Circulating enterolactone concentrations and prognosis of postmenopausal breast cancer: assessment of mediation by inflammatory markers.

Higher lignan exposure has been associated with lower all-cause mortality (ACM) and breast cancer-specific mortality (BCSM) for postmenopausal breast cancer patients. However, the biological mechanisms underpinning these associations are still unclear. We investigated for the first time whether and to what extent the association between enterolactone (ENL), the major lignan metabolite, and postmenopausal breast cancer prognosis is mediated by inflammatory biomarkers. Circulating concentrations of ENL and inflammatory markers were measured in a population-based prospective cohort of 1,743 breast cancer patients recruited between 2002 and 2005 and followed-up until 2009. Hazard ratios (HR) and 95% CIs were estimated using multivariable Cox regression. Mediation analysis was performed to estimate the percentage association between ENL (log2) and ACM, BCSM and distant disease-free survival (DDFS), which is mediated by C-reactive protein (CRP) (log2), as the strongest potential mediator, and also interleukin (IL)-10. Median serum/plasma ENL and CRP concentrations for all patients, including 180 deceased patients, were 23.2 and 17.5 nmol/L, and 3.2 and 6.5 mg/l, respectively. ENL concentrations were significantly inversely associated with ACM, BCSM and DDFS (per doubling of ENL concentrations: HRs 0.93 [0.87, 0.99], 0.91 [0.84, 0.99] and 0.92 [0.87, 0.99]), after adjusting for prognostic factors and BMI. Estimated 18, 14 and 12% of the effects of ENL on ACM, BCSM and DDFS, respectively, were mediated through CRP. No mediational effect of IL-10 was found. We provide first evidence that the proinflammatory marker CRP may partially mediate the association of ENL with postmenopausal breast cancer survival, which supports hormone-independent mechanisms.

Prognostic impact of surgery for early-stage invasive breast cancer on breast cancer-specific survival, overall survival, and recurrence risk: a population-based analysis.

PURPOSE: Recent cohort studies demonstrated better overall survival (OS) or breast cancer-specific survival (BCS) for breast-conserving therapy (BCT) followed by radiation (RT) compared to mastectomy alone (MT). This is the first observational study in which adjustments for a comprehensive set of prognostic factors, adjuvant therapies, mode of detection, and comorbidities were possible to investigate OS, BCS, as well as recurrence risk of patients undergoing BCT + RT, MT + RT, or MT. METHODS: Women aged 50-74 years at diagnosis of early-stage invasive breast cancer (I-IIIa) between 2001 and 2005 at the German population-based case-control study (MARIE study) were recruited and followed prospectively as a case cohort until 2015. Kaplan-Meier estimates and stepwise adjusted multivariable Cox models were used to estimate hazard ratios (HRs) and 95% confidence intervals (95% CI). RESULTS: The 2762 patients included were followed up for a median of 11.9 years (95% CI 11.8-12.0). 74.2% of patients underwent BCT + RT; 10.3% MT + RT and 15.6% MT alone. Compared to patients treated with MT alone, patients treated with BCT + RT showed non-statistically significant improved OS (HR 0.79, 95% CI 0.61-1.02), BCS (HR 0.79, 95% CI 0.55-1.12), and no difference in recurrence risks (HR 1.01, 95% CI 0.74-1.37). For patients treated with MT + RT, there were no differences in OS (HR 1.06, 95% CI 0.75-1.50), BCS (HR 1.17, 95% CI 0.75-1.82), or recurrence risk (HR 1.33, 95% CI 0.89-1.97). CONCLUSIONS: Among patients with early-stage breast cancer, clinical outcomes more than 10 years after diagnosis did not differ between the primary treatment options BCT + RT, MT + RT versus MT alone after full adjustment.

Gene-environment interactions involving functional variants: Results from the Breast Cancer Association Consortium.

Investigating the most likely causal variants identified by fine-mapping analyses may improve the power to detect gene-environment interactions. We assessed the interplay between 70 single nucleotide polymorphisms identified by genetic fine-scale mapping of susceptibility loci and 11 epidemiological breast cancer risk factors in relation to breast cancer. Analyses were conducted on up to 58,573 subjects (26,968 cases and 31,605 controls) from the Breast Cancer Association Consortium, in one of the largest studies of its kind. Analyses were carried out separately for estrogen receptor (ER) positive (ER+) and ER negative (ER-) disease. The Bayesian False Discovery Probability (BFDP) was computed to assess the noteworthiness of the results. Four potential gene-environment interactions were identified as noteworthy (BFDP < 0.80) when assuming a true prior interaction probability of 0.01. The strongest interaction result in relation to overall breast cancer risk was found between CFLAR-rs7558475 and current smoking (ORint = 0.77, 95% CI: 0.67-0.88, pint = 1.8 × 10-4 ). The interaction with the strongest statistical evidence was found between 5q14-rs7707921 and alcohol consumption (ORint =1.36, 95% CI: 1.16-1.59, pint = 1.9 × 10-5 ) in relation to ER- disease risk. The remaining two gene-environment interactions were also identified in relation to ER- breast cancer risk and were found between 3p21-rs6796502 and age at menarche (ORint = 1.26, 95% CI: 1.12-1.43, pint =1.8 × 10-4 ) and between 8q23-rs13267382 and age at first full-term pregnancy (ORint = 0.89, 95% CI: 0.83-0.95, pint = 5.2 × 10-4 ). While these results do not suggest any strong gene-environment interactions, our results may still be useful to inform experimental studies. These may in turn, shed light on the potential interactions observed.

Relationship between menopausal hormone therapy and mortality after breast cancer The MARIEplus study, a prospective case cohort.

Cohort studies of breast cancer (BC) patients, but not of disease-free women at inclusion, have found menopausal hormone therapy (MHT) to be associated with decreased BC specific mortality (BCM). Here, the German population-based MARIEplus BC cohort was analyzed to further elucidate associations of prediagnostic MHT with BCM (and modification by tumor characteristics), recurrence, and secondarily with other cause and overall mortality. Enrolled 2002-2005, incident invasive BC cases (N = 3,321) were followed up for a median of 6.1 years. Cox proportional hazards models adjusted for tumor characteristics, mammography and lifestyle were applied. Compared with never users of MHT, current users at date of diagnosis had significantly lower BCM (Hazard ratio (HR) 0.72, 95% CI 0.53-0.97) and risk of recurrence (HR 0.61, 95% CI 0.46-0.82). The MHT related reduced BCM was confined to patients with low grade tumors (HR 0.44, 95% CI 0.28-0.70; phet = 0.01) and not modified by estrogen receptor or nodal status. BCM decreased with MHT duration in current and increased in past users (phet = 0.015). Mortality due to causes other than BC and overall mortality were also reduced in current MHT users (HR 0.51, 95% CI 0.32-0.81, HR 0.66, 95% CI 0.52-0.86, respectively). Favorable tumor characteristics and mammographic surveillance could not fully explain associations of current MHT use with BCM and recurrence risk. Thus, the study contributes to the evidence that prediagnostic MHT does not have a negative impact on prognosis after BC. The restriction of a reduced BCM to low grade tumors should be confirmed in independent studies.

Genetically Predicted Body Mass Index and Breast Cancer Risk: Mendelian Randomization Analyses of Data from 145,000 Women of European Descent.

BACKGROUND: Observational epidemiological studies have shown that high body mass index (BMI) is associated with a reduced risk of breast cancer in premenopausal women but an increased risk in postmenopausal women. It is unclear whether this association is mediated through shared genetic or environmental factors. METHODS: We applied Mendelian randomization to evaluate the association between BMI and risk of breast cancer occurrence using data from two large breast cancer consortia. We created a weighted BMI genetic score comprising 84 BMI-associated genetic variants to predicted BMI. We evaluated genetically predicted BMI in association with breast cancer risk using individual-level data from the Breast Cancer Association Consortium (BCAC) (cases = 46,325, controls = 42,482). We further evaluated the association between genetically predicted BMI and breast cancer risk using summary statistics from 16,003 cases and 41,335 controls from the Discovery, Biology, and Risk of Inherited Variants in Breast Cancer (DRIVE) Project. Because most studies measured BMI after cancer diagnosis, we could not conduct a parallel analysis to adequately evaluate the association of measured BMI with breast cancer risk prospectively. RESULTS: In the BCAC data, genetically predicted BMI was found to be inversely associated with breast cancer risk (odds ratio [OR] = 0.65 per 5 kg/m2 increase, 95% confidence interval [CI]: 0.56-0.75, p = 3.32 × 10-10). The associations were similar for both premenopausal (OR = 0.44, 95% CI:0.31-0.62, p = 9.91 × 10-8) and postmenopausal breast cancer (OR = 0.57, 95% CI: 0.46-0.71, p = 1.88 × 10-8). This association was replicated in the data from the DRIVE consortium (OR = 0.72, 95% CI: 0.60-0.84, p = 1.64 × 10-7). Single marker analyses identified 17 of the 84 BMI-associated single nucleotide polymorphisms (SNPs) in association with breast cancer risk at p < 0.05; for 16 of them, the allele associated with elevated BMI was associated with reduced breast cancer risk. CONCLUSIONS: BMI predicted by genome-wide association studies (GWAS)-identified variants is inversely associated with the risk of both pre- and postmenopausal breast cancer. The reduced risk of postmenopausal breast cancer associated with genetically predicted BMI observed in this study differs from the positive association reported from studies using measured adult BMI. Understanding the reasons for this discrepancy may reveal insights into the complex relationship of genetic determinants of body weight in the etiology of breast cancer.

A Comprehensive Multistate Model Analyzing Associations of Various Risk Factors With the Course of Breast Cancer in a Population-Based Cohort of Breast Cancer Cases.

We employed a semi-Markov multistate model for the simultaneous analysis of various endpoints describing the course of breast cancer. Results were compared with those from standard analyses using a Cox proportional hazards model. We included 3,012 patients with invasive breast cancer newly diagnosed between 2001 and 2005 who were recruited in Germany for a population-based study, the Mamma Carcinoma Risk Factor Investigation (MARIE Study), and prospectively followed up until the end of 2009. Locoregional recurrence and distant metastasis were included as intermediate states, and deaths from breast cancer, secondary cancer, and other causes were included as competing absorbing states. Tumor characteristics were significantly associated with all breast cancer-related endpoints. Nodal involvement was significantly related to local recurrence but more strongly related to distant metastases. Smoking was significantly associated with mortality from second cancers and other causes, whereas menopausal hormone use was significantly associated with reduced distant metastasis and death from causes other than cancer. The presence of cardiovascular disease at diagnosis was solely associated with mortality from other causes. Compared with separate Cox models, multistate models allow for dissection of prognostic factors and intermediate events in the analysis of cause-specific mortality and can yield new insights into disease progression and associated pathways.

A large-scale assessment of two-way SNP interactions in breast cancer susceptibility using 46,450 cases and 42,461 controls from the breast cancer association consortium.

Part of the substantial unexplained familial aggregation of breast cancer may be due to interactions between common variants, but few studies have had adequate statistical power to detect interactions of realistic magnitude. We aimed to assess all two-way interactions in breast cancer susceptibility between 70,917 single nucleotide polymorphisms (SNPs) selected primarily based on prior evidence of a marginal effect. Thirty-eight international studies contributed data for 46,450 breast cancer cases and 42,461 controls of European origin as part of a multi-consortium project (COGS). First, SNPs were preselected based on evidence (P < 0.01) of a per-allele main effect, and all two-way combinations of those were evaluated by a per-allele (1 d.f.) test for interaction using logistic regression. Second, all 2.5 billion possible two-SNP combinations were evaluated using Boolean operation-based screening and testing, and SNP pairs with the strongest evidence of interaction (P < 10(-4)) were selected for more careful assessment by logistic regression. Under the first approach, 3277 SNPs were preselected, but an evaluation of all possible two-SNP combinations (1 d.f.) identified no interactions at P < 10(-8). Results from the second analytic approach were consistent with those from the first (P > 10(-10)). In summary, we observed little evidence of two-way SNP interactions in breast cancer susceptibility, despite the large number of SNPs with potential marginal effects considered and the very large sample size. This finding may have important implications for risk prediction, simplifying the modelling required. Further comprehensive, large-scale genome-wide interaction studies may identify novel interacting loci if the inherent logistic and computational challenges can be overcome.

Genetic variation in the immunosuppression pathway genes and breast cancer susceptibility: a pooled analysis of 42,510 cases and 40,577 controls from the Breast Cancer Association Consortium.

Immunosuppression plays a pivotal role in assisting tumors to evade immune destruction and promoting tumor development. We hypothesized that genetic variation in the immunosuppression pathway genes may be implicated in breast cancer tumorigenesis. We included 42,510 female breast cancer cases and 40,577 controls of European ancestry from 37 studies in the Breast Cancer Association Consortium (2015) with available genotype data for 3595 single nucleotide polymorphisms (SNPs) in 133 candidate genes. Associations between genotyped SNPs and overall breast cancer risk, and secondarily according to estrogen receptor (ER) status, were assessed using multiple logistic regression models. Gene-level associations were assessed based on principal component analysis. Gene expression analyses were conducted using RNA sequencing level 3 data from The Cancer Genome Atlas for 989 breast tumor samples and 113 matched normal tissue samples. SNP rs1905339 (A>G) in the STAT3 region was associated with an increased breast cancer risk (per allele odds ratio 1.05, 95 % confidence interval 1.03-1.08; p value = 1.4 × 10(-6)). The association did not differ significantly by ER status. On the gene level, in addition to TGFBR2 and CCND1, IL5 and GM-CSF showed the strongest associations with overall breast cancer risk (p value = 1.0 × 10(-3) and 7.0 × 10(-3), respectively). Furthermore, STAT3 and IL5 but not GM-CSF were differentially expressed between breast tumor tissue and normal tissue (p value = 2.5 × 10(-3), 4.5 × 10(-4) and 0.63, respectively). Our data provide evidence that the immunosuppression pathway genes STAT3, IL5, and GM-CSF may be novel susceptibility loci for breast cancer in women of European ancestry.

Association of genetic susceptibility variants for type 2 diabetes with breast cancer risk in women of European ancestry.

PURPOSE: Type 2 diabetes (T2D) has been reported to be associated with an elevated risk of breast cancer. It is unclear, however, whether this association is due to shared genetic factors. METHODS: We constructed a genetic risk score (GRS) using risk variants from 33 known independent T2D susceptibility loci and evaluated its relation to breast cancer risk using the data from two consortia, including 62,328 breast cancer patients and 83,817 controls of European ancestry. Unconditional logistic regression models were used to derive adjusted odds ratios (ORs) and 95 % confidence intervals (CIs) to measure the association of breast cancer risk with T2D GRS or T2D-associated genetic risk variants. Meta-analyses were conducted to obtain summary ORs across all studies. RESULTS: The T2D GRS was not found to be associated with breast cancer risk, overall, by menopausal status, or for estrogen receptor positive or negative breast cancer. Three T2D associated risk variants were individually associated with breast cancer risk after adjustment for multiple comparisons using the Bonferroni method (at p < 0.001), rs9939609 (FTO) (OR 0.94, 95 % CI = 0.92-0.95, p = 4.13E-13), rs7903146 (TCF7L2) (OR 1.04, 95 % CI = 1.02-1.06, p = 1.26E-05), and rs8042680 (PRC1) (OR 0.97, 95 % CI = 0.95-0.99, p = 8.05E-04). CONCLUSIONS: We have shown that several genetic risk variants were associated with the risk of both T2D and breast cancer. However, overall genetic susceptibility to T2D may not be related to breast cancer risk.

Inherited variants in the inner centromere protein (INCENP) gene of the chromosomal passenger complex contribute to the susceptibility of ER-negative breast cancer.

The chromosomal passenger complex (CPC) plays a pivotal role in the regulation of cell division. Therefore, inherited CPC variability could influence tumor development. The present candidate gene approach investigates the relationship between single nucleotide polymorphisms (SNPs) in genes encoding key CPC components and breast cancer risk. Fifteen SNPs in four CPC genes (INCENP, AURKB, BIRC5 and CDCA8) were genotyped in 88 911 European women from 39 case-control studies of the Breast Cancer Association Consortium. Possible associations were investigated in fixed-effects meta-analyses. The synonymous SNP rs1675126 in exon 7 of INCENP was associated with overall breast cancer risk [per A allele odds ratio (OR) 0.95, 95% confidence interval (CI) 0.92-0.98, P = 0.007] and particularly with estrogen receptor (ER)-negative breast tumors (per A allele OR 0.89, 95% CI 0.83-0.95, P = 0.0005). SNPs not directly genotyped were imputed based on 1000 Genomes. The SNPs rs1047739 in the 3' untranslated region and rs144045115 downstream of INCENP showed the strongest association signals for overall (per T allele OR 1.03, 95% CI 1.00-1.06, P = 0.0009) and ER-negative breast cancer risk (per A allele OR 1.06, 95% CI 1.02-1.10, P = 0.0002). Two genotyped SNPs in BIRC5 were associated with familial breast cancer risk (top SNP rs2071214: per G allele OR 1.12, 95% CI 1.04-1.21, P = 0.002). The data suggest that INCENP in the CPC pathway contributes to ER-negative breast cancer susceptibility in the European population. In spite of a modest contribution of CPC-inherited variants to the total burden of sporadic and familial breast cancer, their potential as novel targets for breast cancer treatment should be further investigated.

Common germline polymorphisms associated with breast cancer-specific survival.

INTRODUCTION: Previous studies have identified common germline variants nominally associated with breast cancer survival. These associations have not been widely replicated in further studies. The purpose of this study was to evaluate the association of previously reported SNPs with breast cancer-specific survival using data from a pooled analysis of eight breast cancer survival genome-wide association studies (GWAS) from the Breast Cancer Association Consortium. METHODS: A literature review was conducted of all previously published associations between common germline variants and three survival outcomes: breast cancer-specific survival, overall survival and disease-free survival. All associations that reached the nominal significance level of P value <0.05 were included. Single nucleotide polymorphisms that had been previously reported as nominally associated with at least one survival outcome were evaluated in the pooled analysis of over 37,000 breast cancer cases for association with breast cancer-specific survival. Previous associations were evaluated using a one-sided test based on the reported direction of effect. RESULTS: Fifty-six variants from 45 previous publications were evaluated in the meta-analysis. Fifty-four of these were evaluated in the full set of 37,954 breast cancer cases with 2,900 events and the two additional variants were evaluated in a reduced sample size of 30,000 samples in order to ensure independence from the previously published studies. Five variants reached nominal significance (P <0.05) in the pooled GWAS data compared to 2.8 expected under the null hypothesis. Seven additional variants were associated (P <0.05) with ER-positive disease. CONCLUSIONS: Although no variants reached genome-wide significance (P <5 x 10(-8)), these results suggest that there is some evidence of association between candidate common germline variants and breast cancer prognosis. Larger studies from multinational collaborations are necessary to increase the power to detect associations, between common variants and prognosis, at more stringent significance levels.

Investigation of gene-environment interactions between 47 newly identified breast cancer susceptibility loci and environmental risk factors.

A large genotyping project within the Breast Cancer Association Consortium (BCAC) recently identified 41 associations between single nucleotide polymorphisms (SNPs) and overall breast cancer (BC) risk. We investigated whether the effects of these 41 SNPs, as well as six SNPs associated with estrogen receptor (ER) negative BC risk are modified by 13 environmental risk factors for BC. Data from 22 studies participating in BCAC were pooled, comprising up to 26,633 cases and 30,119 controls. Interactions between SNPs and environmental factors were evaluated using an empirical Bayes-type shrinkage estimator. Six SNPs showed interactions with associated p-values (pint ) <1.1 × 10(-3) . None of the observed interactions was significant after accounting for multiple testing. The Bayesian False Discovery Probability was used to rank the findings, which indicated three interactions as being noteworthy at 1% prior probability of interaction. SNP rs6828523 was associated with increased ER-negative BC risk in women ≥170 cm (OR = 1.22, p = 0.017), but inversely associated with ER-negative BC risk in women <160 cm (OR = 0.83, p = 0.039, pint = 1.9 × 10(-4) ). The inverse association between rs4808801 and overall BC risk was stronger for women who had had four or more pregnancies (OR = 0.85, p = 2.0 × 10(-4) ), and absent in women who had had just one (OR = 0.96, p = 0.19, pint = 6.1 × 10(-4) ). SNP rs11242675 was inversely associated with overall BC risk in never/former smokers (OR = 0.93, p = 2.8 × 10(-5) ), but no association was observed in current smokers (OR = 1.07, p = 0.14, pint = 3.4 × 10(-4) ). In conclusion, recently identified BC susceptibility loci are not strongly modified by established risk factors and the observed potential interactions require confirmation in independent studies.

A polymorphism in the base excision repair gene PARP2 is associated with differential prognosis by chemotherapy among postmenopausal breast cancer patients.

BACKGROUND: Personalized therapy considering clinical and genetic patient characteristics will further improve breast cancer survival. Two widely used treatments, chemotherapy and radiotherapy, can induce oxidative DNA damage and, if not repaired, cell death. Since base excision repair (BER) activity is specific for oxidative DNA damage, we hypothesized that germline genetic variation in this pathway will affect breast cancer-specific survival depending on treatment. METHODS: We assessed in 1,408 postmenopausal breast cancer patients from the German MARIE study whether cancer specific survival after adjuvant chemotherapy, anthracycline chemotherapy, and radiotherapy is modulated by 127 Single Nucleotide Polymorphisms (SNPs) in 21 BER genes. For SNPs with interaction terms showing p<0.1 (likelihood ratio test) using multivariable Cox proportional hazard analyses, replication in 6,392 patients from nine studies of the Breast Cancer Association Consortium (BCAC) was performed. RESULTS: rs878156 in PARP2 showed a differential effect by chemotherapy (p=0.093) and was replicated in BCAC studies (p=0.009; combined analysis p=0.002). Compared to non-carriers, carriers of the variant G allele (minor allele frequency=0.07) showed better survival after chemotherapy (combined allelic hazard ratio (HR)=0.75, 95% 0.53-1.07) and poorer survival when not treated with chemotherapy (HR=1.42, 95% 1.08-1.85). A similar effect modification by rs878156 was observed for anthracycline-based chemotherapy in both MARIE and BCAC, with improved survival in carriers (combined allelic HR=0.73, 95% CI 0.40-1.32). None of the SNPs showed significant differential effects by radiotherapy. CONCLUSIONS: Our data suggest for the first time that a SNP in PARP2, rs878156, may together with other genetic variants modulate cancer specific survival in breast cancer patients depending on chemotherapy. These germline SNPs could contribute towards the design of predictive tests for breast cancer patients.

Determinants of long-term fatigue in breast cancer survivors: results of a prospective patient cohort study.

OBJECTIVE: Fatigue is among the most distressing symptoms across the breast cancer continuum. However, little is known about the factors contributing to long-term persisting fatigue. Therefore, we explored determinants of long-term physical, affective, and cognitive fatigue in a prospective cohort of breast cancer patients. METHODS: Breast cancer patients recruited in a population-based case-control study (MARIE study) provided comprehensive data on sociodemographics, lifestyle, and preexisting medical conditions. At follow-up (median 6.3 years post-diagnosis, MARIEplus), disease-free cancer survivors (N = 1928) reported current fatigue using a validated multidimensional questionnaire. Additionally, survivors retrospectively rated their fatigue levels before diagnosis, during the treatment phase, and 1 year post-surgery. Linear regression analyses were performed. RESULTS: As major determinants of long-term physical, affective, and cognitive fatigue, multiple regression analyses revealed preexisting psychological or depressive disorders, migraine, analgesic use, peripheral arterial obstructive disease (PAOD), and arthritis. A physically inactive lifestyle and obesity were associated with persisting physical fatigue. Aromatase inhibitors were also associated with long-term fatigue, especially cognitive fatigue. Chemotherapy and, to a lower extent, radiotherapy were major contributors to the development of fatigue during the treatment phase, yet were not associated with long-term fatigue. CONCLUSIONS: Although the development of fatigue in breast cancer patients seems largely impacted by cancer therapy, for the long-term persistence of fatigue, preexisting medical or psychological conditions related to depression or pain and lifestyle factors appear to be more relevant. Physicians, psycho-oncologists, and researchers may need to distinguish between acute fatigue during therapy and long-term persisting fatigue with regard to its pathophysiology and treatment.

Genome-wide association study identifies 25 known breast cancer susceptibility loci as risk factors for triple-negative breast cancer.

Triple-negative (TN) breast cancer is an aggressive subtype of breast cancer associated with a unique set of epidemiologic and genetic risk factors. We conducted a two-stage genome-wide association study of TN breast cancer (stage 1: 1529 TN cases, 3399 controls; stage 2: 2148 cases, 1309 controls) to identify loci that influence TN breast cancer risk. Variants in the 19p13.1 and PTHLH loci showed genome-wide significant associations (P < 5 × 10(-) (8)) in stage 1 and 2 combined. Results also suggested a substantial enrichment of significantly associated variants among the single nucleotide polymorphisms (SNPs) analyzed in stage 2. Variants from 25 of 74 known breast cancer susceptibility loci were also associated with risk of TN breast cancer (P < 0.05). Associations with TN breast cancer were confirmed for 10 loci (LGR6, MDM4, CASP8, 2q35, 2p24.1, TERT-rs10069690, ESR1, TOX3, 19p13.1, RALY), and we identified associations with TN breast cancer for 15 additional breast cancer loci (P < 0.05: PEX14, 2q24.1, 2q31.1, ADAM29, EBF1, TCF7L2, 11q13.1, 11q24.3, 12p13.1, PTHLH, NTN4, 12q24, BRCA2, RAD51L1-rs2588809, MKL1). Further, two SNPs independent of previously reported signals in ESR1 [rs12525163 odds ratio (OR) = 1.15, P = 4.9 × 10(-) (4)] and 19p13.1 (rs1864112 OR = 0.84, P = 1.8 × 10(-) (9)) were associated with TN breast cancer. A polygenic risk score (PRS) for TN breast cancer based on known breast cancer risk variants showed a 4-fold difference in risk between the highest and lowest PRS quintiles (OR = 4.03, 95% confidence interval 3.46-4.70, P = 4.8 × 10(-) (69)). This translates to an absolute risk for TN breast cancer ranging from 0.8% to 3.4%, suggesting that genetic variation may be used for TN breast cancer risk prediction.

Circulating 25-hydroxyvitamin D and postmenopausal breast cancer survival: Influence of tumor characteristics and lifestyle factors?

We previously reported that lower post-diagnostic circulating 25-hydroxyvitamin D [25(OH)D] concentrations were associated with higher risk of overall mortality and distant disease in stage I-IV postmenopausal breast cancer survivors. This association was now re-examined in an extended dataset to investigate potential effect modification by tumor characteristics and lifestyle factors. A prospective cohort study was conducted in Germany including 2,177 incident stage I-IV postmenopausal breast cancer patients aged 50-74 years. Patients were diagnosed between 2001 and 2005 and median follow-up time was 5.3 years. Cox proportional hazards models were stratified by age at diagnosis, study center and season of blood collection and adjusted for other prognostic factors. A meta-analysis of studies on circulating 25(OH)D and mortality in breast cancer patients was performed to summarize evidence. Lower concentrations of 25(OH)D were significantly associated with higher risk of overall mortality [hazard ratio (HR) lowest vs. highest tertile = 1.86; 95% confidence interval (CI): 1.22, 2.82; p-trend = 0.002] and distant disease (HR = 1.76; 95% CI: 1.24, 2.49; p-trend = 0.003) in stage I-IIIa but not in stage IIIb-IV breast cancer patients. No significant interaction by lifestyle factors was observed (all p-interaction > 0.05). The meta-analysis yielded significant associations with overall and breast cancer-specific mortality (lowest vs. highest quantile: HR = 1.52; 95% CI: 1.22, 1.88 and HR = 1.74; 95% CI: 1.23, 2.40, respectively). In conclusion, post-diagnostic circulating 25(OH)D concentrations were associated with overall mortality and distant disease in stage I-IIIa postmenopausal breast cancer patients. This association was not strongly modified by lifestyle factors.

Enterolactone concentrations and prognosis after postmenopausal breast cancer: assessment of effect modification and meta-analysis.

We previously reported that high concentrations of enterolactone, a lignan metabolite, are associated with lower mortality in 1,140 breast cancer patients from Germany. Using an extended set of 2,182 patients aged 50-74 years at diagnosis (2001-2005) and prospectively followed up until 2009, we investigated whether the association with mortality differs by lifestyle factors and tumor characteristics. Hazard ratios (HR) and 95% confidence intervals (CI) were estimated using multivariable Cox regression. Potential differential effects by tumor characteristics and lifestyle factors were assessed and a meta-analysis of five studies addressing lignan exposure and breast cancer prognosis was performed to summarize evidence. Median enterolactone concentrations were 17.4 (± 30.5 standard deviation) and 22.9 nmol L(-1) (± 44.8), respectively, for 269 deceased and 1,913 patients still alive. High enterolactone concentrations were significantly associated with lower all-cause mortality (per 10 nmol L(-1) : HR 0.94, 95% CI 0.90-0.98), breast cancer-specific mortality (HR 0.94, 0.89-0.99), and distant disease-free survival (HR 0.94, 0.90-0.98). Associations were found for stage 0-IIIA but not for stage IIIB-IV disease (p(het) = 0.01) and were stronger in patients with BMI <25 kg m(-2) than those with BMI ≥ 25 (p(het) = 0.04). In patients with healthy lifestyle (BMI <25, nonsmoker, physically active), the inverse association with all-cause mortality was still apparent (HR 0.92, 0.85-0.99). The meta-analysis yielded significant associations both for all-cause (HR 0.57, 0.42-0.78) and breast cancer-specific mortality (HR 0.54, 0.39-0.75). Our findings show that high lignan exposure is associated with reduced mortality in breast cancer patients. The inverse association observed in this study cannot be entirely explained by a healthy lifestyle.

A meta-analysis of genome-wide association studies of breast cancer identifies two novel susceptibility loci at 6q14 and 20q11.

Genome-wide association studies (GWAS) of breast cancer defined by hormone receptor status have revealed loci contributing to susceptibility of estrogen receptor (ER)-negative subtypes. To identify additional genetic variants for ER-negative breast cancer, we conducted the largest meta-analysis of ER-negative disease to date, comprising 4754 ER-negative cases and 31 663 controls from three GWAS: NCI Breast and Prostate Cancer Cohort Consortium (BPC3) (2188 ER-negative cases; 25 519 controls of European ancestry), Triple Negative Breast Cancer Consortium (TNBCC) (1562 triple negative cases; 3399 controls of European ancestry) and African American Breast Cancer Consortium (AABC) (1004 ER-negative cases; 2745 controls). We performed in silico replication of 86 SNPs at P ≤ 1 × 10(-5) in an additional 11 209 breast cancer cases (946 with ER-negative disease) and 16 057 controls of Japanese, Latino and European ancestry. We identified two novel loci for breast cancer at 20q11 and 6q14. SNP rs2284378 at 20q11 was associated with ER-negative breast cancer (combined two-stage OR = 1.16; P = 1.1 × 10(-8)) but showed a weaker association with overall breast cancer (OR = 1.08, P = 1.3 × 10(-6)) based on 17 869 cases and 43 745 controls and no association with ER-positive disease (OR = 1.01, P = 0.67) based on 9965 cases and 22 902 controls. Similarly, rs17530068 at 6q14 was associated with breast cancer (OR = 1.12; P = 1.1 × 10(-9)), and with both ER-positive (OR = 1.09; P = 1.5 × 10(-5)) and ER-negative (OR = 1.16, P = 2.5 × 10(-7)) disease. We also confirmed three known loci associated with ER-negative (19p13) and both ER-negative and ER-positive breast cancer (6q25 and 12p11). Our results highlight the value of large-scale collaborative studies to identify novel breast cancer risk loci.

Evaluation of a questionnaire to assess selected infectious diseases and their risk factors : findings of a multicenter study.

BACKGROUND/OBJECTIVES: The risk to die from an infectious disease in Germany has been continuously decreasing over the last century. Since infections are, however, not only causes of death but risk factors for diseases like cardiovascular diseases, it is essential to monitor and analyze their prevalence and frequency, especially in consideration of the increased life expectancy. To gain more knowledge about infectious diseases as risk factors and their implications on the condition and change of the immune status, the German National Cohort (GNC), a population-based prospective cohort study, will recruit 200,000 subjects between 2014 and 2017. In Pretest 1, a feasibility study for the GNC, we evaluated a self-administered and self-report questionnaire on infectious diseases and on the use of health care facilities (hereinafter called "ID Screen") for feasibility and validity. METHODS: From August-November 2011, 435 participants between the ages of 20-69 completed the ID Screen. All subjects had been recruited via a random sample from the local residents' registration offices by 4 of the 18 participating study centers. The questionnaire encompasses 77 variables in six sections assessing items such as 12-month prevalence of infections, cumulative prevalence of infectious diseases, visit of health care facilities and vaccination. The feasibility was amongst others evaluated by assessing the completeness and comprehensiveness of the questionnaire. To assess the questionnaires ability to measure "immune status" and "susceptibility to infections", multivariate analysis was used. RESULTS: The overall practicability was good and most items were well understood, demonstrated by < 2/33 missing questions per questionnaire and only three variables: vaccination for influenza and pneumococci and infection with chickenpox had a frequency > 5 % of missing values. However, direct comparison of the items 12-month prevalence and lifetime prevalence of nephritis/pyelitis showed poor agreement and thereby poor understanding by 80 % of the participants, illustrating the necessity for a clear, lay person appropriate description of rare diseases to increase comprehensibility. The questionnaire will be used to support the assessment of immune dysfunction and frequency of infection. An analysis of these constructs in an exploratory factor analysis revealed limited applicability due to low interitem correlation (Cronbach's α < 0.5). This is corroborated by the extraction of more than one factor with a Kaiser-Meyer-Olkin measure of 0.6 instead of a unidimensional latent construct for "immune status". CONCLUSION: All in all, the ID Screen is a good and reliable tool to measure infectious diseases as risk factors and outcome in general, but requires a better translation of infection specific terms into lay person terms. For the assessment of the overall immune status, the tool has strong limitations. Vaccinations status should also rather be assessed based on vaccination certificates than on participants' recall.

Association of pre-diagnosis physical activity with recurrence and mortality among women with breast cancer.

Evidence is emerging that physical activity (PA) may improve overall survival after breast cancer diagnosis. However, the effect of PA on breast cancer recurrence and on cause-specific mortality is less investigated. We assessed the association of pre-diagnosis PA with recurrence, overall and cause-specific survival in a prospective cohort study in Germany including 3,393 non-metastatic breast cancer patients aged 50-74 years. Cox proportional hazards models were calculated adjusted for relevant prognostic factors. During a median follow-up of 5.6 years, 367 patients deceased. Overall mortality was significantly inversely associated with pre-diagnosis recreational PA. However, this effect was mainly attributed to deaths due to causes other than breast cancer. Multiple fractional polynomial analyses yielded a nonlinear association with markedly increased non-breast cancer mortality for women who did not engage in any sports or cycling in the years before the breast cancer diagnosis with a hazard ratio (HR, none vs. any) of 1.71, 95% confidence interval (1.16, 2.52). There were no further risk reductions with increasing activity levels. The association with breast cancer-specific mortality showed a similar dose-response but was far less pronounced with HR (none vs. any) = 1.22 (0.91, 1.64). In contrast, regarding cancer recurrence the dose-response was linear. However, this association was restricted to estrogen/progesterone receptor-negative (ER-/PR-) cases (p interaction = 0.033) with HR (highest vs. no recreational PA) = 0.53 (0.24, 1.16), p trend = 0.0045. Thus, breast cancer patients with a physically inactive lifestyle pre-diagnosis may decease prematurely irrespective of their cancer prognosis. Higher levels of exercise may reduce the risk of recurrence of ER-/PR- breast tumors.