Cigarette smoking,use of other tobacco products and stomach cancer mortality in US adults: The Cancer Prevention Study II

Cigarette smoking is associated with increased risk of stomach cancer in many studies but there are limited data on this relationship in women and on risk associated with use of tobacco products other than cigarettes. We examined stomach cancer death rates in relation to cigarette smoking in women and use of cigarette, cigar, pipe, or smokeless tobacco in men in a nationwide prospective mortality study in the United States (US). Cohort follow-up from 1982-96 identified 996 and 509 stomach cancer deaths among 467,788 men and 588,053 women, respectively. Cox proportional hazards models were fitted to estimate rate ratios (RR) and 95% confidence intervals (CI) using non-users of tobacco as the referent group. Multivariate-adjusted RRs were the highest for men who currently smoked cigars (RR = 2.29, 95% CI = 1.49-3.51) or cigarettes (RR = 2.16, 95% CI = 1.75-2.67) and both increased with smoking duration. Women who currently (RR = 1.49, 95% CI = 1.18-1.88) or formerly (RR = 1.36, 95% CI = 1.08-1.71) smoked cigarettes were at significantly increased risk, as were men who formerly smoked cigarettes (RR = 1.55, 95% CI = 1.28-1.88), or currently (RR = 1.81, 95% CI = 1.40-2.35) or formerly (RR: 1.57, 95% CI = 1.22-2.03) used more than one type of tobacco. Men who reported a history of chronic indigestion or gastroduodenal ulcer had substantially higher mortality rates associated with current cigarette (RR = 3.45, 95% CI = 2.05-5.80) or cigar (RR = 8.93, 95% CI = 4.02-19.90) smoking, as did men who were current aspirin users. If causal, the estimated proportion of stomach cancer deaths attributable to tobacco use would be 28% in US men and 14% in women. We conclude that prolonged use of tobacco products is associated with increased stomach cancer mortality in men and women. The accumulated evidence from this and other studies support reconsidering stomach cancer as a tobacco-related cancer.     

Tobacco use and stomach cancer in Mizoram, India.

The incidence of stomach cancer in India is lower than that of any other country around the world. However, in Mizoram, one of the north-eastern state of India, a very high age-adjusted incidence of stomach cancer is recorded. A hospital-based case-control study was carried out to identify the influence of tobacco use on the risk of developing stomach cancer in Mizoram. Among the cases, the risk of stomach cancer was significantly elevated among current smokers [odds ratio (OR), 2.3; 95% confidence interval (95% CI), 1.4-8.4] but not among ex-smokers. Higher risks were seen for meiziol (a local cigarette) smokers (OR, 2.2; 95% CI, 1.3-9.3). The increased risk was apparent among subjects who had smoked for >or=30 years. The increased risk was significant with 2-fold increase in risk among the subjects who smoked for >or=11 pack-years. The risk increased with increasing cumulative dose of tobacco smoked (mg). Tuibur (tobacco smoke-infused water), used mainly in Mizoram, was seemed to increased the risk of stomach cancer among current users in both univariate and multivariate models (OR, 2.1; 95% CI, 1.3-3.1). Tobacco chewer alone (OR, 2.6; 95% CI, 1.1-4.2) showed significant risk. Tobacco use in any form [smoking and smokeless (tuibur and chewing)] increased the risk of stomach cancer in Mizoram independently after adjusting for confounding variables.     

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.     

Tar yields of cigarettes and the risk of oesophageal cancer

The relationship between cigarettes with varying tar yields and the risk of oesophageal cancer was evaluated using data from a hospital-based case-control study conducted in Northern Italy on 129 histologically confirmed cases and 426 controls with acute, non-neoplastic of digestive diseases unrelated to tobacco or alcohol consumption. Compared with never-smokers, the relative risks of developing cancer of the oesophagus were 2.9 for subjects who smoked mainly middle- or low-tar (less than 22 mg) cigarettes and 8.9 for those smoking high-tar cigarettes (greater than or equal to 22 mg). The difference between the two categories was evident among ever-smokers and only current smokers, was not explained by adjustment for the major covariates of interest (social class, alcohol consumption and dietary indicators), and persisted when allowance was made for duration of smoking and number of cigarettes smoked per day by means of multiple regression analysis. The present findings suggest that the relation between tar deliveries of cigarettes and risk may be even more marked for oesophageal than for lung cancer. Further, they have important public health implications, in consideration of the current relatively high tar yields of Italian cigarettes, particularly in a few areas of north-eastern Italy where death certification rates from cancer of the oesophagus are among the highest in Europe. Nonetheless, in this study, smokers of prevalently low- to mid-tar cigarettes still did experience a significantly higher oesophageal cancer risk than life-long non-smokers.     

Tobacco use and colon cancer

Smoking cigarettes has been consistently associated with adenomatous polyps. However, only a few studies have reported associations between smoking cigarettes or using other forms of tobacco and colon cancer. A population-based case-control study of colon cancer was conducted in 3 areas in the United States: northern California, Utah and Minnesota. We observed approximately a 50% increase in colon cancer risk from smoking over a pack of cigarettes per day among both men and women. Those who stopped smoking remained at increased risk, even if they stopped over 10 years ago. Our data suggest that the amount smoked may be a more important factor than the total number of years smoked. Smoking neither cigars nor pipes was associated with an increased risk of colon cancer. Among female participants only, those who smoked over 20 cigarettes per day and had a large body mass index were at greater risk of colon cancer than participants who smoked the same amount but were smaller (p for interaction among women = 0.04). Int. J. Cancer, 70:259–264, 1997. © 1997 Wiley-Liss, Inc.     

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.     

Invasive cervical cancer and smoking in Latin America

A case-control study of 667 patients with invasive squamous cell carcinoma of the cervix and 1,430 controls from four Latin American countries showed an age-adjusted relative risk (RR) of 1.2 [95% confidence interval (CI) = 1.0-1.4] for women who had ever smoked, with risk rising to 1.7 (95% CI, 0.8-3.6) for women who smoked greater than or equal to 30 cigarettes per day. The associations were practically eliminated after adjustment for the number of sexual partners and alcohol consumption, probably a surrogate for an unidentified life-style risk factor. Some excess risk persisted among women who smoked for extended periods (RR = 1.5 for greater than or equal to 40 yr), as well as those who began smoking at older ages (RR = 1.7 for greater than 30 yr), which suggests a late-stage effect. In addition, among women who tested positive for human papillomavirus (HPV) type 16 or 18 by filter in situ hybridization, there was an increased risk for women who had ever smoked and a dose-response relationship with the number of cigarettes smoked (adjusted RRs compared with HPV-negative nonsmokers = 5.0 for HPV-positive nonsmokers, 5.5 for less than 10 cigarettes/day, and 8.4 for greater than or equal to 10 cigarettes/day). In contrast, HPV-negative women had no increased risk associated with smoking. These results, from a high-incidence area where intensive smoking among women is still relatively rare, suggest that smoking has a limited effect on cervical cancer risk, possibly only among women with specific types of HPV.     

Smoking, alcohol, diet, dentition and sexual practices in the epidemiology of oral cancer in Poland.

The effect of smoking, drinking, diet, dental care and sexual habits on the risk of oral and pharyngeal cancer was investigated in a case-control study conducted in Warsaw, Poland. The study comprised 122 patients (including 44 females) aged 23-80 years with histologically confirmed cancer of oral cavity and pharynx. Controls were 124 subjects (including 52 females) admitted to the hospital for different non-neoplastic conditions unrelated to tobacco and alcohol consumption, with frequency matched to cases by age and sex. Smoking and drinking were strongly associated with an increased risk of oral cancer. Among consumers of both products, risks of oral cancer tended to combine in a multiplicative fashion and were increased more than 14-fold among those who consumed more than 15 cigarettes and seven or more drinks per day. Cessation of smoking was associated with reduced risk of this cancer. The risks varied by type of cigarettes smoked, being lower among those consuming filtered cigarettes only (OR = 1.6) than nonfilter (OR = 6.5) or mixed (OR = 4.2) cigarettes. High fruit intake was associated with significantly decreased risk (OR = 0.4) with the strongest significant inverse association found for fruit juices and citrus fruits ( < 0.01). After adjustment for tobacco smoking and alcohol drinking, poor dentition as evidenced by missing teeth, frequency of dental check-ups and frequency of teeth brushing emerged as a strong risk factor. Number of missing teeth and frequency of dental check-ups and frequency of tooth brushing showed increased ORs of 9.8, 11.9 and 3.2, respectively. Denture wearing did not affect oral cancer risk. No differences were detected in sexual practices (including oral sex and intercourse with prostitutes). In terms of attributable risk, smoking accounted for 57% of oral cancer cases in Poland, alcohol for 31% and low fruit intake for 12%. Attributable risks for low frequency of tooth brushing and dental check-ups were 56% and 47%, respectively. In conclusion, smoking and drinking cessation and increase of fresh fruit intake are likely to be effective preventive measures against oral cancer. These findings indicate also that poor oral hygiene may be an independent risk factor.     

Associations between smoking, passive smoking, GSTM-1, NAT2, and rectal cancer.

Cigarette smoking has been identified as a risk factor for colon cancer, however, much less is known about the association between cigarette smoking and rectal cancer. The purpose of this article is to evaluate the associations between rectal cancer and active and passive cigarette smoking and other forms of tobacco use. We also evaluate how genetic variants of GSTM-1 and NAT2 alter these associations. A population-based case-control study of 952 incident rectal cancer cases and 1205 controls was conducted. Detailed tobacco use information was collected as part of an interviewer-administered questionnaire. DNA was extracted from blood to examine genetic variants of GSTM-1 and NAT2. Cigarette smoking was associated with an increased risk of rectal cancer in men [odds ratio (OR)=1.5, 95% confidence interval (CI), 1.1-2.1 for current smokers; OR=1.7, 95% CI, 1.3-2.3 for smoking >20 pack-years of cigarettes relative to never-smokers]. After adjusting for active smoking, exposure to cigarette smoke of others also was associated with increased risk among men (OR=1.5, 95% CI, 1.1-2.0). Neither GSTM-1 genotype nor NAT2-imputed phenotype was independently associated with rectal cancer. However, the risk associated with smoking cigarettes among those who were GSTM-1 null relative to those who never smoked and had the GSTM-1 present genotype was OR=2.0 (95% CI, 1.2-3.3). This interaction was of borderline significance (P=0.08). Men who had the combined GSTM-1 present genotype and who were rapid acetylators had no increased risk from cigarette smoking. There were no significant associations between cigarette smoking and rectal cancer among women. This study shows that men who smoke cigarettes, especially those who smoke >20 pack-years, are at increased risk of rectal cancer. This association may be influenced by GSTM-1 genotype. Furthermore, exposure to cigarette smoke of others may increase risk of rectal cancer among men who do not smoke.     

Lung cancer risks in relation to vegetable and fruit consumption and smoking

In a case-control study on lung cancer, risk was analysed in relation to smoking habits and frequency of vegetable and fruit consumption. Lung cancer cases in West Sweden and population controls were interviewed using a questionnaire where the frequency of consumption of dietary items and smoking habits were assessed. The material presented comprises 177 female and 359 male confirmed cases of lung cancer and 916 population controls. There was a dose-response relationship in regard to the number of cigarettes smoked and the number of years smoked, the latter factor being more important. After adjustment for number of cigarettes smoked/day and number of years smoked, the risk for those who seldom consumed vegetables was about twice of that among those who consumed vegetables frequently, both among nonsmokers, smokers and former smokers. This risk increase in relation to vegetable consumption also was present for different smoking categories. A similar tendency, although less pronounced, was found for fruit consumption. The results demonstrate that dietary factors are related to the risk for lung cancer, although smoking is the dominant risk factor.     

Waterpipe Tobacco Smoking and Risk of Stomach Cancer: A Case-Control Study in Vietnamese Men

Objective: This study investigated the impacts of waterpipe tobacco (WTP) and cigarette smoking on stomach cancer development in Vietnamese men. Methods: A total of 80 stomach cancer cases and 146 controls were recruited in a hospital-based case-control study. Data on sociodemographic, anthropometric characteristics, tobacco smoking, and the dietary pattern was obtained based on a semi-quantitative food frequency and demographic lifestyle questionnaire; and venous anti-Helicobacter pylori IgG antibodies were tested by ELISA. Unconditional logistic regression analysis with adjustments for potential confounding was performed to estimate the association between target exposures and stomach cancer. Results: Compared to the never tobacco smokers, the risk of stomach cancer significantly increased among tobacco smokers (OR 2.95, 95%CI 1.26-6.90, p=0.013). Those who early started tobacco smoking before 26 years old had a high risk of SC (OR 3.04, 95%CI 1.29-7.20, p for trend=0.011). For types of tobacco, It was increased risk in exclusively cigarette smokers (OR 2.85, 95%CI 1.19-6.85, p=0.019) and in WPT smokers (OR 3.09, 95%CI 1.24-7.68, p=0.015). The daily frequency and longer duration of exclusively WPT or cigarette smoking tended to be significantly higher SC risk. Conclusions: The findings suggest that tobacco smoking, particularly water pipe tobacco smoking, dramatically and independently increased the risk of stomach cancer.     

Prospective study of smoking, antioxidant intake, and lung cancer in middle-aged women (USA)

Background: Although substantial evidence suggests that higher intake of fruits and vegetables can reduce the adverse impact of smoking on lung cancer risk, great uncertainty exists regarding the specific foods and their constituents that are protective. We therefore examine prospectively the relation between cigarette smoking and lung cancer incidence among women, and quantify the associations between dietary antioxidants, other nutrients, and lung cancer risk.Methods: In a 16-year prospective cohort study (the Nurses'2 Health Study), 593 cases of lung cancer were confirmed during 1,793,327 person-years of follow-up. Dietary data, including vitamin supplement use and food intake, were collected in 1980 using a validated semiquantitative food frequency questionnaire.Results: The risk of lung cancer increased with the number of cigarettes smoked and with early onset of cigarette smoking. The risk decreased rapidly with the discontinuation of smoking but took 15 years to fall to about the level of risk for women who had never smoked. Dietary intake of fat was not related to the risk of lung cancer. Although -carotene intake was not related to risk, intake of carrots showed a strong inverse relation: women who reported consuming five or more carrots per week had a relative risk of 0.4 (95% CI = 0.2–0.8) compared with the risk for women who never ate carrots.Conclusions: Smoking is the most important risk factor for lung cancer in women, as it is in men. Higher vegetable consumption, particularly of carrots, may significantly reduce the risk of lung cancer, but dietary modification cannot be considered a substitute for smoking prevention and cessation.     

Risk of pancreatic cancer in relation to medical history and the use of tobacco, alcohol and coffee

A population-based case-control study was conducted to examine the relationship between certain medical conditions, the use of tobacco, alcohol and coffee, and the incidence of pancreatic cancer. Cases (N = 148) were married men ages 20 through 74 years diagnosed with pancreatic cancer from July 1982 through June 1986. Controls (N = 188) were identified by random digit dialing. Wives, responding as surrogates for both cases and controls, were interviewed by telephone and completed, alone, a food frequency questionnaire. The risk of pancreatic cancer was increased in individuals with a history of diabetes or pancreatitis, and decreased in those with a history of tonsillectomy. Individuals who had ever smoked cigarettes were at elevated risk of disease. This excess risk was confined to current smokers, in whom the odds ratio was 3.2 (95% CI 1.8-5.7); the risk among former smokers resembled that in those who had never smoked. There was no excess risk of pancreatic cancer among those who had ever used other forms of tobacco, including pipe tobacco, cigars and chewing tobacco. After adjustment for demographic and dietary characteristics, there was no association between pancreatic cancer risk and the intake of coffee, beer, red wine, hard liquor or all alcohol combined; a slight reduction in risk was seen among those consuming white wine daily.     

Husband's smoking status and breast cancer risk in Japan: From the Takayama study

The effects of smoking on breast cancer remain unclear. We assessed the associations of subjects' or husbands' smoking status with breast cancer incidence in a population‐based prospective study in Japan. The subjects were 15 719 women aged 35 years or older. The follow up was conducted from September 1992 to March 2008. Cancer incidence was mainly confirmed through regional population‐based cancer registries. Breast cancer was defined as code C50 according to the International Classification of Diseases and Health Related Problems, 10th Revision. Lifestyle, including smoking status, was assessed with a self‐administered questionnaire. Alcohol consumption was assessed with a validated food‐frequency questionnaire. After multivariate adjustments for age, body mass index, alcohol consumption, physical activity, education, age at menarche, age at first delivery, menopausal status, number of children and history of hormone replacement therapy, active smoking was not associated with the risk of breast cancer. Compared with never smokers whose husband had never smoked, the risks of breast cancer were 1.98 (95% CI: 1.03–3.84) among never smokers whose husband was a current smoker of 21 cigarettes per day or more. The increased risk of breast cancer among women having a smoking husband was pronounced among those who did not habitually consume alcohol. These results suggest that exposure to smoke from husbands is a potential risk factor for breast cancer. The impact of alcohol consumption on the increased breast cancer risk from passive smoking needs to be addressed in further studies.     

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.     

Smoking and liver cancer in China: case-control comparison of 36,000 liver cancer deaths vs. 17,000 cirrhosis deaths

Liver cancer and liver cirrhosis are common causes of death in China, where chronic lifelong hepatitis B infection is a major cause of both diseases. To help determine whether smoking is a cofactor for the development of liver cancer, we ascertained retrospectively the smoking habits of 36,000 adults who had died from liver cancer (cases) and 17,000 who had died from cirrhosis (controls) in 24 Chinese cities and 74 rural counties. Calculations of the smoker vs. nonsmoker risk ratios (RR) for liver cancer mortality were standardised for age and locality. Among adult men (aged 35+) there was a 36% excess risk of death from liver cancer among smokers (smoker vs. nonsmoker standardised risk ratio [RR] =1.36, with 95% confidence interval [CI] 1.29-1.43, 2p<0.00001; attributable fraction 18%). In the general male population this indicates absolute risks of death from liver cancer before age 70 of about 4% in smokers and 3% in nonsmokers (in the absence of other causes). Most liver cancer, however, occurs among the 10-12% of men with haematological evidence of chronic hepatitis B infection, so among them the corresponding risks would be about 33% in smokers and 25% in nonsmokers. The RR was approximately independent of age, was similar in urban and rural areas, was not significantly related to the age when smoking started but was significantly (p<0.001) greater for cigarette smokers than for smokers of other forms of tobacco. Among men who smoked only cigarettes, the RR was significantly (p<0.001 for trend) related to daily consumption, with a greater hazard among those who smoked 20/day (RR 1.50, 95% CI 1.39-1.62) than among those who smoked fewer (mean 10/day: RR=1.32, 95% CI 1.23-1.41). Smoking was also associated with a significant excess of liver cancer death in women (RR 1.17, 95% CI 1.06-1.29, 2p=0.003; attributable fraction 3%), but fewer women (17%) than men (62%) were smokers, and their cigarette consumption per smoker was lower. Among women who smoked only cigarettes, there was a significantly greater hazard among those who smoked at least 20/day (mean 22/day: RR=1.45, 95% CI 1.18-1.79) than among those who smoked fewer (mean 8/day: RR=1.09, 95% CI 0.94-1.25). These associations indicate that tobacco is currently responsible for about 50,000 liver cancer deaths each year in China, chiefly among men with chronic HBV infection.     

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.     

Diet and high risk of stomach cancer in Shandong, China

A case-control investigation involving interviews with 564 stomach cancer patients and 1131 population-based controls was conducted to evaluate reasons for the exceptionally high rates of stomach cancer in Linqu, a rural county in Shandong Province in northeast China. Daily consumption of sour pancakes, a fermented indigenous staple, was associated with a 30% increase in risk. Risks of stomach cancer were also increased by 2- to 3-fold among persons with prior chronic gastritis or gastric ulcer, by 80% among those with stomach cancer in a family member, by 50% among men who smoked one or more packs of cigarettes/day, by 40% among those who preferred salty foods, and by 50% among families with moldy grain supplies. In contrast, risks tended to decrease in proportion to increasing consumption of fresh vegetables and fruits. This protective effect was more pronounced for vegetables, with those in the highest quartile of intake at less than one-half the risk of those in the lowest. Stomach cancer risks also declined with increasing dietary intake of carotene, vitamin C, and calcium, but not retinol. These findings provide leads to dietary factors that contribute to the high rates in Linqu, where stomach cancer is the leading cause of cancer and has not yet begun to decline as in other parts of the world.     

Lung cancer and women: results of a French case-control study

Ninety-six women with histologically confirmed lung cancer and 192 matched controls were involved in an international case-control study conducted from 1976 to 1980. The aim of this study was an examination of the effects of different smoking habits, especially the type of cigarettes smoked (light or dark tobacco and filter or nonfilter use) on the occurrence of lung cancer in French females. All these patients were either nonsmokers or lifetime cigarette smokers. Matched relative risk (RR) of smokers compared to nonsmokers was found to be increased for both Kreyberg I (RR = 6.6) and Kreyberg II (RR = 2.1) categories; however, this increase was significant (P less than 0.0001) only for Kreyberg I lung cancer. A significant increase (P less than 0.0001) in matched RR was found with early age at first cigarette smoked, daily consumption, duration of smoking, frequency of inhalation, use of dark tobacco and use of nonfilter cigarettes. Matched RR associated with smokers not always using dark tobacco and those smoking only dark tobacco as compared to nonsmokers were significantly increased (trend test P less than 0.0001). On the contrary, the increase of RR was not significant when either daily consumption, or duration of smoking, or age at first cigarette was taken into account. Lung cancer appeared to be associated with daily consumption and use of nonfilter cigarettes in a matched logistic regression.     

吸烟与原发性肝癌关系的巢式病例对照研究

目的 分析吸烟与上海市区中老年男性原发性肝癌的关系.方法 应用巢式病例对照研究方法,对一个18 244名男性队列随访11年,以队列中213例新发肝癌患者作为病例组,按照患者年龄、采样日期、同居住区等配对条件,从队列中随机抽取1094名健康人作为对照组.使用配对Logistic回归分析,调整可能的混杂因素,估计吸烟对肝癌发生的危险度和95%可信区间(CI).结果 调整肝炎、肝硬化、胆石症或其他胆囊病史及乙型肝炎病毒感染等可能的混杂因素后,男性吸烟者患肝痛的危险性是不吸烟者的1.91倍(95%CI为1.28～2.86),日随着每天吸烟量、吸烟年限和吸烟包年数的增加而增加.每天吸烟≥20支者、吸烟≥40年者和吸烟37包年者患肝癌的相对危险度分别为2.16(95%CI为1.37～3.40)、2.14(95%CI为1.18～3.87)和2.12(95%CI为1.21～3.74).吸烟开始年龄越小,危险性越大,吸烟开始年龄<20岁者患肝癌的危险性为2.57(95%CI为1.50～4.40).结论 吸烟是上海市区男性原发性肝癌的危险因素.