Inverse Association (inverse + association)

Distribution by Scientific Domains
Distribution within Medical Sciences

Kinds of Inverse Association

  • significant inverse association
  • strong inverse association


  • Selected Abstracts


    Inverse Association between T-Cell Immunoglobulin and Mucin Domain-1 and T-bet in a Mouse Model of Allergic Rhinitis,

    THE LARYNGOSCOPE, Issue 6 2007
    Geng Xu MD
    Abstract Background: It has been suggested that human hepatitis A virus cellular receptor, also known as T-cell immunoglobulin and mucin domain-1 (TIM-1), plays an important role in the development of allergic diseases on the basis of epidemiologic data, but the molecular mechanism has been unclear. In a murine model of ovalbumin (OVA)-sensitized allergic rhinitis (AR), we examined the expression of TIM-1 and its correlation with T helper1-associated transcription factor, T-bet, as a potential mediator of T-cell immunoglobulin expression. Methods: Mice were challenged intranasally with OVA to elicit AR. The expression of TIM-1 in nasal tissues was examined by real-time reverse-transcription polymerase chain reaction (RT-PCR), and the surface expression of TIM-1 in peripheral blood mononuclear cells was evaluated by means of flow cytometry. In addition, the expression of TIM-1 as well as T-bet in splenic lymphocytes was examined by Western blotting. Results: TIM-1 mRNA was increased significantly in nasal tissues (P < .05) as seen by real-time RT-PCR. Flow cytometry indicated a differential TIM-1 expression of 135.5 ± 34.2 in the AR group versus 51.1 ± 10.9 in the control group (P < .05). The mean values of normalized TIM-1 were 0.43 ± 0.18 and 0.21 ± 0.10 in AR and control groups, respectively, whereas the mean values of normalized T-bet were 0.22 ± 0.13 and 0.67 ± 0.17 in the AR and control groups, respectively. There was a significant difference in the production of TIM-1 as well as T-bet in AR mice versus control mice (P < .05). The increased production of TIM-1 correlated significantly with the decreased T-bet in spleen tissue of AR mice (r = ,0.52, P < .05). Conclusion: Our experimental model recapitulates an increase in lymphocyte TIM-1 expression seen in AR both locally and systemically. Our results also demonstrate an inverse relationship between lymphocyte TIM-1 and T-bet expression, suggesting a possible mechanism that TIM-1 influences the development of AR. [source]


    Inverse association between farm animal contact and respiratory allergies in adulthood: protection, underreporting or selection?

    ALLERGY, Issue 4 2006
    K. Radon
    Background:, It has been argued that the inverse association between exposure to farm animals and nasal allergies observed in children and adults might be because of self-selection. Aims:, We aimed to assess the health-based selection out of farming in adults. Material and methods:, A cross-sectional study was carried out in a rural region. Overall, 4053 inhabitants (63%) aged 18,44 years responded to a questionnaire on respiratory diseases, life-time exposure to farming environments and potential confounders. For 2678 of these, specific immunoglobulin E to common allergens was available. The outcome was: (i) sensitization and symptoms of nasal allergies (symptomatic sensitization); (ii) sensitization without symptoms of nasal allergies (asymptomatic sensitization). Results:, Farm animal contact in childhood was associated with a decreased risk of symptomatic and asymptomatic sensitization. Continued exposure to farm animals in adulthood further decreased the odds ratio of symptomatic (odds ratio 0.2; 95% confidence interval 0.1, 0.4) but not asymptomatic sensitization (0.7; 0.4, 1.1). Starting farm animal contact in adulthood even increased the odds ratio of asymptomatic sensitization (2.4; 1.1, 5.2). Conclusions:, The preventive effect of childhood contact to farm animals against sensitization continues into adulthood. However, in adulthood self-selection based on symptoms and underreporting of symptoms might also play a role. [source]


    The non-Hodgkin lymphomas: A review of the epidemiologic literature

    INTERNATIONAL JOURNAL OF CANCER, Issue S12 2007
    Dominik D. Alexander
    Abstract The non-Hodgkin lymphomas (NHL) are a heterogeneous group of B-cell and T-cell neoplasms that arise primarily in the lymph nodes. NHL incidence rates in the US doubled between about 1970 and 1990, and stabilized during the 1990s. NHL accounts for ,3.4% of cancer deaths in the US. Although some of the observed patterns in NHL have been related to HIV/AIDS, these conditions cannot fully explain the magnitude of the changes; neither do changes in classification systems nor improved diagnostic capabilities. Studies of occupational and environmental exposures (e.g., pesticides, solvents) have produced no consistent pattern of significant positive associations. Inverse associations with ultraviolet radiation exposure and alcohol and fish intake, and positive associations with meat and saturated fat intake have been reported in several studies; additional studies are needed to confirm or refute these associations. Family history of NHL or other hematolymphoproliferative cancers and personal history of several autoimmune disorders are associated with increased risk of NHL, but are not likely to account for a large proportion of cases. HIV and other infectious agents, such as human herpesvirus 8 and Epstein,Barr, appear to be associated with differing types of NHL, such as some B-cell lymphomas. Future epidemiologic studies should evaluate associations by NHL type, enhance exposure information collected, and elucidate factors that may identify susceptible (or resistant) subpopulations because of genetic, immunologic or other characteristics. The extent to which the etiology of NHL types may differ is important to resolve in ongoing and future studies. © 2007 Wiley-Liss, Inc. [source]


    Specific IgE to allergens in cord blood is associated with maternal immunity to Toxoplasma gondii and rubella virus

    ALLERGY, Issue 11 2008
    M. J. Ege
    Background:, Various studies have found reduced prevalences of atopic sensitization and atopic diseases in children previously exposed to infections or living conditions with a high microbial burden, such as the farming environment. Objective:, We sought to determine the relationships of cord blood immunoglobulin E (IgE) with maternal health conditions before and during pregnancy. Methods:, Pregnant women living in rural areas in five European countries were recruited in the third trimester of pregnancy. Information on maternal health during pregnancy was collected from maternity records and by questionnaires (n = 497). Specific IgE for inhalant and food allergens was assessed in cord blood and peripheral blood samples of the mothers. Results:, Inverse associations of cord blood IgE to seasonal allergens with positive maternal records for Toxoplasma gondii (adjusted odds ratio = 0.37 [0.17,0.81]) and rubella virus (adjusted odds ratio = 0.35 [0.13,0.96]) were found. The previously described effect of prenatal farm exposure on IgE to seasonal allergens was partly confounded by a positive maternal record for T. gondii. The number of maternal siblings, maternal contact to cats during pregnancy or during her first year of life, predicted a positive maternal record for T. gondii. Conclusions:, Maternal immunity to T. gondii and rubella may impact on atopic sensitization in the fetus. A positive T. gondii record explained the previously identified effect of prenatal farm exposure on IgE to seasonal allergens only to a minor extent. [source]


    Correlations of dietary patterns with prostate health

    MOLECULAR NUTRITION & FOOD RESEARCH (FORMERLY NAHRUNG/FOOD), Issue 1 2008
    Maria Stacewicz-Sapuntzakis
    Abstract Both genetic and environmental influences may be involved in etiology of prostate health and prostate cancer. These include ethnic origin, family history, smoking, and diet. Adiposity and excess energy intake are potentially distinct risk factors and positive associations with prostate cancer risk for both were observed among case-control and cohort studies. Some epidemiological studies support an association between dietary fat, particularly saturated or animal fats, and prostate cancer risk. Of these, several suggest reduced risk with low-fat diets high in n-3 fatty acids and increased risk with high-fat diets rich in n-6 fatty acids. Others suggested association with higher meat intake, possibly due to heterocyclic amines and polycyclic aromatic hydrocarbons, produced during grilling or frying. Positive association of prostate cancer risk with dairy intake could involve ,-methylacyl-CoA racemase activity (required for ,-oxidation of phytanic acid present in dairy products and red meat) or the suppression of vitamin D activity by calcium. Inverse associations were observed with dietary intake of plant foods. These include cereals, soy products, and fruit and vegetable sources of carotenoids. Numerous plant constituents may act synergistically in the prevention and inhibition of prostate disorders. These diet-risk associations may lead to future individualized diet recommendations based upon genetic polymorphisms. [source]


    ORIGINAL RESEARCH,ANATOMY/PHYSIOLOGY: Satisfaction (Sexual, Life, Relationship, and Mental Health) Is Associated Directly with Penile,Vaginal Intercourse, but Inversely with Other Sexual Behavior Frequencies

    THE JOURNAL OF SEXUAL MEDICINE, Issue 7 2009
    Stuart Brody PhD
    ABSTRACT Introduction., Some sex therapists and educators assume that many sexual behaviors provide comparable sexual satisfaction. Evidence is required to determine whether sexual behaviors differ in their associations with both sexual satisfaction and satisfaction with other aspects of life. Aims., To test the hypothesis that satisfaction with sex life, life in general, sexual partnership, and mental health correlates directly with frequency of penile,vaginal intercourse (PVI) and inversely with frequency of both masturbation and partnered sexual activity excluding PVI (noncoital sex). Methods., A representative sample of 2,810 Swedes reported frequency of PVI, noncoital sex, and masturbation during the past 30 days, and degree of satisfaction with their sex life, life in general, partnership, and mental health. Main Outcome Measures., Multivariate analyses (for the sexes separately and combined) considering the different satisfaction parameters as dependent variables, and the different types of sexual activities (and age) as putative predictors. Results., For both sexes, multivariate analyses revealed that PVI frequency was directly associated with all satisfaction measures (part correlation = 0.50 with sexual satisfaction), masturbation frequency was independently inversely associated with almost all satisfaction measures, and noncoital sex frequencies independently inversely associated with some satisfaction measures (and uncorrelated with the rest). Age did not confound the results. Conclusions., The results are consistent with evidence that specifically PVI frequency, rather than other sexual activities, is associated with sexual satisfaction, health, and well-being. Inverse associations between satisfaction and masturbation are not due simply to insufficient PVI. Brody S, and Costa RM. Satisfaction (sexual, life, relationship, and mental health) is associated directly with penile-vaginal intercourse, but inversely with other sexual behavior frequencies. J Sex Med 2009;6:1947,1954. [source]


    HbA1c levels in non-diabetic Dutch children aged 8,9 years: the PIAMA birth cohort study

    DIABETIC MEDICINE, Issue 2 2009
    H. Jansen
    Abstract Aim, Glycated haemoglobin (HbA1c) is considered the best index of glycaemic control in established diabetes. It may also be useful in the diagnosis of diabetes and as a screening tool. Little is known about the distribution of HbA1c in healthy children and its predictors. The aim of this study is to describe the distribution of HbA1c in non-diabetic Dutch children aged 8,9 years and to investigate potential associations of HbA1c in this group. Methods HbA1c was measured in 788 non-diabetic children aged 8,9 years participating in the PIAMA birth cohort study. Data on parents and children were collected prospectively by questionnaires. Weight, height and waist and hip circumference of the children were measured when blood samples were taken. Results, Mean (sd) HbA1c was 4.9 ± 0.33%, range 3.5,6.0%. HbA1c was significantly higher in boys (4.9 ± 0.31 vs. 4.9 ± 0.33%) and in children of mothers with gestational diabetes (5.0 ± 0.37 vs. 4.9 ± 0.32%). We found a significant inverse association between HbA1c and haemoglobin (regression coefficient: ,0.169 (95% CI ,0.221 to ,0.118), P < 0.001). HbA1c was not significantly associated with age, body mass index, waist circumference, parental diabetes or maternal body mass index. Conclusions, We found no significant relation between known risk factors for Type 2 diabetes and HbA1c at age 8,9 years. Moreover, there was a significant inverse association between haemoglobin and HbA1c. These results suggest that HbA1c may not only reflect the preceding blood glucose levels, but seems to be determined by other factors as well. [source]


    Post-challenge glucose predicts coronary atherosclerotic progression in non-diabetic, post-menopausal women,

    DIABETIC MEDICINE, Issue 10 2007
    P. B. Mellen
    Abstract Aims, We sought to determine whether fasting or post-challenge glucose were associated with progression of coronary atherosclerosis in non-diabetic women. Methods, We performed a post-hoc analysis of 132 non-diabetic women who underwent 75-g oral glucose tolerance testing. The primary outcome of interest was progression of atherosclerosis determined by baseline and follow-up coronary angiography, a mean of 3.1 ± 0.9 years apart. We analysed the association of change in minimal vessel diameter (,MD) by quartile of fasting and post-challenge glucose using mixed models that included adjustment for age, systolic blood pressure, total : high-density lipoprotein cholesterol ratio, current smoking, lipid-lowering and anti-hypertensive medication use and other covariates. Results, At baseline, participants had a mean age of 65.7 ± 6.7 years and a mean body mass index of 27.9 ± 8.5 kg/m2. Although there were no significant differences in atherosclerotic progression by fasting glucose category (P for trend across quartiles = 0.99), there was a significant inverse association between post-challenge glucose and ,MD (in mm) (Q1 : 0.01 ± 0.03; Q2 : 0.08 ± 0.03; Q3 : 0.13 ± 0.03; Q4 : 0.11 ± 0.03; P for trend = 0.02). Conclusions, In post-menopausal women without diabetes, post-challenge glucose predicts angiographic disease progression. These findings suggest that even modest post-challenge hyperglycaemia influences the pathogenesis of atherosclerotic progression. [source]


    An estrogen receptor , suppressor, microRNA-22, is downregulated in estrogen receptor ,-positive human breast cancer cell lines and clinical samples

    FEBS JOURNAL, Issue 7 2010
    Jianhua Xiong
    Previous studies have suggested that microRNAs (miRNAs) may play important roles in tumorigenesis, but little is known about the functions of most miRNAs in cancer development. In the present study, we set up a cell-based screen using a luciferase reporter plasmid carrying the whole , 4.7 kb 3,-UTR of estrogen receptor , (ER,) mRNA cotransfected with a synthetic miRNA expression library to identify potential ER,-targeting miRNAs. Among all the miRNAs, miR-22 was found to repress robustly the luciferase signal in both HEK-293T and ER,-positive MCF-7 cells. Mutation of the target site was found to abrogate this repression effect of miR-22, whereas antagonism of endogenous miR-22 in MDA-MB-231 cells resulted in elevated reporter signals. We assessed the miR-22 expression patterns in five breast cancer cell lines and 23 clinical biopsies and revealed that there is a significant inverse association between the miR-22 levels and ER, protein expression. To evaluate the potential of miR-22 as a potential therapeutic intervention, we found that reduction of endogenous ER, protein levels and suppression of cancer cell growth could be achieved in MCF-7 cells by miR-22 overexpression in a way that can be recapitulated by the introduction of specific small interfering RNA against ER,. The phenomena can be rescued by the reintroduction of ER,. Taken together, our data indicate that miR-22 was frequently downregulated in ER,-positive human breast cancer cell lines and clinical samples. Direct involvement in the regulation of ER, may be one of the mechanisms through which miR-22 could play a pivotal role in the pathogenesis of breast cancer. [source]


    The Prevalence of Headache and Its Association With Socioeconomic Status Among Schoolchildren in Istanbul, Turkey

    HEADACHE, Issue 5 2009

    Objective., The etiology and pathogenesis of migraine and other types of headache are still under discussion. An interaction of organic, psychological, and psychosocial factors is operative. In this study, we aimed to determine the prevalence of headache and its association with socioeconomic status among schoolchildren. Study Design., A cross-sectional study was performed on 2669 schoolchildren via a parental questionnaire. Socioeconomic status was determined according to the Turkish socioeconomic status scale. Results., The mean age of the students was 8.2 ± 2.4 years. The headache prevalence was 46.2% (95% CI: 44.3-48.1). The prevalence of migraine was 3.4% (95% CI: 2.8-4.1), the prevalence of probable migraine was 8.7% (95% CI: 7.6-9.8), and that of non-migraine headache was 34.1% (95% CI: 32.3-35.9). Multivariate analysis revealed that older age, being a girl, having a family history of headache, and exposure to passive smoking at home were independently associated with headache. There was an inverse association between socioeconomic status and all 3 types of headaches after adjusting for age, sex, family history of headache, and presence of passive smoking. When the group with the lowest socioeconomic status was taken as the reference category, the odds ratios for the highest socioeconomic group were 0.33 (95% CI: 0.16-0.69, P = .003) for the migraine, 0.30 (95% CI: 0.11-0.89, P = .029) for the probable migraine, and 0.34 (95% CI: 0.16-0.72, P = 0.005) for the non-migraine headache. Conclusion., Headache is more common among children with lower socioeconomic groups. Social causation can play a role in the pathogenesis of headache. [source]


    Joint effects of coffee consumption and serum gamma-glutamyltransferase on the risk of liver cancer,

    HEPATOLOGY, Issue 1 2008
    Gang Hu
    Only three Japanese prospective studies have suggested an inverse association between coffee drinking and liver cancer risk. No prospective studies on the association between serum gamma-glutamyltransferase (GGT) and liver cancer risk have been reported. We aimed to determine the single and joint associations of coffee consumption and serum GGT with the risk of primary liver cancer. Study cohorts included 60,323 Finnish participants who were 25-74 years of age and free of any cancer at baseline. During a median follow-up period of 19.3 years (interquartile range: 9.3-29.2 years), 128 participants were diagnosed with an incident liver cancer. The multivariable-adjusted (age, sex, alcohol consumption, education, smoking, diabetes and chronic liver disease at baseline and during follow-up, and body mass index) hazards ratios of liver cancer in participants who drank 0-1, 2-3, 4-5, 6-7, and ,8 cups of coffee daily were 1.00, 0.66, 0.44, 0.38, and 0.32 (P for trend = 0.003), respectively. Further adjustment for serum GGT in subgroup analysis affected the results only slightly. The multivariable-adjusted and coffee-adjusted hazard ratio of liver cancer for the highest versus the lowest quartile of serum GGT was 3.13 (95% confidence interval = 1.22-8.07). The multivariable-adjusted inverse association between coffee consumption and liver cancer risk persisted when stratified by baseline factors: age more/less than 50 years, current smoker/never smoked/ever smoked, alcohol drinker/never drinker, obese/nonobese, and the highest/lowest three quartiles of serum GGT. A combination of very low coffee consumption and high level of serum GGT was associated with nearly nine-fold increased risk. Conclusion: Coffee drinking has an inverse and graded association with the risk of liver cancer. High serum GGT is associated with an increased risk of liver cancer. (HEPATOLOGY 2008.) [source]


    The relationship between varicoceles and obesity in a young adult population

    INTERNATIONAL JOURNAL OF ANDROLOGY, Issue 4 2009
    Chih-Wei Tsao
    Summary To determine whether a relationship between obesity and varicocele occurrence exists, the prevalence and severity of varicoceles related to obesity were investigated in a general population of young males. A total of 1050 young males attending the Navy Recruit Training Center were evaluated from their physical screening examinations. All subjects underwent history taking and physical examinations to evaluate for the presence and severity of varicocele. The anthropometric indexes including body mass index (BMI), waist circumference (WC) and waist-to-hip ratio (WHR) were recorded. All subjects were categorized by quartiles according to each anthropometric index. Means were compared with the Student's t -test. Severity was compared by analysis of variance testing and frequency was analysed using the chi-square method. Statistical significance was considered at p <0.05. A total of 490 (46.67%) subjects had varicoceles. The means of BMI, WC and WHR of those without varicoceles was 23.99 ± 3.82 kg/m2, 83.20 ± 9.97 cm and 0.85 ± 0.05, respectively. These judged values were greater than those with varicoceles (22.02 ± 3.18 kg/m2, 79.19 ± 9.01 cm and 0.83 ± 0.05) (p < 0.001). In the univariate regression analysis, BMI, WC and WHR all had a significantly negative correlation with severity of varicocele (all p < 0.001). Analysis comparing varicocele frequency based on each grade per anthropometric index group was performed. The logistic regression revealed that the prevalence of grade II and III varicoceles showed a statistically inverse association with all three anthropometric indexes. The prevalence and severity of varicoceles inversely correlated with obesity. The present data support the explanation that obesity may result in a decreased nutcracker effect, which accounts for prevention of the renal vein compression by the adipose tissue. [source]


    Serum levels of vitamin D, PTH and calcium and breast cancer risk,a prospective nested case,control study

    INTERNATIONAL JOURNAL OF CANCER, Issue 9 2010
    Martin Almquist
    Abstract Previous studies indicate that calcium and its regulating hormones, i.e., parathyroid hormone (PTH) and vitamin D, might affect breast cancer risk. Evidence also suggests that this relationship could be influenced by menopausal status and BMI. We examined breast cancer risk related to prediagnostic serum levels of vitamin D (25OHD2 and 25OHD3), PTH and calcium using a nested case,control design within the Malmö Diet and Cancer Study. There were 764 incident breast cancer cases, and 764 controls were selected by incidence density matching, using age as the underlying time scale, matching on calendar time at inclusion, menopausal status and age at inclusion. Using logistic regression analysis, odds ratios (OR) with 95% confidence intervals were calculated for breast cancer risk in different quartiles of the analyzed factors. All analyses were adjusted for risk factors for breast cancer, and for levels of albumin, creatinine and phosphate. Analyses were repeated stratified for BMI and menopausal status, and for low vs. high levels of 25OHD3, PTH and calcium. There was a weak, nonsignificant inverse association between breast cancer risk and 25OHD3, and the OR for the 2nd, 3rd and 4th quartiles, as compared to the first, were 0.84 (0.60,1.15), 0.84 (0.60,1.17) and 0.93 (0.66,1.33). Serum calcium was positively associated with breast cancer in premenopausal women (OR for the 4th quartile = 3.10:1.33,7.22 and p for quartile trend = 0.04), and in women with BMI > 25 (OR for the 4th quartile = 1.94:1.12,3.37 and p for trend < 0.01). There was no association between baseline serum PTH and breast cancer risk. [source]


    Physical activity and risk of prostate cancer in the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort

    INTERNATIONAL JOURNAL OF CANCER, Issue 4 2009
    Nina Føns Johnsen
    Abstract The evidence concerning the possible association between physical activity and the risk of prostate cancer is inconsistent and additional data are needed. We examined the association between risk of prostate cancer and physical activity at work and in leisure time in the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort. In our study, including 127,923 men aged 20,97 years from 8 European countries, 2,458 cases of prostate cancer were identified during 8.5 years of followup. Using the Cox proportional hazards model, we investigated the associations between prostate cancer incidence rate and occupational activity and leisure time activity in terms of participation in sports, cycling, walking and gardening; a metabolic equivalent (MET) score based on weekly time spent on the 4 activities; and a physical activity index. MET hours per week of leisure time activity, higher score in the physical activity index, participation in any of the 4 leisure time activities, and the number of leisure time activities in which the participants were active were not associated with prostate cancer incidence. However, higher level of occupational physical activity was associated with lower risk of advanced stage prostate cancer (ptrend = 0.024). In conclusion, our data support the hypothesis of an inverse association between advanced prostate cancer risk and occupational physical activity, but we found no support for an association between prostate cancer risk and leisure time physical activity. © 2009 UICC [source]


    IgE, allergy, and risk of glioma: Update from the San Francisco Bay Area Adult Glioma Study in the Temozolomide era

    INTERNATIONAL JOURNAL OF CANCER, Issue 3 2009
    Joseph L. Wiemels
    Abstract The consistently observed inverse relationship of allergic conditions with glioma risk and our previous demonstration that immunoglobulin E (IgE) levels also were lower in glioma patients than controls suggest that atopic allergy may be related to a mechanism that inhibits or prevents glioma. We sought to extend these results with a new and larger series of patients (n = 535 with questionnaire data; 393 with IgE measures) and controls (n = 532 with questionnaire data; 470 with IgE measures). As expected, glioma cases were less likely than controls to report history of allergies [among self-reported cases, Odds ratios (OR) = 0.59, 95% confidence interval (CI): 0.41,0.85]. IgE levels also were lower in glioma cases versus controls (OR per unit log IgE = 0.89, 95% CI (0.82,0.98). However, this inverse relationship was only apparent among cases receiving temozolomide, a treatment which became part of the "standard of care" for glioblastoma patients during the study period. Among patients receiving temozolomide, IgE levels in cases whose blood samples were obtained within 30 days of diagnosis were slightly higher than controls, whereas IgE levels in cases whose blood sample was obtained >60 days after diagnosis were significantly lower than controls (OR = 0.80; 95% CI: 0.71,0.89). Thus, although our results robustly confirm the inverse association between allergy and glioma, the results for IgE are affected by temozolomide treatments which may have influenced IgE levels. These results have implications for the study of immunologic factors in glioma as well as for immunotherapy protocols for treating glioma. © 2009 UICC [source]


    Greater vegetable and fruit intake is associated with a lower risk of breast cancer among Chinese women

    INTERNATIONAL JOURNAL OF CANCER, Issue 1 2009
    Cai-Xia Zhang
    Abstract The effect of vegetable and fruit consumption on breast cancer risk is controversial. We examined the association between vegetable and fruit intake and breast cancer risk in a hospital-based case,control study conducted in Guangdong, China. Four hundred and thirty-eight cases were frequency matched to 438 controls by age (5-year interval) and residence (rural/urban). Dietary intake was assessed by face-to-face interviews using a validated food frequency questionnaire. Multivariate logistic regression was used to estimate the odds ratios (ORs) and 95% confidence interval (CI) after adjusting for various potential confounders. Total vegetable and fruit intake was found to be inversely associated with breast cancer risk. The ORs of the highest quartile relative to the lowest quartile of total vegetable and fruit intake were 0.28 (95% CI 0.18,0.43) and 0.53 (95% CI 0.34,0.82), respectively. Consumption of individual vegetable and fruit groups such as dark green leafy vegetables, cruciferous vegetables, carrots and tomatoes, banana, watermelon/papaya/cantaloupe were all inversely and significantly related with breast cancer risk. An inverse association was also observed for vitamin A, carotene, vitamin C, vitamin E, and fiber intake. These data indicate that greater intake of vegetables and fruits is associated with a decreased risk of breast cancer among Chinese women residing in Guangdong. © 2009 UICC [source]


    Breast cancer and microbial cancer incidence in female populations around the world: A surprising hyperbolic association

    INTERNATIONAL JOURNAL OF CANCER, Issue 5 2008
    Anamaria Savu
    Abstract Current literature on cancer epidemiology typically discusses etiology of cancer by cancer type. Risks of different cancer types are, however, correlated at population level and may provide etiological clues. We showed previously an unexpected very high positive correlation between breast cancer (BC) and young-adult Hodgkin disease incidence rates. In a population-based case,control study of BC, older ages at the first Epstein,Barr virus exposure, indicated by older ages at onset of infectious mononucleosis, were associated with elevated BC risk. Here we examine BC risk in association with microbial cancer (MC) risk in female populations across the world. MC cancers are cervical, liver and stomach cancers with established causal associations with human papillomaviruses, hepatitis viruses, and helicobacter pylori, respectively. We examined age-adjusted BC and MC incidence rates in 74 female populations around the world with cancer registries. Our analysis suggests that BC and MC rates are inversely associated in a special mathematical form such that the product of BC rate and MC rate is approximately constant across world female populations. A differential equation model with solutions consistent to the observed inverse association was derived. BC and MC rates were modeled as functions of an exposure level to unspecified common factors that influence the 2 rates. In conjunction with previously reported evidence, we submit a hypothesis that BC etiology may have an appreciable link with microbial exposures (and/or immunological responses to them), the lack of which, especially in early life, may elevate BC risk. © 2008 Wiley-Liss, Inc. [source]


    Coffee, tea, caffeine and risk of breast cancer: A 22-year follow-up

    INTERNATIONAL JOURNAL OF CANCER, Issue 9 2008
    Davaasambuu Ganmaa
    Abstract The relation between consumption of coffee, tea and caffeine and risk of breast cancer remains unsettled. We examined data from a large, long-term cohort study to evaluate whether high intake of coffee and caffeine is associated with increased risk of breast cancer. This was a prospective cohort study with 85,987 female participants in the Nurses' Health Study. Consumption of coffee, tea and caffeine consumption was assessed in 1980, 1984, 1986, 1990, 1994, 1998 and the follow-up continued through 2002. We documented 5,272 cases of invasive breast cancer during 1,715,230 person-years. The multivariate relative risks (RRs) of breast cancer across categories of caffeinated coffee consumption were: 1.0 for <1cup/month (reference category), 1.01 (95% confidence interval: 0.92,1.12) for 1 month to 4.9 week, 0.92 (0.84,1.01) for 5 week to 1.9 days, 0.93 (0.85,1.02) for 2,3.9 days, 0.92 (0.82,1.03) for ,4 cups per day (p for trend = 0.14). Intakes of tea and decaffeinated coffee were also not significantly associated with risk of breast cancer. RRs (95% CI) for increasing quintiles of caffeine intake were 1.00, 0.98 (0.90,1.07), 0.92 (0.84,1.00), 0.94 (0.87,1.03) and 0.93 (0.85,1.01) (p for trend = 0.06). A significant inverse association of caffeine intake with breast cancers was observed among postmenopausal women; for the highest quintile of intake compared to the lowest RR 0.88 (95% CI = 0.79,0.97, p for trend = 0.03). We observed no substantial association between caffeinated and decaffeinated coffee and tea consumption and risk of breast cancer in the overall cohort. However, our results suggested a weak inverse association between caffeine-containing beverages and risk of postmenopausal breast cancer. © 2008 Wiley-Liss, Inc. [source]


    Folate metabolism genes, vegetable intake and renal cancer risk in central Europe

    INTERNATIONAL JOURNAL OF CANCER, Issue 8 2008
    Lee E. Moore
    Abstract In a multicenter case-control study of renal cell carcinoma (RCC) conducted in central and eastern Europe, we reported a strong inverse association with high vegetable intake and RCC risk. The odds ratio (OR) for high compared to the lowest tertile of vegetable intake was OR = 0.67; (95% confidence interval (CI): 0.53,0.83; p -trend < 0.001). We hypothesized that variation in key folate metabolism genes may modify this association. Common variation in 5 folate metabolism genes (CBS: Ex9+33C > T (rs234706), Ex13 +41C > T (rs1801181), Ex18 ,391 G > A (rs12613); MTHFR: A222V Ex5+79C > T (rs1801133), Ex8,62A > C (rs1801131); MTR: Ex26 20A > G (rs1805087), MTRR: Ex5+136 T > C (rs161870), and TYMS:IVS2,405 C > T (rs502396), Ex8+157 C > T (rs699517), Ex8+227 A > G (rs2790)) were analyzed among 1,097 RCC cases and 1,555 controls genotyped in this study. Having at least 1 variant T allele of MTHFR A222V was associated with higher RCC risk compared to those with 2 common (CC) alleles (OR = 1.44; 95% CI: 1.17,1.77; p = 0.001). After stratification by tertile of vegetable intake, the higher risk associated with the variant genotype was only observed in the low and medium tertiles (p -trend = 0.001), but not among those in the highest tertile (p -interaction = 0.22). The association remained robust after calculation of the false discovery rate (FDR = 0.05). Of the 3 TYMS SNPs examined, only the TYMS IVS2 ,405 C (rs502396) variant was associated with a significantly lower risk compared to the common genotype (OR = 0.73; 95% CI: 0.57,0.93). Vegetable intake modified the association between all 3 TYMS SNPs and RCC risk (p -interaction < 0.04 for all). In summary, these findings suggest that common variation in MTHFR and TYMS genes may be associated with RCC risk, particularly when vegetable intake is low. © 2007 Wiley-Liss, Inc. [source]


    A case,control study on the dietary intake of mushrooms and breast cancer risk among Korean women

    INTERNATIONAL JOURNAL OF CANCER, Issue 4 2008
    Seo Ah Hong
    Abstract To evaluate the association between dietary mushroom intake and breast cancer risk, a total of 362 women between the ages of 30 and 65 years who were histologically confirmed to have breast cancer were matched to controls by age (±2 years) and menopausal status. Mushroom intake was measured via a food frequency questionnaire that was administered by well-trained interviewers. The associations between the daily intake and the average consumption frequency of mushrooms with breast cancer risk were evaluated using matched data analysis. Both the daily intake (5th vs. 1st quintile, OR = 0.48, 95% CI = 0.30,0.78, p for trend 0.030) and the average consumption frequency of mushrooms (4th vs. 1st quartile, OR = 0.54, 95% CI = 0.35,0.82, p for trend 0.008) were inversely associated with breast cancer risk after adjustment for education, family history of breast cancer, regular exercise [,22.5 MET (metabolic equivalent)-hr/week], BMI (body mass index, Kg/m2), number of children and whether they are currently smoking, drinking or using multivitamin supplements. Further adjustments were made for energy-adjusted carbohydrate, soy protein, folate and vitamin E levels, which tended to attenuate these results. After a stratification was performed according to menopausal status, a strong inverse association was found in postmenopausal women (OR = 0.16, 95% CI = 0.04,0.54, p for trend = 0.0058 for daily intake; OR = 0.17, 95% CI = 0.05,0.54, p for trend = 0.0037 for average frequency), but not in premenopausal women. In conclusion, the consumption of dietary mushrooms may decrease breast cancer risk in postmenopausal women. © 2007 Wiley-Liss, Inc. [source]


    Oral contraceptive use, hormone replacement therapy, reproductive history and risk of colorectal cancer in women

    INTERNATIONAL JOURNAL OF CANCER, Issue 3 2008
    Geoffrey C. Kabat
    Abstract Evidence from epidemiologic studies suggests a possible role of exogenous and endogenous hormones in colorectal carcinogenesis in women. However, with respect to exogenous hormones, in contrast to hormone replacement therapy, few cohort studies have examined oral contraceptive use in relation to colorectal cancer risk. We used data from a large cohort study of Canadian women enrolled in a randomized controlled trial of breast cancer screening to assess the association of oral contraceptive use, hormone replacement therapy and reproductive factors with risk of colorectal cancer, overall and by subsite within the colorectum. Cancer incidence and mortality were ascertained by linkage to national databases. Among 89,835 women aged 40,59 at enrollment and followed for an average of 16.4 years, we identified 1,142 incident colorectal cancer cases. Proportional hazards models were used to estimate the associations between the exposures of interest and risk of colorectal cancer. Ever use of oral contraceptives at baseline was associated with a modest reduction in the risk of colorectal cancer (hazard ratio 0.83, 95% confidence interval 0.73,0.94), with similar effects for different subsites within the colorectum. No trend was seen in the hazard ratios with increasing duration of oral contraceptive use. No associations were seen with use of hormone replacement therapy (ever use or duration of use) or reproductive factors. Our results are suggestive of an inverse association between oral contraceptive use and colorectal carcinogenesis. However, given the lack of a dose,response relationship and the potential for confounding, studies with more complete assessment of exogenous hormone use throughout the life course are needed to clarify this association. © 2007 Wiley-Liss, Inc. [source]


    A prospective study of dietary flavonoid intake and incidence of epithelial ovarian cancer

    INTERNATIONAL JOURNAL OF CANCER, Issue 10 2007
    Margaret A. Gates
    Abstract Flavonoids are antioxidant compounds found in plants, including fruits, vegetables and tea. No prior prospective studies have examined the association between intake of flavonoids in the flavonol and flavone subclasses and ovarian cancer risk. We analyzed the association between intake of 5 common dietary flavonoids and incidence of epithelial ovarian cancer among 66,940 women in the Nurses' Health Study. We calculated each participant's intake of myricetin, kaempferol, quercetin, luteolin and apigenin from dietary data collected at multiple time points, and used Cox proportional hazards regression to model the incidence rate ratio (RR) of ovarian cancer for each quintile of intake. Our analysis included 347 cases diagnosed between 1984 and 2002, and 950,347 person-years of follow-up. There was no clear association between total intake of the 5 flavonoids examined and incidence of ovarian cancer (RR = 0.75 for the highest versus lowest quintile, 95% confidence interval [CI] = 0.51,1.09). However, there was a significant 40% decrease in ovarian cancer incidence for the highest versus lowest quintile of kaempferol intake (RR = 0.60, 95% CI = 0.42,0.87; p -trend = 0.002), and a significant 34% decrease in incidence for the highest versus lowest quintile of luteolin intake (RR = 0.66, 95% CI = 0.49,0.91; p -trend = 0.01). There was evidence of an inverse association with consumption of tea (nonherbal) and broccoli, the primary contributors to kaempferol intake in our population. These data suggest that dietary intake of certain flavonoids may reduce ovarian cancer risk, although additional prospective studies are needed to further evaluate this association. If confirmed, these results would provide an important target for ovarian cancer prevention. © 2007 Wiley-Liss, Inc. [source]


    Fibre intake and renal cell carcinoma: A case-control study from Italy

    INTERNATIONAL JOURNAL OF CANCER, Issue 8 2007
    Carlotta Galeone
    Abstract Only 2 previous studies, conducted in Australia, United States and northern Europe, considered the role of dietary fibre intake on renal cell carcinoma (RCC) risk, and both showed a modest, inverse association. Therefore, we investigated in depth the topic of fibres and RCC, using data from a multicenter case-control study conducted in Italy from 1992 to 2004, including 767 cases with incident, histologically confirmed RCC and 1,534 controls admitted to the same network of hospitals as cases with acute nonmalignant conditions. Multivariate odds ratios (OR) and 95% confidence intervals (CI) were obtained after allowance for major identified confounding factors, including total energy intake. The continuous OR for an increase in intake equal to the difference between the 80th and the 20th percentile were 0.94 (95% CI: 0.82,1.08) for total dietary fibre, 0.98 (95% CI: 0.85,1.13) for soluble noncellulose polysaccharides, 0.92 (95% CI: 0.80,1.05) for total insoluble fibre, 0.90 (95% CI: 0.78,1.04) for cellulose, 0.95 (95% CI: 0.84,1.06) for insoluble noncellulose polysaccharides and 1.06 (95% CI: 0.93,1.21) for lignin. With reference to the sources of fibre, we found an inverse association with vegetable fibre (OR = 0.84, 95% CI: 0.73,0.97), but no association with fruit (OR = 0.98, 95% CI: 0.86,1.12) and grain fibre (OR = 1.05, 95% CI: 0.95,1.15). The inverse association with vegetable fibre may reflect a real favorable effect, or be an indicator of a beneficial role of a diet rich in vegetable on RCC risk. © 2007 Wiley-Liss, Inc. [source]


    Cereal fiber intake may reduce risk of gastric adenocarcinomas: The EPIC-EURGAST study

    INTERNATIONAL JOURNAL OF CANCER, Issue 7 2007
    Mendez M.A.
    Abstract Numerous case-control studies suggest dietary fiber may reduce risk of gastric cancer, but this has not been confirmed prospectively. A previous case-control study reported reduced risk of gastric cardia adenocarcinomas associated with cereal fiber, but not with fruit or vegetable fiber. To date, different food sources of fiber have not been examined with respect to noncardia tumors or diverse histologic sub-types. This study prospectively examines associations between fiber from different food sources and incident gastric adenocarcinomas (GC) among more than 435,000 subjects from 10 countries participating in the European Prospective Investigation into Cancer and Nutrition study. Subjects aged 25,70 years completed dietary questionnaires in 1992,98, and were followed up for a median of 6.7 years. About 312 incident GCs were observed. The relative risk of GC was estimated based on cohort-wide sex-specific fiber intake quartiles using proportional hazards models to estimate hazards ratios (HRs) and 95% confidence intervals (CIs). Intakes of cereal fiber, but not total, fruit or vegetable fiber, were associated with reduced GC risk [adjusted HR for the highest vs. lowest quartile of cereal fiber 0.69, 0.48,0.99]. There was a strong inverse association for diffuse [HR 0.43, 0.22,0.86], but not intestinal type [HR 0.98, 0.54,1.80] tumors. Associations for cardia vs. noncardia tumors were similar to those for overall GC, although cardia associations did not reach significance. Cereal fiber consumption may help to reduce risk of GC, particularly diffuse type tumors. Further study on different food sources of fiber in relation to GC risk is warranted to confirm these relationships. © 2007 Wiley-Liss, Inc. [source]


    Coffee consumption and risk of colorectal cancer in a population-based prospective cohort of Japanese men and women

    INTERNATIONAL JOURNAL OF CANCER, Issue 6 2007
    Kyung-Jae Lee
    Abstract We prospectively examined the association between coffee consumption and the risk of developing colorectal cancer in a large population-based cohort study (the JPHC Study) of Japanese men and women. Data were analyzed from a population-based cohort of 96,162 subjects (46,023 men and 50,139 women). A total of 1,163 incident colorectal cancers were identified during the follow-up period, including 763 cases of colon cancer and 400 of rectal cancer. We observed a significant inverse association between coffee consumption and the risk of developing invasive colon cancer among women. Compared with those who almost never consumed coffee, women who regularly consumed 3 or more cups of coffee per day had a RR of 0.44 (95% CI = 0.19,1.04; p for trend = 0.04) after adjustment for potential confounding factors. However, no significant association was found for rectal cancer in women. In men, no significant decrease was observed in any colorectal cancer site. Further, additional analyses on the association of green tea consumption with colorectal cancer risk found no significant association in men or women. These findings suggest that coffee consumption may lower the risk of colon cancer among Japanese women. © 2007 Wiley-Liss, Inc. [source]


    Fruit and vegetable consumption and lung cancer risk: Updated information from the European Prospective Investigation into Cancer and Nutrition (EPIC)

    INTERNATIONAL JOURNAL OF CANCER, Issue 5 2007
    Jakob Linseisen
    Abstract The association of fruit and vegetable consumption and lung cancer incidence was evaluated using the most recent data from the European Prospective Investigation into Cancer and Nutrition (EPIC), applying a refined statistical approach (calibration) to account for measurement error potentially introduced by using food frequency questionnaire data. Between 1992 and 2000, detailed information on diet and life-style of 478,590 individuals participating in EPIC was collected. During a median follow-up of 6.4 years, 1,126 lung cancer cases were observed. Multivariate Cox proportional hazard models were applied for statistical evaluation. In the whole study population, fruit consumption was significantly inversely associated with lung cancer risk while no association was found for vegetable consumption. In current smokers, however, lung cancer risk significantly decreased with higher vegetable consumption; this association became more pronounced after calibration, the hazard ratio (HR) being 0.78 (95% CI 0.62,0.98) per 100 g increase in daily vegetable consumption. In comparison, the HR per 100 g fruit was 0.92 (0.85,0.99) in the entire cohort and 0.90 (0.81,0.99) in smokers. Exclusion of cases diagnosed during the first 2 years of follow-up strengthened these associations, the HR being 0.71 (0.55,0.94) for vegetables (smokers) and 0.86 (0.78,0.95) for fruit (entire cohort). Cancer incidence decreased with higher consumption of apples and pears (entire cohort) as well as root vegetables (smokers). In addition to an overall inverse association with fruit intake, the results of this evaluation add evidence for a significant inverse association of vegetable consumption and lung cancer incidence in smokers. © 2007 Wiley-Liss, Inc. [source]


    Pesticide use and colorectal cancer risk in the agricultural health study

    INTERNATIONAL JOURNAL OF CANCER, Issue 2 2007
    Won Jin Lee
    Abstract We investigated the relationship between agricultural pesticides and colorectal cancer incidence in the Agricultural Health Study. A total of 56,813 pesticide applicators with no prior history of colorectal cancer were included in this analysis. Detailed pesticide exposure and other information were obtained from self-administered questionnaires completed at the time of enrollment (1993,1997). Cancer incidence was determined through population-based cancer registries from enrollment through December 31, 2002. A total of 305 incident colorectal cancers (212 colon, 93 rectum) were diagnosed during the study period, 1993,2002. Although most of the 50 pesticides studied were not associated with colorectal cancer risk, chlorpyrifos use showed significant exposure response trend (p for trend = 0.008) for rectal cancer, rising to a 2.7-fold (95% confidence interval: 1.2,6.4) increased risk in the highest exposure category. Aldicarb was associated with a significantly increased risk of colon cancer (p for trend = 0.001), based on a small number of exposed cases, with the highest exposure category resulting in a 4.1-fold increased risk (95% confidence interval: 1.3,12.8). In contrast, dichlorophenoxyacetic acid showed a significant inverse association with colon cancer but the association was not monotonic. Our findings should be interpreted cautiously since the literature suggesting that pesticides are related to colorectal cancer is limited. Nonetheless the possibility of an association between exposure to certain pesticides and incidence of colorectal cancer among pesticide applicators deserves further evaluation. © 2007 Wiley-Liss, Inc. [source]


    HPV integration begins in the tonsillar crypt and leads to the alteration of p16, EGFR and c-myc during tumor formation

    INTERNATIONAL JOURNAL OF CANCER, Issue 7 2007
    Se-Heon Kim
    Abstract The prevalence of human papillomavirus (HPV) infection is high in the oropharyngeal mucosal regions, of which the tonsil is the most commonly affected. There may be a link between HPV and the pathogenesis of tonsillar cancer (TC), because of common anatomical characteristics between cervical and tonsillar cancer. We aimed to clarify whether HPV directly affects the oncogenesis and biologic behavior of TC by making a comparison between infection prevalence, physical status and viral loading numbers, and clinicopathologic prognostic factors. To compare HPV-related molecules between TC and tonsillitis (CFT), p16, survivin, HIF-1,, skp-1, cyclin A, cyclin B1, c-myc and EGFR were investigated. We observed a significant difference in HPV prevalence between 52 TCs and 69 CFTs (73.1% vs. 11.6%), and most of the HPVs were type 16 (87.2%) and nonepisomal (94.1%). Most TCs associated with HPV arose from the tonsillar crypts, and tended to be inverted and poorly differentiated. Compared with HPV-negative TC, HPV-positive TC showed a strong association with p16 overexpression (p < 0.0001), and an inverse association with EGFR amplification (p = 0.0478). HPV-16 integration status was strongly associated with c-myc amplification (p = 0.034) and HIF-1, overexpression (p = 0.022). HPV-16 integration could be directly related to tonsillar carcinogenesis initially in tonsillar crypts, followed by cell cycle aberration such as p16 overexpression related to the G1-S phase. © 2006 Wiley-Liss, Inc. [source]


    Micronutrients and the risk of renal cell cancer: A case-control study from Italy

    INTERNATIONAL JOURNAL OF CANCER, Issue 4 2007
    Cristina Bosetti
    Abstract The role of various micronutrients on the risk of renal cell cancer (RCC) was examined in a multicentric case-control study from Italy, in which information on dietary habits were collected using a validated food-frequency questionnaire. Cases were 767 patients (494 men and 273 women) with incident, histologically confirmed RCC; controls were 1,534 subjects (988 men and 546 women) admitted to the same hospitals as cases for a wide spectrum of acute, nonneoplastic conditions. After allowing for energy and other major covariates, a significant inverse association was found for vitamin E (odds ratio, OR, for the highest quintile of intake versus the lowest one 0.56, 95% confidence interval, CI 0.41,0.75), and vitamin C (OR = 0.72, 95% CI = 0.54,0.96), although the trend in risk for vitamin C was of borderline significance. No significant trend of decreasing risk was found for other micronutrients analyzed, although for most of them the risk estimates were below unity for intakes above the lowest. The ORs for the upper quintile of intake when compared with the lowest one were 0.80 (95% confidence interval, CI = 0.59,1.08) for retinol, 0.82 (95% CI = 0.61,1.10) for ,-carotene, 0.90 (95% CI = 0.68,1.20) for ,-carotene, 0.94 (95% CI = 0.73,1.21) for ,-criptoxanthin, 0.85 (95% CI = 0.63,1.14) for lutein/zeaxanthin, 0.76 (95% CI = 0.57,1.01) for vitamin D, 0.75 (95% CI = 0.55,1.01) for thiamine, 0.88 (95% CI = 0.66,1.19) for riboflavin, 0.85 for vitamin B6 (95% CI = 0.64,1.13), 0.85 (95% CI = 0.64,1.12) for folate and 0.80 (95% CI = 0.60,1.07) for niacin. No meaningful associations emerged for lycopene (OR = 1.11). The present findings support a possible beneficial effect of vitamin E and C on RCC. © 2006 Wiley-Liss, Inc. [source]


    Physical activity and lung cancer risk in the European Prospective Investigation into Cancer and Nutrition Cohort

    INTERNATIONAL JOURNAL OF CANCER, Issue 10 2006
    Karen Steindorf
    Abstract Research conducted predominantly in male populations on physical activity and lung cancer has yielded inconsistent results. We examined this relationship among 416,277 men and women from the European Prospective Investigation into Cancer and Nutrition (EPIC). Detailed information on recent recreational, household and occupational physical activity, smoking habits and diet was assessed at baseline between 1992 and 2000. Relative risks (RR) were estimated using Cox regression. During 6.3 years of follow-up we identified 607 men and 476 women with incident lung cancer. We did not observe an inverse association between recent occupational, recreational or household physical activity and lung cancer risk in either males or females. However, we found some reduction in lung cancer risk associated with sports in males (adjusted RR = 0.71; 95% confidence interval 0.50,0.98; highest tertile vs. inactive group), cycling (RR = 0.73; 0.54,0.99) in females and non-occupational vigorous physical activity. For occupational physical activity, lung cancer risk was increased for unemployed men (adjusted RR = 1.57; 1.20,2.05) and men with standing occupations (RR = 1.35; 1.02,1.79) compared with sitting professions. There was no evidence of heterogeneity of physical activity associations across countries, or across any of the considered cofactors. For some histologic subtypes suggestive sex-specific reductions, limited by subgroup sizes, were observed, especially with vigorous physical activity. In total, our study shows no consistent protective associations of physical activity with lung cancer risk. It can be assumed that the elevated risks found for occupational physical activity are not produced mechanistically by physical activity itself but rather reflect exposure to occupation-related lung cancer risk factors. © 2006 Wiley-Liss, Inc. [source]