Association between coffee drinking and K-ras mutations in exocrine pancreatic cancer. PANKRAS II Study Group

STUDY OBJECTIVE: To analyse the relation between coffee consumption and mutations in the K-ras gene in exocrine pancreatic cancer. DESIGN: Case-case study. Consumption of coffee among cases with the activating mutation in the K-ras gene was compared with that of cases without the mutation. SETTING AND PATIENTS: All cases of pancreatic cancer newly diagnosed at five hospitals in Spain during three years were included in the PANKRAS II Study (n = 185, of whom 121 whose tissue was available for molecular analysis are the object of the present report). Over 88% were personally interviewed in hospital. DNA was amplified from paraffin wax embedded tissues, and mutations in codon 12 of K-ras were detected by the artificial RFLP technique. MAIN RESULTS: Mutations were found in tumours from 94 of 121 patients (77.7%). Mutations were more common among regular coffee drinkers than among non-regular coffee drinkers (82.0% v 55.6%, p = 0.018, n = 107). The odds ratio adjusted by age, sex, smoking and alcohol drinking was 5.41 (95% CI 1.64, 17.78). The weekly intake of coffee was significantly higher among patients with a mutated tumour (mean of 14.5 cups/week v 8.8 among patients with a wild type tumour, p < 0.05). With respect to non-regular coffee drinkers, the odds ratio of a mutated tumour adjusted by age, sex, smoking and alcohol drinking was 3.26 for drinkers of 2-7 cups/week, 5.77 for drinkers of 8-14 cups/week and 9.99 for drinkers of > or = 15 cups/week (p < 0.01, test for trend). CONCLUSIONS: Pancreatic cancer cases without activating mutations in the K-ras gene had drank significantly less coffee than cases with a mutation, with a significant dose response relation: the less they drank, the less likely their tumours were to harbour a mutation. In exocrine pancreatic cancer the K-ras gene may be activated less often among non-regular coffee drinkers than among regular drinkers. Caffeine, other coffee compounds or other factors with which coffee drinking is associated may modulate K-ras activation.     

Epidemiology and injuries (1994–2005) resulting from poisonous animals in southern Santa Catarina State,Brazil

Accidents involving poisonous animals in southern Santa Catarina State, Brazil, from 1994 to 2005 were evaluated with the aim of verifying their frequency through the analysis of 2,625 victim’s reports involving poisonous animals from the SINAN (System of Injury Notification Information) files of the Municipal Health Secretary of the AMESC and AMREC microregions, formed by 27 municipalities. Statistical analysis was performed using the chi-square exact test to verify similarities between the AMREC and AMESC microregions, where p values ≤0.05 were considered significant. The results demonstrated that: 52.95% (n = 1,390) of occurrences involved spiders, 18.13% (n = 476) snakes, 5.00% (n = 131) bees, 2.29% (n = 60) caterpillars, 1.41% (n = 37) scorpions, 5.45% (n = 143) other animals and 14.78% (n = 388) unknown. The anatomic region that suffered the most bites was the feet 16.11% (n = 444). Accidents were more frequent in men 54.64% (n = 1.437) than in women 45.25% (n = 1,188). In only 1.18% (n = 31) of cases did recovery present sequelae. The months presenting the highest number of recorded cases were October through March, spring and summer in Brazil. The high frequency of victim recuperation suggests that the public health system is efficient, and the low frequency of recovered victims with sequelae also suggests that this system is fast and well-adjusted. However, there may have been deficiencies in the epidemiologic information system.     

Early life patterns of common infection: a latent class analysis

Early life infection has been implicated in the aetiology of many chronic diseases, most often through proxy measures. Data on ten infectious symptoms were collected by parental questionnaire when children were 6 months old as part of the Avon Longitudinal Study of Parents and Children, United Kingdom. A latent class analysis was used to identify patterns of infection and their relationship to five factors commonly used as proxies: sex, other children in the home, maternal smoking, breastfeeding and maternal education. A total of 10,032 singleton children were included in the analysis. Five classes were identified with differing infectious disease patterns and children were assigned to the class for which they had a highest probability of membership based on their infectious symptom profile: ‘general infection’ (n = 1,252, 12.5%), ‘gastrointestinal’ (n = 1,902, 19.0%), ‘mild respiratory’ (n = 3,560, 35.5%), ‘colds/ear ache’ (n = 462, 4.6%) and ‘healthy’ (n = 2,856, 28.5%). Females had a reduced risk of being in all infectious classes, other children in the home were associated with an increased risk of being in the ‘general infection’, ‘mild respiratory’ or ‘colds/ear ache’ class. Breastfeeding reduced the risk of being in the ‘general infection’ and ‘gastrointestinal’ classes whereas maternal smoking increased the risk of membership. Higher maternal education was associated with an increased risk of being in the ‘mild respiratory’ group. Other children in the home had the greatest association with infectious class membership. Latent class analysis provided a flexible method of investigating the relationship between multiple symptoms and demographic and lifestyle factors.     

The meaning of the opposition between the healthy and the pathological and its consequences

If the healthy and the pathological are not merely judgments qualifiers, but real phenomena, it must be possible to define both of them positively, which, in this context, means as factual contraries. On the other hand, only a privative definition, either of the pathological as ‘non-healthy’, or of the healthy as ‘non-pathological’, can rationally circumscribe all possible states of an organism. This fluctuation between two meanings of the ‘healthy’–‘pathological’ opposition, factual vs. rational, characterizes the ordinary usage of these concepts and puts all philosophical definitions in a hopeless situation. Although a scientific definition may conceal this equivocation by adequately setting out the terms of the problem of discriminating between the ‘healthy’ and the ‘pathological’, it could explain some of the difficulties met in determining ‘gold standards’, in the choice of separators, and in the assessment of the diagnostic qualities of tests.     

An updated review of epidemiologic studies on the relationship between exposure to whole-body vibration and low back pain (1986–1997)

 The aim of this study is to update the information on the epidemiologic evidence of the adverse health effects of whole-body vibration (WBV) on the spinal system by means of a review of the epidemiologic studies published between 1986 and 1997. In a systematic search, using several databases, of epidemiologic studies of low back pain (LBP) disorders and occupations with exposure to WBV, 45 articles were retrieved. The quality of each study was evaluated according to criteria concerning the assessment of vibration exposure, assessment of health effects, and methodology. The epidemiologic studies reaching an adequate score on each of the above-mentioned criteria were included in the final review. A meta-analysis was also conducted in order to combine the results of independent epidemiologic studies. After applying the selection criteria, 17 articles reporting the occurrence of LBP disorders in 22 WBV-exposed occupational groups reached a sufficient score. The study design was cross-sectional for 13 occupational groups, longitudinal for four groups and of case-control type for one group. Two studies included both cross-sectional and follow-up data on the occurrence of LBP disorders in four occupational groups. The main reasons for the exclusion of studies were insufficient quantitative information on WBV exposure and the lack of control groups. The findings of the selected studies and the results of the meta-analysis of both cross-sectional and cohort studies showed that occupational exposure to WBV is associated with an increased risk for LBP, sciatic pain, and degenerative changes in the spinal system, including lumbar intervertebral disc disorders. Owing to the cross-sectional design of the majority of the reviewed studies, this epidemiologic evidence is not sufficient to outline a clear exposure-response relationship between WBV exposure and LBP disorders. Comparing the epidemiologic studies included in this review with those conducted before 1986, it is concluded that research design and the quality of exposure and health effect data in the field of WBV have improved in the last decade. Received: 18 June 1998 / Accepted: 23 October 1998     

Estimating dietary intakes from a brief questionnaire: A simulation study of reliability in a molecular epidemiologic study of pancreatic and biliary diseases

Introduction Brief dietary questionnaires may be useful in research or clinical settings where in-depth assessments are inefficient or impractical. We conducted a simulation study to assess the reliability of a brief food frequency questionnaire (bFFQ) for capturing dietary intakes relative to a detailed survey.Subjects and methods The bFFQ was used in a study of patients with pancreatic and biliary diseases in eastern Spain (n = 605). The structured interview included a section probing the frequency of intakes of 14 food groups, using 4 response categories. Data from a 93-item semi-quantitative food frequency questionnaire (SFFQ) with 9 response categories (n = 1337) was used to: (1) develop estimates of nutrient intakes for each food group, and (2) to simulate how intakes would have been estimated using the bFFQ. The simulation allowed to assess effects of aggregating foods and using abbreviated frequency categories.Results Correlations between actual and simulated intake frequencies exceeded 0.70 for 10 food groups; modest correlations (0.43–0.56) were observed for groups assessed less well using abbreviated frequency categories. Correlations exceeded 0.60 for most nutrients. Concordance was lower for several nutrients, notably retinol, for which substantial proportions were contributed by groups combining foods with highly variable levels of these compounds.Conclusions Intake estimates from the bFFQ may be useful in exploratory analyses of the role of diet in bilio-pancreatic diseases and related etiopathogenic events. Estimates for some nutrients may be less reliable, and should be interpreted with particular caution.*Members of the Multicentre Prospective Study on the Role of K-ras and other Genetic Alterations in the Diagnosis, Prognosis and Etiology of Pancreatic and Biliary Diseases (PANKRAS II) Study Group are mentioned in previous publications.     

Incidence,admission and case-fatality of acute myocardial infarction: weekend versus weekday in a Japanese population: 16-year results from Takashima AMI Registry (1988–2003)

For acute myocardial infarction (AMI), “weekend” has been associated with higher incidence, admission, and fatality. But, very few studies in this regard are available in Japan. Day of the week variation in AMI was examined using an entire community covering 16-year AMI registration data from Japan. Data were obtained from the Takashima AMI Registry, which covers a stable population of approximately 55,000 in central Japan. There were 379 registered first ever AMI cases with 121 fatal events within 28 days of onset during 1988–2003. We divided the days into two groups: ‘Weekend’ (Saturday and Sunday) and ‘Weekdays’ (Monday to Friday). The incidence rate (per 100,000 person-year), admission rate (per 1,000 days) and 28-day case-fatality rates (per 100 events) as well as corresponding rate ratios were calculated with 95% confidence intervals. The distribution of the day of the week for onset, admission and fatality for all subjects was fairly random in our study population; incidence (χ ² test, P = 0.8), admission (χ ² test, P = 0.9) and case-fatality (χ ² test, P = 0.8). The incidence, admission, and case-fatality rates were similar for the 2 day-groups. The incidence rate ratio 1.06 (95% CI: 0.9–1.3), admission ratio 1.03 (95% CI: 0.8–1.3), and case-fatality ratio 1.18 (95% CI: 0.7–1.9) showed no significant risk difference between weekend and weekday. After various adjustments, hazard ratio for weekend AMI in reference to weekday AMI was 1.07 (95% CI: 0.5–2.1). There were no obvious differences in occurrence, hospital admission and acute outcome for AMI patients in the weekday or weekend.     

Occupational exposures and risk of pancreatic cancer

The objective was to analyze the relationship between occupation (and specific occupational exposures) and risk of exocrine pancreatic cancer (EPC). We conducted a multicenter hospital-based case–control study in Eastern Spain. We included 161 incident cases of EPC (59.6% men, 94 with histological confirmation, of whom 80% had ductal adenocarcinoma). Cases were frequency-matched with 455 controls by sex, age and province of residence. Information was elicited using structured questionnaires. Occupations were coded according to the Spanish version of the International Standard Classification of Occupations 1988. Occupational exposure to a selection of carcinogenic substances was assessed with the Finnish Job-Exposure Matrix (FINJEM). Odds ratios (OR) and 95% confidence intervals (CI) were estimated by multiple logistic regression, adjusting for sex, age, province, education, alcohol and smoking. A higher risk of EPC was associated with having worked as ‘Miners, shotfirers, stone cutters and carvers’, ‘Machinery mechanics and fitters’, ‘Building trades workers’ and ‘Motor vehicle drivers’ in men, ‘Office Clerks’ in women, and ‘Waiters’ in both sexes. Cases with ductal adenocarcinomas were more likely to have been exposed to chlorinated hydrocarbon solvents (OR = 4.1, 95% CI: 1.1–15.2, p-trend = 0.04). We also observed significant associations with exposure to ‘synthetic polymer dust exposure’ and ‘ionizing radiation’. Suggestive increases in risk were observed for ‘pesticides’, ‘diesel and gasoline engine exhaust’, and ‘hydrocarbon solvents’. Results support the hypothesis that occupational exposure to chlorinated hydrocarbon solvents is associated with exocrine pancreatic cancer.     

Fasting plasma concentrations of selected flavonoids as markers of their ordinary dietary intake

Summary. Background: Dietary flavonoids, especially flavonols, are discussed as potentially preventive agents in the etiology of diseases such as coronary heart disease, stroke, and cancer. However, their consideration in epidemiologic studies is hampered by difficulties in exposure assessment. Aim of the study: By comparison with dietary intake estimates, fasting plasma flavonoid concentrations should be evaluated as possible biomarkers of the ordinary dietary intake. Methods>: 7-d dietary records were completed by 48 healthy female students. Flavonoid intake was estimated by means of available literature data on the flavonoid content of foods. Fasting plasma samples were taken at the end of the record period for flavonoid determination (HPLC). Results: The mean intake estimates (7-d period) of quercetin, kaempferol, naringenin, and hesperetin amounted to 17.9, 4.7, 12.1, and 17.4 mg/d, respectively; the corresponding mean plasma concentrations were 22.9, 10.7, 8.2, and 22.2 nmol/l. For all four flavonoids significant correlations between 7d-intake results and fasting plasma concentrations (r = 0.30–0.46, p < 0.05) existed. As expected from the known short elimination half-life of some plasma flavonoids, distinctly higher correlation coefficients were found for the relationship between intake estimates for the last day before blood sampling and the fasting plasma concentrations (r = 0.42–0.64; p < 0.01). The intraindividual variation in fasting plasma flavonoid concentrations during ad libitum intake was found to be rather high (mean coefficient of variation between 82 and 91 %; n = 4). Conclusions: The flavonoid content in fasting plasma samples seems to be a suitable biomarker of short-term intake and a possible biomarker of the medium-term intake. Due to the high intraindividual variation the combined use of plasma flavonoid concentrations and dietary intake estimates may be the best choice in epidemiologic studies. Received: 16 February 2002, Accepted: 11 July 2002 Correspondence to: J. Radtke     

Increased incidence of sporadic Creutzfeldt-Jakob disease in the age groups between 70 and 90 years in Belgium

From 1998 a prospective surveillance study of Creutzfeldt-Jakob disease (CJD) has been initiated in Belgium. In addition to epidemiological data, information on cerebrospinal fluid biomarkers, prion protein gene and brain neuropathology was collected. From 1-1-1998 to 31-12-2004, 188 patients were referred to the surveillance system. In 85 patients a ‘definite’ diagnosis of sporadic CJD (sCJD) could be made, whereas 26 patients remained ‘probable’. We further identified two unrelated patients with an E200K mutation, and two patients with a seven octapeptide repeat insertion in one family. In one patient a familial history was noted but genetic analysis was not performed. In 72 patients different final diagnoses were made, Alzheimer’s disease being the most frequent (N = 20). The demographic parameters of the Belgian population were similar to those observed in the rest of Europe. We did notice a significantly increased age-specific incidence (‰>‰6/10⁶/year) of sCJD patients between 70 and 90 years old in the period 2002–2004 compared to 1998–2001 and retrospectively obtained data (1990–1997, p < 0.01). We undertook a detailed clinical and biochemical analysis to investigate this increase but could not identify any reason other than an increased vigilance for the diagnosis.In conclusion, our study identified that in the past sCJD may have been underestimated in patients over age 70 although these patients are both clinically and neurobiochemically similar to the general sCJD phenotype.     

2009年乳山市戊型病毒性肝炎疫情分析

[目的]分析2009年乳山市13月戊型病毒性肝炎疫情流行特征和原因。[方法]对2009年13月份疫情网络法定报告的36例戊型病毒性肝炎病例逐一进行流行病学调查,使用统一调查表格收集个案发病基本情况。[结果]2009年13月戊型病毒性肝炎发病与往年基本一致。33例职业为农民（占91.67%）,发病年龄均在40岁以上;有2例（占5.56%）经常在外就餐,10例（占27.78%）发病前有次数不等的聚餐史;有30例（占83.33%）发病前曾食用过海虹、蚬子、牡蛎等贝类海产品,16例（占44.44%）发病前吃过生葱、生韭菜等生蔬菜,28例（占7.78%）没有饭前便后洗手的良好习惯。[结论]36例戊型病毒性肝炎个案间均不存在关联性,为散发病例,仅2例可能存在家庭聚集性。发病前吃过海产品、生蔬菜,以及农民的不良卫生习惯可能是发病的主要原因。     

敦化市2005-2011年流行性出血热流行趋势分析

目的分析敦化市2005-2011年间流行性出血热(HFRS)的流行趋势,为制定合理的防治措施提供可靠依据。方法利用7年间敦化市HFRS疫情资料对其流行特征和三间分布进行分析。结果敦化市2005-2011年共报告HFRS病例519例,平均发病率为15.44/10万,无死亡病例报告。城区各街道和农村各乡镇均有HFRS病例报告;农村报告病例占85.93%。发病主要集中在5-7月和10月-次年1月,呈现两个发病高峰。男性病例为440例,女性病例为79例;病例多集中在20～50岁之间的青壮年,占总病例数的69.75%。发病以农民为主,占总病例数的64.55%;其次为工人,占总病例数的9.83%。结论在6月和11月两个发病高峰来临前,采取灭鼠、疾病监测、健康教育、接种疫苗等综合性防治措施,是降低HFRS发病率最有效的方法。     

2008年广东省轮状病毒腹泻监测分析

目的掌握轮状病毒腹泻在广东省的流行特征和发病规律,为今后开展有针对性的防控措施提供科学依据。方法从国家疾病监测信息报告系统收集2008年广东省报告的轮状病毒感染个案,采用描述性流行病学方法对所有个案的人群、时间和地区分布特征进行分析。结果2008年全省共报告轮状病毒腹泻病例22 354例,报告发病率为22.7/10万,占其他感染性腹泻病例的20.2%,病例主要分布在珠三角地区的深圳、广州、珠海,分别报告轮状病毒腹泻13 560、4 362、2880例,各占总报告病例数的60.7%、19.5%、12.9%,0、1岁组2个年龄段报告病例数分别占总病例数的54.6%、31.9%,散居儿童占总病例数的94.1%。2008年广东省轮状病毒腹泻在10月后进入流行期,12月初达到流行高峰。深圳市报告其他感染性腹泻病例以实验室诊断病例居多,占78.5%(16 476/20 978),病原学确诊为轮状病毒感染者占实验室诊断病例的82.3%,占总报告病例数的64.6%。全省及深圳市轮状病毒腹泻报告病例发病时间分布均相应与其他感染性腹泻发病时间分布基本一致。全省各地医疗机构轮状病毒检测水平不同,存在较大地区和医院差别。结论轮状病毒...     

北京市西城区2010年手足口病疫情的流行特征分析

目的 分析2010年北京市西城区手足口病疫情流行特征.方法 收集2010年北京市西城区手足口病疫情相关信息,对疫情报告、规模、分布特点、实验室检测等信息进行分析.结果 2010年北京市西城区共报告手足口病聚集性病例疫情40起,暴发疫情2起,波及13 947人,共报告病例175例,平均罹患率1.3％,无重症、住院及死亡病例报告;疫情来源以社区卫生服务中心报告为主(占61.9％),疫情持续时间中位数11 d(10～22d);疫情在辖区各街道均有报告,报告时间以5～7月为主,占68.3％,发病以托幼机构儿童为主,托幼机构疫情占80.9％,托幼儿童病例数占85.7％;42起疫情实验室检测阳性37起,其中CoxA16、EV71、肠道病毒未分型分别占45.9％、27.0％、27.0％.结论 托幼机构是手足口病疫情高发的场所,建立有效的监测系统,早期发现手足口病疫情是防止手足口病局部暴发的重要措施.     

鹿城区2011年-2017年麻疹监测结果及流行特征分析

目的分析温州市鹿城区2011年-2017年麻疹流行病学特征。方法对温州市鹿城区2011年-2017年麻疹监测数据用描述性流行病学方法进行分析。结果2011年-2017年鹿城区共报告麻疹117例,年均发病率为2.10/10万;<8月龄儿童和≥15岁成人分别占全部病例的37.61%和29.06%。8月龄~14岁麻疹病例(39例)和排除病例(85例)中有免疫史者分别占28.21%和78.82%,排除病例免疫史明显高于麻疹病例免疫史,差异有统计学意义(χ^2=29.35,P<0.01)。血清标本采集率、3 d内送达率由2011年48.52%和52.41%提高至2012年80%以上。结论2011年-2017年鹿城区麻疹病例呈现明显下降趋势,但仍需提高适龄儿童含麻疹成分疫苗覆盖率和及时接种率,及早监测和有效处置麻疹疫情,并进一步提高监测的敏感性、特异性和及时性。     

广东省2004-2006年其他感染性腹泻流行特征分析

目的了解广东省其他感染性腹泻的流行病学特征,探索监测系统中可能存在的问题。方法对广东省2004-2006年疾病监测信息报告系统中上报的其他感染性腹泻病例进行描述性流行病学分析。结果2004-2006年广东省共报告其他感染性腹泻病例198 522例,年发病率的范围为64.0/10万~91.8/10万,发病呈逐年上升趋势。5岁以下年龄组占全部发病数的46.13%。8-9月开始其他感染性腹泻发病逐渐增加,2004-2005年的12月下旬出现发病高峰,2006年发病高峰提前到11月中旬。报告发病率居前5位的地级市有江门、珠海、中山、阳江、广州等市。实验室诊断病例占总报告病例数的12.7%,其中轮状病毒在实验室诊断病例中占34.5%。3年共报告其他感染性腹泻暴发疫情8起,主要为诺如病毒(5起)引起。结论广东省2004-2006年其他感染性腹泻流行主要集中在0~5岁散居和托幼儿童,秋冬季是其他感染性腹泻的好发季节,各地其他感染性腹泻的报告严重不均,轮状病毒可能是影响其他感染性腹泻分布的重要因素之一。     

Dietary pattern, inflammation, and incidence of type 2 diabetes in women

BACKGROUND: Inflammation is considered a key mechanism leading to type 2 diabetes, but dietary exposures that lead to inflammation and diabetes are largely unknown. OBJECTIVE: Our objective was to investigate the relation between a dietary pattern associated with biomarkers of inflammation and the incidence of type 2 diabetes. DESIGN: We conducted a nested case-control study of 656 cases of type 2 diabetes and 694 controls among women in the Nurses' Health Study and 2 prospective cohort studies of 35,340 women in the Nurses' Health Study and 89,311 women in the Nurses' Health Study II who were followed for incident diabetes. RESULTS: Through the use of reduced rank regression, we identified a dietary pattern that was strongly related to inflammatory markers in the nested case-control study. This pattern, which was high in sugar-sweetened soft drinks, refined grains, diet soft drinks, and processed meat but low in wine, coffee, cruciferous vegetables, and yellow vegetables, was associated with an increased risk of diabetes (multivariate-adjusted odds ratio comparing extreme quintiles: 3.09; 95% CI: 1.99, 4.79). We identified 1517 incident cases of confirmed type 2 diabetes in the Nurses' Health Study (458,991 person-years) and 724 incident cases in the Nurses' Health Study II (701,155 person-years). After adjustment for body mass index and other potential lifestyle confounders, the relative risks comparing extreme quintiles of the pattern were 2.56 (95% CI: 2.10, 3.12; P for trend < 0.001) in the Nurses' Health Study and 2.93 (95% CI: 2.18, 3.92; P for trend < 0.001) in the Nurses' Health Study II. CONCLUSION: The dietary pattern identified may increase chronic inflammation and raise the risk of developing type 2 diabetes.     

2006-2011年河南省新蔡县HIV／AIDS流行病学特征与趋势分析

目的了解和掌握河南省新蔡县新发现HIV／AIDS流行病学特征和流行趋势,为制定艾滋病防治策略提供科学依据。方法对2006-2011年发现的HIV／AIDS监测、检测资料进行统计分析。结果2006-2011年全县发现HIV感染者及AIDS病人531例,其中HIV感染者118例,AIDS病人413例。传播途径以输入血液／血制品为主,占43．13％;其次为异性性传播（其中婚内性传播131例,婚外性传播38例）,占31．83％;有偿采供血传播占12．24％;母婴传播占5．08％;同性传播占0．75％;静脉吸毒占0．38％;其他及不详占6．59％。结论当前新蔡县预防与控制艾滋病的重点是应加强对1995年以前输入血液／血制品人群的专题调查,及时发现病例,并加强对单阳配偶、阳性育龄妇女、丧偶阳性者的干预管理,预防婚内性传播,同时积极开展高危行为干预措施,减少经性传播的发生。     

Epidemiologic evidence suggests that dietary phytoestrogen intake is associated with reduced risk of breast, endometrial, and prostate cancers

Phytoestrogens are natural estrogen-like plant substances. The possible protective effect of phytoestrogens on cancer risk, particularly on hormone-related cancers, has been the focus of many epidemiologic studies during the last 2 decades. We performed a qualitative review of the epidemiologic literature published in the English language and identified on MEDLINE from 1966 until 24 September 2006 on (1) dietary intake of soy, isoflavones, or lignans; (2) urinary excretion of isoflavones or lignans; (3) blood measurements of isoflavones or lignans in relation to breast, prostate, and endometrial cancer risk. Epidemiologic data do seem to support a small protective effect of isoflavones on breast cancer risk, although timing of exposure and the mechanisms of isoflavones at physiologic levels need to be further explored. The epidemiologic evidence to date is conflicting regarding lignans and breast cancer, but recent studies suggest that the effect may be restricted to premenopausal women, differ by estrogen receptor status, and be modified by diet-gene interactions. The 3 case-control studies on dietary intake of phytoestrogens and endometrial cancer risk have provided some evidence for a protective effect, but more prospective data are needed. There is some epidemiologic evidence for a protective effect of soy or isoflavones on prostate cancer, but corresponding data for lignans are inconclusive. Recent data indicate that diet-gene interactions may modify the effect of phytoestrogens on prostate cancer risk. Prospective studies on dietary lignans in relation to prostate cancer risk are lacking.