was 85% among those who stopped smoking compared to 73% among those who continued to smoke (p less than 0.05). No significant difference was found in the cumulative reinfarction rate between the two groups with different smoking habits.     

Interaction between tobacco and alcohol consumption and the risk of cancers of the upper aero-digestive tract in Brazil

The authors investigated the joint effects of tobacco and alcohol consumption on the risk of squamous cell carcinomas of the upper aero-digestive tract (UADT) using data from a hospital-based case-control study conducted in southern Brazil, 1986-1989. A total of 784 cases of cancers of the mouth, pharynx, and larynx and 1,578 non-cancer controls matched on age, sex, hospital catchment area, and period of admission were interviewed about their smoking and drinking habits and other characteristics. Using logistic regression, evidence was found for interaction between the cumulative exposures for smoking and alcohol on UADT cancer risk. The joint effects for pharyngeal cancers exceeded the levels expected under a multiplicative model for moderate smokers (p = 0.007). There was little statistical evidence, however, for interaction on cancers of the mouth (p = 0.28) or larynx (p = 0.95). Among never smokers, heavy drinkers had 9.2 times (95% confidence interval 1.7, 48.5) greater risk of cancers of mouth, pharynx, and supraglottis than never drinkers, with a dose-response trend (p = 0.013) with cumulative consumption. The authors conclude that the interaction occurring in the pharynx between smoking and alcohol on UADT cancers is not uniform, with varying effects depending on the level of smoking exposure. Alcohol may act as both a promoter for tobacco and as an independent risk factor.     

Smoking reduction,smoking cessation,and incidence of fatal and non-fatal myocardial infarction in Denmark 1976-1998: a pooled cohort study

OBJECTIVE: To analyse the effects of smoking reduction and smoking cessation on incidence of myocardial infarction after adjustment for established cardiovascular risk factors. DESIGN: Prospective cohort study with record linkage to mortality and hospital registers. The association of individual change in smoking with myocardial infarction was examined in Cox proportional hazard analyses with continuous heavy smokers (> or =5 cigarettes/day) as reference. SETTING: Pooled data from three population studies conducted in Copenhagen, Denmark. PARTICIPANTS: 10 956 men and 8467 women with complete information on smoking habits at two examinations five to ten years apart were followed up from the second examination for a first hospital admission or death from myocardial infarction. Mean duration of follow up was 13.8 years. MAIN RESULTS: A total of 643 participants who were heavy smokers at baseline reduced their daily tobacco consumption by at least 50% without quitting between first and second examination, and 1379 participants stopped smoking. During follow up 1658 men and 521 women experienced a fatal or non-fatal myocardial infarction. After adjustment for cardiovascular risk factors, people who stopped smoking had a decreased risk of myocardial infarction, hazard ratio 0.71 (95% confidence intervals 0.59 to 0.85). Smoking reduction was not associated with reduced risk of myocardial infarction, hazard ratio 1.15 (95% confidence intervals 0.94 to 1.40). These associations remained unchanged after controlling for baseline illness in different ways. CONCLUSIONS: Smoking cessation in healthy people reduces the risk of a subsequent myocardial infarction, whereas this study provides no evidence of benefit from reduction in the amount smoked.     

Dipstick haematuria: its association with smoking and nonsteroidal anti-inflammatory drugs.

Of 1015 men over the age of 60, 125 (12.3%) were found to have dipstick haematuria on a single test. Analysis of smoking history revealed a 1.6 fold increased incidence of dipstick haematuria in current smokers as compared with ex-smokers and non-smokers. The relationship with bladder cancer and smoking is discussed. Several commonly used drugs, including nonsteroidal anti-inflammatory preparations, have been implicated as a cause of urinary tract bleeding. In this study of 1015 men over the age of 60, no association was found between the presence of dipstick haematuria and the intake of aspirin, other nonsteroidal anti-inflammatory drugs or warfarin.     

Changes in smoking and drinking behaviour before and during pregnancy in Italian mothers: implications for public health intervention. ICGDUP (Italian Collaborative Group on Drug Use in Pregnancy).

Cigarette and alcohol use before and during pregnancy were studied in 4966 Italian women who delivered single liveborn infants. Using a standardized questionnaire mothers were interviewed in the early postpartum period about pregnancy-related events. Data are part of the Drug Use in Pregnancy (DUP) Study, an international epidemiological co-operative survey conducted under the auspices of the World Health Organization, in 22 countries during 1989-1990. Italian pregnant smokers were women under 30 years of age with a middle-school education or less, and drinkers were 30 years of age and more with more than a middle-school education. When pregnancy was confirmed, most of them cut down smoking and drinking but more so for smoking than drinking: 12% stopped smoking and 6% stopped drinking. Less than 1% gave up both. The more the mother smoked during pregnancy the lower was the infant's birthweight and the association between reduced fetal growth and higher smoking level persisted after controlling for confounding variables. Only smoking habits were associated with delivery of small-for-gestational age babies. A large proportion of Italian women use alcohol and cigarettes before and during pregnancy. Smoking during pregnancy is an important preventable risk factor for the delivery of a small-for-gestational-age child. Thus it may be worth campaigning more vigorously to encourage women to give up smoking during pregnancy.     

Effects of husbands' smoking on the incidence of lung cancer in Korean women

BACKGROUND: Although smoking remains uncommon among Korean women, lung cancer mortality is rapidly escalating. METHODS: We investigated the effects of spousal smoking in 160130 Korean women, aged 40-88, who received health insurance from the Korea Medical Insurance Corporation (KMIC). Exposure data were collected during medical examinations conducted between April 1992 and June 1994. The primary outcome variable was the incidence of lung cancer defined by hospital admissions between July 1994 and December 1997. Standardized rates for the incidence of lung cancer were assessed according to the smoking habits of their husbands. RESULTS: At baseline (n = 160 130), 53.9% of husbands were smokers and 23.3% were ex-smokers, while 1.1% of wives (n = 1756) were current smokers and 0.6% (n = 938) were ex-smokers. During follow-up, 79 cases of lung cancer occurred among non-smoking wives (n = 157436). Wives of heavy smokers were found to have a higher risk of developing lung cancer. The husbands' smoking habits did not affect their wives' risk of developing other cancers such as those of the stomach, liver and cervix, but they did affect breast cancer, which has a significantly higher risk in relation to the longer duration of husbands' smoking. In Poission regression models, adjusting for the age of both husband and wife, socioeconomic status, occupation, residency and vegetable intake, the rate ratio (RR) of lung cancer in non-smoking wives was 1.9 (95% CI: 1.0-3.5) in current smokers and 1.3 (95% CI: 0.6-2.7) in ex-smokers. The RR of lung cancer was 3.1 (95% CI: 1.4-6.6) in wives of husbands who had smoked for 30 years or more compared with wives of non-smoking husbands. CONCLUSION: In Korea, the incidence of lung cancer is higher among non-smoking women whose husbands smoke, and a dose-response relationship seems to exist.     

Randomised controlled trial of anti-smoking advice: final (20 year) results.

STUDY OBJECTIVE--The aim was to measure experimentally the effects in middle aged men of stopping smoking. DESIGN--The study was a randomised controlled trial. SETTING AND SUBJECTS--The subjects were 1445 male smokers, initially aged 40-59 years, who were selected from the Whitehall study survey of 16,016 civil servants on the basis of a high risk of cardiorespiratory disease. MAIN RESULTS--During the next 20 years there were 620 deaths (231 from coronary heart disease), 96 cases of lung cancer, and 159 other cancers. Comparing the intervention with the normal care group, total mortality was 7% lower, fatal coronary heart disease was 13% lower, and lung cancer (deaths+registrations) was 11% lower. An excess rate for other cancers, reported previously, did not persist into the second decade of the trial. CONCLUSIONS--The results are consistent with observational studies, implying that smoking cessation by middle aged men substantially improves their changes of avoiding lung cancer or a fatal heart attack. Our estimate from the trial is that out of every 100 men who stopped smoking, between six and 10 were in consequence alive 20 years later.     

Benefits of smoking cessation for longevity

OBJECTIVES: This study determined the life extension obtained from stopping smoking at various ages. METHODS: We estimated the relation between smoking and mortality among 877,243 respondents to the Cancer Prevention Study II. These estimates were applied to the 1990 US census population to examine the longevity benefits of smoking cessation. RESULTS: Life expectancy among smokers who quit at age 35 exceeded that of continuing smokers by 6.9 to 8.5 years for men and 6.1 to 7.7 years for women. Smokers who quit at younger ages realized greater life extensions. However, even those who quit much later in life gained some benefits: among smokers who quit at age 65 years, men gained 1.4 to 2.0 years of life, and women gained 2.7 to 3.7 years. CONCLUSIONS: Stopping smoking as early as possible is important, but cessation at any age provides meaningful life extensions.