Alcohol consumption and lung cancer risk in never smokers: a meta-analysis

BackgroundThe role of alcohol consumption as an independent risk factor for lung cancer is controversial. Since drinking and smoking are strongly associated, residual confounding by smoking may bias the estimation of alcohol consumption and lung cancer risk relation. Therefore, we undertook a meta-analysis to quantitatively assess the association between alcohol and risk of lung cancer in never smokers.MethodsAfter a literature search in Medline, we included all case–control and cohort studies published up to January 2010 that reported an estimate of the association between alcohol intake and lung cancer risk in never smokers.ResultsWe selected 10 articles, including 1913 never smoker lung cancer cases. The random-effects pooled relative risk (RR) for drinkers versus nondrinkers was 1.21 [95% confidence interval (CI) 0.95–1.55]. The same figure was 1.05 (95% CI 0.89–1.23) after the exclusion of one outlier study. At the dose–response analysis, RR for an increase in alcohol intake of 10 g/day was 1.01 (95% CI 0.92–1.10).ConclusionsAlcohol consumption was not associated with lung cancer risk in never smokers. Even if the synergistic effect of smoking and alcohol cannot be ruled out, our results suggest that alcohol does not play an independent role in lung cancer etiology.     

Dietary patterns associated with male lung cancer risk in the Netherlands Cohort Study.

The objective of this article was to study the association between dietary patterns and lung cancer incidence in the Netherlands Cohort Study on Diet and Cancer. The baseline measurement of this prospective case cohort study that was completed by 58,279 men in 1986 included a self-administered questionnaire on dietary intake, smoking habits, and other covariates. Follow-up was established by computerized record linkage to cancer registries and a pathology register. After 9.3 years of follow-up, 1,426 confirmed cases of incident male lung cancer were detected. Five dietary patterns were identified by exploratory factor analysis in a randomly sampled subcohort (n = 2,190). The dietary pattern labeled "salad vegetables" was associated with decreased risk of lung cancer [rate ratios (RR)(Q5), 0.75; 95% confidence interval (CI), 0.55-1.01], after multivariate adjustment. This inverse association was most evident among current and former smokers. A dietary pattern labeled "sweet foods" was also inversely associated with lung cancer risk (RR(Q5), 0.62; 95% CI, 0.43-0.89). However, the higher intake of monosaccharides and disaccharides, fruits, and lower consumption of alcohol associated with this pattern could not account for its full protective effect. The "pork, processed meat, and potatoes" pattern was nonsignificantly associated with increased risk (RR(Q5), 1.44; 95% CI, 0.99-2.09), and this positive association was most evident among current smokers. The other dietary patterns characterized by brown/white bread substitution and by consumption of cooked vegetables were not associated with lung cancer risk. These results show how studying both single factors and dietary patterns gives more insight into the complex, and often seemingly inconsistent, associations between diet and cancer.     

Intake of flavonoids and risk of cancer in Finnish men: The Kuopio Ischaemic Heart Disease Risk Factor Study

Limited amount of evidence suggests that high intake of flavonoids could be associated with decreased risk of lung and colorectal cancer, but more studies are needed. In this prospective cohort study, we assessed the relation between the intakes of 26 flavonoids from 5 subclasses; flavonols, flavones, flavanones, flavan-3-ols and anthocyanidins, and the risk of lung, prostate and colorectal cancer. The study population consisted of 2,590 middle-aged eastern Finnish men of the prospective population-based Kuopio Ischaemic Heart Disease Risk Factor (KIHD) Study. The mean intake of flavonoids was 131.0 +/- 214.7 mg/day. During the mean follow-up time of 16.2 years, 62 lung, 138 prostate, and 55 colorectal cancers occurred. All lung cancer cases occurred among either current smokers (n = 50) or previous smokers (n = 12). After adjustment for age, examination years, body mass index, smoking status, pack-years of smoking, physical activity and intakes of alcohol, total fat, saturated fat, fiber, vitamin C and E, relative risk (RR) for lung cancer was 0.27 (95% CI: 0.11-0.66) for the highest quarter of total flavonoid intake as compared with the lowest quarter. Out of 5 flavonoid subclasses, flavonols and flavan-3-ols were associated with lung cancer, for the highest quarter of intake the RR were 0.29 (95% CI: 0.11-0.78) and 0.24 (95% CI: 0.09-0.64), respectively. No association between flavonoid intake and risk of prostate or colorectal cancer were found. We conclude that high intake of flavonoids is associated with decreased risk of lung cancer in middle-aged Finnish smoking men.     

Cohort analysis of fruit and vegetable consumption and lung cancer mortality in European men

Our aim was to examine the relationship between fruit and vegetable consumption and lung cancer mortality in a cohort of European males. Around 1970, dietary intake of Finnish, Italian and Dutch middle-aged men was assessed using a cross-check dietary history. Complete baseline information was available for 3,108 men, of whom 1,578 were baseline smokers. We used Cox proportional hazard analyses to calculate risk estimates for the consumption in country-specific tertiles on lung cancer in smokers. During 25 years of follow-up, 149 lung cancer deaths occurred in the smokers. Fruit consumption was inversely associated with lung cancer mortality among smokers; compared with the lowest, adjusted RRs for the intermediate and highest tertiles were 0.56 (0.37-0.84) and 0.69 (0.46-1.02), p-trend 0.05. Only in the Dutch cohort was this association statistically significant [adjusted relative risks (RRs) 1.00, 0.33 (0.16-0.70) and 0.35 (0.16-0.74), p-trend 0.004]. In Finland lung cancer risk was lower with higher fruit intake but not significantly, whereas in Italy no association was observed. Stratifying on cigarette smoking intensity (non, light and heavy) revealed an inverse association in the heavy smokers only [adjusted RRs (95% confidence intervals [CI]) 1; 0.47 (0.26-0.84); 0.40 (0.20-0.78)). Vegetable consumption was not related to lung cancer risk in smokers. However, analyses stratified on cigarette smoking intensity gave some indication for a lower lung cancer risk with higher intake. In conclusion, in this prospective analysis among European smoking men, fruit intake was inversely related to lung cancer mortality. This association was confined to heavy cigarette smokers.     

Alcohol and lung cancer risk among never smokers: A pooled analysis from the international lung cancer consortium and the SYNERGY study

It is not clear whether alcohol consumption is associated with lung cancer risk. The relationship is likely confounded by smoking, complicating the interpretation of previous studies. We examined the association of alcohol consumption and lung cancer risk in a large pooled international sample, minimizing potential confounding of tobacco consumption by restricting analyses to never smokers. Our study included 22 case‐control and cohort studies with a total of 2548 never‐smoking lung cancer patients and 9362 never‐smoking controls from North America, Europe and Asia within the International Lung Cancer Consortium (ILCCO) and SYNERGY Consortium. Alcohol consumption was categorized into amounts consumed (grams per day) and also modelled as a continuous variable using restricted cubic splines for potential non‐linearity. Analyses by histologic sub‐type were included. Associations by type of alcohol consumed (wine, beer and liquor) were also investigated. Alcohol consumption was inversely associated with lung cancer risk with evidence most strongly supporting lower risk for light and moderate drinkers relative to non‐drinkers (>0–4.9 g per day: OR = 0.80, 95% CI = 0.70–0.90; 5–9.9 g per day: OR = 0.82, 95% CI = 0.69–0.99; 10–19.9 g per day: OR = 0.79, 95% CI = 0.65–0.96). Inverse associations were found for consumption of wine and liquor, but not beer. The results indicate that alcohol consumption is inversely associated with lung cancer risk, particularly among subjects with low to moderate consumption levels, and among wine and liquor drinkers, but not beer drinkers. Although our results should have no relevant bias from the confounding effect of smoking we cannot preclude that confounding by other factors contributed to the observed associations. Confounding in relation to the non‐drinker reference category may be of particular importance.     

Tobacco, alcohol use, and risks of laryngeal and lung cancer by subsite and histologic type in Turkey

Effects of tobacco smoking and alcohol use on risks of cancers of thelarynx and lung have been evaluated extensively in industrialized countries.Few studies on the effect of these risk factors have been reported fromdeveloping countries. We conducted a case-control study to evaluate risks oflaryngeal and lung cancers in men by subsite and cell type in relation tosmoking and alcohol drinking in Turkey, a country where smoking and alcoholconsumption patterns are different from those in industrialized countries. Weidentified 832 laryngeal and 1,210 lung cancer cases and 829 controls withinformation on smoking and alcohol use (amount and duration) and histologiccell type from an oncology treatment center of a Social Security Agencyhospital in Istanbul, Turkey, admitted between 1979 and 1984. Both laryngealand lung cancer showed significant associations with smoking and alcoholdrinking, but no monotonic dose-response was obtained for alcohol drinking.Among smokers, the highest risks were observed in the supraglottis region ofthe larynx (odds ratio [OR] = 4.1) after adjustment for age and alcohol use.Among alcohol drinkers, the highest risks were observed in the glottis regionof the larynx (OR = 1.7) after adjustment for age and smoking. In theanalysis by the cell type of lung cancer among ever-smokers, small cell typeshowed the highest risk (OR = 5.4), while it showed no association withalcohol drinking. Cumulative cigarette use (pack-years) and number ofcigarettes per day showed stronger associations than years smoked for bothcancer sites. The relative risks of joint exposure to smoking and alcoholwere 12.2 for laryngeal cancer and 14.1 for lung cancer among heavy smokersand heavy alcohol drinkers. This study provides epidemiologic evidence fromTurkey that smoking and alcohol use are associated with risks of cancers ofthe larynx and lung.     

Dietary acrylamide intake and the risk of cancer among Finnish male smokers

Objective

To assess the association between dietary acrylamide intake and the risk of cancer among male smokers.

Methods

The study consisted of 27,111 male smokers, aged 50–69 years, without history of cancer. They were participants of the Alpha-Tocopherol, Beta-Carotene Cancer Prevention (ATBC) Study in Finland. The men completed a validated dietary questionnaire and a questionnaire on general background characteristics (including smoking habits) at baseline. Incident cases of cancer were identified through the national Finnish Cancer Registry.

Results

During an average 10.2 year follow-up, 1,703 lung cancers, 799 prostate cancers, 365 urothelial cancers, 316 colorectal cancers, 224 stomach cancers, 192 pancreatic cancers, 184 renal cell cancers, and 175 lymphomas were diagnosed. Dietary acrylamide intake was positively associated with the risk of lung cancer; relative risk (RR) in the highest versus the lowest quintile in the multivariable-adjusted model was 1.18 ((95% confidence interval (CI) 1.01–1.38, p for trend 0.11). Other cancers were not associated with acrylamide intake.

Conclusions

High acrylamide intake is associated with increased risk of lung cancer but not with other cancers in male smokers.     

Oral and oropharyngeal cancer in Spain: influence of dietary patterns.

Cancer of the oral cavity and oropharynx is a major public health problem in Spain. Tobacco and alcohol have been identified as the two major risk factors for oral cancer in most western populations. Other risk factors include diets low in fruits and vegetables, but the impact of dietary habits on the risk of these cancers has never been assessed in Spain. The objective of this study was to elucidate the role of dietary habits in oral and oropharyngeal cancer, a multicentric case-control study was conducted in three areas of Spain (Barcelona, Granada and Sevilla) between 1996 and 1999. Cases were 375 patients (71 women), with incident, histologically confirmed cancer of the oral cavity or oropharynx, and controls were 375 subjects (71 women) admitted to hospitals for conditions unrelated to smoking or alcohol drinking. Data were analysed using multivariate logistic regression procedures. After allowance for education, tobacco and alcohol use, a significant inverse association with the risk of oral and oropharyngeal cancer was found for total consumption of total green vegetables (OR 0.54, 95% CI = 0.34-0.87) and total fruit (OR 0.52, 95% CI = 0.34-0.79) with significant trends in risk. We found that the protective effect of each of these food items was consistently larger among current smokers and among heavy alcohol drinkers, following a multiplicative effect model. In conclusion, this study provides further support to the beneficial effect of high intake of vegetables and fruits on the risk of developing cancers of the oral cavity and oropharynx in Spain, particularly among current smokers and heavy alcohol drinkers.     

Dietary folate intake and lung cancer risk in former smokers: a case-control analysis.

No studies have focused on the role of dietary folate intake in risk of lung cancer in former smokers, in whom dietary folate intake is less likely confounded with current smoking. Therefore, we evaluated the association between dietary folate intake and risk of lung cancer in a population of 470 histopathologically confirmed incident lung cancer cases from M. D. Anderson Cancer Center and 472 cancer-free controls from enrollees at a community-based multispecialty physician practice, frequency-matched on age (5 years), sex, and ethnicity. Dietary folate intake levels were estimated from a National Cancer Institute standard food frequency questionnaire. Unconditional logistic regression analyses were used to calculate the crude and adjusted ORs and their 95% CIs. Dietary folate intake from natural food was significantly higher among the controls than among the cases (P < 0.001), and folate intake above the control median value was associated with a 40% decreased risk of lung cancer (adjusted OR, 0.60; 95% CI, 0.45-0.79). A significant inverse dose-response relationship between increasing dietary folate and decreasing risk of lung cancer was also evident (adjusted OR, 1.02; 95% CI, 0.71-1.47; OR, 0.67; 95% CI, 0.46-0.99; and OR, 0.53; 95% CI, 0.35-0.80 for the second, third, and fourth quartiles of average folate intake, respectively; P for trend <0.001). A more pronounced inverse association between dietary folate intake and lung cancer risk was observed among subjects who drank alcohol, had smoked relatively more, those who did not take supplemental folate, and those who reported a family history of lung cancer. Our data suggest that there is a possible protective role of dietary folate in lung carcinogenesis, a finding which may have implications in public health and cancer prevention.     

饮酒与膀胱癌关系的全人群病例对照研究

目的探讨饮酒与膀胱癌发生的关系。方法采用全人群为基础的病例对照研究,共调查1996年1月1日~1998年12月31日期间确诊的上海市区膀胱癌新发病例608例,健康人群对照607例。采用非条件logistic回归分析,调整吸烟等可能的混杂因素,以估计饮酒对膀胱癌发生的危险度及其95%可信区间。结果与不饮酒者相比,男、女性饮酒者患膀胱癌相对危险度分别是1.22(95%CI0.94~1.59)、0.50(95%CI0.13~1.90)。男性随总酒精摄入量增加患膀胱癌的危险有增加趋势,OR值分别为1.10(1~80g/d)和1.56(>80g/d)(趋势检验P=0.043)。男性总酒精摄入量与饮酒年限的联合作用分析表明,与不饮酒者相比,总酒精摄入量超过80g/d、饮酒年限超过40年者患膀胱癌危险度为2.11(95%CI1.11~4.01)。将饮酒分3层、吸烟分4层进行男性饮酒与吸烟的联合作用分析,结果显示总酒精摄入量>80g/d且吸烟≥35包年者的OR值为2.78(95%CI1.46~5.28)。未发现各饮酒种类与男性膀胱癌有显著关联。在不吸烟男性组中的分析显示,饮酒习惯的OR值均没有统计学意义。结论饮酒可能与男性膀胱癌有一定联系,但作用较弱,似乎主要表现为对吸烟男性的作用。     

Physical activity and lung cancer risk in male smokers

We examined the association between physical activity and lung cancer in a prospective cohort of 27,087 male smokers, ages 50-69 years, enrolled in the Alpha-Tocopherol, Beta Carotene Cancer Prevention (ATBC) Study. After an average of 10 years of follow-up, 1,442 lung cancer cases were diagnosed. Cox proportional hazards models were used to estimate the relative risk (RR) and 95% confidence intervals (CI) of lung cancer associated with self-reported occupational and leisure-time activity, adjusted for age, supplement group, body mass index, cigarettes smoked daily, years of smoking, education, energy intake and vegetable intake. There were no associations between occupational, leisure-time or combined categories of physical activity with lung cancer risk; however, age appeared to modify the effect of leisure-time activity (p = 0.02). Within increasing quartiles of age, the RRs (CI) for men active in leisure time compared to sedentary men were 0.77 (0.54-1.09), 0.74 (0.57-0.95), 1.09 (0.89-1.33) and 1.03 (0.88-1.21). These data suggest that among smokers, neither occupational nor leisure-time activity is associated with lung cancer risk. There may, however, be some modest risk reduction associated with leisure activity among younger smokers. Published 2002 Wiley-Liss, Inc.     

Alcohol consumption and lung cancer in White males

Experimental and epidemiologic investigations in alcoholic and nonalcoholic populations have suggested a role of alcohol in lung carcinogenesis. The association between alcohol consumption and lung cancer was investigated among 280 White males with histologically confirmed, primary lung cancer and 564 White male controls, participants in the Western New York Diet Study (United States). Among heavy smokers (over 40 pack-years), total alcohol consumption was associated with an increased risk of lung cancer with adjustment for age, years of education, pack-years of cigarette smoking, and intake of carotenoids and fat. In this group, the odds ratio for drinkers of more than 24 drinks per month was 1.6 compared with those who drank less. Drinkers of more than 12 beers per month were 1.6 times more likely to develop lung cancer than nondrinkers of beer after controlling for age, years of education, and cigarette smoking (95 percent confidence interval = 1.0–2.4, P for trend = 0.003). Occupational and dietary factors did not seem to explain these findings. Although cigarette smoking is the major cause of lung cancer, the role of alcohol, independent or in interaction with cigarette smoking, deserves further investigation.Drs Bandera, Freudenheim, Graham, and Marshall, Ms Swanson, and Mr Brasure and with the Department of Social and Preventive Medicine, State University of New York at Buffalo, Buffalo, NY, USA. Dr Haughey is with the School of Nursing, State University of New York at Buffalo, Buffalo, NY, USA. Dr Wilkinson is with Department of Preventive Medicine and Community Health, University of Texas Medical Branch, Galveston, TX, USA. Address correspondence to Dr Bandera, Department of Social and Preventive Medicine, State University of New York at Buffalo, 270 Farber Hall, Buffalo, NY 14214, USA. This investigation was supported in part by US Public Health Service Grants CA 09051 and CA 11535, and American Cancer Society Grant PDT-434. These data were presented, in part, at the Annual Meeting of the Federation of American Societies of Experimental Biology, Atlanta, GA, USA, 1991; and at the Annual Meeting of the Society for Epidemiologic Research, Buffalo, NY, USA, 1991.     

Prospective study of fruit and vegetable consumption and risk of lung cancer among men and women

BACKGROUND: Diets high in fruits and vegetables have been shown to be associated with a lower risk of lung cancer. beta-Carotene was hypothesized to be largely responsible for the apparent protective effect, but this hypothesis was not supported by clinical trials. METHODS: We examined the association between lung cancer risk and fruit and vegetable consumption in 77 283 women in the Nurses' Health Study and 47 778 men in the Health Professionals' Follow-up Study. Diet was assessed with the use of a food-frequency questionnaire that included 15 fruits and 23 vegetables. We used logistic regression models to estimate relative risks (RRs) of lung cancer within each cohort. All statistical tests were two-sided. RESULTS: We documented 519 lung cancer cases among the women and 274 among the men. Total fruit and vegetable consumption was associated with a modestly lower risk of lung cancer among the women but not among the men. The RR for the highest versus lowest quintile of intake was 0.79 (95% confidence interval [CI] = 0.59-1.06) among the women and 1.12 (95% CI = 0.74-1.69) among the men after adjustment for smoking status, quantity of cigarettes smoked per day, time since quitting smoking, and age at initiation of smoking. However, total fruit and vegetable consumption was associated with a lower risk of lung cancer among never smokers in the combined cohorts, although the reduction was not statistically significant (RR = 0.63; 95% CI = 0.35-1.12 in the highest tertile). CONCLUSION: Higher fruit and vegetable intakes were associated with lower risks of lung cancer in women but not in men. It is possible that the inverse association among the women remained confounded by unmeasured smoking characteristics, although fruits and vegetables were protective in both men and women who never smoked.     

Dietary folate consumption and risk of ovarian cancer: a prospective cohort study.

Deficient dietary folate intake may be associated with increased cancer risk in humans owing to DNA damage resulting from impaired nucleotide excision repair. It is conceivable that an association with folate may be modified by alcohol and/or methionine intake given that alcohol consumption and low methionine intakes both increase dietary folate requirements. In the cohort study reported here, we examined the association between dietary folate intake and ovarian cancer risk, overall and within strata defined by alcohol and methionine intakes. The investigation was conducted in 49 613 Canadian women who were participants in the National Breast Screening Study and who completed self-administered lifestyle and food frequency questionnaires between 1980 and 1985. Linkages to cancer and national mortality databases yielded data on cancer incidence and deaths among cohort members, with follow-up ending between 1998 and 2000. During a mean 16.4 years of follow-up, we observed 264 incident ovarian cancer cases among 48 766 women for whom data were available. Dietary folate intake was associated with a 25% decrease in risk of ovarian cancer for the highest versus the lowest quartile level of intake (hazard ratio=0.75, 95% confidence interval=0.42-1.34, Ptrend=0.25). On stratification by alcohol intake, dietary folate was not associated with ovarian cancer risk among women consuming <4 g/day of alcohol, but there was some suggestion of reduced risk at relatively high levels of folate intake among women consuming > or =4 g/day of alcohol/day (Ptrend=0.09; Pinteraction=0.22). The association between folate and ovarian cancer risk did not vary by strata of methionine intake (Pinteraction=0.98). Our findings, while not statistically significant, suggest that relatively high dietary folate intake may be associated with a reduction in ovarian cancer risk among women with relatively high alcohol consumption and among those with relatively high methionine intake.     

Alcohol and risk of lung cancer among Japanese men: data from a large-scale population-based cohort study,the JPHC study

Objective  Although large-scale studies, including meta-analyses, on the association between alcohol consumption and lung cancer have been reported, the risk of lung cancer in extremely high consumption groups (≥450 g ethanol/week) in both current smokers and nonsmokers remains unclear. Here, we investigated the association between alcohol consumption and lung cancer incidence. Methods  We conducted a population-based prospective cohort study in 46,347 Japanese men aged 40–69 years with no history of cancer at baseline in 1990–1994. We used Cox proportional hazards regression analysis to estimate the hazard ratio (HR) and 95% confidence interval (CI) of lung cancer incidence according to alcohol consumption. Results  During the 14-year follow-up period, we documented 651 cases of lung cancer. We found a positive association between alcohol consumption and lung cancer risk confined to current smokers. Compared with occasional drinkers, the multivariate HRs (95% CI) in the highest category (≥450 g ethanol/week) were 1.31 (0.89–1.94) among total participants, 0.58 (0.26–1.30) (p for trend = 0.49) among nonsmokers, and 1.69 (1.05–2.72) (p for trend = 0.02) among current smokers. Conclusions  Among this population with a large variation in alcohol consumption, alcohol consumption was not an independent risk factor for lung cancer except for current smokers. Study group members are listed in the Appendix.     

Diet, reproductive factors and lung cancer risk among Chinese women in Singapore: evidence for a protective effect of soy in nonsmokers.

The factors associated with risk of lung cancer among nonsmokers have not been fully elucidated, but dietary factors have consistently been shown to play a role. Chinese women are unique in having a high incidence of lung cancer despite a low smoking prevalence. This population is also known to have a high intake of soy, a dietary source of phytoestrogens. We conducted a hospital-based case-control study among Singapore Chinese women, comprising 303 cases and 765 age-matched controls, of whom 176 cases and 663 controls were lifetime nonsmokers. Data on demographic background, reproductive factors and dietary intake of fruit, vegetables and soy foods were obtained by in-person interview. We observed an inverse association between intake of total, cruciferous and non-cruciferous vegetables and risk of lung cancer among smokers. Although smokers in the highest tertile of fruit intake also had a lower risk, this was not statistically significant. Higher intake of soy foods significantly reduced risk of lung cancer among lifetime nonsmokers, but not among smokers. When soy isoflavonoid intake in mg/week was computed based on frequency and portion size of intake of eight common local soy foods, the adjusted OR among nonsmokers for the highest tertile compared to the lowest was 0.56, 95% CI 0.37-0.85 (p for trend <0.01). Fruit intake was also significantly associated with reduced lung cancer risk among nonsmokers, but the effect was not significant after adjustment for soy intake. On the other hand, soy intake remained an independent predictor of risk after controlling for fruit intake. Reproductive effects were also primarily confined to lifetime nonsmokers, among whom having 3 or more livebirths (adjusted OR 0.65, 0.44-0.96) and a menstrual cycle length of more than 30 days (OR 0.46, 0.25-0.84) accorded a significantly reduced risk of lung cancer. Place of birth was significantly associated with risk among nonsmokers (OR 2.6, 1.7-3.9 for China-born vs. local born) but not among smokers. When analysis was restricted to nonsmokers with adenocarcinomas, the dietary effects were consistent or enhanced. On stepwise regression, soy intake and cycle length emerged as the independent dietary and reproductive predictors of lung cancer risk in nonsmokers. These findings are consistent with other evidence suggesting an involvement of estrogen-related pathways in lung cancer among non-smoking women.     

Impact of alcohol drinking on total cancer risk: data from a large-scale population-based cohort study in Japan

We conducted a cohort study of alcohol consumption and total cancer incidence and mortality in 73,281 subjects (35,007 men and 38,274 women) aged 40-59 years old at baseline over a 10-year follow-up period. During 1990-2001, a total of 3403 cases of newly diagnosed cancer and 1208 cancer deaths were identified. In men, the lowest risk of developing cancer was observed among occasional drinkers, and a linear positive association with increased ethanol intake was noted (hazard ratio 1.18 for 1-149 g per week, 1.17 for 150-299 g per week, 1.43 for 300-449 g per week, 1.61 for > or = 450 g per week, P for trend < 0.001). The positive relation was similar for cancer incidence and mortality, but was more striking among current smokers and alcohol-related cancers. Relatively few women were regular drinkers. Our results suggest that increased ethanol intake linearly elevates the risk of cancer, and that nearly 13% of cancers among males in this study were due to heavy drinking (> or = 300 g per week of ethanol), to which smoking substantially contributed. The simultaneous reduction of smoking is therefore important for reducing the effect of alcohol on cancer risk.     

Serum alpha-tocopherol and subsequent risk of lung cancer among male smokers.

BACKGROUND: Higher blood levels of alpha-tocopherol, the predominant form of vitamin E, have been associated in some studies with a reduced risk of lung cancer, but other studies have yielded conflicting results. To clarify this association, we examined the relationship between prospectively collected serum alpha-tocopherol and lung cancer in the Alpha-Tocopherol, Beta-Carotene Cancer Prevention (ATBC) Study cohort. METHODS: The ATBC Study was a randomized, clinical trial of 29 133 white male smokers from Finland who were 50-69 years old and who had received alpha-tocopherol (50 mg), beta-carotene (20 mg), both, or neither daily for 5-8 years. Data regarding medical histories, smoking, and dietary factors were obtained at study entry, as was a serum specimen for baseline alpha-tocopherol determination. alpha-Tocopherol measurements were available for 29 102 of the men, among whom 1144 incident cases of lung cancer were diagnosed during a median observation period of 7.7 years. The association between alpha-tocopherol and lung cancer was evaluated with the use of multivariate proportional hazards regression. RESULTS: A 19% reduction in lung cancer incidence was observed in the highest versus lowest quintile of serum alpha-tocopherol (relative risk = 0.81; 95% confidence interval = 0. 67-0.97). There was a stronger inverse association among younger men (<60 years), among men with less cumulative tobacco exposure (<40 years of smoking), and possibly among men receiving alpha-tocopherol supplementation. CONCLUSIONS: In the ATBC Study cohort, higher serum alpha-tocopherol status is associated with lower lung cancer risk; this relationship appears stronger among younger persons and among those with less cumulative smoke exposure. These findings suggest that high levels of alpha-tocopherol, if present during the early critical stages of tumorigenesis, may inhibit lung cancer development.     

Alcohol drinking and primary liver cancer: a pooled analysis of four Japanese cohort studies

Because studies of the association between alcohol intake and the risk of primary liver cancer use varying cut-off points to classify alcohol intake, it is difficult to precisely quantify this association by meta-analysis of published data. Furthermore, there are limited data for women in prospective studies of the dose-specific relation of alcohol intake and the risk of primary liver cancer. We analyzed original data from 4 population-based prospective cohort studies encompassing 174,719 participants (89,863 men and 84,856 women). After adjustment for a common set of variables, we used Cox proportional hazards regression to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) of primary liver cancer incidence according to alcohol intake. We conducted a meta-analysis of the HRs derived from each study. During 1,964,136 person-years of follow-up, 804 primary liver cancer cases (605 men and 199 women) were identified. In male drinkers, the multivariate-adjusted HRs (95% CI) for alcohol intakes of 0.1-22.9, 23.0-45.9, 46.0-68.9, 69.0-91.9 and ≥92.0 g/day, as compared to occasional drinkers, were 0.88 (0.57-1.36), 1.06 (0.70-1.62), 1.07 (0.69-1.66), 1.76 (1.08-2.87) and 1.66 (0.98-2.82), respectively (p for trend = 0.015). In women, we observed a significantly increased risk among those who drank ≥23.0 g/day, as compared to occasional drinkers (HR: 3.60; 95% CI: 1.22-10.66). This pooled analysis of data from large prospective studies in Japan indicates that avoidance of (1) heavy alcohol drinking (≥69.0 g alcohol/day) in men and (2) moderate drinking (≥23.0 g alcohol/day) in women may reduce the risk of primary liver cancer.     

Vitamin E intake and the lung cancer risk among female nonsmokers: A report from the Shanghai Women's Health Study

Vitamin E includes several tocopherol isoforms, which may reduce lung cancer risk, but past studies evaluating the association between vitamin E intake and lung cancer risk were inconsistent. We prospectively investigated the associations between tocopherol intake from diet and from supplements with lung cancer risk among 72,829 Chinese female nonsmokers aged 40–70 years and participating in the Shanghai Women's Health Study (SWHS). Dietary and supplement tocopherol exposure was assessed by a validated food‐frequency questionnaire at baseline and reassessed for change in intake during follow‐up. Cox proportional hazards models with time‐dependent covariates were used to calculate multivariate‐adjusted hazard ratios (HRs) and 95% confidence interval (CIs) for lung cancer. After 12.02 years of follow‐up, 481 women were diagnosed with lung cancer. Total dietary tocopherol was inversely associated with lung cancer risk among women meeting dietary guidelines for adequate intake (AI) of tocopherol (14 mg/day or more: HR: 0.78; 95% CI 0.60–0.99; compared with the category less than AI). The protective association between dietary tocopherol intake and lung cancer was restricted to women exposed to side‐stream smoke in the home and workplace [HR = 0.53 (0.29–0.97), p‐trend = 0.04]. In contrast, vitamin E supplement use was associated with increased lung cancer risk (HR: 1.33; 95% CI: 1.01–1.73), more so for lung adenocarcinoma risk (HR: 1.79; 95% CI: 1.23–2.60). In summary, dietary tocopherol intake may reduce the risk of lung cancer among female nonsmokers; however, supplements may increase lung adenocarcinoma risk and requires further investigation.