Lung cancer risk associated with cigar and pipe smoking

A case-control study of 1,529 histologically confirmed male lung cancer cases and 2,899 controls matched for sex, age, hospital of admission and interviewer was conducted in France between 1976 and 1980. The results presented concern the effects of smoking habits, especially cigar and pipe use, on the occurrence of lung cancer, in a total of 38 exclusive cigar smokers, 61 exclusive pipe smokers and 586 mixed tobacco smokers. Exclusive cigar or pipe use (RR = 5.6 and 1.6 respectively) has been shown less harmful than exclusive cigarette smoking (RR = 13.3), mixed cigar and cigarette smoking (RR = 8.5) and mixed pipe and cigarette smoking (RR = 8.0). Different inhalation practices were observed according to smoking habits: while among exclusive cigarette smokers 29.8% never inhaled the smoke, among exclusive cigar and exclusive pipe users these percentages were 89.5% and 86.9 respectively. No significant increase with greater exposure to cigar was found among mixed cigar and cigarette smokers after adjustment for exposure to cigarettes, defined by duration and daily consumption of cigarettes (RR = 1.20), and by type of cigarettes smoked--light or dark, filter or nonfilter (RR = 1.13). Similar results were observed among mixed pipe and cigarette smokers after adjustment for cigarette exposure (RR = 0.95 and 1.04).     

Effects of type of smoking (pipe, cigars or cigarettes) on biological indices of tobacco exposure and toxicity

Although all forms of smoking are harmful, smoking pipes or cigars is associated with lower exposure to the lethal products of tobacco products and lower levels of morbidity and mortality than smoking cigarettes. Cytochrome P-450-1A (CYP1A) is a major pathway activating carcinogens from tobacco smoke. Our primary aim was to compare CYP1A2 activity in individuals smoking pipes or cigars only, cigarettes only and in non-smokers. We studied 30 smokers of pipes or cigars only, 28 smokers of cigarettes only, and 30 non-smokers male subjects matched for age. CYP1A2 activity was assessed as the caffeine metabolic ratio in plasma. One-day urine collection was used for determining exposure to products of tobacco metabolism. Nitrosamine and benzo[a]pyrene DNA adducts were measured in lymphocytes. CYP1A2 activity was greater (p<0.0001) in cigarette smokers (median: 0.61; interquartile range: 0.52-0.76) than in pipe or cigar smokers (0.27; 0.21-0.37) and non-smokers (0.34; 0.25-0.42) who did not differ significantly. Urinary cotinine and 1-hydroxypyrene levels were higher in cigarette smokers than in pipe or cigar smokers and higher in the later than in non-smokers. DNA adducts levels were significantly lower in pipe or cigar smokers than in cigarette smokers. In multivariate analysis, cigarette smoking was the only independent predictor of CYP1A2 activity (p<0.0001) and of 1-hydroxypyrene excretion in urine (p=0.0012). In this study, pipe or cigar smoking was associated with lower exposure to products of tobacco metabolism than cigarette smoking and to an absence of CYP1A2 induction. Cigarette smoking was the only independent predictor of CYP1A2 activity in smokers. However, inhalation behaviour, rather than the type of tobacco smoked, may be the key factor linked to the extent of tobacco exposure and CYP1A2 induction. Our results provide a reasonable explanation for the results of epidemiological studies showing pipe or cigar smoking to present fewer health hazards than cigarette smoking.     

Cigar and pipe smoking and lung cancer risk: a multicenter study from Europe

BACKGROUND: Because limited information is available on the quantitative association between consumption of tobacco products other than cigarettes and lung cancer risk, we undertook a case-control study of this relationship. METHODS: We investigated lung cancer risk among smokers of cigars and/or cigarillos only and of pipes only and compared these risks with the risk of smokers of cigarettes only in a case-control study conducted in seven European areas. Our study population consisted of 5621 male case patients with lung cancer and 7255 male control subjects. Each subject or his proxy was interviewed with respect to the subject's smoking history and other risk factors for lung cancer. RESULTS: The odds ratio (OR) for smoking cigars and cigarillos only was 9.0 (95% confidence interval [CI] = 5.8-14.1), based on 43 exposed case patients and 77 exposed control subjects, and the OR for smoking a pipe only was 7.9 (95% CI = 5.3-11.8), representing 61 case patients and 129 control subjects. The OR for smoking cigarettes only was 14.9 (95% CI = 12.3-18.1), based on 4204 case patients and 3930 control subjects. A dose-response relationship was present for duration of use and cumulative consumption both for cigars and cigarillos and for pipe tobacco. An effect was also suggested for inhalation of cigar and cigarillo smoke. The dose-response relationships between lung cancer risk and either duration of smoking or average and cumulative consumption were similar for cigar and cigarillo smoking, pipe smoking, and cigarette smoking. CONCLUSION: Our results suggest that smoking of European cigars, cigarillos, and pipe tobacco might exert a carcinogenic effect on the lung comparable to that of cigarettes.     

Cigar, pipe, and cigarette smoking and bladder cancer risk in European men

Objective: Estimating the risk of bladder cancer from cigar and pipe smoking is complicated by a small number of non-cigarette smokers included in most relevant studies. Methods: We undertook a pooled analysis of the data on men from six published case–control studies from Denmark, France, Germany, and Spain, to assess the association between pipe and cigar smoking and bladder cancer, and to compare it with the risk from cigarette smoking. Complete history of tobacco smoking was ascertained separately for cigarettes, cigars, and pipe. Odds ratios (ORs) were estimated after adjusting for age, study, and employment in high-risk occupations. Results: The pooled data set comprised 2279 cases and 5268 controls, of whom 88 cases and 253 controls smoked only cigars or pipe. The OR for pure cigarette smoking was 3.5 (95% confidence interval [CI] 2.9–4.2), that for pure pipe smoking was 1.9 (95% CI 1.2–3.1) and that for pure cigar smoking was 2.3 (95% CI 1.6–3.5). The increase in the OR of bladder cancer that was observed with duration of smoking was non-significantly lower for cigars than for cigarettes. Conclusion: Our results suggest that smoking of cigars and pipe is carcinogenic to the urinary bladder, although the potency might be lower than for cigarettes.     

The sugar content and the pH of the smoke of cigarette, cigar and pipe tobaccos in relation to lung cancer

The risk of lung cancer is greater in cigarette smokers than in cigar or pipe smokers. In Great Britain, which has a very high lung-cancer death rate, cigarette tobacco (flue-cured) has a high sugar content (up to 20%) while cigar tobacco (aircured) has a low sugar content (0.5—2%). Determinations of the sugar content of the tobacco and the pH of the smoke of cigarettes from more than 30 countries, and of a number of cigar and pipe tobaccos, have been carried out. The main differences found between the characteristics of cigarette and cigar and pipe tobaccos are:

• (1) The high sugar content of the popular brands of cigarettes now smoked in many countries, which results in the production of a smoke of acid pH, becoming progressively more acid during the course of smoking, particularly towards the butt-end of the cigarette when the tar content of the smoke is at its highest;
• (2) The low sugar content of cigar tobacco and of the air-dried tobacco used in the cigarettes of certain countries, which gives a smoke of less acid pH becoming progressively more alkaline during the course of smoking;
• (3) The conditions of smoking in a pipe whereby the smoke from all types of tobacco, with both high and low sugar content, is less acid than that of most cigarettes, and becomes progressively more alkaline during the course of smoking.

Since the satisfaction derived from smoking is mainly due to the pharmacological effects of nicotine, it is suggested that the lower lung cancer incidence in cigar and pipe smokers may be related to the fact that nicotine is more readily absorbed in the form of the free base, at alkaline pH, than in the form of a stable salt, at acid pH. To obtain the same degree of “nicotine satisfaction” as in smoking a pipe or cigar, the smoker of cigarettes giving an acid smoke would tend to smoke more, and to encourage more prolonged and extensive contact of the smoke with the mouth and bronchus, and to take the smoke into his lungs, which would thus suffer greater exposure to the “carcinogenic” effects of the smoke than would be the case with cigar or pipe smokers. In preliminary attempts to devise a “safer” cigarette, the addition of substances which give rise to an alkaline vapour at the usual temperature of combustion of cigarettes has been shown to reverse the character of the smoke of high sugar (fluecured) tobacco cigarettes so that it then resembles that of cigars and pipes in becoming progressively more alkaline during the course of smoking.     

Smoking and bladder cancer. The modifying effect of cigarettes on other factors

A population-based, incidence case-control study was used to assess the effect of cigarette smoking on other risk factors for the development of bladder cancer. White men (n = 332) between the ages of 21 and 84 with bladder cancer were compared with 686 population-based controls. Cigarette smokers were classified by current smoking status as well as by amount, duration, inhalation patterns, age at first having smoked, and years since having stopped smoking. These variables were associated with a change in the risk for bladder cancer. The population-attributable risk associated with cigarette smoking was 48.5%. Risks from the use of other tobacco products such as cigars, pipes, snuff, and chewing tobacco, and from caffeinated coffee, tea, and alcoholic beverages were evaluated in light of cigarette smoking status. Cigarette smoking was shown to be both a confounder and an effect modifier. Risk estimates for bladder cancer associated with caffeinated coffee and alcoholic beverages were decreased after controlling for the effects of cigarette smoking. However, an increased risk of developing bladder cancer from cigar smoking (Odds ratio [OR] = 2.46) and tea drinking (OR = 3.14) was only seen in men who never smoked cigarettes. An increased but not significant risk was also seen for pipe, snuff, and chewing tobacco use in noncigarette smokers. The population-attributable risk from cigars and tea in the population of white men who had never smoked was 6.3% and 18.9%, respectively. Our results suggest that cigarette smoking may obscure other risk factors unless those who never smoked are separately studied.     

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

ABSTRACT: 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.     

Smokeless and other noncigarette tobacco use and pancreatic cancer: a case-control study based on direct interviews.

Cigarette smoking is an important and well-established cause of pancreatic cancer. In contrast, little is known about the effects of smoking cigars, pipes, and use of smokeless tobacco on pancreatic cancer risk. The objective of the present study was to examine the association between noncigarette tobacco use (i.e., cigars, pipes, smokeless tobacco) and pancreatic cancer risk among nonsmokers of cigarettes. A population-based case-control study of pancreatic cancer was conducted during 1986-1989 among residents of Atlanta, Georgia, Detroit, Michigan, and 10 counties in New Jersey. Direct interviews were successfully completed with 526 newly diagnosed pancreatic cancer patients and 2153 controls ages 30-79 years. This analysis was restricted to lifelong nonsmokers of cigarettes and based on interviews with 154 cases newly diagnosed with carcinoma of the exocrine pancreas and 844 population controls who reported no history of cigarette smoking. We observed a consistent pattern of increased risk associated with cigar smoking, although these elevations were not statistically significant. Participants who smoked cigars regularly (i.e., at least one cigar/week for >/=6 months) experienced a 70% increased risk [95% confidence interval (CI): 0.9-3.3], and those who never used other form of tobacco had a 90% increased risk (95% CI: 0.8-4.3). Risk was elevated among those who smoked more than one cigar/day [odds ratio (OR) = 1.8; 95% CI: 0.8-4.2) and among those who smoked cigars > 20 years (OR = 1.9; 95% CI: 0.9-3.9). Trends in risk with increasing amount and duration smoked were consistent but not statistically significant (P = 0.17 and P = 0.16, respectively). Subjects who used smokeless tobacco regularly had a 40% increased risk of pancreatic cancer (95% CI: 0.5-3.6) compared with nonusers of tobacco. We observed a marginally significant increasing risk with increased use of smokeless tobacco (P = 0.04); participants who used >2.5 oz of smokeless tobacco a week had an OR of 3.5 (95% CI: 1.1-11). Long-term use of smokeless tobacco (i.e., >20 years) was also associated with a nonsignificant increased risk (OR = 1.5; 95% CI: 0.6-4.0). In contrast, pipe smokers experienced no increased risk (OR = 0.6; 95% CI: 0.1-2.8). Our results suggest that heavy use of smokeless tobacco, and to a lesser extent, cigar smoking may increase the risk of pancreatic cancer among nonsmokers of cigarettes.     

Dark tobacco and lung cancer in Cuba

A retrospective epidemiologic study of 826 cytologically and/or histologically confirmed lung cancer cases (219 females and 607 males), 979 hospital controls, and 539 neighborhood controls was undertaken in Havana, Cuba, to investigate whether the high lung cancer mortality rates in this country could be explained by the cigarette and cigar consumption habits, including the smoking of dark-tobacco cigarettes. Relative risk(s)(RR) of lung cancer among cigarette smokers were 7.3 in women and 14.1 in men and increased consistently with various measures of exposure to smoke. The findings suggested that duration of smoking, daily number of cigarettes consumed, and inhalation practices have independent effects. Most Cubans smoked dark tobacco. RR were higher for dark-tobacco users than for light-tobacco users (RR = 8.6 vs. 4.6 for women and 14.3 vs. 11.3 for men), but the differences were reduced after adjustment for amount smoked. Cigarette smoking was associated with all histologic types of lung cancer, although the risk for adenocarcinoma was lower than that for the other types. Men who smoked exclusively cigars had a fourfold risk of lung cancer. Mixed smokers (i.e., cigar and cigarette smoker) had a greater RR than cigarette-only smokers (15.0 vs. 14.1), which was perhaps related to the unusually deep and frequent inhalation of cigar smoke. The data support the hypothesis that smoking patterns account for the higher lung cancer mortality in Cuba than in other Latin American countries.     

Pipe smoking and cancers of the upper digestive tract

Pipe smoking has been related to the risk of cancers of the upper digestive and respiratory tract, but quantification of the risk for exclusive pipe smokers is still limited. To analyse the association between exclusive pipe smoking and cancers of the upper digestive tract, we used data from a series of case-control studies conducted in Italy and Switzerland between 1984 and 1999. After excluding cigarette and cigar smokers, 41 male oral and pharyngeal cancer cases, 52 male oesophageal cancer cases and 1,032 male controls were included in the present analysis. Odds ratios (OR) of cancers were estimated by the mean of unconditional multivariate logistic regression, including terms for age, study centre, education, body mass index, and alcohol drinking. Compared to never smokers, exclusive pipe smokers had an OR of 8.7 [95% confidence intervals (CI): 4.0-18.9] of all upper digestive tract cancers. The OR was 12.6 for oral and pharyngeal and 7.2 for oesophageal cancer. Pipe smokers who were also heavy alcohol drinkers had an OR of 38.8 (95% CI: 13.6-110.9) as compared to never smokers and light drinkers. Thus, pipe smoking and heavy alcohol drinking appears to interact at least on a multiplicative model.     

A prospective study on active and environmental tobacco smoking and bladder cancer risk (The Netherlands)

Objective: In a prospective cohort study among 120,852 adult subjects the authors investigated the associations between cigarette, cigar, pipe, environmental tobacco smoking (ETS), and bladder cancer. Methods: In 1986 all subjects completed a questionnaire on cancer risk factors. Follow-up for incident bladder cancer was established by linkage to cancer registries until 1992. The case–cohort analysis was based on 619 cases and 3346 subcohort members. Results: Compared with lifelong non-smokers the age- and sex-adjusted incidence rate ratios (RR) for ex- and current cigarette smokers were 2.1 (95% CI 1.5–3.0) and 3.3 (95% CI 2.4–4.6), respectively. The RR for smoking duration was 1.03 (95% CI: 1.02–1.04) per 1-year increment. The RR per 10 cigarettes/day was 1.3 (95% CI 1.2–1.4). Tar and nicotine exposure increased bladder cancer risk only weakly. It appeared that associations of cigarette smoking characteristics with bladder cancer risk were largely attributable to cigarette smoking duration only. Smoking cessation, age at first exposure, filter-tip usage, cigar and pipe smoking, and ETS were no longer associated with bladder cancer risk after adjustment for frequency and duration of smoking. Conclusions: The authors conclude that current cigarette smokers have a three-fold higher bladder cancer risk than non-smokers. Ex-smokers experience a two-fold increased risk. About half of male bladder cancer and one-fifth of female bladder cancer was attributable to cigarette smoking. Other smoking types (cigar, pipe, or ETS) were not associated with increased risks.     

Risk of bladder cancer by source and type of tobacco exposure: a case-control study

The association between tobacco use and risk of bladder cancer was investigated in a population-based case-control study conducted in Alberta and south-central Ontario, Canada, between 1979 and 1982. In all, 826 histologically-confirmed cancer cases and 792 randomly selected controls, individually matched to cases for age, sex, and area of residence, were recruited into the study. Compared to those who had never smoked cigarettes, males and females who had ever smoked cigarettes had a statistically highly significant 2-fold increase in risk of bladder cancer; for ex-smokers, the risk was intermediate between that for current smokers and never-smokers. There was a dose-dependent increase in risk of bladder cancer with total lifetime cigarette consumption, of similar magnitude for males and females. In males, risk increased with self-reported degree of inhalation in ex-smokers and in current smokers (statistically significant trend), while in females there was no association in current smokers, and a statistically significant inverse association in ex-smokers. Overall, risks of bladder cancer associated with lifetime consumption of plain and filter cigarettes were similar, and there was little evidence to suggest that switching from plain to filter cigarettes was beneficial. Neither passive smoking nor other forms of tobacco consumption (pipes, cigars, chewing tobacco, or snuff) were associated with altered risk of bladder cancer. The population attributable risk for cigarette smoking was about 47% in males and about 33% in females.     

Bladder cancer risk and pipes, cigars, and smokeless tobacco

Interview data from 2982 patients with bladder cancer and 5782 controls selected from the general population were used to assess the effects of non-cigarette tobacco use on bladder cancer risk. Compared to men who had never smoked, those who had smoked pipes but not cigars or cigarettes had a relative risk estimated at 1.23 (95% confidence interval [CI] = 0.75-2.00). Those who smoked cigars but not pipes or cigarettes were estimated to have a relative risk of 1.33 (95% CI = 0.92-1.94). Little evidence of dose response was observed. The excess relative risk to pipe smokers was limited to those who inhaled deeply.     

Snus use,smoking and survival among prostate cancer patients

Smoking is associated with prostate cancer mortality. The Scandinavian smokeless tobacco product snus is a source of nicotine but not the combustion products of smoke and has not been studied with respect to prostate cancer survival. The study is nested among 9,582 men with incident prostate cancer within a prospective cohort of 336,381 Swedish construction workers. Information on tobacco use was collected at study entry between 1971 and 1992, and categorized into (i) never users of any tobacco, (ii) exclusive snus: ever users of snus only, (iii) exclusive smokers: ever smokers (cigarette, cigar and/or pipe) only and (iv) ever users of both snus and smoking. Hazard ratios for prostate cancer‐specific and total mortality for smoking and snus use based on Cox proportional hazards models adjusted for age, calendar period at diagnosis and body mass index at baseline. During 36 years of follow‐up, 4,758 patients died—2,489 due to prostate cancer. Compared to never users of tobacco, exclusive smokers were at increased risk of prostate cancer mortality (HR 1.15, 95% CI: 1.05–1.27) and total mortality (HR 1.17, 95% CI: 1.09–1.26). Exclusive snus users also had increased risks for prostate cancer mortality (HR 1.24, 95% CI: 1.03–1.49) and total mortality (HR 1.19, 95% CI: 1.04–1.37). Among men diagnosed with nonmetastatic disease, the HR for prostate cancer death among exclusive snus users was 3.17 (95% CI: 1.66–6.06). The study is limited by a single assessment of tobacco use prior to diagnosis. Snus use was associated with increased risks of prostate cancer and total mortality among prostate cancer patients. This suggests that tobacco‐related components such as nicotine or tobacco‐specific carcinogens may promote cancer progression independent of tobacco's combustion products.     

Risk of lung cancer among cigarette and pipe smokers in southern China.

Studies in Shanghai and in north-east China indicate that cigarette smoking is a major contributor to the high rates of lung cancer in those areas, but doubts persist regarding the influence of cigarette use on lung cancer rates in other areas of China. In addition, the risk of lung cancer associated with other methods of tobacco consumption--in particular, the use of bamboo water-pipes and long-stem pipes--is uncertain. A population-based case-control study of 427 male lung cancer patients residing in a mining area of Southern China and 1,011 controls was carried out to address this and other issues. Of these patients, 63% smoked cigarettes and (water and long-stem) pipes; 17% and 14% smoked only cigarettes or pipes, respectively; and 6% did not smoke. Compared to non-smokers, smokers of cigarettes only, smokers of pipes only and mixed smokers were at increased risk; OR = 2.6 (95% CI 1.1-6.2), 1.8 (95% CI 0.8-4.2) and 4.1 (95% CI 2.3-9.2), respectively. Risk increased with duration of tobacco use; however, the rate of increase with years of cigarette use was significantly greater than for years of pipe use (p = 0.03). In addition, risks increased 8-fold in the highest quartile of number of cigarettes per day compared to non-cigarette smokers vs. 2.3-fold for the highest quartile of number of liang (50 g) smoked per month compared to non-pipe-smokers; the trends in the ORs differed significantly (p less than 0.001). Results suggest that, in this area of China, tobacco use is an important cause of lung cancer, and that smoking cigarettes may be more deleterious than smoking pipes (primarily water pipes).     

A cohort study of tobacco use,diet, occupation,and lung cancer mortality

In 1966, a cohort of White males aged 35 or over, who were policy-holders with the Lutheran Brotherhood Insurance Society (United States), completed a mail questionnaire on tobacco use, diet, and demographic characteristics. During the 20 years of follow-up, 219 lung cancer deaths occurred. Besides the strong relationship with cigarette smoking, we observed an effect on lung cancer risk among current users of cigars or pipes who were nonsmokers of cigarettes (relative risk [RR]=3.5, 95 percent confidence interval[CI]=1.0–12.6) or who were past/occasional users of cigarettes (RR=2.7, CI=1.4–5.3). In addition, elevated risks (from 1.5 to 2.6) of lung cancer were found among craftsmen and laborers, with the highest risks among subjects who worked in the mining or manufacturing industry. No association between current (as of 1966) use of beer or hard liquor and lung cancer was observed, although past users were at elevated risk. An inverse association between lung cancer and intake of fruits was observed, and risks of lung cancer were lower among persons in the highest dietary intake quintiles of vitamins A and C. Except for oranges, however, none of the inverse associations with fruits or dietary nutrients had statistically significant trends. The findings from this cohort study add to the evidence of an adverse effect of cigar/pipe smoking and possibly protective effect of dietary factors on lung cancer risk.     

Cigarette smoking and liver cancer among US veterans

The relationship of tobacco use with risk of primary liver cancer was investigated using data from a 26-year mortality follow-up of nearly 250,000 US veterans, mostly from World War I. Significantly increased risks for liver cancer (289 deaths) were associated with most forms of tobacco use, including pipe and cigar smoking. Elevated relative tisks (RRs) were seen for current cigarette smokers (RR=2.4; 95 percent confidence interval [CI] 1.6–3.5) and former cigarette smokers (RR=1.9, 1.2–2.9). A strong dose-response relationship (P<0.001) was found for cigarette smoking, with smokers of 40 or more cigarettes per day having almost a fourfold risk (RR=3.8, 1.9–8.0). Risks were also found to increase significantly with years of cigarette use and with earlier age at the start of cigarette smoking. These results are consistent with those of other cohort and case-control studies, suggesting that cigarette smoking may be related to the risk of liver cancer.All authors are in the Epidemiology and Biostatistics Program, Division of Cancer Etiology, National Cancer Institute. Address correspondence to Dr Hsing at Executive Plaza North, Room 415, Bethesda, MD 20892, USA.     

Risk factors for cancer of the tongue and the mouth. A case-control study from northern Italy.

BACKGROUND. The role of tobacco and alcohol consumption and the frequency of intake of a selected number of indicator foods as causes of cancer were investigated in a case-control study conducted in northern Italy. METHODS. One hundred two men with cancer of the tongue, 104 patients with cancer of the mouth, and 726 control subjects (the latter admitted to the hospital for acute nonneoplastic disease without respiratory illness) were interviewed. RESULTS. Similarly strong associations were observed with cigarette smoking (odds ratio [OR], 10.5 and 11.8 for current smokers versus never smokers in cancer of the tongue and mouth, respectively) and alcohol (OR, 3.4 and 3.0 for > or = 60 versus < or = 19 drinks/week). The risk conferred by pipe or cigar smoking, although based on only 12 smokers who did not smoke cigarettes, seemed, however, to be lower for cancer of the tongue (OR, 3.4) than cancer of the mouth (OR, 21.9). Selected indicator foods and beverages, including green vegetables, carrots, fresh fruits, whole-grain bread and pasta, coffee, and tea also affected the cancer risk similarly in the two sites. The beneficial influence of such foods and beverages seemed, however, to be more marked for cancer of the mouth than for cancer of the tongue. CONCLUSIONS. This study suggested that, although none of the differences in the effects between cancer sites was statistically significant, tobacco from pipes and cigars and the cleansing effect of some foods of plant origin and nonalcoholic beverages may influence the risk of cancer of the tongue less strongly than the risk of cancer of the mouth.     

Smoking and drinking in relation to cancers of the oral cavity, pharynx, larynx, and esophagus in northern Italy

A hospital-based case-control study of upper aerodigestive tract tumors was conducted between June 1986 and June 1989 in Northern Italy. One hundred fifty-seven male cases of oral cavity cancer, 134 of pharyngeal cancer, 162 of laryngeal cancer, and 288 of esophageal cancer, and 1272 male inpatients with acute conditions unrelated to tobacco and alcohol were interviewed. Odds ratios for current smokers of cigarettes were 11.1 for oral cavity, 12.9 for pharynx, 4.6 for larynx, and 3.8 for esophagus. For all 4 sites, the risk increased with increasing number of cigarettes and duration of smoking habits and, with the exception of esophageal cancer, decreased with increasing age at the start of and years since quitting smoking. Smokers of pipes and cigars showed a more elevated risk of cancer of the oral cavity and esophagus than did cigarette smokers. Significantly increased risks emerged also in heavy drinkers (odds ratio greater than 60 versus greater than or equal to 19 drinks/week = 3.4, 3.6, 2.1, and 6.0 for oral cavity, pharynx, larynx, and esophagus, respectively), deriving predominantly from wine consumption.     

Smoking habits and risk of cancers other than lung cancer: 28 years' follow-up of 26,000 Norwegian men and women

The impact of tobacco smoking on lung cancer risk has been investigated thoroughly since the 1950s, but other types of cancer also have been associated with smoking. In the present study, the aim was to explore the variation in risk connected with cigarette, cigar, and pipe smoking of suspected smoking-associated cancers other than lung cancer. Data were obtained from a survey of a random sample of the Norwegian population. A self-administered mailed questionnaire, which included questions about smoking habits, was completed by 26,000 men and women in 1965 (response rate: 76 percent). The cohort was followed from 1966 through 1993, including registration of all incident cancer cases. A dose-response relationship of cigarette smoking to the risk of urinary bladder cancer and cancers of the upper digestive and respiratory tract was observed. For the latter forms of cancer, a dose-response relationship of pipe smoking also was observed. In cancer of the pancreas, a stronger association between cigarette smoking and cancer risk was observed when the analysis was confined to histologically confirmed cases only. Current cigarette smokers at baseline had a significantly higher risk of cervical cancer than those who never smoked cigarettes. In cancers of the stomach, colon, rectum, breast, corpus uteri, ovary, and prostate, and in leukemia, no association between smoking and cancer risk was observed.Authors are with the Cancer Registry of Norway, Oslo, Norway. Address correspondence to Mr Engeland, The Cancer Registry of Norway, Institute for Epidemiological Cancer Research, Montebello, N-0310 Oslo, Norway. This work was supported by grant no. 95080/001 from the Norwegian Cancer Society and Contract PH-64-499 from the US National Cancer Institute.