Examining breast cancer growth and lifestyle risk factors: early life, childhood, and adolescence

Synthesis and antiproliferative evaluation of novel 3,5,8-trisubstituted coumarins against breast cancer

Aim: This study focused on designing and synthesizing novel derivatives of 3,5,8-trisubstituted coumarin. Results: The synthesized compounds, particularly compound 5, exhibited significant cytotoxic effects on MCF-7 cells, surpassing staurosporine, and reduced toxicity toward MCF-10A cells, highlighting potential pharmacological advantages. Further, compound 5 altered the cell cycle and significantly increased apoptosis in MCF-7 cells, involving both early (41.7-fold) and late stages (33-fold), while moderately affecting necrotic signaling. The antitumor activity was linked to a notable reduction (4.78-fold) in topoisomerase IIβ expression. Molecular modeling indicated compound 5's strong affinity for EGFR, human EGF2 and topoisomerase II proteins. Conclusion: These findings highlight compound 5 as a multifaceted antitumor agent for breast cancer.

Breast composition during and after puberty: the Chilean Growth and Obesity Cohort Study

BACKGROUND

Breast density (BD) is a strong risk factor for breast cancer. Little is known about how BD develops during puberty. Understanding BD trajectories during puberty and its determinants could be crucial for promoting preventive actions against breast cancer (BC) at early ages. The objective of this research is to characterize % fibroglandular volume (%FGV), absolute fibroglandular volume (AFGV), and breast volume (BV) at different breast Tanner stages until 4-year post menarche in a Latino cohort and to assess determinants of high %FGV and AFGV during puberty and in a fully mature breast.

METHODS

This is a longitudinal follow-up of 509 girls from low-middle socioeconomic status of the Southeast area of Santiago, recruited at a mean age of 3.5 years. The inclusion criteria were singleton birth born, birthweight between 2500 and 4500 g with no medical or mental disorder. A trained dietitian measured weight and height since 3.5 years old and sexual maturation from 8 years old (breast Tanner stages and age at menarche onset). Using standardized methods, BD was measured using dual-energy X-ray absorptiometry (DXA) in various developmental periods (breast Tanner stage B1 until 4 years after menarche onset).

RESULTS

In the 509 girls, we collected 1,442 breast DXA scans; the mean age at Tanner B4 was 11.3 years. %FGV increased across breast Tanner stages and peaked 250 days after menarche. AFGV and BV peaked 2 years after menarche onset. Girls in the highest quartiles of %FGV, AFGV, and BV at Tanner B4 and B5 before menarche onset had the highest values thereafter until 4 years after menarche onset. The most important determinants of %FGV and AFGV variability were BMI z-score (R2 = 44%) and time since menarche (R2 = 42%), respectively.

CONCLUSION

We characterize the breast development during puberty, a critical window of susceptibility. Although the onset of menarche is a key milestone for breast development, we observed that girls in the highest quartiles of %FGV and AFGV tracked in that group afterwards. Following these participants in adulthood would be of interest to understand the changes in breast composition during this period and its potential link with BC risk.

Investigating the Relationship between Birthweight and Breast Cancer from A Non-Linear and Mediation Perspective

Background

Epidemiological studies have shown a positive relationship between birthweight and breast cancer; however, inconsistent, sometimes even controversial, observations emerged. We re-explored the association between them in the UK Biobank cohort.

Methods

Relying on the UK Biobank cohort data of white British volunteers recruited between 2006 and 2010 (5,760 cases and 162,778 controls), we evaluated the causal mediation between birthweight and breast cancer, with age of menarche and age at menopause as two potential mediators under the traditional mediation analysis framework. The non-linear relationship between birthweight and breast cancer was also investigated by including the square of birthweight or discretized birthweight categories (<2.5, 2.5~4.0, or >4.0). Furthermore, we performed a stratification analysis in terms of the menopause status.

Results

Birthweight can indirectly influence breast cancer risk in adulthood via the path of age of menarche or age at menopause, and found statistical evidence supporting the existence of suggestive non-linear association between birthweight and breast cancer (β=0.062 and P=0.004 for the square of birthweight) although failing to discover a linear relationship (P=0.230). We also demonstrated such non-linear association seemed more pronounced and robust for premenopausal women compared with postmenopausal ones (27.5% vs. 19.5% increase in breast cancer risk).

Conclusion

This study provided an in-depth insight into the observed relationship between birthweight and breast cancer and revealed that non-linear impact and causal mediation commonly drive the connection between the two traits.

Adolescent- and adult-initiated alcohol exposure in mice differentially promotes tumorigenesis and metastasis of breast cancer

BACKGROUND

Alcohol exposure increases the risk of breast cancer. Alcohol consumption by adolescents is a serious social and public health issue. This study investigated the impact of adolescent alcohol consumption on mammary tumorigenesis and progression and compared it to that of adult alcohol exposure in animal models.

METHODS

Female adolescent (5 weeks) and adult (8 weeks) MMTV-Wnt1 mice were exposed to alcohol either chronically or acutely. For chronic alcohol exposure, animals were fed a liquid diet containing 6.7% ethanol for 23 weeks. For acute exposure, animals were treated with ethanol (2.5 g/kg, 25% w/v) via intraperitoneal (IP) injection for 15 days.

RESULTS

In control animals, the tumor latency was 18.5 to 22 weeks. Both chronic and acute alcohol exposure in adolescent mice significantly shortened the tumor latency to 9.5 and 8.4 weeks, respectively. However, adult-initiated alcohol exposure had little effect on the tumor latency. Both adolescent- and adult-initiated alcohol exposure significantly increased lung metastasis. Adolescent-initiated alcohol exposure but not adult-initiated alcohol exposure increased the breast cancer stem cell population. Adolescent-initiated alcohol exposure significantly altered the proliferation of mammary epithelial cells, ductal growth, and the formation of terminal end buds in the mammary glands. Adolescent-initiated alcohol exposure but not adult-initiated alcohol exposure increased estradiol levels in the blood. Acute adolescent alcohol exposure also significantly increased blood progesterone levels. Furthermore, adolescent-initiated alcohol exposure activated PAK1 and p38γ MAPK, critical regulators of mammary tumorigenesis and aggressiveness, respectively, while adult-initiated alcohol exposure activated only p38γ MAPK. In addition, both adolescent and adult alcohol exposure significantly decreased the levels of a prognostic marker miR200b.

CONCLUSIONS

Adolescent-initiated alcohol exposure enhanced both tumorigenesis and aggressiveness of mammary tumors, while adult-initiated alcohol exposure mainly promoted tumor metastasis. Thus, adolescent mice were more sensitive than adult mice in response to alcohol-induced tumor promotion.

Somatic DNA Damage Response and Homologous Repair Gene Alterations and Its Association With Tumor Variant Burden in Breast Cancer Patients With Occupational Exposure to Pesticides

Homologous recombination is a crucial pathway that is specialized in repairing double-strand breaks; thus, alterations in genes of this pathway may lead to loss of genomic stability and cell growth suppression. Pesticide exposure potentially increases cancer risk through several mechanisms, such as the genotoxicity caused by chronic exposure, leading to gene alteration. To analyze this hypothesis, we investigated if breast cancer patients exposed to pesticides present a different mutational pattern in genes related to homologous recombination (BRCA1, BRCA2, PALB2, and RAD51D) and damage-response (TP53) concerning unexposed patients. We performed multiplex PCR-based assays and next-generation sequencing (NGS) of all coding regions and flanking splicing sites of BRCA1, BRCA2, PALB2, TP53, and RAD51D in 158 unpaired tumor samples from breast cancer patients on MiSeq (Illumina) platform. We found that exposed patients had tumors with more pathogenic and likely pathogenic variants than unexposed patients (p = 0.017). In general, tumors that harbored a pathogenic or likely pathogenic variant had a higher mutational burden (p < 0.001). We also observed that breast cancer patients exposed to pesticides had a higher mutational burden when diagnosed before 50 years old (p = 0.00978) and/or when carrying BRCA1 (p = 0.0138), BRCA2 (p = 0.0366), and/or PALB2 (p = 0.00058) variants, a result not found in the unexposed group. Our results show that pesticide exposure impacts the tumor mutational landscape and could be associated with the carcinogenesis process, therapy response, and disease progression. Further studies should increase the observation period in exposed patients to better evaluate the impact of these findings.

Growth Rate in Childhood and Adolescence and the Risk of Breast and Prostate Cancer: A Population-Based Study

Growth rate is regulated by hormonal pathways that might affect early cancer development. We explored the association between rate of growth in height from ages 8 to 13 years (childhood) and from age 13 to attainment of adult height (adolescence), as measured at study entry, and the risk of breast or prostate cancer. Participants were 2,037 Icelanders born during 1915-1935, who took part in the Reykjavik Study, established in 1967. Height measurements were obtained from school records and at study entry. We used multivariable Cox regression models to calculate hazard ratios with 95% confidence intervals of breast and prostate cancer by rates of growth in tertiles. During a mean follow-up of 66 years (women) and 64 years (men), 117 women were diagnosed with breast cancer and 118 men with prostate cancer (45 with advanced disease). Women in the highest growth-rate tertile in adolescence had a higher risk of breast cancer (hazard ratio = 2.4, 95% confidence interval: 1.3, 4.3) compared with women in the lowest tertile. A suggestive inverse association was observed for highest adolescent growth rate in men and advanced prostate cancer: hazard ratio = 0.4, 95% confidence interval: 0.2, 1.0. Rapid growth, particularly in adolescence may affect cancer risk later in life.

The Association Between Breast Density and Gut Microbiota Composition at 2 Years Post-Menarche: A Cross-Sectional Study of Adolescents in Santiago, Chile

The gut microbiome has been linked to breast cancer via immune, inflammatory, and hormonal mechanisms. We examined the relation between adolescent breast density and gut microbial composition and function in a cohort of Chilean girls. This cross-sectional study included 218 female participants in the Growth and Obesity Cohort Study who were 2 years post-menarche. We measured absolute breast fibroglandular volume (aFGV) and derived percent FGV (%FGV) using dual energy X-ray absorptiometry. All participants provided a fecal sample. The gut microbiome was characterized using 16S ribosomal RNA sequencing of the V3-V4 hypervariable region. We examined alpha diversity and beta diversity across terciles of %FGV and aFGV. We used MaAsLin2 for multivariable general linear modeling to assess differential taxa and predicted metabolic pathway abundance (MetaCyc) between %FGV and aFGV terciles. All models were adjusted for potential confounding variables and corrected for multiple comparisons. The mean %FGV and aFGV was 49.5% and 217.0 cm³, respectively, among study participants. Similar median alpha diversity levels were found across %FGV and aFGV terciles when measured by the Shannon diversity index (%FGV T1: 4.0, T2: 3.9, T3: 4.1; aFGV T1: 4.0, T2: 4.0, T3: 4.1). %FGV was associated with differences in beta diversity (R^{2 =}0.012, p=0.02). No genera were differentially abundant when comparing %FGV nor aFGV terciles after adjusting for potential confounders (q > 0.56 for all genera). We found no associations between predicted MetaCyc pathway abundance and %FGV and aFGV. Overall, breast density measured at 2 years post-menarche was not associated with composition and predicted function of the gut microbiome among adolescent Chilean girls.

Evaluating Anticancer and Immunomodulatory Effects of Spirulina (Arthrospira) platensis and Gamma-Tocotrienol Supplementation in a Syngeneic Mouse Model of Breast Cancer

Nutrition can modulate host immune responses as well as promote anticancer effects. In this study, two nutritional supplements, namely gamma-tocotrienol (γT3) and Spirulina, were evaluated for their immune-enhancing and anticancer effects in a syngeneic mouse model of breast cancer (BC). Five-week-old female BALB/c mice were fed Spirulina, γT3, or a combination of Spirulina and γT3 (Spirulina + γT3) for 56 days. The mice were inoculated with 4T1 cells into their mammary fat pad on day 28 to induce BC. The animals were culled on day 56 for various analyses. A significant reduction (p < 0.05) in tumor volume was only observed on day 37 and 49 in animals fed with the combination of γT3 + Spirulina. There was a marked increase (p < 0.05) of CD4/CD127+ T-cells and decrease (p < 0.05) of T-regulatory cells in peripheral blood from mice fed with either γT3 or Spirulina. The breast tissue of the combined group showed abundant areas of necrosis, but did not prevent metastasis to the liver. Although there was a significant increase (p < 0.05) of MIG-6 and Cadherin 13 expression in tumors from γT3-fed animals, there were no significant (p > 0.05) differences in the expression of MIG-6, Cadherin 13, BIRC5, and Serpine1 upon combined feeding. This showed that combined γT3 + Spirulina treatment did not show any synergistic anticancer effects in this study model.

Neither soyfoods nor isoflavones warrant classification as endocrine disruptors: a technical review of the observational and clinical data

Soybeans are a rich source of isoflavones, which are classified as phytoestrogens. Despite numerous proposed benefits, isoflavones are often classified as endocrine disruptors, based primarily on animal studies. However, there are ample human data regarding the health effects of isoflavones. We conducted a technical review, systematically searching Medline, EMBASE, and the Cochrane Library (from inception through January 2021). We included clinical studies, observational studies, and systematic reviews and meta-analyses (SRMA) that examined the relationship between soy and/or isoflavone intake and endocrine-related endpoints. 417 reports (229 observational studies, 157 clinical studies and 32 SRMAs) met our eligibility criteria. The available evidence indicates that isoflavone intake does not adversely affect thyroid function. Adverse effects are also not seen on breast or endometrial tissue or estrogen levels in women, or testosterone or estrogen levels, or sperm or semen parameters in men. Although menstrual cycle length may be slightly increased, ovulation is not prevented. Limited insight could be gained about possible impacts of in utero isoflavone exposure, but the existing data are reassuring. Adverse effects of isoflavone intake were not identified in children, but limited research has been conducted. After extensive review, the evidence does not support classifying isoflavones as endocrine disruptors.

Polycyclic Aromatic Hydrocarbons and Mammary Cancer Risk: Does Obesity Matter too?

Breast cancer risk remains incompletely explained, and higher incidence rates of breast cancer over recent times and in urban and industrialized areas suggest environmental causes. Polycyclic aromatic hydrocarbons (PAH) are ubiquitous in the environment and epidemiological and rodent studies have shown associations between exposure to PAH and breast cancer incidence as well as mammary tumorigenesis. In addition, in vitro and rodent studies have implicated alterations in estrogen receptor alpha (Erα) signaling pathways following PAH exposure in limited experimental studies. However, our understanding of these mechanisms is incomplete. Sahay et al. addressed this gap by examining the effect of PAH exposure on epigenetic and transcriptional regulation of genes in the Erα pathway in a mouse cohort exposed to aerosolized PAH at proportions measured in urban air. In addition to alterations in the Erα signaling pathway in the pregnant mice and in their offspring and grandoffspring, the investigators observed higher body weights in mice exposed to PAH compared to the control. Given that associations between mammary tissue adiposity, systemic adiposity, and breast cancer risk have been observed previously, the finding of higher body weight in the PAH exposure group raises the possibility that body weight might influence the association between PAH exposure and breast cancer risk. Along with new analyses, we discuss the possibility that body weight may modify the association between PAH exposure, mammary cellular proliferation, and mammary gland ductal hyperplasia in offspring and grandoffspring mice and future research that may be needed to delineate these associations.

Birth Weight and Subsequent Risk of Total Leukemia and Acute Leukemia: A Systematic Review and Meta-Analysis

Objective: Birth weight, an important indicator of fetal nutrition and degree of development, may affect the risk of subsequent leukemia. At present, little is known about the effect of birth weight on acute myeloid leukemia (AML) and whether there is a dose-dependent relationship of birth weight with acute lymphoid leukemia (ALL) and AML. To address these questions, the present work aimed to systematically investigate the relationship between birth weight and the risk of subsequent leukemia based on the current epidemiological studies Methods: Relevant studies were systematically retrieved from electronic databases PubMed, Embase, and Cochrane Library, from inception to May 15th, 2021. Finally, 28 studies (including 21 case-control studies and 7 cohort studies) were included for the final meta-analysis. Results in cohort studies were performed by risk ratios (RRs), while those in case-control studies by odds ratios (ORs), and all results were assessed by adopting the random-effect model. Besides, a dose-dependent analysis was conducted based on the cohort studies. Results: Compared with the population with normal birth weight (NBW), the population with high birth weight (HBW) might have an increased risk of leukemia (OR 1.33, 95%CI 1.20-1.49; I ² 0%). Meanwhile, low birth weight (LBW) was associated with a decreased risk of ALL, as evidenced from the pooled analysis of case-control studies (OR 0.83, 95% CI 0.75-0.92; I ² 23.3%). However, relative to NBW population, the HBW population might have an increased risk of ALL (OR 1.28, 95% CI 1.20-1.35; I ² 7%). There was no obvious evidence supporting the relationship between LBW and the risk of AML from the pooled analysis of case-control studies (OR, 1.11 95% CI 0.87-1.42; I ² 31.7%). Conclusions: Overall, in children and young adults, HBW population may be associated with the risks of subsequent leukemia and AML relative to NBW population, but the supporting dose-dependent evidence is lacking. In addition, compared with NBW population, there is stronger evidence supporting a significantly increased risk of subsequent ALL in HBW population, and a decreased risk in LBW population in a dose-dependent manner. More prospective studies with large samples are warranted in the future to validate and complement these findings.

Advanced Parental Age at Conception and Sex Affects Mitochondrial DNA Copy Number in Human and Fruit Flies

Aging is a multifactorial trait caused by early as well as late-life circumstances. A society trend that parents deliberately delay having children is of concern to health professionals, for example as advanced parental age at conception increases disease risk profiles in offspring. We here aim to study if advanced parental age at conception affects mitochondrial DNA content, a cross-species biomarker of general health, in adult human twin offspring and in a model organism. We find no deteriorated mitochondrial DNA content at advanced parental age at conception, but human mitochondrial DNA content was higher in females than males, and the difference was twofold higher at advanced maternal age at conception. Similar parental age effects and sex-specific differences in mitochondrial DNA content were found in Drosophila melanogaster. In addition, parental longevity in humans associates with both mitochondrial DNA content and parental age at conception; thus, we carefully propose that a poorer disease risk profile from advanced parental age at conception might be surpassed by superior effects of parental successful late-life reproduction that associate with parental longevity.

Higher Dietary Inflammatory Index Scores are Associated with Increased Odds of Benign Breast Diseases in a Case-Control Study

Purpose

Dietary inflammatory index (DII) is a new tool for assessing the inflammatory potential of diet. Since there is no study that has investigated the association of DII and benign breast diseases (BBD), the aim of our study was to compare DII scores in patients with and without BBD.

Methods

One hundred and eleven (111) subjects with BBD and 104 healthy women attending the Iranian Center for Breast Cancer affiliated with the Academic Center for Education, Culture and Research were enrolled in a case–control study. Dietary data collected using a 168‑item validated food frequency questionnaire (FFQ). Energy-adjusted DII was calculated based on FFQ. Socio demographic data were collected by interview. In addition, physical activity was measured by the International Physical Activity Questionnaire (IPAQ). Weight, height and waist circumference were also measured.

Results

After adjustment for multiple confounding variables, participants at the highest tertile of DII had increased OR for BBD (OR=1.7, 95% CI=0.75–3.95) (P-trend =0.04).

Conclusion

The increased chance of BBD was suggested with a higher consumption of diets with inflammatory potential. However, this result should be interpreted with caution as OR was not statistically significant. Interventional studies are warranted to elucidate the role of inflammatory diets in the development of BBD.

Reproductive characteristics are associated with gene-specific promoter methylation status in breast cancer

BACKGROUND

Reproductive characteristics are well-established risk factors for breast cancer, but the underlying mechanisms are not fully resolved. We hypothesized that altered DNA methylation, measured in tumor tissue, could act in concert with reproductive factors to impact breast carcinogenesis.

METHODS

Among a population-based sample of women newly diagnosed with first primary breast cancer, reproductive history was assessed using a life-course calendar approach in an interviewer-administered questionnaire. Methylation-specific polymerase chain reaction and Methyl Light assays were used to assess gene promotor methylation status (methylated vs. unmethylated) for 13 breast cancer-related genes in archived breast tumor tissue. We used case-case unconditional logistic regression to estimate adjusted odds ratios (ORs) and 95% confidence intervals (CIs) for associations with age at menarche and parity (among 855 women), and age at first birth and lactation (among a subset of 736 parous women) in association with methylation status.

RESULTS

Age at first birth > 27 years, compared with < 23 years, was associated with lower odds of methylation of CDH1 (OR = 0.44, 95% CI = 0.20-0.99) and TWIST1 (OR = 0.48, 95% CI = 0.28-0.82), and higher odds of methylation of BRCA1 (OR = 1.63, 95% CI = 1.14-2.35). Any vs. no lactation was associated with higher odds of methylation of the PGR gene promoter (OR = 1.59, 95% CI = 1.01-2.49). No associations were noted for parity and methylation in any of the genes assayed.

CONCLUSIONS

Our findings indicate that age at first birth, lactation and, perhaps age at menarche, are associated with gene promoter methylation in breast cancer, and should be confirmed in larger studies with robust gene coverage.

Early-Life Growth and Benign Breast Disease

Using prospective data from the Early Determinants of Mammographic Density study (United States, 1959-2008, n = 1121), we examined the associations between maternal body size, birth size, and infant and early childhood growth during 3 time periods (0-4 months, 4-12 months, and 1-4 years) and benign breast disease (BBD) using multivariable logistic regression with generalized estimating equations. A total of 197 women (17.6%) reported receiving a diagnosis of BBD by a physician. Higher body mass index at age 7 years was inversely associated with BBD risk. Rapid weight gain from age 1 year to 4 years, defined as an increase of least 2 major percentiles (e.g., 5th, 10th, 25th, 50th, 75th, and 95th) relative to stable growth, defined as remaining within 2 percentiles, was also inversely associated with BBD (odds ratio (OR) = 0.51, 95% confidence interval (CI): 0.23, 1.15). In contrast, rapid weight gain in infancy was positively associated with BBD relative to stable growth (from 0 to 4 months, OR = 1.65, 95% CI: 1.04, 2.62; from 4 to 12 months, 1.85, 95% CI: 0.89, 3.85), independent of birth weight, which was not associated with BBD. Our results suggest that patterns of early-life weight gain are important to BBD risk. Thus, susceptibility to BBD, like susceptibility to breast cancer, might start in early life.

Ultraviolet radiation exposure and breast cancer risk in the Nurses' Health Study II

Supplemental Digital Content is available in the text.

Background:

Ultraviolet (UV) radiation exposure, the primary source of vitamin D for most people, may reduce breast cancer risk. To date, epidemiologic studies have shown inconsistent results.

Methods:

The Nurses’ Health Study II is a U.S. nationwide prospective cohort of female registered nurses. A UV exposure model was linked with geocoded residential address histories. Early-life UV exposure was estimated based on the state of residence at birth, age 15, and age 30. Self-reported breast cancer was confirmed from medical records. Time-varying Cox regression models adjusted for established breast cancer risk factors were used to calculate hazard ratios (HRs) and 95% confidence intervals (CIs).

Results:

From 1989 to 2013, 3,959 invasive breast cancer cases occurred among 112,447 participants. Higher UV exposure during adulthood was not associated with invasive breast cancer risk overall (adjusted HR comparing highest to lowest quintile = 1.00; 95% CI = 0.90, 1.11, P for trend = 0.64) or according to estrogen receptor (ER) status. There were suggestive inverse associations between ER− breast cancer and early-life UV exposure at birth (adjusted HR = 0.94; 95% CI = 0.88, 1.01 per interquartile range increase [15.7 mW/m²]), age 15 (adjusted HR = 0.96; 95% CI = 0.89, 1.04 per 18.0 mW/m²), and age 30 (adjusted HR = 0.90; 95% CI = 0.82, 1.00 per 27.7 mW/m²).

Conclusions:

Ambient UV exposure during adulthood was not associated with risk of invasive breast cancer overall or by ER status. However, we observed suggestive inverse associations between early-life UV exposure and ER− breast cancer risk.

Do Birth Weight and Weight Gain During Infancy and Early Childhood Explain Variation in Mammographic Density in Women in Midlife? Results From Cohort and Sibling Analyses

High birth weight is associated with increased breast cancer risk and, less consistently, with higher mammographic density. In contrast, adolescent body size has been consistently, negatively associated with both MD and breast cancer risk. It is unclear when the direction of these associations changes and whether weight gain in infancy is associated with MD. We evaluated the associations of birth weight and postnatal weight (measured at 4 months, 1 year, and 4 years) by absolute and velocity measures (relative within-cohort percentile changes) with adult mammographic density, assessed using a computer-assisted thresholding program (Cumulus), using linear regression models with generalized estimating equations to account for correlation between siblings in the Early Determinants of Mammographic Density study (1959-2008; n = 700 women with 116 sibling sets; mean age = 44.1 years). Birth weight was positively associated with dense area (per 1-kg increase, β = 3.36, 95% confidence interval (CI): 0.06, 6.66). Weight gains from 0 months to 4 months and 1 year to 4 years were negatively associated with dense area (for 10-unit increase in weight percentile, β = -0.65, 95% CI: -1.23, -0.07, and β = -1.07, 95% CI: -1.98, -0.16, respectively). Findings were similar in the sibling subset. These results support the hypothesis that high birth weight is positively associated with increased breast density and suggest that growth spurts starting in early infancy reduce mammographic dense area in adulthood.

Associations of adult-attained height and early life energy restriction with postmenopausal breast cancer risk according to estrogen and progesterone receptor status

Adult-attained height is a marker for underlying mechanisms, such as cell growth, that may also influence postmenopausal breast cancer (BC) risk, perhaps specifically hormone-sensitive BC subtypes. Early life energy restriction may inhibit these mechanisms, resulting in shorter height and a reduced postmenopausal BC risk. Women (62,573) from the Netherlands Cohort Study completed a self-administered questionnaire in 1986 when 55-69 years old, and were followed-up for 20.3 years (case-cohort: N_subcohort = 2,438; N_cases = 3,354). Cox multivariable-adjusted hazard ratios (HR) and 95% confidence intervals (CI) were estimated for BC risk overall and by estrogen and progesterone receptor subtypes in relation to height and early life energy restriction during the Hunger Winter, War Years, and Economic Depression. Although energy restriction can only influence longitudinal growth in women exposed before and/or during the growth spurt, it may also influence BC risk when occurring after the growth spurt, possibly through different growth processes. Therefore, Cox analyses were additionally conducted according to timing of energy restriction in relation to the growth spurt. Height was associated with an increased BC risk (HR_{per 5cm} = 1.07, 95%CI:1.01-1.13), particularly hormone receptor-positive BC. Energy restriction before and/or during the growth spurt was associated with a decreased hormone receptor-positive BC risk. Energy restriction during the Hunger Winter increased the estrogen receptor-negative BC risk regardless of the timing of energy restriction. In conclusion, height and energy restriction before and/or during the growth spurt were both associated with hormone receptor-positive BC risk, in the direction as expected, indicating critical exposure windows for hormonal growth-related mechanisms.

Growth Trajectories, Breast Size, and Breast-Tissue Composition in a British Prebirth Cohort of Young Women

Mammographic percent density, the proportion of fibroglandular tissue in the breast, is a strong risk factor for breast cancer, but its determinants in young women are unknown. We examined associations of magnetic resonance imaging (MRI) breast-tissue composition at age 21 years with prospectively collected measurements of body size and composition from birth to early adulthood and markers of puberty (all standardized) in a sample of 500 nulliparous women from a prebirth cohort of children born in Avon, United Kingdom, in 1991-1992 and followed up to 2011-2014. Linear models were fitted to estimate relative change in MRI percent water, which is equivalent to mammographic percent density, associated with a 1-standard-deviation increase in the exposure of interest. In mutually adjusted analyses, MRI percent water was positively associated with birth weight (relative change (RC) = 1.03, 95% confidence interval (CI): 1.00, 1.06) and pubertal height growth (RC = 1.07, 95% CI: 1.02, 1.13) but inversely associated with pubertal weight growth (RC = 0.86, 95% CI: 0.84, 0.89) and changes in dual-energy x-ray absorptiometry percent body fat mass (e.g., for change between ages 11 years and 13.5 years, RC = 0.96, 95% CI: 0.93, 0.99). Ages at thelarche and menarche were positively associated with MRI percent water, but these associations did not persist upon adjustment for height and weight growth. These findings support the hypothesis that growth trajectories influence breast-tissue composition in young women, whereas puberty plays no independent role.

Pubertal and adult windows of susceptibility to a high animal fat diet in Trp53-null mammary tumorigenesis

Premenopausal breast cancer is associated with increased animal fat consumption among normal weight, but not overweight women (Farvid et al., 2014). Our previous findings in obesity-resistant BALB/c mice similarly showed promotion of carcinogen-induced mammary tumorigenesis by a diet high in saturated animal fat (HFD). This effect was specific to pubertal versus adult HFD. This study identifies the effects of HFD during puberty versus adulthood in Trp53-null transplant BALB/c mice and investigates its mechanism of enhancing tumorigenesis. Either pubertal or adult HFD is sufficient to increase incidence of Trp53-null mammary tumors. Puberty-restricted HFD exposure promoted tumor cell proliferation, increased angiogenesis, and increased recruitment of total and M2 macrophages in epithelial tumors. Adult-restricted exposure to HFD similarly increased proliferation, angiogenesis, recruitment of total and M2 macrophages, and additionally reduced apoptosis. Adult HFD also increased incidence of spindle cell carcinomas resembling claudin-low breast cancer, and thus adult HFD in the Trp53-null transplantation system may be a useful model for human claudin low breast cancer. Importantly, these results on Trp53-null and our prior studies on DMBA-induced mammary tumorigenesis demonstrate a pubertal window of susceptibility to the promotional effects of HFD, indicating the potential of early life dietary intervention to reduce breast cancer risk.

The association of early life socioeconomic position on breast cancer incidence and mortality: a systematic review

OBJECTIVES

We conducted a systematic review of the literature relating early life socioeconomic position (SEP) to breast cancer incidence and mortality from a critical period and life-course trajectory perspective.

METHODS

PubMed, EMBASE and Web of Science were searched to identify cohort studies that evaluated the impact of early life SEP indicators on the incidence and/or mortality from breast cancer in adulthood.

RESULTS

Nine distinct studies evaluated the relationship between early life SEP and breast cancer between 1990 and 2016. Five reports assessed breast cancer incidence and five assessed breast cancer mortality as outcomes; one study assessed both incidence and mortality. While lower early life SEP was associated with reduced breast cancer incidence and increased breast cancer mortality in the US, studies conducted in Europe were unable to establish a consistent association.

CONCLUSIONS

We found moderate support for the association between early life SEP and incidence and mortality from breast cancer. The impact of early life SEP on breast cancer incidence and mortality appeared to vary between countries. We urge further investigation of the role of lifelong SEP trajectories in breast cancer outcomes.

Childhood Socioeconomic Position and Pubertal Onset in a Cohort of Multiethnic Girls: Implications for Breast Cancer

Background: Higher socioeconomic position (SEP) has been associated with increased risk of breast cancer. Its relationship with earlier age of pubertal onset, a risk factor for breast cancer, is less clear.Methods: We studied the relationship of SEP to pubertal onset in a multiethnic cohort of 1,237 girls ages 6 to 8 years at baseline. Girls in three U.S. cities were followed for 5 to 8 years with annual clinical examinations from 2004 to 2012. SEP measures were examined for associations with pubertal onset, assessed by breast budding (thelarche) and pubic hair development (adrenarche). Analyses were conducted with accelerated failure time models using a Weibull distribution, with left, right, and interval censoring.Results: Higher body mass index percentage at entry to the study and black or Hispanic race/ethnicity were the strongest predictors of age at pubertal onset. An SEP index comprising household family income, mother's education, and home ownership was an independent predictor of thelarche in adjusted models for all girls together and for white and Latina, separately, but not black girls, and the relationship varied by study site. The SEP index was not related to adrenarche in adjusted models. Overall, girls from the lowest quintile of SEP entered puberty on average 6% earlier than girls from the highest quintile (time ratio = 0.94; 95% confidence interval 0.91-0.97) in adjusted models.Conclusions: Our results suggest that early-life SEP may influence the timing of pubertal development.Impact: Factors related to lower SEP in childhood can adversely affect early development in ways that may increase the risk of breast cancer. Cancer Epidemiol Biomarkers Prev; 26(12); 1714-21. ©2017 AACR.

Health impact of childhood and adolescent soy consumption

Soyfoods have been intensely researched, primarily because they provide such abundant amounts of isoflavones. Isoflavones are classified as both plant estrogens and selective estrogen receptor modulators. Evidence suggests that these soybean constituents are protective against a number of chronic diseases, but they are not without controversy. In fact, because soyfoods contain such large amounts of isoflavones, concerns have arisen that these foods may cause untoward effects in some individuals. There is particular interest in understanding the effects of isoflavones in young people. Relatively few studies involving children have been conducted, and many of those that have are small in size. While the data are limited, evidence suggests that soy does not exert adverse hormonal effects in children or affect pubertal development. On the other hand, there is intriguing evidence indicating that when soy is consumed during childhood and/or adolescence, risk of developing breast cancer is markedly reduced. Relatively few children are allergic to soy protein, and most of those who initially are outgrow their soy allergy by 10 years of age. The totality of the available evidence indicates that soyfoods can be healthful additions to the diets of children, but more research is required to allow definitive conclusions to be made.

Body size from birth through adolescence in relation to risk of benign breast disease in young women

PURPOSE

Body size, from birth throughout adulthood, is associated with breast cancer risk, but few studies have investigated early-life body size and benign breast disease (BBD), a well-established breast cancer risk factor. We consider whether prenatal factors and size at birth, 10, 18 year, and intervening growth, are related to BBD risk.

METHODS

The Growing Up Today Study includes 9032 females who completed questionnaires annually from 1996 to 2001, then 2003, 2005, 2007, 2010, and 2013. In 1996, their mothers provided pregnancy-related data. From 2005 to 2013, participants (18 year+) reported whether they had ever been diagnosed with biopsy-confirmed BBD (N = 142 cases).

RESULTS

Girls had greater adiposity (BMI; kg/m2) at 10 year if they were larger at birth, if mother's pre-pregnancy BMI was higher, or if gestational weight gain was greater (all p < .01). Maternal height was (positively) associated (p < .05) with adolescent peak height growth velocity (PHV; in./year). Greater 10 year adiposity was associated with lower PHV and less height growth 10-18 year (both p < .01). Adiposity at 10 year was inversely associated with BBD (OR 0.83/(kg/m2), p < .01) as was increasing adiposity 10-18 year (OR 0.85/(kg/m2), p = .01). In a separate model, 10 year height (OR 1.13/in., p = .02) and height growth 10-18 year (OR 1.19/in.; p < .01) were positively associated. PHV was similarly positively associated (OR 2.58, p = .01, fastest versus slowest growth quartiles). In a multivariable model of BBD risk, gestational weight gain (daughters at highest risk if <20 lb gained), PHV (slowest growing girls at lowest risk), age 10 year height (positive), and BMI (inverse) were the most critical childhood risk factors (each p < .05).

CONCLUSIONS

Body size factors from pregnancy through adolescence were independently associated with BBD risk in young women.

Lifecourse socioeconomic status and cancer-related risk factors: Analysis of the WHO study on global ageing and adult health (SAGE)

Few studies have examined cancer-related risk factors in relation to SES across the lifecourse in low to middle income countries. This analysis focuses on adult women in India, China, Mexico, Russia and South Africa, and examines the association between individual, parental and lifecourse SES with smoking, alcohol, BMI, nutrition and physical activity. Data on 22,283 women aged 18 years and older were obtained from the 2007 WHO Study on Global Aging and Adult Health (SAGE). Overall, 34% of women had no formal education, 73% had mothers with no formal education and 73% of women had low lifecourse SES. Low SES women were almost four times more likely to exceed alcohol use guidelines (OR: 3.86, 95% CI: 1.23-12.10), and 68% more likely to smoke (OR: 1.68, 95% CI: 1.01-2.80) compared with higher SES. Women with low SES mothers and fathers were more likely to have poor nutrition (Mothers OR: 1.59, 95% CI: 1.17-2.16; Fathers OR: 1.33, 95% CI: 1.11-1.59) and more likely to smoke (Mothers OR: 1.46, 95% CI: 1.15-1.87; Fathers OR: 2.17, 95% CI: 1.80-2.63) compared with those with high SES parents. Women with stable low lifecourse SES were more likely to smoke (OR: 2.55, 95% CI: 1.47-4.43), while those with declining lifecourse SES were more likely to exceed alcohol use guidelines (OR: 3.63, 95% CI: 1.07-12.34). Cancer-related risk factors varied significantly by lifecourse SES, suggesting that cancer prevention strategies will need to be tailored to specific sub-groups in order to be most effective.

Early life growth, socioeconomic status, and mammographic breast density in an urban US birth cohort

PURPOSE

Rapid infant and childhood growth has been associated with chronic disease later in life, including breast cancer. Early life socioeconomic status (SES) influences childhood growth, but few studies have prospective measures from birth to consider the effects of early life growth and SES on breast cancer risk.

METHODS

We used prospectively measured early life SES and growth (percentile weight change in height and weight between each pair of consecutive time points at birth, 4 months, 1 and 7 years). We performed linear regression models to obtain standardized estimates of the association between 1 standard deviation increase in early life SES and growth and adult mammographic density (MD), a strong risk factor for breast cancer, in a diverse birth cohort (n = 151; 37% white, 38% black, 25% Puerto Rican; average age at mammogram = 42.4).

RESULTS

In models adjusted for race/ethnicity, prenatal factors, birthweight, infant and childhood growth, and adult body mass index, percentile weight change from 1 year to 7 years was inversely associated with percent MD (standardized coefficient (Stdβ) = -0.28, 95% CI: -0.55 to -0.01), and higher early life SES was positively associated with percent MD (Stdβ = 0.24, 95% CI: 0.04-0.43). Similar associations were observed for dense area, but those estimates were not statistically significant.

CONCLUSIONS

These results suggest opposite and independent effects of early life SES and growth on MD.

Dietary patterns and benign breast diseases: a case-control study

Several studies have investigated the relation between benign breast diseases (BBD) and food intake. However, dietary patterns of these patients have not been taken into consideration up to now. The aim of this study is to determine the association between dietary patterns and BBD. In this case-control study, ninety-six patients with BBD and seventy controls were selected from women attending the Iranian Center for Breast Cancer affiliated with Academic Center for Education, Culture and Research. Demographic, physical activity and semi-quantitative FFQ were completed. The main dietary patterns were extracted by factor analysis. Two major dietary patterns emerged: Healthy dietary pattern including fish, poultry, eggs, low-fat dairy products, vegetables, legumes, nuts and seeds, whole grains, oil and mayonnaise, olives, fruits; and Unhealthy dietary pattern including red meats, organ and processed meats, high-fat dairy products, refined grains, sweets and desserts, animal and solid fats. After adjustment for age, BMI and energy intake, the participants in the highest tertile of Healthy dietary pattern (OR 0·44; 95 % CI 0·20, 0·99) were less likely to have BBD compared with those in the first tertile. After adjustment for other confounding variables, this relationship still remained close to significant level. However, higher consumption of Unhealthy dietary pattern was not associated with the risk of BBD. In conclusion, Healthy dietary pattern might be inversely associated with the risk of BBD; however, this result should be interpreted with caution. Future studies are needed to confirm our findings.

Early Life Body Fatness, Serum Anti-Müllerian Hormone, and Breast Density in Young Adult Women

BACKGROUND

Emerging evidence suggests positive associations between serum anti-Müllerian hormone (AMH), a marker of ovarian function, and breast cancer risk. Body size at young ages may influence AMH levels, but few studies have examined this. Also, no studies have examined the relation of AMH levels with breast density, a strong predictor of breast cancer risk.

METHODS

We examined associations of early life body fatness, AMH concentrations, and breast density among 172 women in the Dietary Intervention Study in Children (DISC). Height and weight were measured at baseline (ages 8-10) and throughout adolescence. Serum AMH concentrations and breast density were assessed at ages 25-29 at the DISC 2006 Follow-up visit. We used linear mixed effects models to quantify associations of AMH (dependent variable) with quartiles of age-specific youth body mass index (BMI) Z-scores (independent variable). We assessed cross-sectional associations of breast density (dependent variable) with AMH concentration (independent variable).

RESULTS

Neither early life BMI nor current adult BMI was associated with AMH concentrations. There were no associations between AMH and percent or absolute dense breast volume. In contrast, women with higher AMH concentrations had significantly lower absolute nondense breast volume (Ptrend < 0.01).

CONCLUSIONS

We found no evidence that current or early life BMI influences AMH concentrations in later life. Women with higher concentrations of AMH had similar percent and absolute dense breast volume, but lower nondense volume.

IMPACT

These results suggest that AMH may be associated with lower absolute nondense breast volume; however, future prospective studies are needed to establish temporality. Cancer Epidemiol Biomarkers Prev; 25(7); 1151-7. ©2016 AACR.

Perinatal and childhood factors and risk of breast cancer subtypes in adulthood

BACKGROUND

Accumulated exposure to hormones and growth factors during early life may influence the future risk of breast cancer (BC). This study examines the influence of childhood-related, socio-demographic and anthropometric variables on BC risk, overall and by specific pathologic subtypes.

METHODS

This is a case-control study where 1539 histologically-confirmed BC cases (23-85 years) and 1621 population controls, frequency matched by age, were recruited in 10 Spanish provinces. Perinatal and childhood-related characteristics were directly surveyed by trained staff. The association with BC risk, globally and according to menopausal status and pathologic subtypes, was evaluated using logistic and multinomial regression models, adjusting for tumor specific risk factors.

RESULTS

Birth characteristics were not related with BC risk. However, women with high socioeconomic level at birth presented a decreased BC risk (OR=0.45; 95% CI=0.29-0.70), while those whose mothers were aged over 39 years at their birth showed an almost significant excess risk of hormone receptor positive tumors (HR+) (OR=1.35; 95% CI=0.99-1.84). Women who were taller than their girl mates before puberty showed increased postmenopausal BC risk (OR=1.26; 95% CI=1.03-1.54) and increased HR+ BC risk (OR=1.26; 95% CI=1.04-1.52). Regarding prepubertal weight, while those women who were thinner than average showed higher postmenopausal BC risk (OR=1.46; 95% CI=1.20-1.78), associated with HR+ tumors (OR=1.34; 95% CI=1.12-1.61) and with triple negative tumors (OR=1.56; 95% CI=1.03-2.35), those who were heavier than average presented lower premenopausal BC risk (OR=0.64; 95% CI=0.46-0.90) and lower risk of epidermal growth factor receptor positive tumors (OR=0.61; 95% CI=0.40-0.93).

CONCLUSION

These data reflect the importance of hormones and growth factors in the early stages of life, when the mammary gland is in development and therefore more vulnerable to proliferative stimuli.

Prenatal factors and infant feeding in relation to risk of benign breast disease in young women

Benign breast disease (BBD) is a well-established risk factor for breast cancer, but little work has considered a girl's early life and her risk for BBD in adulthood. We investigated factors, from pre-conception through infant feeding practices, in relation to subsequent BBD risk in young women. The Growing Up Today Study (GUTS) includes 9032 females, born 1980-1987, who completed questionnaires annually from 1996 through 2001, then 2003, 2005, 2007, 2010, and 2013. In 1996, their mothers provided each participant's birth weight and length, gestational age, biological father's height, and infant feeding factors (e.g., breast-fed, type of formula). In 1999, their mothers reported maternal pre-pregnancy weight and weight gain during index pregnancy. Beginning in 2005, daughters (18 years+) reported whether they had ever been diagnosed with biopsy-confirmed BBD (n = 142 cases, through 2013). Logistic regression estimated associations between early life factors and biopsy-confirmed BBD. Girls whose mother's BMI prior to pregnancy was 20-25 kg/m(2) were at lower risk of BBD as young women (OR = 0.66, p = 0.04, vs. maternal pre-pregnancy BMI < 20). Girls whose mothers gained 20 + pounds (vs. <20 pounds) during pregnancy were at lower risk (among full-term singleton births: OR = 0.48, p = 0.007, if mother gained 20-35 pounds). However, neither birth weight nor BMI at birth were associated with subsequent BBD risk. We found no evidence that infant feeding practices were linked to BBD. A healthy maternal BMI before pregnancy and sufficient weight gain during pregnancy may produce daughters at lower risk for BBD as young women. Further examination of these findings is needed.

Racial and ethnic disparities in the impact of obesity on breast cancer risk and survival: a global perspective

Obesity is a global concern, affecting both developed and developing countries. Although there are large variations in obesity and breast cancer rates worldwide and across racial/ethnic groups, most studies evaluating the impact of obesity on breast cancer risk and survival have been conducted in non-Hispanic white women in the United States or Europe. Given the known racial/ethnic differences in tumor hormone receptor subtype distribution, obesity prevalence, and risk factor profiles, we reviewed published data for women of African, Hispanic, and Asian ancestry in the United States and their countries of origin. Although the data are limited, current evidence suggests a stronger adverse effect of obesity on breast cancer risk and survival in women of Asian ancestry. For African Americans and Hispanics, the strength of the associations appears to be more comparable to that of non-Hispanic whites, particularly when accounting for subtype and menopausal status. Central obesity seems to have a stronger impact in African-American women than general adiposity as measured by body mass index. International data from countries undergoing economic transition offer a unique opportunity to evaluate the impact of rapid weight gain on breast cancer. Such studies should take into account genetic ancestry, which may help elucidate differences in associations between ethnically admixed populations. Overall, additional large studies that use a variety of adiposity measures are needed, because the current evidence is based on few studies, most with limited statistical power. Future investigations of obesity biomarkers will be useful to understand possible racial/ethnic biological differences underlying the complex association between obesity and breast cancer development and progression.

Early Diet and Later Cancer Risk: Prospective Associations of Dietary Patterns During Critical Periods of Childhood with the GH-IGF Axis, Insulin Resistance and Body Fatness in Younger Adulthood

Early life, adiposity rebound, and puberty represent critical growth periods when food choices could have long-term relevance for cancer risk. We aimed to relate dietary patterns during these periods to the growth hormone-insulin-like-growth-factor (GH-IGF) axis, insulin resistance, and body fatness in adulthood. Data from the Dortmund Nutritional and Anthropometric Longitudinally Designed (DONALD) Study participants with outcome data at 18-37 years, and ≥2 dietary records during early life (1-2 yr; n = 128), adiposity rebound (4-6 years, n = 179), or puberty (girls 9-14, boys 10-15 yr; n = 213) were used. Dietary patterns at these ages were derived by 1) reduced rank regression (RRR) to explain variation in adult IGF-I, IGF-binding protein-3 (IGFBP-3), homoeostasis model assessment for insulin resistance (HOMA-IR) and fat-mass index; 2) principal component analysis (PCA). Regarding RRR, the patterns "cake/canned fruit/cheese & eggs" (early life), "sweets & dairy" (adiposity rebound) and "high-fat foods" (pubertal boys) were independently associated with higher adult HOMA-IR. Furthermore, the patterns "favorable carbohydrate sources" (early life), "snack & convenience foods" (adiposity rebound), and "traditional & convenience carbohydrates" (pubertal boys) were related to adult IGFBP-3 (P trend < 0.01). PCA identified "healthy" patterns for all periods, but none was associated with the outcomes (P trend > 0.1). In conclusion, dietary patterns during sensitive growth periods may be of long-term relevance for adult insulin resistance and IGFBP-3.

Association of estrogen receptor gene polymorphisms with human precocious puberty: a systematic review and meta-analysis

This study aims to estimate the association between ESR1 polymorphisms (PvuII and XbaI) and ESR2 polymorphisms (RsaI and AluI) with precocious puberty. Relevant studies published before March 2014 were retrieved by a electronic search among nine databases. Meta-analysis of the pooled odds ratios (ORs) with 95% confidence intervals (CIs) was calculated. Four eligible case-control studies including 491 precocious puberty patients and 370 healthy controls were identified. Three studies reported ESR1 PvuII and XbaI polymorphism and one study reported ESR2 RsaI and AluI polymorphism. Increment of precocious puberty risk was associated with PvuII polymorphism in the heterosis model ((CT) versus TT: OR 1.42, 95% CI: 1.05-1.91, p = 0.02). Risk of precocious puberty was associated with XbaI polymorphism in the dominant model (GG + GA versus AA: OR 1.48, 95% CI: 1.11-1.97, p = 0.007) and the heterosis model (GA versus AA: OR 1.68, 95% CI: 1.23-2.29, p = 0.001). This meta-analysis suggests that ESR1 XbaI and PvuII polymorphisms are associated with precocious puberty susceptibility, and the relationship between ESR2 RsaI and AluI polymorphism with precocious puberty remains to be further investigated. Well-designed studies with large sample size among different polymorphisms and ethnicities are in urgent need to provide and update reliable data for comprehensive and definite conclusion.

Birth weight and risk factors for cardiovascular disease and type 2 diabetes in US children and adolescents: 10 year results from NHANES

Previous studies have shown that birth weight and other birth characteristics may be associated with risk for type 2 diabetes and cardiovascular disease (CVD) later in life; however, results using large US national survey data are limited. Our goal was to determine the aforementioned associations using nationally representative data. We studied children and adolescents 6-15 years using data from the National Health and Nutrition Examination Survey cycles 2001-2010. Survey and examination data included demographic and early childhood characteristics, current health status, physical activity information, anthropometric measurements, dietary data (total energy, saturated fat, sodium, and sugar intakes), biomarkers related to selected risk factors of CVD [systolic blood pressure (SBP), plasma C-reactive protein (CRP) and lipid profiles], and type 2 diabetes [fasting glucose, insulin, and homeostasis model assessment (HOMA)]. Birth weight (proxy-reported) was inversely associated with SBP among girls; SBP levels increased 1.4 mmHg for each 1,000 g decrease in birth weight (p = 0.003) after controlling for potential confounders. Birth weight was not associated with levels of CRP or lipid profiles across the three racial groups. In addition, birth weight was inversely related to levels of fasting insulin and HOMA among non-Hispanic Whites; for each 1,000 g decrease in birth weight, fasting insulin levels increased 9.1% (p = 0.007) and HOMA scores increased 9.8% (p = 0.007). Birth weight was inversely associated with the levels of SBP, fasting insulin, and HOMA. These results support a role for birth weight, independent of the strong effects of current body weight status, in increasing risk for CVD and type 2 diabetes.

Body mass index at early adulthood, subsequent weight change and cancer incidence and mortality

Obesity later in adulthood is associated with increased risks of many cancers. However, the effect of body fatness in early adulthood, and change in weight from early to later adulthood on cancer risk later in life is less clear. We used data from 13,901 people aged 45-64 in the Atherosclerosis Risk in Communities cohort who at baseline (1987-1989) self-reported their weight at the age of 25 and had weight and height measured. Incident cancers were identified through 2006 and cancer deaths were ascertained through 2009. Multivariable Cox proportional hazard models were used to relate body mass index (BMI) at age 25 and percent weight change from age 25 to baseline to cancer incidence and mortality. After adjusting for weight change from age 25 until baseline, a 5 kg/m(2) increment in BMI at age 25 was associated with a greater risk of incidence of all cancers in women [hazard ratio (95% confidence interval): 1.10 (1.02-1.20)], but not in men. Associations with incident endometrial cancer were strong [1.83 (1.47-2.26)]. After adjusting for BMI at age 25, a 5% increment in weight from age 25 to baseline was associated with a greater risk of incident postmenopausal breast cancer [1.05 (1.02-1.07)] and endometrial cancer [1.09 (1.04-1.14)] in women and incident colorectal cancer [1.05 (1.00-1.10)] in men. Excess weight during young adulthood and weight gain from young to older adulthood may be independently associated with subsequent cancer risk. Excess weight and weight gain in early adulthood should be avoided.

Elevated CXCL1 expression in breast cancer stroma predicts poor prognosis and is inversely associated with expression of TGF-β signaling proteins

Background

CXCL1 is a chemotactic cytokine shown to regulate breast cancer progression and chemo-resistance. However, the prognostic significance of CXCL1 expression in breast cancer has not been fully characterized. Fibroblasts are important cellular components of the breast tumor microenvironment, and recent studies indicate that this cell type is a potential source of CXCL1 expression in breast tumors. The goal of this study was to further characterize the expression patterns of CXCL1 in breast cancer stroma, determine the prognostic significance of stromal CXCL1 expression, and identify factors affecting stromal CXCL1 expression.

Methods

Stromal CXCL1 protein expression was analyzed in 54 normal and 83 breast carcinomas by immunohistochemistry staining. RNA expression of CXCL1 in breast cancer stroma was analyzed through data mining in http://www.Oncomine.org. The relationships between CXCL1 expression and prognostic factors were analyzed by univariate analysis. Co-immunofluorescence staining for CXCL1, α-Smooth Muscle Actin (α-SMA) and Fibroblast Specific Protein 1 (FSP1) expression was performed to analyze expression of CXCL1 in fibroblasts. By candidate profiling, the TGF-β signaling pathway was identified as a regulator of CXCL1 expression in fibroblasts. Expression of TGF-β and SMAD gene products were analyzed by immunohistochemistry and data mining analysis. The relationships between stromal CXCL1 and TGF-β signaling components were analyzed by univariate analysis. Carcinoma associated fibroblasts isolated from MMTV-PyVmT mammary tumors were treated with recombinant TGF-β and analyzed for CXCL1 promoter activity by luciferase assay, and protein secretion by ELISA.

Results

Elevated CXCL1 expression in breast cancer stroma correlated with tumor grade, disease recurrence and decreased patient survival. By co-immunofluorescence staining, CXCL1 expression overlapped with expression of α-SMA and FSP1 proteins. Expression of stromal CXCL1 protein expression inversely correlated with expression of TGF-β signaling components. Treatment of fibroblasts with TGF-β suppressed CXCL1 secretion and promoter activity.

Conclusions

Increased CXCL1 expression in breast cancer stroma correlates with poor patient prognosis. Furthermore, CXCL1 expression is localized to α-SMA and FSP1 positive fibroblasts, and is negatively regulated by TGF-β signaling. These studies indicate that decreased TGF-β signaling in carcinoma associated fibroblasts enhances CXCL1 expression in fibroblasts, which could contribute to breast cancer progression.

Electronic supplementary material

The online version of this article (doi:10.1186/1471-2407-14-781) contains supplementary material, which is available to authorized users.

Dietary energy density is positively associated with breast density among young women

BACKGROUND

Breast density is an established predictor of breast cancer risk, and there is considerable interest in associations of modifiable lifestyle factors, such as diet, with breast density.

OBJECTIVE

To determine whether dietary energy density (ED) is associated with percent dense breast volume (%DBV) and absolute dense breast volume (ADBV) in young women.

DESIGN

A cross-sectional analysis was conducted with women who participated in the Dietary Intervention Study in Children Follow-Up Study. %DBV and ADBV were measured by magnetic resonance imaging. Diet was assessed by three 24-hour recalls. Dietary ED (kilocalories/gram) was calculated using three methods: food only, food and caloric beverages, and food and all beverages.

PARTICIPANTS/SETTING

One hundred seventy-two women (aged 25 to 29 years) who were enrolled in the Dietary Intervention Study in Children Follow-Up Study. Participants who reported breast augmentation or reduction surgery or were pregnant or lactating within 3 months before breast density assessment were excluded.

MAIN OUTCOME MEASURES

ADBV and %DBV.

STATISTICAL ANALYSES PERFORMED

Multivariable linear mixed effects models were used. Final models were adjusted for race, smoking status, education, parity, duration of sex hormone use, whole body percent fat, childhood body mass index z score, and energy from beverages.

RESULTS

After adjustment, each 1 kcal/g unit increase in food-only ED was associated with a 25.9% (95% CI 6.2% to 56.8%) increase in %DBV (P=0.01). Childhood body mass index z score modified the association between food-only ED and %DBV such that a significant positive association was observed only in women who were heavier as children. Food-only ED was not associated with ADBV in all women, but a borderline significant positive association was observed in women who had higher childhood body mass index z scores.

CONCLUSIONS

This is the first report to suggest a potential role for dietary ED in breast density; the effects of long-term exposure to high-ED diets on breast cancer risk remain unknown.

Birth weight and subsequent risk of cancer

BACKGROUND

We aimed to determine the association between self-reported birth weight and incident cancer in the Women's Health Initiative Observational Study cohort, a large multiethnic cohort of postmenopausal women.

METHODS

65,850 women reported their birth weight by category (<6 lbs, 6-7 lbs 15 oz, 8-9 lbs 15 oz, and ≥10 lbs). All self-reported, incident cancers were adjudicated by study staff. We used Cox proportional hazards regression to estimate crude and adjusted hazard ratios (aHR) for associations between birth weight and: (1) all cancer sites combined, (2) gynecologic cancers, and (3) several site-specific cancer sites.

RESULTS

After adjustments, birth weight was positively associated with the risk of lung cancer (p=0.01), and colon cancer (p=0.04). An inverse trend was observed between birth weight and risk for leukemia (p=0.04). A significant trend was not observed with breast cancer risk (p=0.67); however, women born weighing ≥10 lbs were less likely to develop breast cancer compared to women born between 6 lbs-7 lbs 15 oz (aHR 0.77, 95% CI 0.63, 0.94).

CONCLUSION

Birth weight category appears to be significantly associated with the risk of any postmenopausal incident cancer, though the direction of the association varies by cancer type.

Exposures in early life: associations with DNA promoter methylation in breast tumors

There is evidence that epigenetic changes occur early in breast carcinogenesis. We hypothesized that early-life exposures associated with breast cancer would be associated with epigenetic alterations in breast tumors. In particular, we examined DNA methylation patterns in breast tumors in association with several early-life exposures in a population-based case-control study. Promoter methylation of E-cadherin, p16 and RAR-β2 genes was assessed in archived tumor blocks from 803 cases with real-time methylation-specific PCR. Unconditional logistic regression was used for case-case comparisons of those with and without promoter methylation. We found no differences in the prevalence of DNA methylation of the individual genes by age at menarche, age at first live birth and weight at age 20. In case-case comparisons of premenopausal breast cancer, lower birth weight was associated with increased likelihood of E-cadherin promoter methylation (OR = 2.79, 95% CI, 1.15-6.82, for ⩽2.5 v. 2.6-2.9 kg); higher adult height with RAR-β2 methylation (OR = 3.34, 95% CI, 1.19-9.39, for ⩾1.65 v. <1.60 m); and not having been breastfed with p16 methylation (OR = 2.75, 95% CI, 1.14-6.62). Among postmenopausal breast cancers, birth order was associated with increased likelihood of p16 promoter methylation. Being other than first in the birth order was inversely associated with likelihood of ⩾1 of the three genes being methylated for premenopausal breast cancers, but positively associated with methylation in postmenopausal women. These results suggest that there may be alterations in methylation associated with early-life exposures that persist into adulthood and affect breast cancer risk.

Birthweight, early life body size and adult mammographic density: a review of epidemiologic studies

PURPOSE

To evaluate the association between birth weight and early life body size with adult mammographic density in the peer-reviewed literature.

METHODS

A comprehensive literature search was conducted through January, 2014. English language articles that assessed adult mammographic density (MD) in relation to early life body size (≤18 years old), or birthweight were included.

RESULTS

Nine studies reported results for early life body size and %MD. Both exposure and outcome were assessed at different ages using multiple methods. In premenopausal women, findings were inconsistent; two studies reported significant, inverse associations, one reported a non-significant, inverse association, and two observed no association. Reasons for these inconsistencies were not obvious. In postmenopausal women, four of five studies supported an inverse association. Two of three studies that adjusted for menopausal status found significant, inverse associations. Birthweight and %MD was evaluated in nine studies. No association was seen in premenopausal women and two of three studies reported positive associations in postmenopausal women. Three of four studies that adjusted for menopausal status found no association.

DISCUSSION

Early life body size and birthweight appear unrelated to %MD in premenopausal women while an inverse association in postmenopausal women is more likely. Although based on limited data, birthweight and %MD appear positively associated in postmenopausal women. Given the small number of studies, the multiple methods of data collection and analysis, other methodologic issues, and lack of consistency in results, additional research is needed to clarify this complex association and develop a better understanding of the underlying biologic mechanisms.

Identification of ApoA1, HPX and POTEE genes by omic analysis in breast cancer

Breast cancer is the most common cancer among women and accounts for 23% of all female types of cancers. It is well recognized that breast cancer represents a heterogeneous group of tumors, and the molecular events involved in the progression to cancer remain undetermined. Moreover, available prognostic and predictive markers are not sufficient for the accurate determination of the risk for many breast cancer patients. Thus, it is necessary to discover new molecular markers for accurate prediction of clinical outcome and individualized therapy. In the present study, we performed omics-based whole-genome trancriptomic and whole proteomic profiling with network and pathway analyses of breast tumors to identify gene expression patterns related to clinical outcome. A total of 20 samples from tumors and 14 normal appearing breast tissues were analyzed using both gene expression microarrays and LC-MS/MS. We identified 585 downregulated and 413 upregulated genes by gene expression microarrays. Among these genes, HPX, POTEE and ApoA1 were the most significant genes correlated with the proteomic profile. Our data revealed that these identified genes are closely related to breast cancer and may be involved in robust detection of disease progression.

Is soy intake related to age at onset of menarche? A cross-sectional study among adolescents with a wide range of soy food consumption

Background

Early onset of menarche may negatively influence the future health of adolescent girls. Several factors affect the timing of menarche but it is not clear if soy foods consumption around pubertal years plays a role; thus, we examined its relation to age at onset of menarche (AOM) in a high soy-consuming population.

Methods

We conducted a cross-sectional study on 339 girls ages 12–18 years attending middle and high schools near two Seventh-day Adventist universities in California and Michigan using a web-based dietary questionnaire and physical development tool. Soy consumption (categorized as total soy, meat alternatives, tofu/traditional soy, and soy beverages) was estimated from the questionnaire, while AOM was self-reported. Data analyses included descriptive statistics, Cox proportional hazards ratios, Kaplan-Meier curves and Poisson regression with adjustment for relevant confounders.

Results

Mean (SD) intakes were: total soy,12.9 (14.4) servings/week; meat alternatives, 7.0 (8.9) servings/week; tofu/traditional soy foods, 2.1 (3.8) servings/week; soy beverages, 3.8 (6.3) servings/week. Mean AOM was 12.5 (1.4) y for those who reached menarche. Consumption of total soy and the 3 types of soy foods was not significantly associated with AOM and with the odds for early- or late-AOM. Adjustment for demographic and dietary factors did not change the results.

Conclusion

Soy intake is not associated with AOM in a population of adolescent girls who have a wide range of, and relatively higher, soy intake than the general US population. Our finding suggests that the increasing popularity of soy in the US may not be associated with AOM.

Birth weight, childhood body mass index, and height in relation to mammographic density and breast cancer: a register-based cohort study

Introduction

High breast density, a strong predictor of breast cancer may be determined early in life. Childhood anthropometric factors have been related to breast cancer and breast density, but rarely simultaneously. We examined whether mammographic density (MD) mediates an association of birth weight, childhood body mass index (BMI), and height with the risk of breast cancer.

Methods

13,572 women (50 to 69 years) in the Copenhagen mammography screening program (1991 through 2001) with childhood anthropometric measurements in the Copenhagen School Health Records Register were followed for breast cancer until 2010. With logistic and Cox regression models, we investigated associations among birth weight, height, and BMI at ages 7 to 13 years with MD (mixed/dense or fatty) and breast cancer, respectively.

Results

8,194 (60.4%) women had mixed/dense breasts, and 716 (5.3%) developed breast cancer. Childhood BMI was significantly inversely related to having mixed/dense breasts at all ages, with odds ratios (95% confidence intervals) ranging from 0.69 (0.66 to 0.72) at age 7 to 0.56 (0.53 to 0.58) at age 13, per one-unit increase in z-score. No statistically significant associations were detected between birth weight and MD, height and MD, or birth weight and breast cancer risk. BMI was inversely associated with breast cancer, with hazard ratios of 0.91 (0.83 to 0.99) at age 7 and 0.92 (0.84 to 1.00) at age 13, whereas height was positively associated with breast cancer risk (age 7, 1.06 (0.98 to 1.14) and age 13, 1.08 (1.00 to 1.16)). After additional adjustment for MD, associations of BMI with breast cancer diminished (age 7, 0.97 (0.88 to 1.06) and age 13, 1.01 (0.93 to 1.11)), but remained with height (age 7, 1.06 (0.99 to 1.15) and age 13, 1.09 (1.01 to 1.17)).

Conclusions

Among women 50 years and older, childhood body fatness was inversely associated with the breast cancer risk, possibly via a mechanism mediated by MD, at least partially. Childhood tallness was positively associated with breast cancer risk, seemingly via a pathway independent of MD. Birth weight was not associated with MD or breast cancer in this age group.

Body size in early life and breast cancer risk in African American and European American women

PURPOSE

There is growing evidence that body size in early life influences lifetime breast cancer risk, but little is known for African American (AA) women.

METHODS

We evaluated body size during childhood and young adulthood and breast cancer risk among 1,751 cases [979 AA and 772 European American (EA)] and 1,673 controls (958 AA and 715 EA) in the Women's Circle of Health Study. Odds ratio (OR) and 95 % confidence intervals (CI) were computed using logistic regression models while adjusting for potential covariates.

RESULTS

Among AA women, being shorter at 7-8 years compared to peers was associated with increased postmenopausal breast cancer risk (OR 1.68, 95 % CI 1.02-2.74), and being heavier at menarche with decreased postmenopausal breast cancer risk, although of borderline significance (OR 0.45, 95 % CI 0.20-1.02). For EA women, being shorter from childhood through adolescence, particularly at menarche, was associated with reduced premenopausal breast cancer risk (OR 0.55, 95 % CI 0.31-0.98). After excluding hormone replacement therapy users, an inverse association with postmenopausal breast cancer was found among EA women reporting to be heavier than their peers at menarche (OR 0.18, 95 % CI 0.04-0.79). The inverse relationship between BMI at age 20 and breast cancer risk was stronger and only statistically significant in EA women. No clear association with weight gain since age 20 was found.

CONCLUSIONS

Findings suggest that the impact of childhood height on breast cancer risk may differ for EA and AA women and confirm the inverse association previously reported in EA populations with adolescent body fatness, in AA women.

Invited commentary: are dietary intakes and other exposures in childhood and adolescence important for adult cancers?

In this issue of the Journal, Nimptsch et al. (Am J Epidemiol. 2013;178(2):172-183) report significant associations between female adolescents' poultry consumption in high school and subsequent reduced risk of colorectal adenomas in adulthood. Consumption of red meat or fish was not related to risk, but replacement with poultry reduced the risk of later adenomas. Most epidemiologic studies of adult diseases lack exposure data from the distant past. By focusing on a cancer precursor lesion and using a variety of methods to assess data quality, the investigators address concerns about the quality of distant recall. These findings add to the growing evidence that links childhood and adolescent lifestyle and environmental exposures with subsequent risk of cancers arising in adulthood. Highlights of the literature on this topic and methodological challenges are summarized. Future studies would benefit from incorporating measures of lifestyle, diet, environmental exposures, and other risk factors from early in life and from validation and other data quality checks of such measurements. Sources of historical data on children's and adolescents' exposures should be sought and evaluated in conjunction with subsequent exposures in relationship to adult-onset cancers.

Effects of maternal dietary exposure to cadmium during pregnancy on mammary cancer risk among female offspring

Background:

Since heavy metal cadmium is an endocrine disrupting chemical, we investigated whether maternal exposure to cadmium during the pregnancy alters mammary tumorigenesis among female offspring.

Methods:

From gestation day 10 to day 19, pregnant rat dams were fed modified American Institute of Nutrition (AIN93G) diet containing 39% energy from fat (baseline diet), or the baseline diet containing moderate (75 μg/kg of feed) or high (150 μg/kg) cadmium levels. Some dams were injected with 10 μg 17β-estradiol (E2) daily between gestation days 10 and 19.

Results:

Rats exposed to a moderate cadmium dose in utero were heavier and exhibited accelerated puberty onset. Both moderate and high cadmium dose led to increased circulating testosterone levels and reduced the expression of androgen receptor in the mammary gland. The moderate cadmium dose mimicked the effects of in utero E2 exposure on mammary gland morphology and increased both the number of terminal end buds and pre-malignant hyperplastic alveolar nodules (HANs), but in contrast to the E2, it did not increase 7, 12-dimethylbenz (a) anthracene-induced mammary tumorigenesis.

Conclusions:

The effects of in utero cadmium exposure were dependent on the dose given to pregnant dams: Moderate, but not high, cadmium dose mimicked some of the effects seen in the in utero E2 exposed rats, such as increased HANs in the mammary gland.

Amphiregulin mediates progesterone-induced mammary ductal development during puberty

Introduction

Puberty is a period of increased susceptibility to factors that cause increased breast cancer risk in adulthood. Mammary end buds (EBs) that develop during puberty are believed to be the targets of breast cancer initiation. Whereas the role of estrogen (E) has been extensively studied in pubertal mammary gland development, the role of progesterone (P) during puberty is less defined.

Methods

Pubertal and prepubertal ovariectomized mice were treated with vehicle control (C), E, P, or E+P. Mammary glands from these mice were analyzed for changes in morphology, proliferation, and expression of the downstream targets amphiregulin (AREG) and receptor activator of NF-κB ligand (RANKL).

Results

P, acting specifically through the progesterone receptor, induced increases in mammary gland proliferation and EB formation that were associated with increased AREG expression in ducts and EBs. E, acting specifically through the estrogen receptor, produced similar responses also mediated by AREG. Blocking AREG action by treatment with an EGFR inhibitor completely abrogated the effect of P on EB formation and proliferation and significantly reduced proliferation within ducts. P also increased expression of RANKL, primarily in ducts. Treatment with RANK-Fc, an inhibitor of RANKL, reduced P-dependent proliferation in ducts and to a lesser extent in EB, but did not cause EB regression.

Conclusions

These results demonstrate a novel P-specific effect through AREG to cause EB formation and proliferation in the developing mammary gland both before and during puberty. Thus, hormones and/or factors in addition to E that upregulate AREG can promote mammary gland development and have the potential to affect breast cancer risk associated with pubertal mammary gland development.

Diet across the Lifespan and the Association with Breast Density in Adulthood

Studies have shown inconsistent results regarding the association between dietary factors across the lifespan and breast density and breast cancer in women. Breast density is a strong risk factor for breast cancer, and the mechanism through which it influences cancer risk remains unclear. Breast density has been shown to be modifiable, potentially through dietary modifications. The goal of this paper is to summarize the current studies on diet and diet-related factors across all ages, determine which dietary factors show the strongest association with breast density, the most critical age of exposure, and identify future directions. We identified 28 studies, many of which are cross-sectional, and found that the strongest associations are among vitamin D, calcium, dietary fat, and alcohol in premenopausal women. Longitudinal studies with repeated dietary measures as well as the examination of overall diet over time are needed to confirm these findings.