Beer consumption and rectal cancer

The association of beer drinking with cancer of the rectum was investigated in a case-control study of 130 male and 88 female rectal cancer cases and 336 male and 249 female controls. Information was obtained on consumption of beer, wine, and hard liquor throughout adulthood (quantity and duration), as well as on smoking and sociodemographic characteristics. Beer intake was not significantly associated with estimated risk of rectal cancer in females but was in males, with an increasing gradient in the odds ratio (OR) with increasing beer consumption. For drinkers of 32 or more ounces of beer per day, the OR was 3.5 (95% CI 1.8-7.0). No association was seen with duration of beer drinking. Wine and hard liquor consumption showed no association with the development of rectal cancer. In multiple logistic regression analyses, the relative risk for beer drinking was reduced slightly when potential confounding variables were included in the model (RR adjusted for religion and education: 2.7, 95% CI 1.3-5.7). The study results are discussed in the light of other epidemiological studies of rectal cancer and beer drinking. We conclude from the aggregate evidence that the association of beer drinking with rectal cancer is probably not causal and that the slightly elevated OR's observed for males in this study are most likely due to incomplete control for confounding variables.     

Oral contraceptive use does not protect against large bowel cancer

The association between oral contraceptive (OC) use and colorectal cancer was examined in 190 female colorectal cancer cases and 200 age-matched female controls in data derived from a population-based study of large bowel cancer, "The Melbourne Colorectal Cancer Study" conducted in Melbourne, Australia. There were 47 cases (24 colon cancer, 23 rectal cancer cases) and 39 controls, who were past OC users. After adjustment was made for the confounding factors of age, number of children and age at birth of first child, a statistically significant risk was found among rectal cancer OC users, but not among colon cancer OC users (RR rectal cancer = 2.04, 95% CI = 1.00-4.14, p = 0.04; RR colon cancer = 1.17, 95% CI = 0.59-2.29, p = 0.60). These risks were not affected by adjustment for socioeconomic level, country of birth, religion, previous diet and family history of colorectal cancer. Rectal cancer risk was higher among those OC users who were also beer drinkers (RR = 6.96, 95% CI 2.09-23.1, p = 0.001).     

The relations of alcoholic beverage use to colon and rectal cancer

The authors prospectively studied the incidence of cancers of the colon and rectum in 106,203 men and women, both white and black, who supplied data at northern California Kaiser Permanente facilities about use of alcoholic beverages in 1978-1984. Analysis controlling for age, sex, race, body mass index, coffee use, total serum cholesterol, and education showed a positive association of alcohol use to both types of cancer, which was stronger for rectal cancer (trend test, p = 0.03) than for colon cancer (trend test, p = 0.11). When persons with a daily intake of three or more drinks were compared with abstainers, relative risk for rectal cancer was 3.17 (95% confidence interval (CI): 1.05-9.57) and relative risk for colon cancer was 1.71 (95% CI: 0.92-3.19). Women with a daily intake of three or more drinks had a relative risk for colon cancer of 2.56 (95% CI: 1.03-6.40) compared with 1.16 (95% CI: 0.46-2.90) for men. Among drinkers, preference for wine, beer, or hard liquor had no significant independent relation to either type of cancer; those who preferred beer were at slightly greater risk of rectal cancer, but those who preferred wine were more likely to develop colon cancer. These data suggest that total alcohol use, but no one specific beverage type, is associated with increased risk of rectal cancer.     

Heavy drinking, but not moderate or intermediate drinking, increases the risk of intracerebral hemorrhage

An increased risk of intracerebral hemorrhage among heavy consumers of alcohol has been demonstrated in several epidemiologic studies. The effect of moderate or intermediate intakes is, however, unclear. Although several studies provide evidence for a protective effect, this conclusion may be spurious, resulting from the inclusion, within the zero intake (reference) group, of past drinkers who have recently abstained for health reasons. The present study describes the relation between alcohol consumption and intracerebral hemorrhage among 331 case-control pairs recruited in Melbourne, Australia. Heavy drinking was associated with an increased risk of intracerebral hemorrhage (odds ratio (OR) 3.4, 95% confidence interval (CI) = 1.4-8.4). The odds ratio of intracerebral hemorrhage with moderate drinking, when compared with never drinkers, was 0.7, (95% CI = 0.4-1.2) and was 0.6 (95% CI = 0.4-1.0) when compared with nondrinkers (never drinkers plus past drinkers). Wine drinkers were apparently protected from intracerebral hemorrhage (OR 0.5, 95% CI = 0.2-0.9). These results are consistent with the possibility that moderate drinking may confer protection from intracerebral hemorrhage, but this protection may be less than that previously reported.     

结肠癌和直肠癌危险因素的巢式病例对照研究

目的：探讨结肠癌和直肠癌的危险因素。方法：应用巢式病例对照研究方法,对一个6万余人队列随访10年队列中196例新发结、直肠癌病例作为病例组;从该队列中随机抽取980名正常人作为对照组,对有关暴露因素进行单因素分析和多因素非条件logistic回归分析,结果：年龄在病例组和对照之间差异有显著性,病例组年龄高于对照组,且结肠癌的发病年龄高于直肠癌。多因素分析表明,除年龄外,粘液血便中、肠息肉史与结肠癌关系密切,OR值分别为：2．961（95％CI：1．202－7．298）和8．941（95％CI：1．820－43．926）,饮用混合水与直肠癌的OR值为1．823（95％CI:1．024－3．247）。结论：结、直肠癌的危险因素不尽相同。除年龄是结、直肠癌发病的一个共同重要因素外,肠息肉史和粘液血便史与结肠癌有关联,而饮用混合水则与直肠癌关系密切。     

Coffee and amyotrophic lateral sclerosis: a possible preventive role

The relation between coffee intake and risk of amyotrophic lateral sclerosis (ALS) was investigated in 377 newly diagnosed ALS patients from 4 Italian population-based registries in the European ALS Consortium (EURALS Group) (2007-2010). For each patient, 2 age- and sex-matched hospital controls were selected, one from a neurology department and one from a nonneurologic department. Two additional healthy control groups were identified from local general practitioners' (GPs') lists (n = 99) and residents of the same area as a cancer cohort (n = 7,057). Coffee intake was defined in terms of status (ever consuming coffee daily for ≥6 months vs. never), duration, and history (never, former, or current). Ever coffee drinkers comprised 74.7% of ALS patients, 80.4% of neurologic controls, 85.6% of nonneurologic controls (P = 0.0004), 88.9% of GP controls (P = 0.0038), and 86.0% of cancer cohort controls (P < 0.0001). Current coffee drinkers comprised 60.2% of ALS patients, 70.2% of neurologic controls (P = 0.0294), 76.4% of nonneurologic controls (P < 0.0001), and 82.3% of GP controls (P = 0.0002); duration of intake was ≥30 years for 62.3%, 67.7%, 74.7%, and 72.6%. ALS patients had lower lifetime coffee exposure: Odds ratios were 0.7 (95% confidence interval (CI): 0.5, 1.1), 0.6 (95% CI: 0.4, 0.8), and 0.4 (95% CI: 0.2, 0.9) in comparison with neurologic, nonneurologic, and GP controls, respectively. In current (vs. never) coffee drinkers, odds ratios were 0.7 (95% CI: 0.5, 1.0), 0.5 (95% CI: 0.3, 0.7), and 0.4 (95% CI: 0.2, 0.8), respectively. These findings provide epidemiologic evidence of an inverse correlation between coffee intake and ALS risk.     

Association of fluids from beverages with risk of rectal cancer

Little information is available about how fluid intake from beverages and sources of fluid intake influence risk of rectal cancer. We examined these associations with risk of incident rectal cancer in a population-based case-control study of 952 cases and 1,205 controls living in northern California and Utah. We also determined if intake of fiber (soluble and insoluble), physical activity, and nonsteroidal anti-inflammatory medications (NSAIDs) or aspirin modified the associations between fluid intake and rectal cancer. We identified a modest inverse association of water intake (odds ratio, OR = 0.70; 95% confidence interval, CI = 0.48, 1.02) and total fluid intake (high vs. low OR = 0.70; 95% CI = 0.46, 1.06) with risk of rectal cancer in men and a positive association with juice among women (high vs. low OR = 1.56; 95% CI = 1.00, 2.41). Risk of rectal cancer increased nonsignificantly among men with beer consumption, among women with high white wine use, and among men and women with high long-term alcohol use. NSAIDs modified the association of alcohol consumption with rectal cancer: 1) risk associated with beer increased among men who did not take NSAIDs and had a high beer intake (OR = 1.60; 95% CI = 1.08, 2.39) and 2) risk associated with long-term alcohol intake increased in a linear fashion in women who did not use NSAIDs (OR = 1.98; 95% CI = 1.15, 3.40). Risk of rectal cancer increased among estrogen-negative women if they consumed any beer or white wine but decreased among estrogen-positive women with beer. In men, low intake of water and low insoluble fiber intake were associated with increased risk of rectal cancer beyond that of either factor alone (OR = 1.82; 95% CI = 1.11, 3.00). The interactions of fiber with water intake suggest that bowel motility may be the mechanism responsible for modification of rectal cancer risk for water. Associations of alcohol to risk for rectal cancer may be related to cellular hyperproliferation and may be modified by NSAID use.     

Bladder cancer, tobacco smoking, coffee and alcohol drinking in Brescia, northern Italy

The association between tobacco smoking, the consumption of coffee and alcohol and bladder cancer was investigated in a hospital-based case-control study in Brescia, northern Italy. A total of 172 incident cases (135 men and 37 women) and 578 controls (398 men and 180 women) were enrolled. As expected, cigarette smoking was strongly associated with bladder cancer. The odds ratios (OR) for coffee drinking adjusted for age, education, residence and cigarette smoking in current drinkers were 2.6 (95% confidence interval, CI: 1.1–6.1) in men and 5.2 (95% CI: 1.0–30.4) in women. A dose-response relationship was found in men, with the highest risk in the highest category of exposure: drinkers of more than 5 cups per day had an OR of 4.5 (95% CI: 1.2–16.8). The ORs for current alcohol drinkers were 2.1 (95% CI: 1.0–4.8) in men and 3.4 (95% CI: 1.2–9.7) in women; according to grams of ethanol drunk per day (grams/day, g/d) the ORs were: 1.7 (1–20 g/d), 1.6 (21–40 g/d), 4.3 (41–60 g/d) and 4.6 (61+ g/d) in men and 3.1 (1–20 g/d) and 3.9 (21+ g/d) in women. These results suggest that regular consumption of both coffee and alcohol can be independently associated with an increased bladder cancer risk.     

Processed Meat and Colorectal Cancer Risk: A Pooled Analysis of Three Italian Case-Control Studies

To add evidence to the limited data available from southern Europe, we assessed the association between processed meat consumption and colorectal cancer risk. We analyzed data from three case-control studies conducted between 1985 and 2010 in various Italian areas, including a total of 3745 incident cases and 6804 hospital-based controls. We calculated odds ratios (ORs) and 95% confidence intervals (CIs) by unconditional multiple logistic regression models. The median consumption of processed meat was around 20 g/day both in cases and controls. The OR of colorectal cancer was 1.02 (95% CI 0.99–1.04) for an increase of 10 g/day of processed meat. The association was statistically significant for colon cancer (OR 1.03, 95% CI 1.00–1.06), particularly for proximal colon cancer (OR 1.09, 95% CI 1.04–1.14), while there was no relation with rectal cancer (OR 0.99, 95% CI 0.95–1.03). The OR of proximal colon cancer was 1.38 (95% CI 1.08–1.75) for the highest sex-specific tertile of consumption (>25 g/day for men, >21.5 for women) compared with the lowest (<15 g/day), whereas no significant ORs were found for other anatomical subsites. Our findings indicate that there is no association with colorectal cancer overall, in the presence, however, of a positive association with proximal colon cancer.     

PPARgamma, energy balance, and associations with colon and rectal cancer

Peroxisome proliferator-activated receptor-gamma (PPARgamma) has been hypothesized as being involved in colorectal cancer given its role in adipocyte development and insulin resistance. In this study we evaluated the association between the Pro12Ala (P12A) PPARgamma polymorphism and body mass index (BMI), waist-to-hip ratio (WHR), physical activity level, and energy intake and risk of colorectal cancer using data from a population-based, case-control study of colon cancer (1,577 cases and 1,971 controls) and rectal cancer (794 cases and 1,001 controls). We further evaluated how the P12A PPARgamma polymorphism is associated with obesity and fat pattern in the control population. The odd ratio for PPARgamma PA or AA genotype relative to the PP genotype for colon cancer was 0.9 (95% confidence interval, CI=0.8-1.0) and for rectal cancer was 1.2 (95% CI=1.0-1.5) adjusting for race, age, and sex. P12A PPARgamma did not significantly interact with BMI, WHR, energy intake, and energy expenditure to alter risk of colon or rectal cancer. Furthermore, the P12A PPARgamma polymorphism was not associated with obesity or WHR in the control population; it did not interact with energy intake or energy expenditure to alter risk of obesity or large WHR. These data do not support the hypothesis that the P12A PPARgamma polymorphism is associated with colon or rectal cancer through regulation of energy balance.     

Selenium,Folate, and Colon Cancer

Selenium is an essential trace element that has been implicated in cancer risk; however, study results have been inconsistent with regard to colon cancer. Our objectives were to 1) investigate the association between selenium and colon cancer, 2) evaluate possible effect measure modifiers, and 3) evaluate potential biases associated with the use of postdiagnostic serum selenium measures. The North Carolina Colon Cancer Study is a large population-based, case-control study of colon cancer in North Carolina between 1996 and 2000 (n = 1,691). Nurses interviewed patients about diet and lifestyle and drew blood specimens, which were used to measure serum selenium. Individuals who had both high serum selenium (> 140 mcg/l) and high reported folate (> 354 mcg/day) had a reduced relative risk of colon cancer [odds ratio (OR) = 0.5, 95% confidence interval (CI) = 0.4–0.8). The risk of colon cancer for those with high selenium and low folate was approximately equal to the risk among those with low selenium and low folate (OR = 1.1, 95% CI = 0.7–1.5) as was the risk for those with low selenium and high folate (OR = 0.9, 95% CI = 0.7–1.2). We did not find evidence of bias due to weight loss, stage at diagnosis, or time from diagnosis to selenium measurement. High levels of serum selenium and reported folate jointly were associated with a substantially reduced risk of colon cancer. Folate status should be taken into account when evaluating the relation between selenium and colon cancer in future studies. Importantly, weight loss, stage at diagnosis, or time from diagnosis to blood draw did not appear to produce strong bias in our study.     

Cancer and polyps of the colorectum and lifetime consumption of beer and other alcoholic beverages

Two parallel case-control studies were conducted in the Marseilles metropolitan area of France from 1979 to 1985 on cancers and adenomatous polyps of the colorectum. All cases of cancer (n = 389) and polyps (n = 252) were incident and histologically confirmed. Controls (n = 641) matched for sex and age were selected among patients undergoing functional reeducation for injury or trauma in one of five hospital centers. Intake of alcoholic beverages was investigated by questions on daily or weekly intake of wine, beer, apéritifs, and distillates during different life periods. Questions on alcoholic beverages were integrated in a detailed diet history interview questionnaire. The risk of rectal cancer was elevated in male beer drinkers (relative risk = 1.73, 95% confidence interval 1.01-2.95) and in men and women combined (relative risk = 1.71), while beer consumption was not associated with colon cancer. Total ethanol intake and consumption of wine and distillates were not associated with the risk of cancer of the colon or rectum, nor with risk of polyps. Adjustment in the statistical analysis for energy intake and for other dietary variables (fiber from fruits and fiber from vegetables), which were found to be risk factors in the study, did not substantially change the results found for beer and other alcoholic beverages. Etiologic hypotheses related to nitrosamine content of beer are discussed in the light of growing epidemiologic evidence that beer consumption specifically increases the risk of rectal cancer.     

Do Tobacco and Alcohol Modify Protective Effects of Diet on Oral Carcinogenesis?

Recent systematic reviews concluded that the frequent consumption of fruits and vegetables is inversely associated with the risk of oral cancer. We assessed this association, specifically comparing results obtained to nonsmokers and smokers, as well to nondrinkers and drinkers. We conducted a case-control study involving 296 patients with oral squamous cell carcinoma (cases) attended in 3 major hospitals of São Paulo, Brazil, paired with 296 controls, recruited from outpatient units of the same hospitals. Multivariate models assessed the effect of fruits and salads according to smoking and drinking. The intake of fruit was associated with the prevention of the disease in the specific assessment among light [odds ratio (OR) = 0.46; 95% confidence interval (CI) = 0.27–0.78) and heavy (OR = 0.30; 95% CI = 0.14–0.65) smokers. The same was observed for vegetables consumption. For nonsmokers, no fruit (OR = 50; 95% CI = 0.22–1.12) or vegetable (for tomato, OR = 0.53; 95% CI = 0.31–0.93) was associated with reduced risk of oral and oropharyngeal cancer. Similar results were found in the stratified analysis according to drinking status with OR = 0.51 (95% CI = 0.30–0.87) and 0.18 for fruits (95% CI = 0.07–0.45), respectively, for light and heavy drinkers. This observation suggests that the protective effect of fruit and salad intake may modulate the deleterious effects from tobacco and alcohol.     

Physical activity and colorectal cancer

Physical activity has been inconsistently associated with rectal cancer despite the consistent association between physical activity and colon cancer. In this study, the authors evaluated the association between physical activity and rectal cancer using the same questionnaire used to evaluate the previously reported association with colon cancer. A population-based study of 952 incident cases of cancer in the rectum and rectosigmoid junction and 1,205 age- and sex-matched controls was conducted in Utah and northern California at the Kaiser Permanente Medical Care Program between 1997 and 2002. Vigorous physical activity was associated with reduced risk of rectal cancer in both men and women (odds ratio (OR) = 0.60, 95% confidence interval (CI): 0.44, 0.81 for men; OR = 0.59, 95% CI: 0.40, 0.86 for women). Among men, moderate levels of physical activity also were associated with reduced risk of rectal cancer (OR = 0.70, 95% CI: 0.51, 0.97). Participation in vigorous activity over the past 20 years conferred the greatest protection for both men and women (OR = 0.55, 95% CI: 0.39, 0.78 for men; OR = 0.44, 95% CI: 0.30, 0.67 for women). In summary, physical activity was associated with reduced risk of rectal cancer in these data. The reduced risk was similar to that previously observed for colon cancer.     

绿茶与子宫内膜癌关系的病例对照研究

目的探讨饮茶特别是绿茶与子宫内膜癌的关系。方法采用以人群为基础的病例对照研究,调查上海市1997年1月至2002年12月间已确诊年龄30～69岁的子宫内膜癌患者(n=995)和全人群对照(n=1087)的一般情况、月经生育史、饮食及营养素、个人生活习惯、激素相关因素、疾病及家族史等资料,采用非条件logistic回归模型分析饮茶与子宫内膜癌的关系。结果与从未饮茶者相比,有饮茶史者患子宫内膜癌的危险略降低(OR=0.82,P=0.0466)。饮茶主要对绝经前女性有保护作用(OR=0.74,95%CI:0.54～1.01);以从不饮茶者为参比组,饮淡茶、浓淡适中及浓茶者的OR值分别为0.72、0.88和0.44,趋势检验有统计学意义(P=0.0431)。在不吸烟不饮酒者中,饮绿茶对子宫内膜癌有保护作用(OR=0.77,P=0.0199);每周饮绿茶频率越高,患子宫内膜癌的危险性越低;以从未饮茶者为参比组,每周饮绿茶<7次及≥7次者OR值分别为0.90(95%CI:0.53～1.54)和0.76(95%CI:0.60～0.95),趋势检验P=0.0163;饮绿茶量越大危险性越低,每月饮绿茶≤100g、～200g及>200g者的OR值分别为0.76、0.87和0.74,趋势检验有统计学意义。结论饮茶特别是绿茶对子宫内膜癌可能有弱的保护作用,且该作用可能局限于绝经前女性。     

Alcohol and breast cancer in an area with high alcohol consumption

The association between alcohol drinking and breast cancer risk was investigated in 132 breast cancer cases and 499 controls with acute conditions unrelated to alcohol or any of the suspected risk factors for breast cancer, in an area which shows among the highest levels of alcohol consumption and prevalence of alcohol-related diseases in Europe (i.e. Pordenone Province, Northeastern part of Italy). Compared with non-drinkers, the multivariate odds ratio (OR) for ever drinkers was 1.5 (95% confidence interval, CI: 0.8-2.6). The risks for wine (the almost exclusive source of alcohol in the present investigation) were 1.2 for up to 1 drink, 1.4 for up to two drinks, 1.9 for up to 3 and 1.6 for over 3 drinks per day. Time-related factors (i.e. drinking habit duration and age at start of drinking) did not seem to be risk indicators.     

Alcohol consumption and the risk of acute myocardial infarction in women.

STUDY OBJECTIVE--To investigate the relationship between alcohol consumption and the risk of acute myocardial infarction in women. DESIGN--This was a hospital based, case-control study carried out between 1983 and 1990. Main outcome measures were average daily number of drinks of various alcoholic beverages consumed and corresponding multivariate relative risk estimates and 95% confidence intervals (CI). SETTING--A network including major teaching and general hospitals in northern Italy. SUBJECTS--Cases were 298 women with acute myocardial infarction but no history of ischaemic heart disease and controls 685 women admitted to hospital for acute conditions, unrelated to alcohol consumption or to known or suspected risk factors for ischaemic heart disease. MEASUREMENTS AND MAIN RESULTS--Compared with non-drinkers, the estimated relative risks (RR) were 0.7 (95% CI 0.5, 1.0) for one drink or less per day, 0.8 (95% CI 0.6, 1.2) for more than one to two drinks per day, 1.4 (95% CI 0.8, 2.3) for more than two to three, and 2.6 (95% CI 1.5, 4.6) for more than three drinks per day. These estimates were consistent across strata of selected covariates, including age, education, and smoking. Allowance for major identified risk factors for myocardial infarction did not materially modify the risk estimate for light drinkers (RR 0.7, 95% CI 0.5, 1.1), but reduced the RR in heavy drinkers to 1.8 (95% CI 0.9, 3.5). CONCLUSIONS--This study indicates that women who do not drink alcohol have a risk of myocardial infarction that is higher than that of light drinkers, although the protection of light drinking was not significant. Among drinkers, however, there was a significant direct trend in risk with dose. The raised risks in heavy drinkers may reflect a real association or result from other unfavourable characteristics or habits associated with high alcohol consumption.     

Alcohol and breast cancer

We examined breast cancer incidence in a cohort of about 69,000 women who answered detailed questions about alcohol consumption from 1979 to 1984. Among women with no prior cancer, breast cancer had developed in 303 by the end of 1984 for an age-adjusted incidence of 1.3/1,000 person years of follow-up. In analysis controlling only for age there was a progressive increase in breast cancer incidence corresponding to each higher level of reported alcohol consumption. In multivariate analyses controlling for age, race, body mass, and smoking, the relative risk at 1-2 drinks/day was 1.5 (95% confidence interval (CI) 1.0-2.3), at 3-5 drinks/day was 1.5 (95% CI 0.8-2.8), and at 6 or more drinks/day was 3.3 (95% CI 1.2-9.3). Past drinkers tended to have been heavier drinkers than current drinkers and had a relative risk of 2.2 (95% CI 1.2-3.9). Study of wine, beer, and liquor use did not suggest that any particular alcoholic beverage was responsible. Significant associations with heavy alcohol consumption were strongest among white and postmenopausal women. This study adds support to the growing evidence that alcohol may be a risk factor for development of breast cancer.     

Meta-analysis of studies on individual consumption of chlorinated drinking water and bladder cancer

STUDY OBJECTIVE: To evaluate whether consumption of chlorinated drinking water is associated with bladder cancer. DESIGN: A bibliographic search was conducted and the authors selected studies evaluating individual consumption of chlorinated drinking water and bladder cancer. The authors extracted from each study risk estimates for intermediate and long term (>40 years) consumption of chlorinated water, stratified by sex when possible, and performed meta-analysis for the two exposure levels. A meta-analysis was also performed of the dose-response regression slopes. SETTING: Populations in Europe and North America. PARTICIPANTS: Those included in six case-control studies (6084 incident bladder cancer cases, 10,816 controls) and two cohort studies (124 incident bladder cancer cases) fulfilling the inclusion criteria. MAIN RESULTS: Ever consumption of chlorinated drinking water was associated with an increased risk of bladder cancer in men (combined OR=1.4, 95%CI 1.1 to 1.9) and women (combined OR=1.2, 95%CI 0.7 to 1.8). The combined OR for mid-term exposure in both genders was 1.1 (95% CI 1.0 to 1.2) and for long term exposure was 1.4 (95%CI 1.2 to 1.7). The combined estimate of the slope for a linear increase in risk was 1.13 (95% CI 1.08 to 1.20) for 20 years and 1.27 (95% CI 1.15 to 1.43) for 40 years of exposure in both sexes. CONCLUSIONS: This meta-analysis of the best available epidemiological evidence indicates that long term consumption of chlorinated drinking water is associated with bladder cancer, particularly in men. The observed relative risk is only moderately high, but the population attributable risk could be important as the vast majority of the population of industrialised countries is potentially exposed to chlorination byproducts for long time periods.     

Menopausal hormones and breast cancer in a biracial population

OBJECTIVES: This study examined the association between menopausal hormones and breast cancer in a biracial population. METHODS: Logistic regression was used to calculate odds ratios for breast cancer associated with hormone use among 397 cases and 425 controls, all menopausal women. RESULTS: Odds ratios for ever use of hormones were 0.8 (95% confidence interval [CI] = 0.5, 1.2) for White women and 0.7 (95% CI = 0.4, 1.2) for Black women. Risk was not increased with longer duration of use or more recent use. CONCLUSIONS: Breast cancer risk was not increased among White or Black women who used menopausal hormones, despite patterns of use varying considerably between races.