Case-cohort Sample Research Articles

Pleiotropy between language impairment and broader behavioral disorders\u2014an investigation of both common and rare genetic variants

BackgroundLanguage plays a major role in human behavior. For this reason, neurodevelopmental and psychiatric disorders in which linguistic ability is impaired could have a big impact on the individual’s social interaction and general wellbeing. Such disorders tend to have a strong genetic component, but most past studies examined mostly the linguistic overlaps across these disorders; investigations into their genetic overlaps are limited. The aim of this study was to assess the potential genetic overlap between language impairment and broader behavioral disorders employing methods capturing both common and rare genetic variants.MethodsWe employ polygenic risk scores (PRS) trained on specific language impairment (SLI) to evaluate genetic overlap across several disorders in a large case-cohort sample comprising ~13,000 autism spectrum disorder (ASD) cases, including cases of childhood autism and Asperger’s syndrome, ~15,000 attention deficit/hyperactivity disorder (ADHD) cases, ~3000 schizophrenia cases, and ~21,000 population controls. We also examine rare variants in SLI/language-related genes in a subset of the sample that was exome-sequenced using the SKAT-O method.ResultsWe find that there is little evidence for genetic overlap between SLI and ADHD, schizophrenia, and ASD, the latter being in line with results of linguistic analyses in past studies. However, we observe a small, significant genetic overlap between SLI and childhood autism specifically, which we do not observe for SLI and Asperger’s syndrome. Moreover, we observe that childhood autism cases have significantly higher SLI-trained PRS compared to Asperger’s syndrome cases; these results correspond well to the linguistic profiles of both disorders. Our rare variant analyses provide suggestive evidence of association for specific genes with ASD, childhood autism, and schizophrenia.ConclusionsOur study provides, for the first time, to our knowledge, genetic evidence for ASD subtypes based on risk variants for language impairment.

Circulating vitamin D concentrations and breast cancer incidence among Black/African-American and non-Black Hispanic/Latina women

BACKGROUND AND AIM: Vitamin D has anti-carcinogenic properties and may protect against breast cancer. Although Black/African American women and Hispanic/Latina women have lower circulating vitamin D levels than non-Hispanic white women, few studies have examined the association between vitamin D and breast cancer within these racial/ethnic groups. Using a case-cohort sample of Black/African American and non-Black Hispanic/Latina women from the US-based Sister Study cohort, we estimated the association between circulating 25-hydroxyvitamin D [25(OH)D] and incident breast cancer. METHODS: We compared concentrations of circulating 25(OH)D in blood samples collected at baseline from 405 women (281 Black/African American, 124 non-Black Hispanic/Latina) who developed breast cancer to concentrations in 1,511 women (1,061 Black/African American, 450 non-Black Hispanic/Latina) randomly selected from the cohort. Participants were aged 35-74 years and had a sister previously diagnosed with breast cancer but no breast cancer themselves at enrollment (2003-2009). Race/ethnicity was self-identified and 25(OH)D and 24,25(OH)2D, a biomarker of vitamin D catabolism, were assessed using liquid chromatography/tandem mass spectrometry. We used multivariable-adjusted Cox proportional hazards models to estimate hazard ratios (HRs) and 95% confidence intervals (CIs). RESULTS:Over a mean follow-up period of 9.2 years, women with blood 25(OH)D concentrations greater than the median level for the sub-cohort (22.6 ng/mL) had lower breast cancer rates than women with concentrations 22.6 ng/mL (HR=0.76, 95% CI: 0.59-0.97). The inverse association appeared stronger among non-Black Hispanic/Latina women (HR=0.55, 95% CI: 0.34-0.88) than among Black/African American women (HR=0.88, 95% CI: 0.66-1.17; p-for-heterogeneity=0.08). We did not see clear differences in the association by menopausal status, time since blood draw, or according to tumor characteristics. Neither 24,25(OH)2D nor the 24,25(OH)2D to 25(OH)D ratio were associated with breast cancer risk. CONCLUSIONS:This prospective study provides further evidence that vitamin D may be inversely associated with breast cancer incidence in non-Black Hispanic/Latina and Black/African American women. KEYWORDS: Cancer and cancer precursors, Biomarkers of exposure, Environmental epidemiology, Environmental disparities, Molecular epidemiology

Pharmacogenetic genotype and phenotype frequencies in a large Danish population-based case-cohort sample

Pharmacogenetics aims to improve clinical care by studying the relationship between genetic variation and variable drug response. Large population-based datasets could improve our current understanding of pharmacogenetics from selected study populations. We provide real-world pharmacogenetic frequencies of genotypes and (combined) phenotypes of a large Danish population-based case-cohort sample (iPSYCH2012; data of the Integrative Psychiatric Research consortium). The genotyped sample consists of 77,684 individuals, of which 51,464 individuals had diagnoses of severe mental disorders (SMD case-cohort) and 26,220 were individuals randomly selected from the Danish population (population cohort). Array-based genotype data imputed to 8.4 million genetic variants was searched for a selected pharmacogenetic panel of 42 clinically relevant variants and a CYP2D6 gene deletion and duplication. We identified 19 of 42 variants. Minor allele frequencies (MAFs) were consistent with previously reported MAFs, and did not differ between SMD cases and population cohorts. Almost all individuals carried at least one genetic variant (> 99.9%) and 87% carried three or more genetic variants. When genotypes were translated into phenotypes, also > 99.9% of individuals had at least one divergent phenotype (i.e. divergent from the common phenotypes considered normal, e.g. extensive metabolizer). The high number of identified individuals with at least one pharmacogenetic variant or divergent phenotype indicates the importance of pharmacogenetic panel-based genotyping. Combined CYP2C19-CYP2D6 phenotypes revealed that 72.7% of individuals had divergent phenotypes for one or both enzymes. As CYP2D6 and CYP2C19 have an important role in the metabolism of psychotropic drugs, this indicates the relevance of pharmacogenetic testing specifically in individuals using psychotropic drugs.

Polygenic liability, stressful life events and risk for secondary-treated depression in early life: a nationwide register-based case-cohort study.

In this study, we examined the relationship between polygenic liability for depression and number of stressful life events (SLEs) as risk factors for early-onset depression treated in inpatient, outpatient or emergency room settings at psychiatric hospitals in Denmark. Data were drawn from the iPSYCH2012 case-cohort sample, a population-based sample of individuals born in Denmark between 1981 and 2005. The sample included 18 532 individuals who were diagnosed with depression by a psychiatrist by age 31 years, and a comparison group of 20 184 individuals. Information on SLEs was obtained from nationwide registers and operationalized as a time-varying count variable. Hazard ratios and cumulative incidence rates were estimated using Cox regressions. Risk for depression increased by 35% with each standard deviation increase in polygenic liability (p < 0.0001), and 36% (p < 0.0001) with each additional SLE. There was a small interaction between polygenic liability and SLEs (β = -0.04, p = 0.0009). The probability of being diagnosed with depression in a hospital-based setting between ages 15 and 31 years ranged from 1.5% among males in the lowest quartile of polygenic liability with 0 events by age 15, to 18.8% among females in the highest quartile of polygenic liability with 4+ events by age 15. These findings suggest that although there is minimal interaction between polygenic liability and SLEs as risk factors for hospital-treated depression, combining information on these two important risk factors could potentially be useful for identifying high-risk individuals.

Pharmacogenetics and adhd treatment outcomes in the danish population-based IPSYCH sample

IntroductionPharmacogenetics (PGx) studies genetic variance and related differences in drug outcomes. The aim of PGx testing is to increase therapy efficacy and safety, by applying e.g. dose adjustments in patients with a specific geno- or phenotype. PGx guidelines for psychotropic drugs are available (PGx drugs), including atomoxetine used in the treatment of attention deficit hyperactivity disorder (ADHD). In Denmark, broad implementation of PGx is currently still low, possibly due to the lack of population-based studies investigating the real-world impact of PGx variability.ObjectivesThe aim of this study is to investigate the association of PGx variability (patients’ genotype/phenotype) in users of atomoxetine and different treatment outcomes in a large population-based sample of individuals with ADHD.MethodsThis study will use data of the large Danish population-based iPSYCH case-cohort study sample including information on genetic variants, prescription drug use and outcome data, e.g. psychiatric and somatic hospitalizations and death. The study population comprises all individuals diagnosed with ADHD born 1981-2005 with at least one prescription for atomoxetine between 1995 and 2016. All individuals will be categorized according to their CYP2D6 phenotypes. We will perform Cox regression analysis to estimate the hazard ratios comparing the rates of the different outcomes in people with different phenotypes adjusted for a number of confounding factors.ResultsWe have identified approximately 20,000 individuals with ADHD, of whom an estimated 10-20% have filled at least one prescription of atomoxetine.ConclusionsWe expect results in the beginning of 2021.DisclosureWe thank the iPSYCH consortium, in specific the iPSYCH PI’s (Merete Nordentoft, Anders Børglum, Preben B. Mortensen, Ole Mors, Thomas Werge and David M. Hougaard). The iPSYCH project is funded by the Lundbeck Foundation Denmark and the universities and un

Cell cycle progression score and PTEN as prognostic factors for metastasis in intermediate- and high-risk prostate cancer overall, and in those who also received salvage radiotherapy.

247 Background: The cell cycle progression (CCP) score and PTEN have never been evaluated together as prognostic markers for risk of metastasis in a radical prostatectomy (RP) cohort of men with National Comprehensive Cancer Network intermediate- and high-risk prostate cancer (PCa), nor in such patients who also received salvage radiation (SRT) alone or with androgen deprivation (SRT+ADT). This study evaluated CCP score and PTEN in both settings. Methods: Participants were treated with RP at Johns Hopkins from 2007-2015. Paraffin-embedded RP tissue was analyzed blind to clinical outcome at Myriad Genetics, for CCP score using qRT-PCR, and PTEN by immunohistochemistry. For overall evaluation of CCP and PTEN in intermediate- and high-risk men a case-cohort sample was selected. Intermediate- and high-risk men with biochemical recurrence who received SRT or SRT+ADT were also sampled to provide a population at particularly high risk. Metastasis-free survival (MFS) was analyzed with the proportional hazards model, weighted for case-cohort design for the overall analysis, and adjusted for CAPRA-S. The clinical cell-cycle risk (CCR) score, a fixed algorithm combining CCP and CAPRA-S was also analyzed in both contexts. Data were analyzed independently by Johns Hopkins and Myriad Genetics. Results: The case-cohort consisted of 209 men, including 47% with Gleason score &gt;4+3, 48% extra-prostatic extension, and 18% with seminal vesicle or lymph node involvement; 42 (20%) developed metastasis. In univariate analyses CCP, CAPRA-S, and PTEN were all highly significant. In multivariable analysis, only CCP and CAPRA-S retained significance (Table section A). CCR was also strongly prognostic, HR=7.9 (95% CI 4.4, 14.5) per unit change, p&lt;0.00001. SRT (56%) or SRT+ADT (44%) were received by 172 men, of whom 78% had Gleason &gt;4+3, 48% extra-prostatic extension, and 34% seminal vesicle or lymph node involvement; 19 (11%) developed metastases. Again, CCP and CAPRA-S, but not PTEN, were statistically significant (Table section B). CCR was also statistically significant, HR=1.7 (95% CI 1.2, 2.4), p=0.002. Conclusions: This is the first comparison, in a recent cohort of intermediate- and high-risk men, of CCP score and PTEN as risk factors for metastasis, and first evaluation in such men receiving SRT. In both multivariable settings, CCP score, but not PTEN, was significantly associated with MFS, adjusted for CAPRA-S. CCR, a fixed algorithm that combines CCP and CAPRA-S was also significant in both settings. [Table: see text]

Association Between Serum Iron Biomarkers and Breast Cancer.

Iron is both essential to life and potentially toxic at higher levels. Epidemiologic studies of iron and breast cancer are sparse, with substantial heterogeneity found in a recent meta-analysis. Evidence based on a comprehensive set of iron biomarkers and a large sample size could help clarify relationships between iron body stores and breast cancer risk. A case-cohort sample of 6,008 women, including 3,011 incident cases, has been followed for a median of 7.9 years. We estimated breast cancer HRs with Cox models, including age as the primary time scale and including in turn iron, ferritin, percent transferrin saturation, and their first principal component (PC) both as categorical (quartiles) and continuous measures. Adjusted HRs for the highest versus lowest quartiles of iron, ferritin, and transferrin saturation (95% confidence interval) were 1.06 (0.90-1.25), 1.03 (0.87-1.23), and 0.94 (0.80-1.12), respectively, and 1.06 (0.90-1.25) for the first principal component (PC). Associations were similar when follow-up time was restricted to ≤4 or >2 years. Post hoc analyses suggested low iron stores were associated with reduced breast cancer risk, in both pre- and postmenopause and the obese. A study with one of the largest sample sizes to date and with all three measures of circulating iron, ferritin, and transferrin saturation does not support a strong association between elevated iron stores and breast cancer risk. Further investigation of low iron may be warranted. These results do not support a strong association between iron overload and breast cancer incidence.

Risk of Early-Onset Depression Associated With Polygenic Liability, Parental Psychiatric History, and Socioeconomic Status

Combining information on polygenic risk scores (PRSs) with other known risk factors could potentially improve the identification of risk of depression in the general population. However, to our knowledge, no study has estimated the association of PRS with the absolute risk of depression, and few have examined combinations of the PRS and other important risk factors, including parental history of psychiatric disorders and socioeconomic status (SES), in the identification of depression risk. To assess the individual and joint associations of PRS, parental history, and SES with relative and absolute risk of early-onset depression. This case-cohort study included participants from the iPSYCH2012 sample, a case-cohort sample of all singletons born in Denmark between May 1, 1981, and December 31, 2005. Hazard ratios (HRs) and absolute risks were estimated using Cox proportional hazards regression for case-cohort designs. The PRS for depression; SES measured using maternal educational level, maternal marital status, and paternal employment; and parental history of psychiatric disorders (major depression, bipolar disorder, other mood or psychotic disorders, and other psychiatric diagnoses). Hospital-based diagnosis of depression from inpatient, outpatient, or emergency settings. Participants included 17 098 patients with depression (11 748 [68.7%] female) and 18 582 (9429 [50.7%] male) individuals randomly selected from the base population. The PRS, parental history, and lower SES were all significantly associated with increased risk of depression, with HRs ranging from 1.32 (95% CI, 1.29-1.35) per 1-SD increase in PRS to 2.23 (95% CI, 1.81-2.64) for maternal history of mood or psychotic disorders. Fully adjusted models had similar effect sizes, suggesting that these risk factors do not confound one another. Absolute risk of depression by the age of 30 years differed substantially, depending on an individual's combination of risk factors, ranging from 1.0% (95% CI, 0.1%-2.0%) among men with high SES in the bottom 2% of the PRS distribution to 23.7% (95% CI, 16.6%-30.2%) among women in the top 2% of PRS distribution with a parental history of psychiatric disorders. This study suggests that current PRSs for depression are not more likely to be associated with major depressive disorder than are other known risk factors; however, they may be useful for the identification of risk in conjunction with other risk factors.

Proportional Subdistribution Hazards Model for Competing Risks in Case-Cohort Studies

Competing risks refer to the situation where there are multiple causes of failure and the occurrence of one type of event prohibits the occurrence of the other types of event or alters the chance to observe them. In large cohort studies with long-term follow-up, there are often competing risks. When the failure events are rare, or the information on certain risk factors is difficult or costly to measure for the full cohort, a case-cohort study design can be a desirable approach. In this paper, we consider a semiparametric proportional subdistribution hazards model in the presence of competing risks in case-cohort studies. The subdistribution hazards function, unlike the cause-specific hazards function, gives the advantage of outlining the marginal probability of a particular type of event. We propose estimating equations based on inverse probability weighting techniques for the estimation of the model parameters. In the estimation methods, we considered a weighted availability indicator to properly account for the case-cohort sampling scheme. We also proposed a Breslow-type estimator for the cumulative baseline subdistribution hazard function. The resulting estimators are shown, using empirical processes and martingale properties, to be consistent and asymptotically normally distributed. The performance of the proposed methods in finite samples are examined through simulation studies by considering different levels of censoring and event of interest percentages. The simulation results from the different scenarios suggest that the parameter estimates are reasonably close to the true values of the respective parameters in the model. Finally, the proposed estimation methods are applied to a case-cohort sample from the Sister Study, in which we illustrated the proposed methods by studying the association between selected CpGs and invasive breast cancer in the presence of ductal carcinoma in situ as competing risk.

Endothelial dysfunction and the risk of heart failure in a community-based study: the Multi-Ethnic Study of Atherosclerosis.

AimsWe aimed to investigate the association between endothelial dysfunction, assessed by brachial flow‐mediated dilation (FMD), and the incidence of heart failure (HF) in the community‐based Multi‐Ethnic Study of Atherosclerosis.Methods and resultsBrachial artery FMD was measured in a nested case‐cohort sample including 3496 of 6814 Multi‐Ethnic Study of Atherosclerosis participants without prevalent cardiovascular disease (mean age 61 years, 50% women). Multivariable probability‐weighted Cox proportional hazards analysis was used to examine the association between FMD and incident HF. We also investigated the association between FMD and HF with reduced vs. preserved ejection fraction [HFrEF (left ventricular ejection fraction <45%) vs. HFpEF (left ventricular ejection fraction ≥45%)]. During follow‐up (median 12 years), 149 participants developed incident HF (incidence rate 3.7 events per 1000 person years). There were 56 HFrEF and 69 HFpEF events (incidence rates 1.4 and 1.7 events per 1000 person years, respectively). In multivariable models adjusted for established HF risk factors (age, sex, race/ethnicity, body mass index, systolic blood pressure, antihypertensive treatment, heart rate, diabetes mellitus, history of myocardial infarction, current smoker, and former smoker status), individuals in the highest quartile of FMD (reflecting better endothelial function) had a lower HF risk compared with individuals in the lowest quartile [hazard ratio 0.53, 95% confidence interval (CI) 0.31–0.95]. Lower risk according to higher FMD was particularly evident for HFrEF, but not for HFpEF (hazard ratio per standard deviation increase 0.79, 95% CI 0.64–0.97 vs. 0.99, 95% CI 0.78–1.26, respectively). Results remained similar after adjustment for baseline natriuretic peptide levels. The addition of FMD to established HF risk factors generally rendered no or only modest improvement in C‐statistics [C‐statistics for model with established HF risk factors: 0.774, and with the addition of FMD: 0.776 (delta C 0.002, 95% confidence interval −0.002 to 0.006)].ConclusionsEndothelial dysfunction was independently associated with HF in this community cohort, suggesting a pathophysiological contribution of endothelial function to the development of HF, in particular HFrEF. However, the value of FMD measurements for HF risk prediction seems limited.

Bone Turnover Markers Do Not Predict Fracture Risk in Type 2 Diabetes.

Type 2 diabetes (T2D) is characterized by increased fracture risk despite higher BMD and reduced bone turnover. BMD underestimates fracture risk in T2D, but the predictive role of bone turnover markers (BTMs) on fracture risk in T2D has not been explored. Thus, we sought to determine whether BTMs predict incident fractures in subjects with T2D. For this case-cohort study, we used data from the Health, Aging, and Body Composition (Health ABC) Study of well-functioning older adults, aged 70 to 79 years at baseline (April 1997-June 1998). The case-cohort sample consisted of (i) the cases, composed of all 223 participants who experienced incident fractures of the hip, clinical spine, or distal forearm within the first 9 years of study follow-up; and (ii) the subcohort of 508 randomly sampled participants from three strata at baseline (T2D, prediabetes, and normoglycemia) from the entire Health ABC cohort. A total of 690 subjects (223 cases, of whom 41 were in the subcohort) were included in analyses. BTMs (C-terminal telopeptide of type I collagen [CTX], osteocalcin [OC], and procollagen type 1 N-terminal propeptide [P1NP]) were measured in archived baseline serum. Cox regression with robust variance estimation was used to estimate the adjusted hazard ratio (HR) for fracture per 20% increase in BTMs. In nondiabetes (prediabetes plus normoglycemia), fracture risk was increased with higher CTX (HR 1.10; 95% confidence interval [CI], 1.01 to 1.20 for each 20% increase in CTX). Risk was not increased in T2D (HR 0.92; 95% CI, 0.81 to 1.04; p for interaction .045). Similarly, both OC and P1NP were associated with higher risk of fracture in nondiabetes, but not in T2D, with p for interaction of .078 and .109, respectively. In conclusion, BTMs did not predict incident fracture risk in T2D but were modestly associated with fracture risk in nondiabetes. © 2020 American Society for Bone and Mineral Research.

Genetic factors underlying the bidirectional relationship between autoimmune and mental disorders – Findings from a Danish population-based study

BackgroundPrevious studies have indicated the bidirectionality between autoimmune and mental disorders. However, genetic studies underpinning the co-occurrence of the two disorders have been lacking. In this study, we examined the potential genetic contribution to the association between autoimmune and mental disorders and investigated the genetic basis of overall autoimmune disease. MethodsWe used diagnostic information from patients with seven autoimmune diseases and six mental disorders from the Danish population-based case-cohort sample (iPSYCH2012). We explored the epidemiological association using survival analysis and modelled the effect of polygenic risk scores (PRSs) on autoimmune and mental diseases. Genetic factors were investigated using GWAS and imputed HLA alleles in the iPSYCH cohort. ResultsOf 64,039 individuals, a total of 43,902 (68.6%) were diagnosed with mental disorders and 1383 (2.2%) with autoimmune diseases. There was a significant comorbidity between the two disease classes (P = 2.67 × 10−7, OR = 1.38, 95%CI = 1.22–1.56), with an overall bidirectional association, wherein individuals with autoimmune diseases had an increased risk of subsequent mental disorders (HR = 1.13, 95%CI: 1.07–1.21, P = 7.95 × 10−5) and vice versa (HR = 1.27, 95%CI = 1.16–1.39, P = 8.77 × 10−15). Adding PRSs to these adjustment models did not have an impact on the associations. PRSs for autoimmune diseases were only slightly associated with increased risk of mental disorders (HR = 1.01, 95%CI: 1.00–1.02, p = 0.038), whereas PRSs for mental disorders were not associated with autoimmune diseases overall. Our GWAS highlighted 12 loci on chromosome 6 (minimum P = 2.74 × 10−36, OR = 1.80, 95% CI: 1.64–1.96), which were implicated in gene regulation through bioinformatic functional analyses, thereby identifying new candidate genes for overall autoimmune disease. Moreover, we observed 20 human leukocyte antigen (HLA) alleles strongly associated, either positively or negatively, with overall autoimmune disease, but we did not find significant evidence of their associations with overall mental disorders. A GWAS of a comorbid diagnosis of an autoimmune disease and a mental disorder identified a genome-wide significant locus on chromosome 7 as well (P = 1.43 × 10−8, OR = 10.65, 95%CI = 3.21–35.36). ConclusionsOur findings confirm the overall comorbidity and bidirectionality between autoimmune diseases and mental disorders and identify HLA genes which are significantly associated with overall autoimmune disease. Additionally, we identified several new candidate genes for overall autoimmune disease and ranked them based on their association with the investigated diseases.

Genetic liability to ADHD and substance use disorders in individuals with ADHD.

1) To investigate whether genetic liability to attention-deficit/hyperactivity disorder (ADHD), indexed by polygenic risk scores for ADHD (PRS-ADHD), is associated with substance use disorders (SUD) in individuals with ADHD. 2) To investigate whether other individual- or family-related risk factors for SUD could mediate or confound this association. Population-based cohort study SETTING AND PARTICIPANTS: ADHD cases in the iPSYCH sample (a Danish case-cohort sample of genotyped cases with specific mental disorders), born in Denmark between 1981 and 2003 (N=13 116). Register-based information on hospital diagnoses of SUD was available until December 31, 2016. We estimated odds ratios (ORs) with 95% confidence intervals (CIs) for any SUD as well as for different SUD types (alcohol, cannabis, and other illicit drugs) and severities (use, abuse, and addiction), with effect sizes corresponding to a comparison of the highest PRS-ADHD decile to the lowest. PRS-ADHD were associated with any SUD (OR=1.30, 95% CI: 1.11-1.51). Estimates were similar across different types and severity levels of SUD. Other risk factors for SUD (male sex, age at ADHD diagnosis, comorbid conduct problems, and parental factors including SUD, mental disorders, and socio-economic status) were independently associated with increased risk of SUD. PRS-ADHD explained a minor proportion of the variance in SUD (0.2% on the liability scale) compared to the other risk factors. The association between PRS-ADHD and any SUD was slightly attenuated (OR=1.21, 95% CI: 1.03-1.41) after adjusting for the other risk factors for SUD. Furthermore, associations were nominally higher in females than in males (ORfemales =1.59, 95% CI: 1.19-2.12, ORmales =1.18, 95% CI: 0.98-1.42). A higher genetic liability to attention-deficit/hyperactivity disorder appears to be associated with higher risks of substance use disorders in individuals with attention-deficit/hyperactivity disorder.

Independent Validation of EarlyR Gene Signature in BIG 1-98: A Randomized, Double-Blind, Phase III Trial Comparing Letrozole and Tamoxifen as Adjuvant Endocrine Therapy for Postmenopausal Women With Hormone Receptor-Positive, Early Breast Cancer.

BackgroundEarlyR gene signature in estrogen receptor–positive (ER+) breast cancer is computed from the expression values of ESPL1, SPAG5, MKI67, PLK1, and PGR. EarlyR has been validated in multiple cohorts profiled using microarrays. This study sought to verify the prognostic features of EarlyR in a case-cohort sample from BIG 1–98, a randomized clinical trial of ER+ postmenopausal breast cancer patients treated with adjuvant endocrine therapy (letrozole or tamoxifen).MethodsExpression of EarlyR gene signature was estimated by Illumina cDNA-mediated Annealing, Selection, and Ligation assay of RNA from formalin-fixed, paraffin-embedded primary breast cancer tissues in a case-cohort subset of ER+ women (N = 1174; 216 cases of recurrence within 8 years) from BIG 1–98. EarlyR score and prespecified risk strata (≤25 = low, 26–75 = intermediate, >75 = high) were “blindly” computed. Analysis endpoints included distant recurrence–free interval and breast cancer–free interval at 8 years after randomization. Hazard ratios (HRs) and test statistics were estimated with weighted analysis methods.ResultsThe distribution of the EarlyR risk groups was 67% low, 19% intermediate, and 14% high risk in this ER+ cohort. EarlyR was prognostic for distant recurrence–free interval; EarlyR high-risk patients had statistically increased risk of distant recurrence within 8 years (HR = 1.73, 95% confidence interval = 1.14 to 2.64) compared with EarlyR low-risk patients. EarlyR was also prognostic of breast cancer–free interval (HR = 1.74, 95% confidence interval = 1.21 to 2.62).ConclusionsThis study confirmed the prognostic significance of EarlyR using RNA from formalin-fixed, paraffin-embedded tissues from a case-cohort sample of BIG 1–98. EarlyR identifies a set of high-risk patients with relatively poor prognosis who may be considered for additional treatment. Further studies will focus on analyzing the predictive value of EarlyR signature.

Pre-diagnostic derivatives of reactive oxygen metabolites and the occurrence of lung, colorectal, breast and prostate cancer: An individual participant data meta-analysis of two large population-based studies.

Oxidative stress may be involved in carcinogenesis and biomarkers of oxidative stress like derivatives of reactive oxygen metabolites (d-ROM) may be useful for cancer prediction. However, no previous study assessed the association of pre-diagnostic d-ROM measurements with cancer incidence. We measured serum d-ROM levels in a cohort sample of n = 4,345 participants of the German ESTHER study and in a case-cohort sample of the Norwegian Tromsø study (cancer cases: n = 941; subcohort: n = 1,000). Moreover, d-ROM was repeatedly measured at follow-ups of both studies. Hazard ratios (HRs) and 95% confidence intervals (95% CIs) were derived by (weighted) multivariable-adjusted Cox regression with time-dependent modeling of d-ROM levels for incident lung, colorectal, breast and prostate cancer. Individual study results were pooled by random effects meta-analysis. The HRs (95% CI) for comparison of top and bottom d-ROM tertile were statistically significant for lung (1.90 [1.25-2.89]), colorectal (1.70 [1.15-2.51]) and breast cancer incidence (1.45 [1.01-2.09]) but not for prostate cancer incidence (1.20 [0.84-1.72]). In conclusion, this individual participant data meta-analysis of two large population-based cohort studies with repeated d-ROM measurements yielded evidence for an involvement of high oxidative stress in carcinogenesis. Given the observed associations of pre-diagnostic d-ROM measurements with lung, colorectal and breast cancer incidence, subjects with increased serum d-ROM levels should be recommended to reduce these levels by lifestyle changes including smoking cessation, a healthy diet and an increase in physical activity.

Inference on treatment effect modification by biomarker response in a three-phase sampling design.

An objective in randomized clinical trials is the evaluation of "principal surrogates," which consists of analyzing how the treatment effect on a clinical endpoint varies over principal strata subgroups defined by an intermediate response outcome under both or one of the treatment assignments. The latter effect modification estimand has been termed the marginal causal effect predictiveness (mCEP) curve. This objective was addressed in two randomized placebo-controlled Phase 3 dengue vaccine trials for an antibody response biomarker whose sampling design rendered previously developed inferential methods highly inefficient due to a three-phase sampling design. In this design, the biomarker was measured in a case-cohort sample and a key baseline auxiliary strongly associated with the biomarker (the "baseline surrogate measure") was only measured in a further sub-sample. We propose a novel approach to estimation of the mCEP curve in such three-phase sampling designs that avoids the restrictive "placebo structural risk" modeling assumption common to past methods and that further improves robustness by the use of non-parametric kernel smoothing for biomarker density estimation. Additionally, we develop bootstrap-based procedures for pointwise and simultaneous confidence intervals and testing of four relevant hypotheses about the mCEP curve. We investigate the finite-sample properties of the proposed methods and compare them to those of an alternative method making the placebo structural risk assumption. Finally, we apply the novel and alternative procedures to the two dengue vaccine trial data sets.

Vitamin D, DNA methylation, and breast cancer

BackgroundVitamin D has anticarcinogenic and immune-related properties and may protect against some diseases, including breast cancer. Vitamin D affects gene transcription and may influence DNA methylation.MethodsWe studied the relationships between serum vitamin D, DNA methylation, and breast cancer using a case-cohort sample (1070 cases, 1277 in subcohort) of non-Hispanic white women. For our primary analysis, we used robust linear regression to examine the association between serum 25-hydroxyvitamin D (25(OH)D) and methylation within a random sample of the cohort (“subcohort”). We focused on 198 CpGs in or near seven vitamin D-related genes. For these 198 candidate CpG loci, we also examined how multiplicative interactions between methylation and 25(OH)D were associated with breast cancer risk. This was done using Cox proportional hazards models and the full case-cohort sample. We additionally conducted an exploratory epigenome-wide association study (EWAS) of the association between 25(OH)D and DNA methylation in the subcohort.ResultsOf the CpGs in vitamin D-related genes, cg21201924 (RXRA) had the lowest p value for association with 25(OH)D (p = 0.0004). Twenty-two other candidate CpGs were associated with 25(OH)D (p < 0.05; RXRA, NADSYN1/DHCR7, GC, or CYP27B1). We observed an interaction between 25(OH)D and methylation at cg21201924 in relation to breast cancer risk (ratio of hazard ratios = 1.22, 95% confidence interval 1.10–1.34; p = 7 × 10−5), indicating a larger methylation-breast cancer hazard ratio in those with high serum 25(OH)D concentrations. We also observed statistically significant (p < 0.05) interactions for six other RXRA CpGs and CpGs in CYP24A1, CYP27B1, NADSYN1/DHCR7, and VDR. In the EWAS of the subcohort, 25(OH)D was associated (q < 0.05) with methylation at cg24350360 (EPHX1; p = 3.4 × 10−8), cg06177555 (SPN; p = 9.8 × 10−8), and cg13243168 (SMARCD2; p = 2.9 × 10−7).Conclusions25(OH)D concentrations were associated with DNA methylation of CpGs in several vitamin D-related genes, with potential links to immune function-related genes. Methylation of CpGs in vitamin D-related genes may interact with 25(OH)D to affect the risk of breast cancer.

Lipoprotein(a) and Cardiovascular Risk Prediction Among Women

BackgroundAlthough lipoprotein(a) [Lp(a)] is associated with incident cardiovascular disease (CVD), its contribution to prediction remains controversial. ObjectivesThis study examined the association and clinical utility of Lp(a) with incident CVD in women. MethodsA turbidimetric assay assessed Lp(a) in 3 cohorts of women (the WHS [Women’s Health Study] [N = 24,558], a case-cohort sample from the WHI [Women’s Health Initiative] Observational Study [n = 1,815 cases, subcohort n = 1,989], and the JUPITER [Justification for Use of Statins in Prevention] trial [n = 2,569]) and in men from JUPITER (n = 5,161). A WHS derivation sample (n = 16,400) determined the form of association with incident CVD. This was tested in WHS validation data (n = 8,158) and the other study samples. Models including traditional CV risk factors but with and without Lp(a) were compared using risk reclassification. ResultsIn the WHS, there was a curvilinear association, with increased CVD risk among those with Lp(a) >50 mg/dl, but only among women with total cholesterol (TC) >220 mg/dl. In the WHS test sample, there was a small but significant change in the C-statistic (0.790 to 0.797; p = 0.035) but no improvement in measures of reclassification. This pattern was replicated among women in the WHI and JUPITER trial. In contrast, there was a strong association of Lp(a) with CVD among men with low TC levels in JUPITER. ConclusionsIn 3 cohorts of women, Lp(a) was associated with CVD only among those with high TC, and improvement in prediction was minimal. These data have implications for Lp(a) in clinical practice among women and for trials of Lp(a)-lowering agents.

Biomarkers Associated with Death After Initiating Treatment for Tuberculosis and HIV in Patients with Very Low CD4 Cells.

Background:The risk of short-term death for treatment naive patients dually infected with Myco-bacterium tuberculosis and HIV may be reduced by early anti-retroviral therapy. Of those dying, mechanisms responsible for fatal outcomes are unclear. We hypothesized that greater malnutrition and/or inflammation when initiating treatment are associated with an increased risk for death.Methods:We utilized a retrospective case-cohort design among participants of the ACTG A5221 study who had baseline CD4 < 50 cells/mm3. The case-cohort sample consisted of 51 randomly selected participants, whose stored plasma was tested for C-reactive protein, cytokines, chemokines, and nutritional markers. Cox proportional hazards models were used to assess the association of nutritional, inflammatory, and immunomodulatory markers for survival.Results:The case-cohort sample was similar to the 282 participants within the parent cohort with CD4 <50 cells/mm3. In the case cohort, 7 (14%) had BMI < 16.5 (kg/m2) and 17 (33%) had BMI 16.5-18.5(kg/m2). Risk of death was increased per 1 IQR width higher of log10 transformed level of C-reactive protein (adjusted hazard ratio (aHR) = 3.42 [95% CI = 1.33-8.80], P = 0.011), inter-feron gamma (aHR = 2.46 [CI = 1.02-5.90], P = 0.044), MCP-3 (3.67 [CI = 1.08-12.42], P = 0.037), and with IL-15 (aHR = 2.75 [CI = 1.08-6.98], P = 0.033) and IL-17 (aHR = 3.99 [CI = -1.06-15.07], P = 0.041). BMI, albumin, hemoglobin, and leptin levels were not associated with risk of death.Conclusions:Unlike patients only infected with M. tuberculosis for whom malnutrition and low BMI increase the risk of death, this relationship was not evident in our dually infected patients. Risk of death was associated with significant increases in markers of global inflammation along with soluble biomarkers of innate and adaptive immunity.

Iron status in relation to cancer risk and mortality: Findings from a population‐based prospective study

While experimental evidence suggests potential carcinogenic effects of increased iron load, there is a lack of data on iron status and cancer risk from epidemiological studies. Here, we evaluated prediagnostic serum concentrations of ferritin, iron and transferrin as well as transferrin saturation (TSAT) in relation to cancer risk and mortality in a prospective study by multivariable Cox regression analyses. A case-cohort sample of the population-based EPIC-Heidelberg Study including a random subcohort (n = 2738) and incident cases of breast cancer (n = 627), prostate cancer (n = 554), lung cancer (n = 195), colorectal cancer (n = 256) and cancer death (n = 759) was used. Ferritin levels were inversely associated with breast cancer risk in the multivariable Cox regression model, with a hazard ratio (HR) of 0.67 [95% confidence interval: 0.49, 0.92] for women in the highest quartile compared to those in the lowest quartile. Neither ferritin nor the other markers of iron status were significantly associated with colorectal, prostate or lung cancer risk. An inverse association was observed between ferritin and total cancer mortality (HR: 0.70 [0.53, 0.92]). There were no significant overall associations between serum iron, transferrin or TSAT and cancer mortality. The present findings do not support the notion of increased iron load constituting a cancer risk factor in the general population. By contrast, our analyses revealed inverse associations between ferritin levels and breast cancer risk as well as cancer mortality.