Dietary patterns and risk of oesophageal cancers: a population-based case-control study

Epidemiological studies investigating the association between dietary intake and oesophageal cancer have mostly focused on nutrients and food groups instead of dietary patterns. We conducted a population-based case-control study, which included 365 oesophageal adenocarcinoma (OAC), 426 oesophagogastric junction adenocarcinoma (OGJAC) and 303 oesophageal squamous cell carcinoma (OSCC) cases, with frequency matched on age, sex and geographical location to 1580 controls. Data on demographic, lifestyle and dietary factors were collected using self-administered questionnaires. We used principal component analysis to derive three dietary patterns: 'meat and fat', 'pasta and pizza' and 'fruit and vegetable', and unconditional logistic regression models to estimate risks of OAC, OGJAC and OSCC associated with quartiles (Q) of dietary pattern scores. A high score on the meat-and-fat pattern was associated with increased risk of all three cancers: multivariable-adjusted OR 2·12 (95 % CI 1·30, 3·46) for OAC; 1·88 (95% CI 1·21, 2·94) for OGJAC; 2·84 (95% CI 1·67, 4·83) for OSCC (P-trend <0·01 for all three cancers). A high score on the pasta-and-pizza pattern was inversely associated with OSCC risk (OR 0·58, 95 % CI 0·36, 0·96, P for trend=0·009); and a high score on the fruit-and-vegetable pattern was associated with a borderline significant decreased risk of OGJAC (OR for Q4 v. Q1 0·66, 95% CI 0·42, 1·04, P=0·07) and significantly decreased risk of OSCC (OR 0·41, 95% CI 0·24, 0·70, P for trend=0·002). High-fat dairy foods appeared to play a dominant role in the association between the meat-and-fat pattern and risk of OAC and OGJAC. Further investigation in prospective studies is needed to confirm these findings.     

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。     

Occupation and bladder cancer: a population-based,case-control study in Iowa

While considerable efforts have been made to investigate the role of occupation and industry in the risk of bladder cancer, many reported associations have not been consistent, and strong evidence of increased risk is apparent for few occupational groups. To further examine the issue, a large, population-based, case-control study was conducted in the state of Iowa among both men and women. A total of 1452 incident bladder cancer cases and 2434 controls were included in the study. Occupational history was collected from respondents for each job held for 5 years or longer since age 16. Among men, excess risk was observed for industries including plumbing, heating, and air conditioning (odds ratio [OR], = 2.2; 95% confidence interval [CI], 1.0 to 5.0); rubber and plastic products (OR = 3.1; 95% CI, 1.2 to 8.5), motor vehicle parts and supplies (OR = 4.5; 95% CI, 1.2 to 16.5), and occupations including supervisors for transportation and material moving (OR = 6.5; 95% CI, 1.4 to 29.9), material-moving-equipment operators (OR = 1.9; 95% CI, 1.0 to 3.6), automobile mechanics (OR = 1.6; 95% CI, 1.0 to 2.6), painters (OR = 2.7; 95% CI, 1.0 to 7.7), and metal- and plastic-working machine operators (OR = 2.0; 95% CI, 1.1 to 3.4). Among women, significant excess risk was observed for secondary school teachers and record clerks. Housekeepers and butlers and workers in laundering and dry cleaning were also at increased risk. In conclusion, these results suggest that occupational exposures may play a significant role in the risk of bladder cancer.     

First-trimester maternal alcohol consumption and the risk of infant oral clefts in Norway: a population-based case-control study

Although alcohol is a recognized teratogen, evidence is limited on alcohol intake and oral cleft risk. The authors examined the association between maternal alcohol consumption and oral clefts in a national, population-based case-control study of infants born in 1996-2001 in Norway. Participants were 377 infants with cleft lip with or without cleft palate, 196 with cleft palate only, and 763 controls. Mothers reported first-trimester alcohol consumption in self-administered questionnaires completed within a few months after delivery. Logistic regression was used to calculate odds ratios and 95% confidence intervals, adjusting for confounders. Compared with nondrinkers, women who reported binge-level drinking (>or=5 drinks per sitting) were more likely to have an infant with cleft lip with or without cleft palate (odds ratio = 2.2, 95% confidence interval: 1.1, 4.2) and cleft palate only (odds ratio = 2.6, 95% confidence interval: 1.2, 5.6). Odds ratios were higher among women who binged on three or more occasions: odds ratio = 3.2 for cleft lip with or without cleft palate (95% confidence interval: 1.0, 10.2) and odds ratio = 3.0 for cleft palate only (95% confidence interval: 0.7, 13.0). Maternal binge-level drinking may increase the risk of infant clefts.     

Differences in risk estimations from a hospital and a population-based case-control study

A hospital-based and population-based case-control study of cervical cancer (in situ and invasive) was conducted in urban Utah to determine if methods of respondent selection affect estimates of risk for variables thought to be associated with the disease. Population cases (N = 409) and cases from two large hospitals (N = 124) were identified through the Utah Cancer Registry. Population-based controls (N = 379) were identified through random-digit dialing; hospital-based controls (N = 150) with gynaecological disorders other than cancers and elective abortions were chosen from the same hospitals as the cases for the hospital study. Both control groups were frequency matched to cases by age. Approximately 79% of the identified cases and 85% of the selected controls completed interviews conducted in their homes. Most risk estimates were lower in the hospital-based study because of the more case-like attributes of this group. Stratified analysis for social class led to adjusted risk estimates which were lower than the unadjusted risk estimates for the population-based study, but not for the hospital-based study. The close social class matching in the hospital-based study seems to have led to concurrent overmatching on other risk factors since many of these are closely related to social class. Findings are discussed in terms of implications for case-control study design.     

液体总摄人量和小便次数与上海市区居民膀胱癌危险性的关系

目的 探讨液体总摄入量和小便次数与上海市区居民膀胱癌危险性的关系.方法 采用全人群病例对照研究,共调查1996年1月1日至1998年12月31日期间诊断的上海市区膀胱癌新发病例608例,以及性别、年龄配对的人群对照607名.采用非条件logistic回归模型,调整可能的混杂因素,估计液体总摄人量和小便次数与膀胱癌发生的OR值及95%CI(α=0.05).结果 每天液体总摄人量及夜晚(即睡眠时间内)小便次数与膀胱癌发生的危险性无统计学意义的相关.白昼(即非睡眠时间内)通常小便次数与膀胱癌危险性呈负相关.调整年龄、性别、是否吸烟、液体总摄入量及其他因素后,与白昼通常小便次数≤3次者相比,小便次数为4、5及≥6次者的OR值分别为0.72(95%CI:0.49～1.05)、0.60(95%CI:0.41～0.87)和0.62(95%CI:0.43～0.90),趋势检验有统计学意义(P=0.014).与白昼通常小便次数≤3次者相比,白昼通常小便次数≥6次的吸烟者和不吸烟者的OR值分别为0.72(95%CI:0.45～1.15)和0.46(95%CI:0.25～0.87).与每天液体总摄入量≤750ml且白昼通常小便次数≤3次者相比,每天液体总摄人量＞1500ml且白昼通常小便次数≥6次者膀胱癌的危险性降低了57%,有统计学意义的相关性.结论 不憋尿且多饮水,尤其不吸烟者可以降低膀胱癌发生的危险性.     

Racial differences in bladder cancer risk: a case-control study

To determine why the incidence rate of transitional cell bladder cancer in whites in the United States is approximately twice that in blacks, the authors examined data from a large population-based case-control study of bladder cancer conducted in 1978 involving 2,982 cases and 5,782 controls. The relative risk of transitional cell carcinoma for whites compared with blacks was 1.9 before adjustment for the major bladder cancer risk factors, whereas after adjustment for cigarette smoking and occupation it was 1.6 (95% confidence interval (CI): 1.3-2.1). Further adjustment for other risk factors, including history of a bladder infection and a family history of urinary tract cancer, did not alter this estimate. The elevated risk of white compared with blacks was limited, however, to cases whose disease was confined to the mucosa and submucosa. Among cases whose disease had extended to the bladder musculature or beyond, whites were at slightly reduced risk compared with blacks. This suggests that whites may be diagnosed with conditions that go undetected in blacks but that are unlikely as a group to progress to more extensive disease. Because of the population-based nature of the study, it was possible to determine that if bladder cancer incidence among whites of both sexes was reduced to the level among blacks, total incidence in the United States would fall by 36 per cent.     

A method for spatial analysis of risk in a population-based case-control study

Spatial distributions of disease occurrence and risk have traditionally served as a tool for identifying exposures of public health concern. Current software for manipulating geographic data (GIS) now allows many kinds of analyses not feasible before. This paper presents a method for producing a "picture" of disease risks based on residential history data from a population based case-control study. We illustrate the method using geographically coded data on individual-level risk factors, such as age and smoking, from a cancer study of the Upper Cape Cod region of Massachusetts for 1983-1986. Our results show the association between lung cancer and residential location as an indicator of exposure. Crude and adjusted odds ratios were estimated by adaptive rate stabilization and mapped using kriging as an interpolation method to examine the risk of lung cancer in the region. The crude and adjusted surfaces for various smoothing parameters were compared to identify areas of increased lung cancer not explained by standard risk factors. Such spatial patterns of disease risk may provide clues to exposures of importance or confirm associations with previously suspected exposures.     

Cigarette smoking and risk of Hodgkin's disease: a population-based case-control study

Previous reports offer limited support for an association between cigarette smoking and Hodgkin's disease. The authors investigated dose-response effects for smoking in relation to the risk of Hodgkin's disease using data from the Selected Cancers Study. Cases (n = 343) were men aged 32-60 years identified from eight US population-based cancer registries in 1984-1988. Controls (n = 1,910) were men recruited by random digit telephone dialing and frequency matched to cases by age and registry. Conditional logistic regression was used to calculate odds ratios and 95% confidence intervals adjusted for age, registry, race/ethnicity, Jewish upbringing, education, and childhood domicile. Compared with never smokers, current smokers had a significantly increased risk of Hodgkin's disease (odds ratio (OR) = 1.8, 95% confidence interval (CI): 1.3, 2.9). Risks increased linearly (p < 0.001) with increasing packs per day (OR(>or=2) = 2.5, 95% CI: 1.6, 4.0), years (OR(>or=30) = 2.4, 95% CI: 1.5, 3.9), and pack-years (OR(>40) = 2.7, 95% CI: 1.8, 4.3) of smoking. These associations were significant for the nodular sclerosis and mixed cellularity subtypes but were much stronger for mixed cellularity. Stratified analyses by age (42 years) and subtype suggested that the effects of smoking are more closely related to histology than age. In contrast to findings from previous studies, these data suggest that smoking is an important preventable risk factor for Hodgkin's disease.     

Occupation and risk of pancreatic cancer: a population-based case-control study in iowa

OBJECTIVE: Previous epidemiological studies have inconsistently linked various occupations and industries to pancreatic cancer risk. METHODS: We analyzed data from a population-based case-control study conducted in Iowa involving 376 histologically confirmed incident pancreatic cancer cases and 2434 control subjects. RESULTS: A significantly increased risk was observed among men who worked in the following industries: chemical and allied products, transportation, and elementary and secondary schools. Increased risks also were observed in men who were employed as truck drivers; railroad brake, signal, and switch operators; purchasing agents and buyers; teachers; insurance agents; and retail supervisors. Among women, a significantly increased risk of pancreatic cancer was found for employment in furniture and home furnishing stores, and a borderline significantly increased risk among textile sewing machine operators and tenders. CONCLUSIONS: Working in several occupations and industries was associated with an increased risk of pancreatic cancer in this study, and these associations warrant further investigation.     

Occupation and breast cancer risk in Polish women: a population-based case-control study

BACKGROUND: The etiology of breast cancer is not well understood and the role of occupational exposures in breast carcinogenesis is still uncertain. METHODS: The population-based case-control study included 2,386 incident breast cancer cases diagnosed in 2000-2003, and 2,502 controls. Lifetime occupational histories and information on other potential breast cancer risk factors were obtained through personal interviews. Conditional logistic regression analyses calculated odds ratios (ORs) associated with various occupations and industries after control for potential confounders. RESULTS: We found statistically significant excesses of breast cancer among engineers (OR=2.0; 95% CI: 1.0-3.8), economists (2.1; 1.1-3.8), sales occupations-retail (1.2; 1.0-1.5), and other sales occupations (1.2; 1.0-1.5). Industries showing significantly elevated risks included special trade contractors (2.2; 1.2-4.3), electronic and electric equipment manufacturers (1.7; 1.1-2.7); and public administration/general government n.e.c. (2.7; 1.3-5.7). Each of these findings was supported by a statistically significant positive trend for duration of employment (P<0.05). A decreased breast cancer risk was observed in janitors and cleaners (0.7; 0.5-0.8). CONCLUSIONS: In this study, we found few associations for breast cancer and occupations or industries. The suggestive findings for the electronic and electric equipment manufacturing industry and for the occupations with potential exposure to magnetic fields deserve further evaluation.     

中年男性饮酒与血脂异常关系的病例-对照研究

目的探讨饮酒对中年男性血脂的影响。方法选取2011年6月至2012年6月于山东大学第二医院住院或体检的30～65岁男性,221例血脂异常患者作为病例组,233例血脂正常者作为对照组,对研究对象进行问卷调查和体格检查。采用单因素和非条件多因素Logistic回归分析饮酒与血脂异常的关系。结果与对照组比较,随着每日酒精摄入量的增加血脂异常患病危险增加,OR值分别为:1.52(≤25g/d)、1.83(25～50g/d)、3.11(>50g/d);TG异常危险随饮酒量的增加而升高,OR值分别是:1.98(≤25g/d)、2.79(25～50g/d)、4.37(>50g/d)。Logistic回归分析显示平均每日酒精摄入量(g/d)(OR=1.007,95%CI1.002～1.012)是血脂异常的危险因素。结论饮酒可能是中年男性血脂异常的危险因素。     

Methylenetetrahydrofolate reductase (MTHFR) variants and bladder cancer: a population-based case-control study

Functional variants in the methylenetetrahydrofolate reductase (MTHFR) gene, including the 677C>T and 1298A>C polymorphisms, have been associated with a moderately reduced risk of several cancers, including colorectal cancers. While recent studies have investigated the role of these polymorphisms on bladder cancer susceptibility, results have been mixed. To clarify the role of MTHFR polymorphisms on bladder cancer risk, we genotyped MTHFR 677C > T and MTHFR 1298A > C in a population-based study of bladder cancer of 352 patients and 551 controls from New Hampshire, USA. The allelic frequency was 35.6% for MTHFR 677C>T and 40.4% for MTHFR 1298A > C among controls. We found no evidence of a main gene effect for either polymorphism (adjusted OR for MTHFR 677C>T variants versus the reference genotype = 1.1; 95% CI, 0.8-1.4 and adjusted OR for MTHFR 1298A>C variants versus the reference genotype = 1.0; 95% CI, 0.7-1.4). Odds ratios did not appear to differ by smoking status or gender. We observed differences in the risk estimates for the MTHFR polymorphisms by arsenic exposure, but they were not statistically significant (P = 0.67 for MTHFR 677C > T and P = 0.12 for MTHFR 1298A>C). Thus, our findings do not support the presence of a main gene effect. The possibility that MTHFR polymorphism affects susceptibility to environmental exposures warrants further consideration.     

Meat consumption and risk of stomach cancer in Uruguay: a case-control study

We previously reported an association between meat intake and stomach cancer in Uruguay: in that analysis, we did not control for total energy intake. To better study the relationship between intake of meat and meat constituents and gastric cancer, we conducted a further case-control study including 123 cases and 282 controls who were enrolled between September 1997 and August 1999. Total meat intake (highest tertile) was associated with an odds ratio (OR) of 4.6 [95% confidence interval (CI) = 2.3-9.0]. After adjustment for total energy intake and intake of proteins and total fat by the residuals method, the OR was 1.7 (95% CI = 0.7-4.0). The energy-adjusted OR for high intake of processed meat was 1.9 (95% CI = 1.1-3.5). Intake of fried, barbecued, and salted meat and 2-amino-1-methyl-6-phenyl-imidazo[4,5-b]pyridine was not associated with risk of gastric cancer. The energy-adjusted OR of high intake of nitrosodimethylamine was 1.5 (95% CI = 0.9-2.8). These results suggest that, in a country with elevated meat consumption, total energy intake and intake of proteins and fat are powerful confounders in the relationship between meat intake and gastric cancer risk. However, a modest independent effect of meat, in particular of processed meat, is suggested.     

Infections and risk of type I diabetes in childhood: a population-based case-control study

Objective: This study focuses on the evaluation of some infectious diseases as risk determinants of type I diabetes mellitus (DM). Methods: A population-based case–control study was carried out by referring to the type I DM population-based register of the Abruzzo region of Italy as it includes all type I DM cases since January 1 1990, the point at which the register became operative. The pediatric population (age: 0–14), living in the same municipalities of the cases, was selected as the control population. Data were collected through questionnaires submitted by a physician to parents of cases and controls. Conditional logistic regression models were used to evaluate association between determinants and onset of type I DM. Results: The risk of diabetes for children exposed to only one infection (morbilli, parotitis, rubella, pertussis or varicella) is not statistically significant: OR: 0.778; CI: 0.427–1.370. On the contrary, when two infections are contracted statistically significant results occur: OR: 2.375; CI: 1.149–4.914; for more than two infections values are: OR: 6.786; CI: 2.881–17.877. No substantial difference in odds ratios (ORs) after adjustment for confounding variables was found. A significant decrease in OR was noted for pertussis and MMR vaccinations, respectively: OR: 0.015; CI: 0.001–0.251; OR: 0.400; CI: 0.201–0.799. Conclusions: Since the higher the number of contracted infections, the higher the risk of diabetes, contracted infections can be considered potential accelerating factors of clinical manifestation of type I DM. Therefore multiple exposures might speed up the onset of diabetes in children. This study suggests the utility of applying the risk model method to wider populations, especially if the geographical variability of standardised incidence rates of type I DM in pediatric age is taken into consideration.     

Utility of proxy versus index respondent information in a population-based case-control study of rapidly fatal cancers

PURPOSE: This work provides an empirical assessment of the usefulness of obtaining exposure data from proxy respondents. METHODS: Two independent case groups were formed in data from a population-based case-control study. One case set was derived from proxy respondents. The second case series was derived from respondents who self-reported. The second case group was matched to the proxy case group for age, cancer site, and sex. These data were compared with a control group for completeness of information and identifying heterogeneity of risk estimates for a variety of variables. Index cases and controls were matched to the 829 available proxy respondents for sex, age (5-year groups), and cancer site. RESULTS: Proxy respondents provided levels of complete information similar to index cases and controls for height and weight; occupational physical activity; consumption of coffee, alcohol, and cigarettes; and family history of cancer. Proxies had more missing responses for variables concerning recreational physical activity, clinical depression, age at first menstruation, use of oral contraceptives, and occupational exposure to pesticides. Polytomous logistic regression models found only a few examples of meaningful heterogeneity among all variables, limited to models for coffee consumption and cigarette smoking. CONCLUSIONS: Our data suggest that proxy respondents, especially parents and spouses, provide adequately complete information for many, but not all, exposures common in epidemiologic studies.     

Occupational risk factors for brain cancer: a population-based case-control study in Iowa

A number of occupations and industries have been inconsistently associated with the risk of brain cancer. To further explore possible relationships, we conducted a population-based case-control study of brain glioma in the state of Iowa, involving 375 histologically confirmed incident cases and 2434 population-based controls. Among men, the industries and/or occupations that had a significantly increased risk for employment of more than 10 years included roofing, siding, and sheet metalworking; newspaper work; rubber and plastics products, particularly tires and inner tubes; miscellaneous manufacturing industries; wholesale trade of durable goods, grain, and field beans; cleaning and building service occupations; miscellaneous mechanics and repairers; and janitors and cleaners. Subjects who worked in plumbing, heating, and air conditioning; electrical services; gasoline service stations; and military occupations also experienced a significantly increased risk. Among women, significant excess risk was observed for occupations in agricultural services and farming, apparel and textile products, electrical and electronic equipment manufacturing, various retail sales, record-keeping, and restaurant service. Workers in industries with a potential for gasoline or motor exhaust exposures experienced a non-significant excess risk of brain glioma.