miR-Blood - a small RNA atlas of human blood components

miR-Blood is a high-quality, small RNA expression atlas for the major components of human peripheral blood (plasma, erythrocytes, thrombocytes, monocytes, neutrophils, eosinophils, basophils, natural killer cells, CD4+ T cells, CD8+ T cells, and B cells). Based on the purified blood components from 52 individuals, the dataset provides a comprehensive repository for the expression of 4971 small RNAs from eight non-coding RNA classes.

Early Detection of Lung Cancer Using Small RNAs

INTRODUCTION

Lung cancer remains the deadliest cancer in the world, and lung cancer survival is heavily dependent on tumor stage at the time of detection. Low-dose computed tomography screening can reduce mortality; however, annual screening is limited by low adherence in the United States of America and still not broadly implemented in Europe. As a result, less than 10% of lung cancers are detected through existing programs. Thus, there is a great need for additional screening tests, such as a blood test, that could be deployed in the primary care setting.

METHODS

We prospectively recruited 1384 individuals meeting the National Lung Screening Trial demographic eligibility criteria for lung cancer and collected stabilized whole blood to enable the pipetting-free collection of material, thus minimizing preanalytical noise. Ultra-deep small RNA sequencing (20 million reads per sample) was performed with the addition of a method to remove highly abundant erythroid RNAs, and thus open bandwidth for the detection of less abundant species originating from the plasma or the immune cellular compartment. We used 100 random data splits to train and evaluate an ensemble of logistic regression classifiers using small RNA expression of 943 individuals, discovered an 18-small RNA feature consensus signature (miLung), and validated this signature in an independent cohort (441 individuals). Blood cell sorting and tumor tissue sequencing were performed to deconvolve small RNAs into their source of origin.

RESULTS

We generated diagnostic models and report a median receiver-operating characteristic area under the curve of 0.86 (95% confidence interval [CI]: 0.84-0.86) in the discovery cohort and generalized performance of 0.83 in the validation cohort. Diagnostic performance increased in a stage-dependent manner ranging from 0.73 (95% CI: 0.71-0.76) for stage I to 0.90 (95% CI: 0.89-0.90) for stage IV in the discovery cohort and from 0.76 to 0.86 in the validation cohort. We identified a tumor-shed, plasma-bound ribosomal RNA fragment of the L1 stalk as a dominant predictor of lung cancer. The fragment is decreased after surgery with curative intent. In additional experiments, results of dried blood spot collection and sequencing revealed that small RNA analysis could potentially be conducted through home sampling.

CONCLUSIONS

These data suggest the potential of a small RNA-based blood test as a viable alternative to low-dose computed tomography screening for early detection of smoking-associated lung cancer.

Genetically Determined Reproductive Aging and Coronary Heart Disease: A Bidirectional 2-sample Mendelian Randomization

BACKGROUND

Accelerated reproductive aging, in women indicated by early natural menopause, is associated with increased coronary heart disease (CHD) risk in observational studies. Conversely, an adverse CHD risk profile has been suggested to accelerate menopause.

OBJECTIVES

To study the direction and evidence for causality of the relationship between reproductive aging and (non-)fatal CHD and CHD risk factors in a bidirectional Mendelian randomization (MR) approach, using age at natural menopause (ANM) genetic variants as a measure for genetically determined reproductive aging in women. We also studied the association of these variants with CHD risk (factors) in men.

DESIGN

Two-sample MR, using both cohort data as well as summary statistics, with 4 methods: simple and weighted median-based, standard inverse-variance weighted (IVW) regression, and MR-Egger regression.

PARTICIPANTS

Data from EPIC-CVD and summary statistics from UK Biobank and publicly available genome-wide association studies were pooled for the different analyses.

MAIN OUTCOME MEASURES

CHD, CHD risk factors, and ANM.

RESULTS

Across different methods of MR, no association was found between genetically determined reproductive aging and CHD risk in women (relative risk estimateIVW = 0.99; 95% confidence interval (CI), 0.97-1.01), or any of the CHD risk factors. Similarly, no associations were found in men. Neither did the reversed analyses show evidence for an association between CHD (risk factors) and reproductive aging.

CONCLUSION

Genetically determined reproductive aging is not causally associated with CHD risk (factors) in women, nor were the genetic variants associated in men. We found no evidence for a reverse association in a combined sample of women and men.

A blood-based miRNA signature with prognostic value for overall survival in advanced stage non-small cell lung cancer treated with immunotherapy

Immunotherapies have recently gained traction as highly effective therapies in a subset of late-stage cancers. Unfortunately, only a minority of patients experience the remarkable benefits of immunotherapies, whilst others fail to respond or even come to harm through immune-related adverse events. For immunotherapies within the PD-1/PD-L1 inhibitor class, patient stratification is currently performed using tumor (tissue-based) PD-L1 expression. However, PD-L1 is an accurate predictor of response in only ~30% of cases. There is pressing need for more accurate biomarkers for immunotherapy response prediction. We sought to identify peripheral blood biomarkers, predictive of response to immunotherapies against lung cancer, based on whole blood microRNA profiling. Using three well-characterized cohorts consisting of a total of 334 stage IV NSCLC patients, we have defined a 5 microRNA risk score (miRisk) that is predictive of overall survival following immunotherapy in training and independent validation (HR 2.40, 95% CI 1.37-4.19; P < 0.01) cohorts. We have traced the signature to a myeloid origin and performed miRNA target prediction to make a direct mechanistic link to the PD-L1 signaling pathway and PD-L1 itself. The miRisk score offers a potential blood-based companion diagnostic for immunotherapy that outperforms tissue-based PD-L1 staining.

Sensitivity of Fecal Immunochemical Test for Colorectal Cancer Detection Differs According to Stage and Location

BACKGROUND & AIMS

Fecal immunochemical tests (FITs) are widely used for colorectal cancer (CRC) screening. FITs detect most CRCs. Although detection of CRC at early stages is most relevant for reducing CRC mortality, there is limited evidence for the stage-specific sensitivity of the FIT in CRC detection. We estimated stage- and location-specific sensitivities of a quantitative FIT in a large cohort of patients with CRC.

METHODS

Fecal samples were collected before treatment from 435 patients with newly diagnosed CRC. Sensitivities of a quantitative FIT (FOB Gold, Sentinel Diagnostics; Milano, Italy) for tumors of different T stages and overall TNM stages (according to Union for International Cancer Control) were calculated at the cutoff recommended by the manufacturer (17 μg/g feces) and at alternative cutoffs, ranging from 10 to 40 μg/g feces, overall and stratified by tumor location.

RESULTS

At the cutoff recommended by the manufacturer, the FIT detected T1 tumors with 52% sensitivity (95% CI, 37%-67%), T2 tumors with 79% sensitivity (95% CI, 68%-88%), T3 tumors with 93% sensitivity (95% CI, 89%-95%), and T4 tumors with 84% sensitivity (95% CI, 72%-92%) (P_trend < .0001). The FIT detected stage I cancers with 68% sensitivity (95% CI, 57%-78%), stage II cancers with 92% sensitivity (95% CI, 87%-96%), stage III cancers with 82% sensitivity (95% CI, 73%-89%), and stage IV cancers with 89% sensitivity (95% CI, 80%-95%) (P_trend 0.01). The FIT detected T1 colorectal tumors with sensitivity values that were 22%-52% lower than for tumors of other T stages and stage I CRC with sensitivity values that were 11%-33% lower than for later-stage CRCs, at any of the evaluated cutoff values. The FIT detected T1 and stage I CRCs in the distal colon with sensitivity values of 32% and 52%, respectively.

CONCLUSIONS

Although the FIT identifies patients with CRC with overall high sensitivity, it can miss approximately one-third of stage I CRCs. Studies are needed to increase noninvasive detection of early-stage CRC.

Prevalence of a First-Degree Relative With Colorectal Cancer and Uptake of Screening Among Persons 40 to 54 Years Old

BACKGROUND & AIMS

People with a first-degree relative with colorectal cancer (CRC) are recommended to start CRC screening at age 40. However, there is limited information on how many people in different age groups have a known family history of CRC and how many of them have had a colonoscopy.

METHODS

We set up a multicenter, cross-sectional, population-based study in Germany to determine what proportions of persons in age groups from 40 to 54 years old have a known family history of CRC. We invited 160,000 persons to participate in an online survey from 2015 through 2016. We investigated what proportions of persons in each age group reported a family history of CRC and what proportions of persons underwent a colonoscopy examination using descriptive statistics and multiple logistic regression models.

RESULTS

Of 28,711 responders to the online questionnaire (8428 were age 40-44 years, 9879 were age 45-49 years, and 10,404 were age 50-54 years), 2705 stated that they had a first-degree relative with CRC (9.4%). The prevalence of a first-degree relative with CRC increased with age: 7.5%, 9.6%, and 10.9% for people 40 to 44 years old, 45 to 49 years old, and 50 to 54 years old, respectively. The prevalence of a first-degree relative who received a diagnosis of CRC at age 70 years or older increased steadily with each age group. Although a greater proportion of people with a family history of CRC had undergone a colonoscopy examination (54.5%) than people without a family history of CRC (25.7%; P < .0001), large proportions of people within this risk group were not in compliance with the guidelines (54.8%, 47.6%, and 38.6% for ages 40-44 y, 45-49 y, and 50-54 y, respectively).

CONCLUSIONS

One in 10 persons in Germany age 40 to 54 years old has a first-degree relative with CRC. Guidelines recommend initiation of screening at ages 40 to 45 years for people with a family history, yet at this age many people do not have a family history of CRC yet, and almost half of persons 40 to 54 years old with a family history of CRC have not yet received a screening colonoscopy.

Multiplex quantitation of 270 plasma protein markers to identify a signature for early detection of colorectal cancer

Blood-based protein biomarker signatures might be an alternative or supplement to existing methods for early detection of colorectal cancer (CRC) for population-based screening. The objective of this study was to derive a protein biomarker signature for early detection of CRC and its precursor advanced adenoma (AA). In a two-stage design, 270 protein markers were measured by liquid chromatography/multiple reaction monitoring/mass spectrometry in plasma samples of discovery and validation sets. In the discovery set consisting of 100 newly diagnosed CRC cases and 100 age- and sex-matched controls free of neoplasm at screening colonoscopy, the algorithms predicting the presence of early- or late-stage CRC were derived by Lasso regression and .632 + bootstrap. The prediction algorithms were then externally validated in an independent validation set consisting of participants of screening colonoscopy including 56 participants with CRC, 99 with AA and 99 controls without any colorectal neoplasms. Three different signatures for all-, early- and late-stage CRC consisting of five-, three- and eight-protein markers were obtained in the discovery set with areas under the curves (AUCs) after .632 + bootstrap adjustment of 0.85, 0.83 and 0.96, respectively. External validation in the representative screening population yielded AUCs of 0.79 (95% CI, 0.70-0.86), 0.79 (95% CI, 0.66-0.89) and 0.80 (95% CI, 0.70-0.89) for all-, early- and late-stage CRCs, respectively. The three-marker early-stage algorithm yielded an AUC of 0.65 (95% CI, 0.56-0.73) for detection of AA in the validation set. Although not yet competitive with available stool-based tests for CRC early detection, the identified proteins may contribute to the development of powerful blood-based tests for early detection of CRC and its precursors AAs.

Multiplex screening of 275 plasma protein biomarkers to identify a signature for early detection of colorectal cancer

Blood-based protein biomarkers may be an attractive option for early detection of colorectal cancer (CRC). Here, we used a two-stage design to measure 275 protein markers by proximity extension assay (PEA), first in plasma samples of a discovery set consisting of 98 newly diagnosed CRC cases and 100 age- and gender-matched controls free of neoplasm at screening colonoscopy. An algorithm predicting the presence of early- or late-stage CRC was derived by least absolute shrinkage and selection operator regression with .632+ bootstrap method, and the algorithms were then validated using PEA again in an independent validation set consisting of participants of screening colonoscopy with and without CRC (n = 56 and 102, respectively). Three different signatures for all-, early-, and late-stage CRC consisting of 9, 12, and 11 protein markers were obtained in the discovery set with areas under the curves (AUCs) after .632 + bootstrap adjustment of 0.92, 0.91, and 0.96, respectively. External validation among participants of screening colonoscopy yielded AUCs of 0.76 [95% confidence interval (95% CI), 0.67-0.84], 0.75 (95% CI, 0.62-0.87), and 0.80 (95% CI, 0.68-0.89) for all-, early-, and late-stage CRC, respectively. Although the identified protein markers are not competitive with the best available stool tests, these proteins may contribute to the development of powerful blood-based tests for CRC early detection in the future.

Evaluation and Validation of Plasma Proteins Using Two Different Protein Detection Methods for Early Detection of Colorectal Cancer

Objective: Plasma protein biomarkers could be an efficient alternative for population-based screening for early detection of colorectal cancer (CRC). The objective of this study was to evaluate and validate plasma proteins individually and as a signature for early detection of CRC. Methods: In a three-stage design, proteins were measured firstly by liquid chromatography/multiple reaction monitoring-mass spectrometry (LC/MRM-MS) and later by proximity extension assay (PEA) in a discovery set consisting of 96 newly diagnosed CRC cases and 94 controls free of neoplasms at screening colonoscopy. Two algorithms (one for each measurement method) were derived by Lasso regression and .632+ bootstrap based on 11 proteins that were included in both the LC/MRM-MS and PEA measurements. Additionally, another algorithm was constructed from the same eleven biomarkers plus amphireglin, the most promising protein marker in the PEA measurements that had not been available from the LC/MRM-MS measurements. Lastly the three prediction signatures were validated with PEA in independent samples of participants of screening colonoscopy (CRC (n = 56), advanced adenoma (n = 101), and participants free of neoplasm (n = 102)). Results: The same four proteins were included in all three prediction signatures; mannan binding lectin serine protease 1, osteopontin, serum paraoxonase lactonase 3 and transferrin receptor protein 1, and the third prediction signature additionally included amphiregulin. In the independent validation set from a true screening setting, the five-marker blood-based signature including AREG presented areas under the curves of 0.82 (95% CI, 0.74–0.89), 0.86 (95% CI, 0.77–0.92) and 0.76 (95% CI, 0.64–0.86) for all, early and late stages CRC, respectively. Conclusion: Two different measurement methods consistently identified four protein markers and an algorithm additionally including amphiregulin, a marker measured by PEA only, showed promising performance for detecting early stage CRC in an independent validation in a true screening setting. These proteins may be potential candidates for blood-based tests for early detection of CRC.

Association of menopausal characteristics and risk of coronary heart disease: a pan-European case-cohort analysis

BACKGROUND

Earlier age at menopause has been associated with increased risk of coronary heart disease (CHD), but the shape of association and role of established cardiovascular risk factors remain unclear. Therefore, we examined the associations between menopausal characteristics and CHD risk; the shape of the association between age at menopause and CHD risk; and the extent to which these associations are explained by established cardiovascular risk factors.

METHODS

We used data from EPIC-CVD, a case-cohort study, which includes data from 23 centres from 10 European countries. We included only women, of whom 10 880 comprise the randomly selected sub-cohort, supplemented with 4522 cases outside the sub-cohort. We conducted Prentice-weighted Cox proportional hazards regressions with age as the underlying time scale, stratified by country and adjusted for relevant confounders.

RESULTS

After confounder and intermediate adjustment, post-menopausal women were not at higher CHD risk compared with pre-menopausal women. Among post-menopausal women, earlier menopause was linearly associated with higher CHD risk [HRconfounder and intermediate adjusted per-year decrease = 1.02, 95% confidence interval (CI) = 1.01-1.03, p = 0.001]. Women with a surgical menopause were at higher risk of CHD compared with those with natural menopause (HRconfounder-adjusted = 1.25, 95% CI = 1.10-1.42, p < 0.001), but this attenuated after additional adjustment for age at menopause and intermediates (HR = 1.12, 95% CI = 0.96-1.29, p = 0.15). A proportion of the association was explained by cardiovascular risk factors.

CONCLUSIONS

Earlier and surgical menopause were associated with higher CHD risk. These associations could partially be explained by differences in conventional cardiovascular risk factors. These women might benefit from close monitoring of cardiovascular risk factors and disease.

Effect of a Single Aspirin Dose Prior to Fecal Immunochemical Testing on Test Sensitivity for Detecting Advanced Colorectal Neoplasms: A Randomized Clinical Trial

IMPORTANCE

Fecal immunochemical tests for hemoglobin are widely used for colorectal cancer (CRC) screening. Observational studies suggested that sensitivity of fecal immunochemical tests for detecting advanced neoplasms could be increased by acetylsalicylic acid (aspirin), especially among men.

OBJECTIVE

To evaluate the potential to increase sensitivity of fecal immunochemical tests by administering a single 300-mg oral aspirin dose 2 days before stool sampling.

DESIGN, SETTING, AND PARTICIPANTS

A randomized, placebo-controlled, double-blind trial was conducted in 14 gastroenterology practices and 4 hospitals in Germany, and included 2422 men and women aged 40 to 80 years scheduled for colonoscopy, with no recent use of aspirin or other drugs with antithrombotic effects (enrollment from June 2013 to November 2016, and final follow-up January 27, 2017).

INTERVENTIONS

Administration of a single tablet containing 300 mg of aspirin (n = 1208) or placebo (n = 1214) 2 days before fecal sampling for fecal immunochemical test.

MAIN OUTCOME AND MEASURES

The primary outcome was sensitivity of a quantitative fecal immunochemical test at 2 predefined cutoffs (10.2 and 17-μg Hb/g stool) for detecting advanced neoplasms (colorectal cancer or advanced adenoma).

RESULTS

Among 2422 randomized patients (mean [SD] age, 59.6 [7.9] years; 1219, 50%, men), 2134 were included in the analysis (78% for primary screening colonoscopy, 22% for diagnostic colonoscopy). Advanced neoplasms were identified in 224 participants (10.5%), including 8 participants (0.4%) with CRC and 216 participants (10.1%) with advanced adenoma. Sensitivity was 40.2% in the aspirin group and 30.4% in the placebo group (difference 9.8%, 95% CI, -3.1% to 22.2%, P = .14) at cutoff 10.2-μg Hb/g stool and 28.6% in the aspirin and 22.5% in the placebo group (difference 6.0%, 95% CI, -5.7% to 17.5%, P = .32) at cutoff 17-μg Hb/g stool.

CONCLUSIONS AND RELEVANCE

Among adults aged 40 to 80 years not using aspirin or other antithrombotic medications, administration of a single dose of oral aspirin prior to fecal immunochemical testing, compared with placebo, did not significantly increase test sensitivity for detecting advanced colorectal neoplasms at 2 predefined cutoffs of a quantitative fecal immunochemical test.

TRIAL REGISTRATION

Deutsches Register Klinischer Studien Identifier: DRKS00003252; EudraCT Identifier: 2011-005603-32/DE.

Clinical trial protocol of the ASTER trial: a double-blind, randomized, placebo-controlled phase III trial evaluating the use of acetylsalicylic acid (ASA) for enhanced early detection of colorectal neoplasms

ᅟ

Immunochemical fecal occult blood tests (iFOBTs) are increasingly used for colorectal cancer (CRC) screening. In our preceding observational study, sensitivity for detecting advanced colorectal neoplasms by iFOBT was 70.8% among users of low-dose acetylsalicylic acid compared with 35.9% among non-users (p = 0.001), whereas there were only very small differences in specificity. In receiver operating characteristics (ROC) analyses, the area under the curve (AUC) was much higher for acetylsalicylic acid users than for non-users, with particularly strong differences in men (0.87 versus 0.68, p = 0.003). These findings suggested that use of acetylsalicylic acid before conduct of iFOBT might be a promising approach to improve non-invasive screening for CRC.

Methods/design

In this randomized, double-blind, placebo-controlled trial, the diagnostic performance of two iFOBTs for detecting advanced colorectal neoplasms after a single low-dose of acetylsalicylic acid (300 mg) compared to placebo is evaluated. Acetylsalicylic acid or placebo is administered at least 5 days before a planned, study-independent colonoscopic screening in 2400 participants aged 40 to 80 years. Stool samples are obtained before and on three different days after the single dose of acetylsalicylic acid or placebo. In addition, optional blood samples are taken for future biomarker analyses. The diagnostic performance of the iFOBTs will be compared to the results of the colonoscopy as a gold standard for the diagnosis of colorectal neoplasms. Additionally, gender-specific performance of the tests and gain in diagnostic performance by test application on multiple days will be evaluated.

Discussion

If the findings from our preceding observational study will be confirmed in this large trial, the proposed low-risk, inexpensive intervention would considerably improve the diagnostic accuracy of iFOBTs and thus lead to enhanced early detection of colorectal neoplasms. Thus, the results of this trial may have a large public health impact.

Trial registration

This trial was registered before recruitment of the participants in www.clinicaltrialsregister.eu on the 30th of May 2012: EudraCT No.: 2011–005603-32 and in www.drks.de on 13th of March 2012: German Clinical Trials Register DRKS-ID: DRKS00003252.

Electronic supplementary material

The online version of this article (10.1186/s12885-018-4826-3) contains supplementary material, which is available to authorized users.

Biomarker discovery study of inflammatory proteins for colorectal cancer early detection demonstrated importance of screening setting validation

OBJECTIVES

Most studies identifying inflammatory markers for early detection of colorectal cancer (CRC) were conducted using clinically manifest cases. We aimed to identify circulating inflammatory biomarkers for early detection of CRC and validate them in both a clinical setting and a true screening setting.

STUDY DESIGN AND SETTING

A total of 92 inflammatory proteins were quantified in baseline plasma samples from individuals clinically diagnosed with CRC and neoplasm-free controls matched on age and sex (training set). A multimarker panel was selected and evaluated in samples from another clinical setting (validation set C) and a screening setting (validation set S).

RESULTS

In the training set (N = 330), a five-biomarker signature was selected that provided an area under curve (AUC) of 0.85 and 60.9% sensitivity to detect CRC at 90% specificity. When this algorithm was applied to validation set C (N = 318), the AUC (0.80) and sensitivity (49.5%) at 90% specificity for CRC diagnosis were only slightly lower than those in the training set. By contrast, the diagnostic performance of the algorithm in validation set S (N = 126) from a true screening setting was much poorer, with an AUC of 0.59 and a sensitivity of 28.6% at 90% specificity.

CONCLUSIONS

An inflammation-related protein panel with apparently good diagnostic properties for CRC detection was identified and confirmed in an independent clinical validation set. However, the biomarker combination performed substantially worse in a validation sample from a true screening setting. Our results underline the importance of validation in screening settings subsequently to novel signature discovery for cancer early detection.

Study protocol of the RaPS study: novel risk adapted prevention strategies for people with a family history of colorectal cancer

BACKGROUND

People aged 40-60 years with a family history (FH) of colorectal cancer (CRC) in 1st degree relatives (FDRs) have a 2- to 4-fold increased risk of CRC compared to the average risk population. Therefore, experts recommend starting CRC screening earlier for this high-risk group. However, information on prevalence of relevant colonoscopic findings in this group is sparse, and no risk adapted screening offers are implemented in the German health care system. For example, screening colonoscopy is uniformly offered from age 55 on, regardless of family history. Thus, we initiated a multicenter epidemiological study - the RaPS study (Risk adapted prevention strategies for colorectal cancer) - with the following aims: to determine the prevalence of having a FH of CRC in FDR in the German population aged 40-54 years; to investigate the prevalence of colorectal neoplasms among people with a FDR; and to develop risk-adapted prevention strategies for this high-risk group based on the collected information.

METHODS/DESIGN

A random sample of 160.000 persons from the general population aged 40-54 years from the catchment areas of three study centers in Germany (Dresden, Munich and Stuttgart) are contacted to assess FH of CRC by an online-questionnaire. Those with a FH of CRC in FDRs are invited to the study centers for individual consultation regarding CRC prevention. Participants are asked to donate blood and stool samples and medical records of colonoscopies will be obtained. Prevalence of CRC and its precursors will be evaluated. Furthermore, genetic, epigenetic and proteomic biomarkers in blood and microbiomic biomarkers in stool will be investigated. Risk markers and their eligibility for risk adapted screening offers will be examined.

DISCUSSION

This study will provide data on the prevalence of colorectal neoplasms among persons with a FH of CRC in the age group 40-54 years, which will enable us to derive evidence based screening strategies for this high-risk group.

TRIAL REGISTRATION

This trial was registered retrospectively in the German Clinical Trials Register (DRKS) on 29th of December 2016: German Clinical Trials Register DRKS-ID: DRKS00007842 .

Circulating prolactin and in situ breast cancer risk in the European EPIC cohort: a case-control study

INTRODUCTION

The relationship between circulating prolactin and invasive breast cancer has been investigated previously, but the association between prolactin levels and in situ breast cancer risk has received less attention.

METHODS

We analysed the relationship between pre-diagnostic prolactin levels and the risk of in situ breast cancer overall, and by menopausal status and use of postmenopausal hormone therapy (HT) at blood donation. Conditional logistic regression was used to assess this association in a case-control study nested within the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort, including 307 in situ breast cancer cases and their matched control subjects.

RESULTS

We found a significant positive association between higher circulating prolactin levels and risk of in situ breast cancer among all women [pre-and postmenopausal combined, ORlog2=1.35 (95% CI 1.04-1.76), Ptrend=0.03]. No statistically significant heterogeneity was found between prolactin levels and in situ cancer risk by menopausal status (Phet=0.98) or baseline HT use (Phet=0.20), although the observed association was more pronounced among postmenopausal women using HT compared to non-users (Ptrend=0.06 vs Ptrend=0.35). In subgroup analyses, the observed positive association was strongest in women diagnosed with in situ breast tumors<4 years compared to ≥4 years after blood donation (Ptrend=0.01 vs Ptrend=0.63; Phet=0.04) and among nulliparous women compared to parous women (Ptrend=0.03 vs Ptrend=0.15; Phet=0.07).

CONCLUSIONS

Our data extends prior research linking prolactin and invasive breast cancer to the outcome of in situ breast tumours and shows that higher circulating prolactin is associated with increased risk of in situ breast cancer.

Reproductive and menstrual factors and risk of differentiated thyroid carcinoma: the EPIC study

Differentiated thyroid carcinoma (TC) is threefold more common in women than in men and, therefore, a role of female hormones in the etiology of differentiated TC has been suggested. We assessed these hypotheses in the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort. Among 345,157 women (mean age 51) followed for an average of 11 years, 508 differentiated TC cases were identified. Hazard ratios (HRs) and 95% confidence intervals (CIs) were estimated using Cox proportional hazards regression models. No significant associations were observed between differentiated TC risk and number of pregnancies, breast feeding, menopausal status, and age at menarche and at menopause. Significant associations were found with history of infertility problems (HR 1.70; 95% CI 1.12-2.60), a recent pregnancy (HR for ≤ 5 vs. >5 years before recruitment 3.87; 95% CI 1.43-10.46), menopause type (HR for surgical vs. natural menopause: 2.16; 95% CI 1.41-3.31), oral contraceptive (OC) use at recruitment (HR: 0.48; 95% CI 0.25-0.92) and duration of OC use (HR for ≥ 9 vs. ≤ 1 year: 0.66; 95% CI: 0.50-0.89). An increased risk was also found with hormone replacement therapy use at recruitment (HR = 1.30, 95% CI 1.02-1.67), but this was not significant after adjustment for type of menopause (HR = 1.22, 95% CI 0.95-1.57). Overall, our findings do not support a strong role of reproductive and menstrual factors, and female hormone use in the etiology of differentiated TC. The few observed associations may be real or accounted for by increased surveillance in women who had infertility problems, recent pregnancies or underwent surgical menopause.

Prolactin determinants in healthy women: A large cross-sectional study within the EPIC cohort

BACKGROUND

Experimental and epidemiologic data suggest that higher circulating prolactin is associated with breast cancer risk; however, how various risk factors for breast cancer influence prolactin levels in healthy women is not clear.

METHODS

We analyzed cross-sectional associations between several suggested reproductive and lifestyle risk factors for breast cancer and circulating prolactin among pre- and postmenopausal women, taking into account the use of current postmenopausal hormone therapy, among 2,560 controls from a breast cancer nested case-control study within the EPIC cohort.

RESULTS

Adjusted geometric mean prolactin levels were significantly higher among premenopausal women, and among postmenopausal women using hormone therapy compared with nonusers (8.2, 7.0, and 6.3 ng/mL, respectively; Pcat = <0.0001). Furthermore, prolactin levels were significantly higher among users of combined estrogen-progestin hormone therapy compared with users of estrogen-alone hormone therapy (6.66 vs. 5.90 ng/mL; Pcat = 0.001). Prolactin levels were lower among parous women compared with nulliparous women (8.61 vs. 10.95 ng/mL; Pcat = 0.0002, premenopausal women); the magnitude of this difference depended on the number of full-term pregnancies (22.1% lower, ≥3 vs. 1 pregnancy, Ptrend = 0.01). Results for parity were similar but lower in magnitude among postmenopausal women. Prolactin did not vary by other studied factors, with the exception of lower levels among postmenopausal smokers compared with never smokers.

CONCLUSIONS

Our study shows that current hormone therapy use, especially the use of combined hormone therapy, is associated with higher circulating prolactin levels in postmenopausal women, and confirms prior findings of lower circulating prolactin in parous women.

IMPACT

Our study extends the knowledge linking various breast cancer risk factors with circulating prolactin.

Circulating prolactin and breast cancer risk among pre- and postmenopausal women in the EPIC cohort

BACKGROUND

Experimental and epidemiological evidence suggests that prolactin might play a role in the etiology of breast cancer. We analyzed the relationship of prediagnostic circulating prolactin levels with the risk of breast cancer by menopausal status, use of postmenopausal hormone replacement therapy (HRT) at blood donation, and by estrogen and progesterone receptor status of the breast tumors.

PATIENTS AND METHODS

Conditional logistic regression was used to analyze the data from a case-control study nested within the prospective European EPIC cohort, including 2250 invasive breast cancer and their matched control subjects.

RESULTS

Statistically significant heterogeneity in the association of prolactin levels with breast cancer risk between women who were either pre- or postmenopausal at the time of blood donation was observed (Phet = 0.04). Higher serum levels of prolactin were associated with significant increase in the risk of breast cancer among postmenopausal women [odds ratio (OR)Q4-Q1 = 1.29 (95% confidence interval, CI, 1.05-1.58), Ptrend = 0.09]; however, this increase in risk seemed to be confined to women who used postmenopausal HRT at blood donation [ORQ4-Q1 = 1.45 (95% CI 1.08-1.95), Ptrend = 0.01], whereas no statistically significant association was found for the non-users of HRT [ORQ4-Q1 = 1.11 (95%CI 0.83-1.49), Ptrend = 0.80] (Phet = 0.08). Among premenopausal women, a statistically non-significant inverse association was observed [ORQ4-Q1 = 0.70 (95% CI 0.48-1.03), Ptrend = 0.16]. There was no heterogeneity in the prolactin-breast cancer association by hormone receptor status of the tumor.

CONCLUSION

Our study indicates that higher circulating levels of prolactin among the postmenopausal HRT users at baseline may be associated with increased breast cancer risk.

Primary Preventive Potential for Stroke by Avoidance of Major Lifestyle Risk Factors

Background and Purpose—

Because primary prevention of stroke is a priority, our aim was to assess the primary preventive potential of major lifestyle risk factors for stroke in middle-aged women and men.

Methods—

Among 23 927 persons, 551 (195 women and 356 men) had a first diagnosis of stroke during an average follow-up of 12.7 years. Using Cox proportional hazards models, we estimated the associations of adiposity, smoking, physical activity, alcohol consumption, and diet with risk of developing stroke. A competing risk model built from cause-specific proportional hazards models accounting for concurrent risk of death was used to calculate relative and absolute reductions in stroke occurrences that could have been achieved by maintaining a healthy lifestyle pattern.

Results—

Obesity, smoking, alcohol consumption, diet, and physical inactivity were each identified as modifiable lifestyle risk factors for stroke. About 38% of stroke cases were estimated as preventable through adherence to a healthy lifestyle profile (never smoking, maintaining optimal body mass index and waist circumference, performing physical exercise, consuming a moderate quantity of alcohol, and following a healthy dietary pattern). Age-specific estimates of 5-year incidence rates for stroke in the actual cohort and in a hypothetical, comparable cohort of individuals following a healthy lifestyle would be reduced from 153 to 94 per 100 000 women and from 261 to 161 per 100 000 men for the age group 60 to 65 years.

Conclusions—

Our analysis confirms the strong primary prevention potential for stroke based on avoidance of excess body weight, smoking, heavy alcohol consumption, unhealthy diet, and physical inactivity.

Insulin-like growth factor I and risk of breast cancer by age and hormone receptor status-A prospective study within the EPIC cohort

Experimental evidence shows cross-talk in mammary cells between estrogen, insulin-like growth factor I (IGF-I) and their respective receptors and possible synergistic effects of estrogen receptor (ER) activation and increased IGF-I signaling with regard to breast tumor development, and epidemiological evidence suggests that circulating IGF-I levels may be related more to the risk of ER-positive than ER-negative breast cancer. Using a case-control study nested within the prospective European EPIC cohort (938 breast cancer cases and 1,394 matched control subjects), we analyzed the relationships of prediagnostic serum IGF-I levels with the risk of estrogen and progesterone receptor-positive and -negative breast tumors. IGF-I levels were positively associated with the risk of ER+ breast tumors overall (pre- and postmenopausal women combined, odds ratio (OR)Q4-Q1 = 1.41 [95% confidence interval (CI) 1.01-1.98] for the highest vs. lowest quartile; OR = 1.17 [95% CI 1.04-1.33] per 1-standard deviation (SD) increase in IGF-I, ptrend = 0.01) and among women who were diagnosed with breast cancer at 50 years or older (ORQ3-Q1 = 1.38 [95% CI 1.01-1.89]; OR = 1.19 [95% CI 1.04-1.36] per 1-SD increase in IGF-I, ptrend = 0.01) but not with receptor-positive disease diagnosed at an earlier age. No statistically significant associations were observed for ER- breast tumors overall and by age at diagnosis. Tests for heterogeneity by receptor status of the tumor were not statistically significant, except for women diagnosed with breast cancer at 50 years or older (phet = 0.03 for ER+/PR+ vs. ER-/PR- disease). Our data add to a global body of evidence indicating that higher circulating IGF-I levels may increase risk specifically of receptor-positive, but not receptor-negative, breast cancer diagnosed at 50 years or older.

Premenopausal serum sex hormone levels in relation to breast cancer risk, overall and by hormone receptor status - results from the EPIC cohort

Results from prospective studies on premenopausal serum hormone levels in relation to breast cancer risk have been inconclusive, especially with regard to tumor subtypes. Using a case-control study nested within the prospective European Prospective Investigation into Cancer and Nutrition (EPIC) cohort (801 breast cancer cases and 1,132 matched control subjects), we analyzed the relationships of prediagnostic serum estradiol, free estradiol, progesterone, testosterone, free testosterone and sex hormone-binding globulin (SHBG) levels with the risk of breast cancer by estrogen and progesterone receptor-positive and -negative breast tumors and by age at diagnoses. Higher prediagnostic serum levels of testosterone and free testosterone were associated with an increased overall risk of breast cancer [ORQ4-Q1  = 1.56 (95% CI 1.15-2.13), ptrend  = 0.02 for testosterone and ORQ4-Q1  = 1.33 (95% CI 0.99-1.79), ptrend  = 0.04 for free testosterone], but no significant risk association was observed for estradiol, free estradiol, progesterone and SHBG. Tests for heterogeneity between receptor-positive and -negative tumors were not significant. When analysis were stratified by age at tumor diagnosis, the odds ratios observed for estradiol were stronger and borderline significant for breast cancer diagnosed at age less than 50 [ORQ4-Q1  = 1.32 (95% CI 0.87-2.01), ptrend  = 0.05] compared to breast cancer diagnosed at age 50 or above [ORQ4-Q1  = 0.94 (95% CI 0.60-1.47), ptrend  = 0.34, phet  = 0.04]. In conclusion, our data indicate that higher premenopausal circulating testosterone levels are associated with an increased risk of developing breast cancer, but do not show a significant association of estradiol or progesterone with breast cancer risk, overall, by menstrual cycle phase or by tumor receptor status, although a possible risk increase with higher estradiol levels for tumors diagnosed before age 50 was seen.

Reproductive factors and risk of hormone receptor positive and negative breast cancer: a cohort study

Background

The association of reproductive factors with hormone receptor (HR)-negative breast tumors remains uncertain.

Methods

Within the EPIC cohort, Cox proportional hazards models were used to describe the relationships of reproductive factors (menarcheal age, time between menarche and first pregnancy, parity, number of children, age at first and last pregnancies, time since last full-term childbirth, breastfeeding, age at menopause, ever having an abortion and use of oral contraceptives [OC]) with risk of ER-PR- (n = 998) and ER+PR+ (n = 3,567) breast tumors.

Results

A later first full-term childbirth was associated with increased risk of ER+PR+ tumors but not with risk of ER-PR- tumors (≥35 vs. ≤19 years HR: 1.47 [95% CI 1.15-1.88] p_trend < 0.001 for ER+PR+ tumors; ≥35 vs. ≤19 years HR: 0.93 [95% CI 0.53-1.65] p_trend = 0.96 for ER-PR- tumors; P_het = 0.03). The risk associations of menarcheal age, and time period between menarche and first full-term childbirth with ER-PR-tumors were in the similar direction with risk of ER+PR+ tumors (p_het = 0.50), although weaker in magnitude and statistically only borderline significant. Other parity related factors such as ever a full-term birth, number of births, age- and time since last birth were associated only with ER+PR+ malignancies, however no statistical heterogeneity between breast cancer subtypes was observed. Breastfeeding and OC use were generally not associated with breast cancer subtype risk.

Conclusion

Our study provides possible evidence that age at menarche, and time between menarche and first full-term childbirth may be associated with the etiology of both HR-negative and HR-positive malignancies, although the associations with HR-negative breast cancer were only borderline significant.

Adherence to the World Cancer Research Fund/American Institute for Cancer Research guidelines and risk of death in Europe: results from the European Prospective Investigation into Nutrition and Cancer cohort study1,4

BACKGROUND

In 2007, the World Cancer Research Fund (WCRF) and the American Institute for Cancer Research (AICR) issued recommendations on diet, physical activity, and weight management for cancer prevention on the basis of the most comprehensive collection of available evidence.

OBJECTIVE

We investigated whether concordance with WCRF/AICR recommendations is related to risk of death.

DESIGN

The current study included 378,864 participants from 9 European countries enrolled in the European Prospective Investigation into Cancer and Nutrition study. At recruitment (1992-1998), dietary, anthropometric, and lifestyle information was collected. A WCRF/AICR score, which incorporated 6 of the WCRF/AICR recommendations for men [regarding body fatness, physical activity, foods and drinks that promote weight gain, plant foods, animal foods, and alcoholic drinks (score range: 0-6)] and 7 WCRF/AICR recommendations for women [plus breastfeeding (score range: 0-7)], was constructed. Higher scores indicated greater concordance with WCRF/AICR recommendations. Associations between the WCRF/AICR score and risks of total and cause-specific death were estimated by using Cox regression analysis.

RESULTS

After a median follow-up time of 12.8 y, 23,828 deaths were identified. Participants within the highest category of the WCRF/AICR score (5-6 points in men; 6-7 points in women) had a 34% lower hazard of death (95% CI: 0.59, 0.75) compared with participants within the lowest category of the WCRF/AICR score (0-2 points in men; 0-3 points in women). Significant inverse associations were observed in all countries. The WCRF/AICR score was also significantly associated with a lower hazard of dying from cancer, circulatory disease, and respiratory disease.

CONCLUSION

Results of this study suggest that following WCRF/AICR recommendations could significantly increase longevity.

Dietary flavonoid and lignan intake and breast cancer risk according to menopause and hormone receptor status in the European Prospective Investigation into Cancer and Nutrition (EPIC) Study

Evidence on the association between dietary flavonoids and lignans and breast cancer (BC) risk is inconclusive, with the possible exception of isoflavones in Asian countries. Therefore, we investigated prospectively dietary total and subclasses of flavonoid and lignan intake and BC risk according to menopause and hormonal receptor status in the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort. The study included 334,850 women, mostly aged between 35 and 70 years from ten European countries. At baseline, country-specific validated dietary questionnaires were used. A flavonoid and lignan food composition database was developed from the US Department of Agriculture, the Phenol-Explorer and the UK Food Standards Agency databases. Cox regression models were used to analyse the association between dietary flavonoid/lignan intake and the risk of developing BC. During an average 11.5-year follow-up, 11,576 incident BC cases were identified. No association was observed between the intake of total flavonoids [hazard ratio comparing fifth to first quintile (HRQ5-Q1) 0.97, 95 % confidence interval (CI): 0.90-1.04; P trend = 0.591], isoflavones (HRQ5-Q1 1.00, 95 % CI: 0.91-1.10; P trend = 0.734), or total lignans (HRQ5-Q1 1.02, 95 % CI: 0.93-1.11; P trend = 0.469) and overall BC risk. The stratification of the results by menopausal status at recruitment or the differentiation of BC cases according to oestrogen and progesterone receptors did not affect the results. This study shows no associations between flavonoid and lignan intake and BC risk, overall or after taking into account menopausal status and BC hormone receptors.

Flavour development in pork. Influence of flavour precursor concentrations in longissimus dorsi from pigs with different raw meat qualities

Flavour development and overall eating quality of pan-fried pork chops of longissimus dorsi from eight different raw meat qualities aged for 4 and 15 days were assessed by a trained sensory panel. The raw meat qualities were obtained through combinations of strategic feeding/fasting (control vs. low glycogen concentration), slaughter live-weight (84kg vs. 110kg), and gender (female vs. castrate). The flavour development was investigated for possible correlation with the concentrations of selected individual flavour precursors present in the raw meat: monosaccharides, IMP and degradation products, fatty acids, lactate and thiamine. Differences in precursor concentrations between the raw meat qualities were observed with feeding/fasting and ageing as the main factors with the largest influence of all experimental factors. However, the concentrations of the precursors could not explain the differences in sensory perception of the pan-fried pork chops. Overall, the differences were small.

Monitoring of warmed-over flavour in pork using the electronic nose - correlation to sensory attributes and secondary lipid oxidation products

Sensory analysis of meatballs was carried out to monitor the warmed-over flavour (WOF) development in cooked, cold-stored (at 4°C for 0, 2 and 4days) and reheated meatballs derived from M. longissimus dorsi (LD) and M. semimembranosus (SM) of pigs fed a standard diet supplemented with either 3% of rapeseed oil or 3% of palm oil. This was performed in combination with measurement of volatile compounds using a solid-state-based gas sensor array system (electronic nose) and gas chromatography/mass spectrometry together with measurement of thiobarbitoric acid reactive substances (TBARS). Subsequently, to elucidate the relations and predictability between the obtained data, the gas sensor responses were correlated with chemical (volatile and non-volatile secondary lipid oxidation products) and sensory data (flavour and odour attributes), using partial least squares regression modelling (PLSR). The TBARS, hexanal, pentanal, pentanol and nonanal all correlated to the sensory attributes associated to WOF formation. Moreover, the responses from eight of the MOS (metal oxide semiconductor) sensors within the electronic nose proved to be significantly related to WOF characteristics detected by both sensory and chemical analysis, while six of the MOSFET (metal oxide semiconductor field effect transistor) sensors were related to freshly cooked meat attributes determined by sensory analysis. The obtained results show the potential of the present gas sensor technology to monitor WOF formation in pork.

Development of inosine monophosphate and its degradation products during aging of pork of different qualities in relation to basic taste and retronasal flavor perception of the meat

Inosine monophosphate (IMP) and its degradation products, ribose and hypoxanthine, are all considered to be important constituents in meat flavor formation and development. The present study explored the fate of IMP during the aging of two qualities of pork (pH >5.7 and 5.5 < pH < 5.6) and the potential relationship between IMP, hypoxanthine, and sensory attributes of pork registered both as retronasal and basic taste responses in whole meat, meat juice, and the remaining meat residue. During aging the concentration of IMP decreased with a simultaneous increase in the concentrations of inosine, hypoxanthine, and ribose. The rates at which IMP was degraded to inosine and inosine to hypoxanthine during aging were found to be in agreement with the known rate constants of the dephosphorylation of IMP and the hydrolysis of inosine, respectively. Moreover, high-pH pork resulted in a significantly higher concentration of hypoxanthine throughout storage compared with low-pH pork due to an initially higher concentration of IMP in high-pH meat. The sensory analysis showed increasing intensity in bitterness and saltiness of pork as a function of aging, with the intensity being most pronounced in the meat juice. The increasing bitterness of the pork as a function of aging coincided with the higher content of hypoxanthine in these samples, thereby suggesting that degradation of IMP to hypoxanthine might influence pork flavor. In contrast, IMP was associated with nonaged meat and the sensory attributes meaty and brothy.