The role of plasma microseminoprotein-beta in prostate cancer: an observational nested case-control and Mendelian randomization study in the European prospective investigation into cancer and nutrition

BACKGROUND

Microseminoprotein-beta (MSP), a protein secreted by the prostate epithelium, may have a protective role in the development of prostate cancer. The only previous prospective study found a 2% reduced prostate cancer risk per unit increase in MSP. This work investigates the association of MSP with prostate cancer risk using observational and Mendelian randomization (MR) methods.

PATIENTS AND METHODS

A nested case-control study was conducted with the European Prospective Investigation into Cancer and Nutrition (EPIC) with 1871 cases and 1871 matched controls. Conditional logistic regression analysis was used to investigate the association of pre-diagnostic circulating MSP with risk of incident prostate cancer overall and by tumour subtype. EPIC-derived estimates were combined with published data to calculate an MR estimate using two-sample inverse-variance method.

RESULTS

Plasma MSP concentrations were inversely associated with prostate cancer risk after adjusting for total prostate-specific antigen concentration [odds ratio (OR) highest versus lowest fourth of MSP = 0.65, 95% confidence interval (CI) 0.51-0.84, Ptrend = 0.001]. No heterogeneity in this association was observed by tumour stage or histological grade. Plasma MSP concentrations were 66% lower in rs10993994 TT compared with CC homozygotes (per allele difference in MSP: 6.09 ng/ml, 95% CI 5.56-6.61, r2=0.42). MR analyses supported a potentially causal protective association of MSP with prostate cancer risk (OR per 1 ng/ml increase in MSP for MR: 0.96, 95% CI 0.95-0.97 versus EPIC observational: 0.98, 95% CI 0.97-0.99). Limitations include lack of complete tumour subtype information and more complete information on the biological function of MSP.

CONCLUSIONS

In this large prospective European study and using MR analyses, men with high circulating MSP concentration have a lower risk of prostate cancer. MSP may play a causally protective role in prostate cancer.

Survival of 86,690 patients with thyroid cancer: A population-based study in 29 European countries from EUROCARE-5

BACKGROUND

Incidence rates of thyroid cancer (TC) increased in several countries during the last 30 years, while mortality rates remained unchanged, raising important questions for treatment and follow-up of TC patients. This study updates population-based estimates of relative survival (RS) after TC diagnosis in Europe by sex, country, age, period and histology.

METHODS

Data from 87 cancer registries in 29 countries were extracted from the EUROCARE-5 dataset. One- and 5-year RS were estimated using the cohort approach for 86,690 adult TC patients diagnosed in 2000-2007 and followed-up to 12/31/2008. RS trends in 1999-2007 and 10-year RS in 2005-2007 were estimated using the period approach.

RESULTS

In Europe 2000-2007, 5-year RS after TC was 88% in women and 81% in men. Survival rates varied by country and were strongly correlated (Pearson ρ = 75%) with country-specific incidence rates. Five-year RS decreased with age (in women from >95% at age 15-54 to 57% at age 75+), from 98% in women and 94% in men with papillary TC to 14% in women and 12% in men with anaplastic TC. Proportion of papillary TC varied by country and increased over time, while survival rates were similar across areas and periods. In 1999-2007, 5-year RS increased by five percentage points for all TCs but only by two for papillary and by four for follicular TC. Ten-year RS in 2005-2007 was 89% in women and 79% in men.

CONCLUSIONS

The reported increasing TC survival trend and differences by area are mainly explained by the varying histological case-mix of cases.

Insulin-like growth factor I and risk of epithelial invasive ovarian cancer by tumour characteristics: results from the EPIC cohort

BACKGROUND

Prospective studies on insulin-like growth factor I (IGF-I) and epithelial ovarian cancer (EOC) risk are inconclusive. Data suggest risk associations vary by tumour characteristics.

METHODS

We conducted a nested case-control study in the European Prospective Investigation into Cancer and Nutrition (EPIC) to evaluate IGF-I concentrations and EOC risk by tumour characteristics (n=565 cases). Multivariable conditional logistic regression models were used to estimate associations.

RESULTS

We observed no association between IGF-I and EOC overall or by tumour characteristics.

CONCLUSIONS

In the largest prospective study to date was no association between IGF-I and EOC risk. Pre-diagnostic serum IGF-I concentrations may not influence EOC risk.

Dietary intake of acrylamide and endometrial cancer risk in the European Prospective Investigation into Cancer and Nutrition cohort

BACKGROUND

Three prospective studies have evaluated the association between dietary acrylamide intake and endometrial cancer (EC) risk with inconsistent results. The objective of this study was to evaluate the association between acrylamide intake and EC risk: for overall EC, for type-I EC, and in never smokers and never users of oral contraceptives (OCs). Smoking is a source of acrylamide, and OC use is a protective factor for EC risk.

METHODS

Cox regression was used to estimate hazard ratios (HRs) for the association between acrylamide intake and EC risk in the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort. Acrylamide intake was estimated from the EU acrylamide monitoring database, which was matched with EPIC questionnaire-based food consumption data. Acrylamide intake was energy adjusted using the residual method.

RESULTS

No associations were observed between acrylamide intake and overall EC (n=1382) or type-I EC risk (n=627). We observed increasing relative risks for type-I EC with increasing acrylamide intake among women who both never smoked and were non-users of OCs (HRQ5vsQ1: 1.97, 95% CI: 1.08-3.62; likelihood ratio test (LRT) P-value: 0.01, n=203).

CONCLUSIONS

Dietary intake of acrylamide was not associated with overall or type-I EC risk; however, positive associations with type I were observed in women who were both non-users of OCs and never smokers.

Intake of total omega-3 fatty acids, eicosapentaenoic acid and docosahexaenoic acid and risk of coronary heart disease in the Spanish EPIC cohort study

BACKGROUND AND AIMS

The evidence about the benefits of omega-3 fatty acid intake on coronary heart disease (CHD) is not consistent. We thus aimed to assess the relation between dietary intake of total omega-3 fatty acids (from plant and marine foods) and marine polyunsaturated fatty acids (PUFAs), eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), on the risk of CHD in the Spanish cohort of the European Prospective Investigation into Cancer and Nutrition (EPIC).

METHODS AND RESULTS

The analysis included 41,091 men and women aged 20-69 years, recruited from 1992 to 1996 and followed-up until December 2004. Omega-3 fatty acid intake was estimated from a validated dietary questionnaire. Only participants with definite incident CHD event were considered as cases. Cox regression models were used to assess the association between the intake of total omega-3 fatty acids, EPA or DHA and CHD. A total of 609 participants (79% men) had a definite CHD event. Mean intakes of total omega-3 fatty acids, EPA and DHA were very similar in the cases and in the cohort, both in men and women. In the multivariate adjusted model, omega-3 fatty acids, EPA and DHA were not related to incident CHD in either men or women. The hazard ratios (HR) for omega-3 were 1.23 in men (95% CI 0.94-15.9, p = 0.20); and 0.77 in women (95% CI 0.46-1.30, p = 0.76).

CONCLUSION

In the Spanish EPIC cohort, with a relatively high intake of fish, no association was found between EPA, DHA and total omega-3 fatty acid intake and risk of CHD.

Major dietary patterns and risk of coronary heart disease in middle-aged persons from a Mediterranean country: the EPIC-Spain cohort study

BACKGROUND AND AIM

No previous study has assessed the association between major dietary patterns and the risk of coronary heart disease (CHD) in a large cohort from a Mediterranean country.

METHODS AND RESULTS

We studied prospectively 40,757 persons, aged 29-69 years, participating in the Spanish cohort of the EPIC study. Food consumption was collected between 1992 and 1996 with a validated history method. Individuals were followed-up until 2004 through record linkage with hospital discharge registers, population-based registers of myocardial infarction, and mortality registers to ascertain CHD events (fatal and non-fatal acute myocardial infarction or angina requiring revascularization). Two major dietary patterns were identified from factor analysis. The first pattern was labeled as Westernized, because of the frequent consumption of refined cereals and red meat; the second was called the evolved Mediterranean pattern, because of the frequent intake of plant-based foods and olive oil. During a median follow-up of 11 years, 606 CHD events were ascertained. No association was found between the Westernized pattern and CHD risk. In contrast, the score for the evolved Mediterranean pattern was inversely associated with CHD risk (p for trend = 0.0013); when compared with the lowest quintile of the evolved Mediterranean pattern score, the multivariable hazard ratios for CHD were 0.77 (95% confidence interval 0.61-0.98) for the second quintile, 0.64 (95% CI 0.50-0.83) for the third quintile, 0.56 (95% CI 0.43-0.73) for the fourth quintile, and 0.73 (95% CI 0.57-0.94) for the fifth quintile.

CONCLUSION

A Mediterranean diet, as consumed in this study population, was associated with a lower risk of CHD.

Association of plasma markers of cholesterol homeostasis with metabolic syndrome components. A cross-sectional study

BACKGROUND AND AIMS

Increased plasma phytosterols, which reflect enhanced cholesterol absorption, have been related to an increased risk of cardiovascular disease (CVD). However, high CVD risk conditions, such as obesity, diabetes and the metabolic syndrome (MetS) have been associated with reduced cholesterol absorption. We investigated associations between plasma noncholesterol sterols and MetS components.

METHODS AND RESULTS

With a cross-sectional design, we related MetS components to plasma noncholesterol sterol-to-cholesterol ratios measured by gas chromatography in 674 dyslipidemic patients and 361 healthy subjects participating in a prospective cohort study. Plasma phytosterol-to-cholesterol ratios were inversely associated with all components of the MetS. In the dyslipidemic group, multivariable analyses showed that a 1-SD increase in sitosterol-to-cholesterol ratio was associated with a reduced risk for any MetS feature, ranging from 0.57 (95% CI, 0.45 to 0.71) for visceral adiposity to 0.82 (95% CI, 0.69 to 0.98) for high blood pressure. The risk of having MetS was nearly halved, with ORs of 0.49 (95% CI, 0.38 to 0.64) or 0.56 (95% CI, 0.44-0.70), depending on the definition. Results were opposed for plasma lathosterol, a marker of cholesterol synthesis. Most findings were reproduced in the healthy cohort. ApoE genotype was unrelated to plasma noncholesterol sterols.

CONCLUSION

In both dyslipidemic and healthy populations, MetS is associated with increased plasma lathosterol, a cholesterol synthesis marker, and decreased plasma sitosterol, a marker of cholesterol absorption. Elevated plasma phytosterols related to a lower frequency of cardiometabolic risk factors, suggesting that they are associated with a reduced CVD risk.

Cancer incidence and mortality in Spain: estimates and projections for the period 1981-2012

BACKGROUND

National indicators of cancer burden are essential information for cancer surveillance and health planning, so that in countries with partial registration coverage and geographically variable risk patterns, such as Spain, this is even more relevant. This article provides estimates of cancer incidence in Spain for all cancers combined, with the single exception of non-melanoma skin cancer, and for major cancer sites over the period 1981-2006, with projections up to 2012.

PATIENTS AND METHODS

Estimates were obtained by applying the MIAMOD method, a statistical back-calculation approach, to derive incidence from mortality and relative survival data.

RESULTS

During the period 1981-2012, age-standardised incidence rates for all cancers rose from the beginning of the period and started to decline from 2000 onwards among men, and increased across the whole period among women. Differences in incidence trends between men and women might be attributable to the gender-specific case-mix of sites for all cancers, and to differences in risk factors specific to certain cancer sites in men and women, with smoking being the main factor accounting for these differences between the sexes.

CONCLUSIONS

Estimates and projections of cancer incidence and mortality show divergent trends in Spain by sex and tumour type. This information is basic for planning and enhancing public health strategies and resources.

Variation in intakes of calcium, phosphorus, magnesium, iron and potassium in 10 countries in the European Prospective Investigation into Cancer and Nutrition study

BACKGROUND/OBJECTIVES

Adequate mineral intake is important for the maintenance of bone health, cellular function and general metabolism, and possibly in the aetiology of cancer and other chronic diseases. This study aimed at investigating variation in intakes of selected minerals across 10 European countries participating in the EPIC (European Prospective Investigation into Cancer and Nutrition) study.

METHODS

Nutrient intakes for 36 034 subjects, aged between 35 and 74 years, in 27 centres were obtained using standardized 24-h dietary recall software (EPIC-SOFT). Mean intakes of calcium, phosphorus, magnesium, iron and potassium were calculated by centre and weighted by season and day of the week and were also stratified by age group. The contribution of food groups to total nutrient intake was calculated.

RESULTS

There was clear geographical variability in intakes, with differences ranging from 35% for magnesium to 90% for iron in men and 36% for potassium to 75% for calcium in women, and a twofold difference in sources of haem iron (meat and fish). There was a geographical gradient in iron intake, with higher intakes in Southern than in Northern Europe and also around a twofold north-south gradient in the contribution of fruits and vegetables to potassium intake. Compared with reference intakes, the majority of age groups and centres had intakes above the recommended levels. Dairy foods and products contributed the most to calcium and phosphorus intake in almost all centres. Cereals and cereal products contributed the most to magnesium and iron intakes, except in Greece and Germany.

CONCLUSIONS

Intakes of minerals vary substantially throughout Europe, with some geographical variability in their food sources.

Incidence of acute myocardial infarction in the Spanish epic cohort

BACKGROUND

There is some evidence that Mediterranean diet reduces risk of ischemic heart disease, and this is to be investigated in the Spanish cohort of the European Prospective Investigation into Cancer and Nutrition (EPIC). In this paper we present the incidence of acute myocardial infarction (AMI) in four EPIC Spanish cohorts.

METHOD

Incidence cases were ascertained in EPIC cohort during the follow up period (from recruitment to the end of 2004), by means of self-report questionnaires, hospital morbidity and mortality registries, and population AMI registries. Analysis was restricted to aged 45 to 74. The present study included data from 13,704 women and 19,410 men, after excluding a priori participants with prevalent AMI. Age standardized incidence rate for each cohort was estimated and compared with the available population rates.

RESULTS

The Median duration of follow-up was 9.3 years, yielding a total of 297,704 person-years. 391 men and 99 women presented AMI in the four cohorts studied. Age standardized AMI rates in men of the EPIC cohorts go from the lowest 302 (CI: 268-335) per 100.000 person-year of Gipuzkoa to the highest 330 (CI: 293-367) of Navarra. Women in Navarra presented the lowest AMI incidence with 60 (CI: 43-77) per 100,000 and the highest was observed in Murcia (114, CI: 91-137). The AMI incidence in all EPIC centres are close to the population incidence rates and in any case these are within the EPIC 95% CI.

CONCLUSIONS

The comparison of incidence in EPIC with population rates shows very good agreement for acute myocardial infarction.

Prevalence of obesity in 4-18-year-old population in the Basque Country, Spain

The objective of the study was to estimate the prevalence of overweight and obesity in children and adolescents in the Basque Country, Spain. It consisted of an analysis of baseline data of the Nutrition Survey, a cross-sectional study, carried out in 2004-2005. The study population comprised child and adolescent living in the Basque Country. The analysis was carried out in a representative random sample of 1178 people aged 4-18 years. Anthropometric examinations were undertaken by trained observers using standardized methods and included measurements of weight and height. Subjects were classified into different body mass index categories, according to the International Obesity Task Force guidelines. A 5.4% of the population studied was obese; 6% of males and 4.7% of females, the highest in the 11-14 age group in boys (7.2%) and in the 4-6 age group in girls (12.5%). Overweight (22.9%) was slightly higher in girls. The highest prevalence of excess weight (overweight+obesity) was observed in girls aged 4-6 years (38.4%), decreasing with age. Subjects in the 15-18 age group rated 16.6%. Boys evidenced a higher excess weight rate in the 11-14 (32.9%) and 7-10 (32%) age groups; the lowest rate was found in the 4-6 age group. Prevalence of obesity was higher in the less privileged socio-economic strata (6.9% vs. 5.2%), for both boys and girls. However, this trend was observed only in girls for overweight (25.9% vs. 21.8%). This study shows a high prevalence of obesity and overweight in the studied population and similar to other European countries and regions.

Consumption of cruciferous vegetables and glucosinolates in a Spanish adult population

OBJECTIVE

To assess the intake of glucosinolates and cruciferous vegetables among Spanish adults.

DESIGN

Cross-sectional analysis of a prospective cohort study.

SETTING

The Spanish cohort of the European Prospective Investigation into Cancer and Nutrition (EPIC).

SUBJECTS

We analysed data from 40 684 men and women aged 35-64 years from the EPIC-Spain cohort. The usual diet was assessed by means of the dietary history method, and glucosinolate intake was calculated using a published food composition database.

RESULTS

The average intake of cruciferous vegetables was 11.3 g/day, accounting for about 5% of total vegetable consumption, whereas the daily intake of total glucosinolates was 6.5 mg, among which 35% were of indole type. The absolute intake of glucosinolates was in average higher in men than in women (6.8 vs 6.2 mg/day), whereas glucosinolate density per energy unit was higher in women's diet (3.4 vs 2.7 mg/4200 kJ). Northern regions consumed in average 36% more glucosinolates than Southern regions (7.3 vs 5.4 mg/day). There was a positive association of glucosinolate intake with body mass index, physical activity, educational level and an inverse relationship with alcohol consumption.

CONCLUSIONS

Contrary to the pattern seen for total vegetable intake, our estimate of consumption of cruciferous vegetables, and hence of glucosinolates, is relatively low within Europe, which in turn is lower than in North America and several Asian populations.

Validity of self reported diagnoses of cancer in a major Spanish prospective cohort study

INTRODUCTION

This study aims to assess the validity of self reported diagnoses of cancer by persons recruited for the Spanish EPIC (European prospective investigation into cancer and nutrition) cohort study and to identify variables associated with correctly reporting a diagnosis of cancer.

METHODS

41 440 members of EPIC were asked at the time of recruitment whether they had been diagnosed with cancer and the year of diagnosis and site. The process of validating self reported diagnoses of cancer included comparison of the cohort database with the data from the population based cancer registries. Cancer diagnostic validity tests were calculated. The association between a correct report and certain sociodemographic, tumour related, or health related variables were analysed by logistic regression.

RESULTS

The overall sensitivity of self reported diagnoses of cancer is low (57.5%; 95% CI: 51.9 to 63.0), the highest values being shown by persons with a higher level of education or with a family history of cancer and the lowest values by smokers. Breast and thyroid cancers are those with the highest diagnostic validity and uterus, bladder, and colon-rectum those with the lowest. In both sexes the variables showing a significant association with a correct report of cancer are: higher education level, number of previous pathologies, invasive tumour, and, in women, a history of gynaecological surgery.

CONCLUSIONS

The overall sensitivity of self reported diagnoses of cancer is comparatively low and it is not recommended in epidemiological studies for identifying tumours. However, self reported diagnoses might be highly valid for certain tumour sites, malignant behaviour, and average to high levels of education.

IGF-I, IGFBP-3 and breast cancer risk in women: The European Prospective Investigation into Cancer and Nutrition (EPIC)

Blood concentrations of insulin-like growth factor-I (IGF-I) and insulin-like growth factor binding protein-3 (IGFBP-3) have recently been associated with breast cancer risk, notably in women who developed breast cancer at a young age. Prospective studies published so far, however, were relatively small and odds ratio (OR) estimates imprecise. We present the results of a large prospective case-control study nested within the European Prospective Investigation into Cancer and Nutrition on total IGF-I, IGFBP-3 and breast cancer risk including 1081 incident cases of invasive breast cancer and 2098 matched control subjects. Increasing IGF-I and IGFBP-3 concentrations were associated with a significant increase in breast cancer risk in women who developed breast cancer after 50 years of age (highest vs lowest quintile OR 1.38 (95% confidence interval (CI) 1.02-1.86), P = 0.01, and 1.44 (95% CI 1.04-1.98), P = 0.01, respectively), but no relationship was observed in younger women (OR = 1.03 (95% CI 0.60-1.77), P = 0.81 for IGF-I, and OR = 0.92 (95% CI 0.50-1.70), P = 0.69 for IGFBP-3). There was, however, significant heterogeneity in the relationship of breast cancer with serum IGF-I and IGFBP-3 levels depending on the time interval between blood donation and tumor diagnosis. A reduction in breast cancer risk with increasing IGF-I concentrations was observed in cases with a diagnosis of cancer less than 2 years after blood donation, (OR = 0.76 (95% CI 0.57-1.03)), while an increase in risk was observed for women with a later diagnosis (above or equal to two years after blood collection, OR = 1.51 (95% CI 1.19-1.91)). A similar pattern was observed for IGFBP-3. This study confirms previous findings for an association of serum IGF-I and IGFBP-3 concentrations with breast cancer risk, particularly for women with a later diagnosis of cancer, but it does not support the hypothesis of an involvement of IGF-I in younger women.

Polymorphisms of genes coding for insulin-like growth factor 1 and its major binding proteins, circulating levels of IGF-I and IGFBP-3 and breast cancer risk: results from the EPIC study

Insulin-like growth factor I (IGF-I) stimulates cell proliferation and can enhance the development of tumours in different organs. Epidemiological studies have shown that an elevated level of circulating IGF-I is associated with increased risk of breast cancer, as well as of other cancers. Most of circulating IGF-I is bound to an acid-labile subunit and to one of six insulin-like growth factor binding proteins (IGFBPs), among which the most important are IGFBP-3 and IGFBP-1. Polymorphisms of the IGF1 gene and of genes encoding for the major IGF-I carriers may predict circulating levels of IGF-I and have an impact on cancer risk. We tested this hypothesis with a case–control study of 807 breast cancer patients and 1588 matched control subjects, nested within the European Prospective Investigation into Cancer and Nutrition. We genotyped 23 common single nucleotide polymorphisms in IGF1, IGFBP1, IGFBP3 and IGFALS, and measured serum levels of IGF-I and IGFBP-3 in samples of cases and controls. We found a weak but significant association of polymorphisms at the 5′ end of the IGF1 gene with breast cancer risk, particularly among women younger than 55 years, and a strong association of polymorphisms located in the 5′ end of IGFBP3 with circulating levels of IGFBP-3, which confirms previous findings. Common genetic variation in these candidate genes does not play a major role in altering breast cancer risk in Caucasians.

European Prospective Investigation into Cancer and Nutrition (EPIC) calibration study: rationale, design and population characteristics

The European Prospective Investigation into Cancer and Nutrition (EPIC), which covers a large cohort of half a million men and women from 23 European centres in 10 Western European countries, was designed to study the relationship between diet and the risk of chronic diseases, particularly cancer. Information on usual individual dietary intake was assessed using different validated dietary assessment methods across participating countries. In order to adjust for possible systematic over- or underestimation in dietary intake measurements and correct for attenuation bias in relative risk estimates, a calibration approach was developed. This approach involved an additional dietary assessment common across study populations to re-express individual dietary intakes according to the same reference scale. A single 24-hour diet recall was therefore collected, as the EPIC reference calibration method, from a stratified random sample of 36 900 subjects from the entire EPIC cohort, using a software program (EPIC-SOFT) specifically designed to standardise the dietary measurements across study populations. This paper describes the design and populations of the calibration sub-studies set up in the EPIC centres. In addition, to assess whether the calibration sub-samples were representative of the entire group of EPIC cohorts, a series of subjects' characteristics known possibly to influence dietary intakes was compared in both population groups. This was the first time that calibration sub-studies had been set up in a large multi-centre European study. These studies showed that, despite certain inherent methodological and logistic constraints, a study design such as this one works relatively well in practice. The average response in the calibration study was 78.3% and ranged from 46.5% to 92.5%. The calibration population differed slightly from the overall cohort but the differences were small for most characteristics and centres. The overall results suggest that, after adjustment for age, dietary intakes estimated from calibration samples can reasonably be interpreted as representative of the main cohorts in most of the EPIC centres.