Search

Featured Application: The new breast measurement coordinate system proposed in this study offers a practical tool for accurately measuring breast dimensions in adolescent females, particularly during their dynamic growth stages. This system can be utilized in designing ergonomically optimized bras and other wearable products that provide a better fit and greater comfort. Additionally, it holds potential for use in medical assessments, sports science, and ergonomic studies, where precise breast measurements are essential for evaluating health and performance. Selecting an appropriate bra product has long been a challenge for adolescent girls, whose breasts are rapidly growing. This challenge arises due to the absence of a rational benchmark for breast measurement. Traditional benchmarks are based on ergonomic principles, using reference points located on the human skeleton. However, the breast lacks a bone structure for support, leading to highly variable measurement results. In this study, the jugular notch and the xiphoid process were selected as breast measurement points according to academic principles. Their accuracy, stability, and deviation were experimentally investigated through tactile assessment of adolescent girls at different stages of development. Based on the experimental results, a novel breast measurement coordinate system was established, and its accuracy was verified by conversion calculations using a geodetic coordinate system. The results indicated that the numerical calculation of the breast shape was more accurate using the newly established breast measurement coordinate system. [ABSTRACT FROM AUTHOR]

Objective: Serum luteinising hormone (LH) concentration has been reported to be lower in girls with overweight and obesity (OW/OB) as compared with girls with normal weight (NW). This study aimed to evaluate peak serum LH concentration during gonadotropin‐releasing hormone analogue (GnRHa) test in girls with OW/OB and NW who had central precocious puberty (CPP) and to determine peak serum LH cut‐off for diagnosing CPP in girls with OW/OB. Design, Patients and Measurements: Medical records of 971 girls with premature breast development who underwent subcutaneous GnRHa (100 µg of triptorelin acetate) test were reviewed. All girls were classified as either CPP or premature thelarche. All of them were further classified into two groups according to their body mass index as NW and OW/OB groups for each Tanner stage. Results: There were 634 and 337 girls in NW and OW/OB groups, respectively. CPP was diagnosed in 600 girls (249 had Tanner stage II and 351 had Tanner stage III). There were no differences in peak serum LH concentrations between CPP girls with NW and OW/OB. Peak serum LH cut‐off of 5 IU/L (the current widely used cut‐off) had a sensitivity and a specificity of 75% and 90%, respectively in NW group. Peak serum LH cut‐off for CPP diagnosis was lower at 4 IU/L in the OW/OB group with greater sensitivity and specificity of 86% and 93%, respectively. The results were reproducible for each Tanner stage of breasts. Conclusion: Lower peak serum LH cut‐off to 4 IU/L for diagnosing CPP in girls with OW/OB should be considered to avoid underdiagnosis of the condition. [ABSTRACT FROM AUTHOR]

Selecting an appropriate bra product has long been a challenge for adolescent girls, whose breasts are rapidly growing. This challenge arises due to the absence of a rational benchmark for breast measurement. Traditional benchmarks are based on ergonomic principles, using reference points located on the human skeleton. However, the breast lacks a bone structure for support, leading to highly variable measurement results. In this study, the jugular notch and the xiphoid process were selected as breast measurement points according to academic principles. Their accuracy, stability, and deviation were experimentally investigated through tactile assessment of adolescent girls at different stages of development. Based on the experimental results, a novel breast measurement coordinate system was established, and its accuracy was verified by conversion calculations using a geodetic coordinate system. The results indicated that the numerical calculation of the breast shape was more accurate using the newly established breast measurement coordinate system.

Background There is limited research on whether physical activity (PA) in early childhood is associated with the timing of pubertal events in girls. Methods We used data collected over 2011–16 from the LEGACY Girls Study (n  = 984; primarily aged 6–13 years at study enrolment), a multicentre North American cohort enriched for girls with a breast cancer family history (BCFH), to evaluate if PA is associated with age at thelarche, pubarche and menarche. Maternal-reported questionnaire data measured puberty outcomes, PA in early childhood (ages 3–5 years) and total metabolic equivalents of organized PA in middle childhood (ages 7–9 years). We used interval-censored Weibull parametric survival regression models with age as the time scale and adjusted for sociodemographic factors, and we tested for effect modification by BCFH. We used inverse odds weighting to test for mediation by body mass index-for-age z-score (BMIZ) measured at study enrolment. Results Being highly active vs inactive in early childhood was associated with later thelarche in girls with a BCFH [adjusted hazard ratio (aHR) = 0.39, 95% CI = 0.26–0.59), but not in girls without a BCFH. In all girls, irrespective of BCFH, being in the highest vs lowest quartile of organized PA in middle childhood was associated with later menarche (aHR = 0.70, 95% CI = 0.50–0.97). These associations remained after accounting for potential mediation by BMIZ. Conclusion This study provides new data that PA in early childhood may be associated with later thelarche in girls with a BCFH, also further supporting an overall association between PA in middle childhood and later menarche. [ABSTRACT FROM AUTHOR]

Background: Feminizing gender-affirming hormone therapy (GAHT) for transgender individuals traditionally includes estradiol and androgen deprivation. Research has demonstrated that breast size as a result of GAHT in transgender women is often limited. Therefore, transgender women often choose to undergo breast augmentation surgery. Progesterone is important for breast development in cisgender women during puberty. A potential role for progesterone in breast development in transgender women has not been investigated in a randomized controlled experimental set-up. The primary objective of this study is to explore the effects on breast volume of addition of oral progesterone to GAHT with estradiol in transgender women after vaginoplasty or orchiectomy. Secondary objectives include assessment of safety, satisfaction, mood, sleep and sexual pleasure. Methods: This is a non-blinded, non-placebo, randomized controlled trial using a factorial design in adult transgender individuals assigned male sex at birth who have undergone GAHT for at least one year and underwent vaginoplasty or orchiectomy. The study design allows for rapid assessment of potential synergistic effects of various dose combinations of estradiol and progesterone on breast volume change: Ninety participants will be randomized into six groups of 15 subjects each, receiving either the baseline dose of estradiol, the baseline dose of estradiol and progesterone 200 mg daily, the baseline dose of estradiol and progesterone 400 mg daily, twice the baseline dose of estradiol, twice the baseline dose of estradiol and progesterone 200 mg daily or twice the baseline dose of estradiol and progesterone 400 mg daily, all for a duration of 12 months. The main study parameters include changes in breast volume as determined by 3D measurements. Participants will be followed-up with laboratory testing including serum progesterone concentrations as well as surveys for satisfaction, mood, sleep quality and sexual pleasure. Discussion: This study will indicate whether progesterone is safe and of additional value with regard to breast volume change in transgender individuals receiving feminizing GAHT. The results of this study will be useful for innovation of feminizing GAHT. Trial registration: WHO International Clinical Trials Registry Platform: EUCTR2020-001952-16-NL; date of registration: 12 December 2020 https://trialsearch.who.int/Trial2.aspx?TrialID=EUCTR2020-001952-16-NL. [ABSTRACT FROM AUTHOR]

Stressful environments have been associated with earlier menarche. We hypothesized that anxiety, and possibly other internalizing symptoms, are also associated with earlier puberty in girls. The Lessons in Epidemiology and Genetics of Adult Cancer From Youth (LEGACY) Girls Study (2011-2016) included 1,040 girls aged 6-13 years at recruitment whose growth and development were assessed every 6 months. Prepubertal maternal reports of daughter's internalizing symptoms were available for breast onset (n = 447), pubic hair onset (n = 456), and menarche (n = 681). Using Cox proportional hazard regression, we estimated prospective hazard ratios and 95% confidence intervals for the relationship between 1 standard deviation of the percentiles of prepubertal anxiety, depression, and somatization symptoms and the timing of each pubertal outcome. Multivariable models included age, race/ethnicity, study center, maternal education, body mass index percentile, and family history of breast cancer. Additional models included maternal self-reported anxiety. A 1-standard deviation increase in maternally reported anxiety in girls at baseline was associated with earlier subsequent onset of breast (hazard ratio (HR) = 1.22, 95% confidence interval (CI): 1.09, 1.36) and pubic hair (HR = 1.15, 95% CI: 1.01, 1.30) development, but not menarche (HR = 0.94, 95% CI: 0.83, 1.07). The association of anxiety with earlier breast development persisted after adjustment for maternal anxiety. Increased anxiety in young girls may indicate risk for earlier pubertal onset.

Context: Age of pubertal onset has been decreasing in many countries but there have been no data on pubertal development in Chinese children over the last decade. Objective: The primary objective of the study was to evaluate the current status of sexual maturation in Chinese children and adolescents. Secondary objectives were to examine socioeconomic, lifestyle, and auxological associations with pubertal onset. Methods: In this national, cross-sectional, community-based health survey, a multistage, stratified cluster random sampling method was used to select a nationally representative sample, consisting of 231 575 children and adolescents (123 232 boys and 108 343 girls) between 2017 and 2019. Growth parameters and pubertal staging were assessed by physical examination. Results: Compared to 10 years previously, the median age of Tanner 2 breast development and menarche were similar at 9.65 years and 12.39 years respectively. However, male puberty occurred earlier with a median age of testicular volume ≥4 mL of 10.65 years. Pubertal onset did occur earlier at the extremes, with 3.3% of the girls with breast development at 6.5-6.99 years old, increasing to 5.8% by 7.5-7.99 years old. Early pubertal onset was also noted in boys, with a testicular volume ≥ 4 mL noted in 1.5% at 7.5-7.99 years, increasing to 3.5% at 8.5-8.99 years old. Obesity and overweight increased risk of developing earlier puberty relative to normal weight in both boys and girls. Conclusion: Over the past decade, pubertal development is occurring earlier in Chinese children. While the cause is multifactorial, overweight and obesity are associated with earlier puberty onset. The currently used normative pubertal data of precocious puberty may not be applicable to diagnose precocious puberty. [ABSTRACT FROM AUTHOR]

BackgroundPolycyclic aromatic hydrocarbons (PAHs) are a class of ubiquitous, environmental chemicals that may have endocrine disrupting capabilities. We investigated whether childhood exposure to PAHs was associated with adiposity and pubertal timing in a longitudinal study of 404 girls enrolled in the Northern California site of the Breast Cancer and the Environment Research Program cohort.MethodsBaseline urinary samples from girls aged 6-8-years-old were assayed for 2-naphthol, fluorene metabolites, phenanthrene metabolites, 1-hydroxypyrene, and sum of PAH metabolites. Mixed-effects linear models were used to estimate how concentrations of PAH metabolites were related to changes in girl's body mass index (BMI) and waist-to-height ratio from age 7 through 16 years old. Accelerated failure time models were used to estimate age of pubertal onset (Tanner stages 2 or higher for breast and pubic hair development).ResultsHigher adiposity measurements among high tertiles of baseline PAH metabolites were evident at age 7 years old and increased thereafter (i.e., BMI for all PAH metabolites, waist-to-height ratio for fluorene and phenanthrene metabolites) or leveled off (i.e., waist-to-height ratio for 2-naphthol, 1-hydroxypyrene, sum of PAHs). Among girls overweight/obese at baseline, median age of breast development onset for high tertiles was 9.1-9.4 years old compared with 10-10.2 years old for low tertiles for all PAH metabolites; in contrast, found no association or slightly later onset of breast development for girls with normal weight at baseline.DiscussionThese results suggest that exposure to specific PAHs during childhood may influence adiposity throughout adolescence and effect pubertal timing.

Milk carbohydrates Lactose and oligosaccharides are the most predominant nutrients in human milk, lactose being present at about 75 g/L compared to cow's milk, which has only about 50 g/L ([35]). Structural components of human milk separated by various centrifugation methods include milk fat globules, casein micelles, milk cells, exosomes, and bacteria often referred to as microbiota. Keywords: breast development; estrogen; human milk; progesterone; secretory activation EN breast development estrogen human milk progesterone secretory activation 64 70 7 06/20/23 20230601 NES 230601 Introduction In this article, the development of the mammary gland in the human fetus is described followed by a comparison of the situation and anatomy of the mammary glands in the human with the glands in rodents and dairy animals. Recent studies of the cells in human milk have shown that the large proportion of cells in human milk are lactocytes that retain many characteristics of milk secreting cells and offer an interesting medium for the study of the molecular biology of human lactation. [Extracted from the article]

Background Earlier onset of breast development (thelarche) is associated with increased breast cancer risk. Identifying modifiable factors associated with earlier thelarche may provide an opportunity for breast cancer risk reduction starting early in life, which could especially benefit girls with a greater absolute risk of breast cancer due to family history. Methods We assessed associations of maternal pre-pregnancy body mass index (BMI), physical activity during pregnancy, gestational weight gain and daughters' weight and length at birth with age at thelarche using longitudinal Weibull models in 1031 girls in the Lessons in Epidemiology and Genetics of Adult Cancer from Youth (LEGACY) Girls Study—a prospective cohort of girls, half of whom have a breast cancer family history (BCFH). Results Girls whose mothers had a pre-pregnancy BMI of ≥25 and gained ≥30 lbs were 57% more likely to experience earlier thelarche than girls whose mothers had a pre-pregnancy BMI of <25 and gained <30 lbs [hazard ratio (HR) = 1.57, 95% CI: 1.16, 2.12]. This association was not mediated by childhood BMI and was similar in girls with and without a BCFH (BCFH: HR = 1.41, 95% CI: 0.87, 2.27; No BCFH: HR = 1.62, 95% CI: 1.10, 2.40). Daughters of women who reported no recreational physical activity during pregnancy were more likely to experience earlier thelarche compared with daughters of physically active women. Birthweight and birth length were not associated with thelarche. Conclusion Earlier thelarche, a breast cancer risk factor, was associated with three potentially modifiable maternal risk factors—pre-pregnancy BMI, gestational weight gain and physical inactivity—in a cohort of girls enriched for BCFH. [ABSTRACT FROM AUTHOR]

Simple Summary: Transgender women experience gender dysphoria due to a gender assignment at birth that is incongruent with their gender identity. Transgender people undergo different surgical procedures and receive sex steroids hormones to reduce psychological distress and to induce and maintain desired physical changes. A search of the existing literature dedicated to hormone regimens used for treating male to female patients, their impact on breast tissue (tissue development, incidence and type of breast lesions observed) and breast cancer risk provided the available information for this review. An evaluation of breast cancer risk is complicated because of the heterogeneity of administered treatments and a lack of long-term follow-up studies. Transgender women experience gender dysphoria due to a gender assignment at birth that is incongruent with their gender identity. Transgender people undergo different surgical procedures and receive sex steroids hormones to reduce psychological distress and to induce and maintain desired physical changes. These persons on feminizing hormones represent a unique population to study the hormonal effects on breast development, to evaluate the risk of breast cancer and perhaps to better understand the precise role played by different hormonal components. In MTF (male to female) patients, hormonal treatment usually consists of antiandrogens and estrogens. Exogenous hormones induce breast development with the formation of ducts and lobules and an increase in the deposition of fat. A search of the existing literature dedicated to hormone regimens for MTF patients, their impact on breast tissue (incidence and type of breast lesions) and breast cancer risk provided the available information for this review. The evaluation of breast cancer risk is currently complicated by the heterogeneity of administered treatments and a lack of long-term follow-up in the great majority of studies. Large studies with longer follow-up are required to better evaluate the breast cancer risk and to understand the precise mechanisms on breast development of each exogenous hormone. [ABSTRACT FROM AUTHOR]

Secular trends in puberty refer to the changes observed over time in the onset and progression of puberty in populations. One of the most notable secular trends in recent years it is the declining age of puberty timing. The secular trend in early breast development (thelarche) refers to the observed phenomenon of girls entering puberty at progressively younger ages over successive generations. The aim of this study is to assess the breast development stages among girls, comparing four ethnicities in the northwestern part of North Macedonia. Material and methods: An assessment of breast development stages was conducted, which included the cross-sectional study evaluation of 480 sampled girls aged 6-13 years from four different ethnicities. Breast development was assessed using Tanner and Whitehouse method which categorizes breast development into five stages (B1 to B5) based on specific physical characteristics. Results: The prevalence of breast development stages according to age shows that B2 increased gradually from 2.6% at 6+ years to 8.0% at 7+, 13.5% at 8+, and 30.6% at 9+. The highest prevalence was observed at 10+ years with 43.1% and at 11+ years with 25.8%. The mean age of reaching breast development stage B2 in the entire sample of girls was 9.38 +/- 1.3 years. Among the four ethnicities, the lowest average age was observed among Roma girls (9.11 +/- 1.19 years), followed by Turkish girls (9.13 +/- 0.63 years), Macedonian girls (9.41 +/- 1.22 years), and Albanian girls (9.43 +/- 1.44 years). Conclusion: At our study the prevalence of stage B2 breast development at 6 and 7 years, is worth emphasizing because the occurrence of secondary sexual characteristics before the age of 8 may indicate a possible sign of early onset of puberty. Early thelarche, occurring before the age of 8, has become a topic of interest due to its potential psychological, social, and long-term health implications. [ABSTRACT FROM AUTHOR]

The thirteenth annual workshop of the European Network for Breast Development and Cancer (ENBDC) Laboratories Annual Workshop took place on the 28–30 April 2022 in Weggis, Switzerland and focused on methods in mammary gland biology and breast cancer. Sixty scientists participated in the ENBDC annual workshop which had not been held in person since 2019 due to the global COVID-19 pandemic. Topics spanned the mammary gland biology field, ranging from lactation biology and embryonic development, single cell sequencing of the human breast, and stunning cutting-edge imaging of the mouse mammary gland and human breast as well as breast cancer research topics including invasive progression of the pre-invasive DCIS stage, metabolic determinants of endocrine therapy resistance, models for lobular breast cancer, and how mutational landscapes of normal breast during age and pregnancy determine cancer risk. The latest findings from participating researchers were presented through oral presentations and poster sessions and included plenty of unpublished work. [ABSTRACT FROM AUTHOR]

Introduction: Breast tissue in infancy is a rather undescribed phenomenon. We aimed to describe the prevalence and progression of palpable breast tissue in healthy boys and girls aged 0-1 years and to evaluate clinical markers, individual serum hormone concentrations as well as combined hormone profiles as determinants of the persistence of breast tissue. Methods: In total, 233 term infants (119 boys, 114 girls) were included and followed from birth until 1 year of age in The COPENHAGEN Minipuberty Study (ClinicalTrials.gov #NTC02784184). Infants were followed up to six times with a clinical examination and serum sampling. Principal component analyses (PCAs) produced combined hormone profiles. Results: A total of 98% of all infants aged 0-1 year exhibited breast tissue at some point. 50% still had breast tissue present at 0.5-0.6 years in girls and 0.3- 0.4 years in boys (‘persistent’). At one year, more girls than boys had breast tissue present (p=0.010). Most clinical and hormonal markers did not differ in infants with/without persistent breast tissue. However, in those with persistent breast tissue, estradiol (first visit, girls, p=0.034), androstenedione, corticosterone, cortisol (first visit, boys, all p<0.050), length (first visit, boys, p=0.030), and testicular volume (0.3-0.4 years, p=0.040) were higher, while IGF-I (0.3-0.4, boys, p=0.033) was lower. In boys, a combined, PCA-derived hormone profile (first visit) was able to predict the persistence of breast tissue (area under the curve=83%) better than any single marker. Discussion: Palpable breast tissue in infancy is common in both sexes although it persists in significantly more girls than boys at one year of age. Data supports both the early origin of breast tissue (in utero- and early postnatal) as well as a role of endogenous hormone production in later development and maintenance. [ABSTRACT FROM AUTHOR]

Abstract Background Early age at breast development (thelarche) has been associated with increased breast cancer risk. Average age at thelarche has declined over time, but there are few established risk factors for early thelarche. We examined associations between pre- and postnatal exposures and age at thelarche in a US cohort of women born between 1928 and 1974. Methods Breast cancer-free women ages 35–74 years who had a sister diagnosed with breast cancer were enrolled in the Sister Study from 2003 to 2009 (N = 50,884). At enrollment, participants reported information on early-life exposures and age at thelarche, which we categorized as early (≤ 10 years), average (11–13 years), and late (≥ 14 years). For each exposure, we estimated odds ratios (ORs) and 95% confidence intervals (CIs) for early and late thelarche using polytomous logistic regression, adjusted for birth cohort, race/ethnicity and family income level in childhood. Results Early thelarche was associated with multiple prenatal exposures: gestational hypertensive disorder (OR = 1.25, 95% CI 1.09–1.43), diethylstilbestrol use (OR = 1.23, 95% CI 1.04–1.45), smoking during pregnancy (OR = 1.20, 95% CI 1.13–1.27), young maternal age (OR 1.30, 95% CI 1.16–1.47 for

IntroductionBreast tissue in infancy is a rather undescribed phenomenon. We aimed to describe the prevalence and progression of palpable breast tissue in healthy boys and girls aged 0-1 years and to evaluate clinical markers, individual serum hormone concentrations as well as combined hormone profiles as determinants of the persistence of breast tissue.MethodsIn total, 233 term infants (119 boys, 114 girls) were included and followed from birth until 1 year of age in The COPENHAGEN Minipuberty Study (ClinicalTrials.gov #NTC02784184). Infants were followed up to six times with a clinical examination and serum sampling. Principal component analyses (PCAs) produced combined hormone profiles.ResultsA total of 98% of all infants aged 0-1 year exhibited breast tissue at some point. 50% still had breast tissue present at 0.5-0.6 years in girls and 0.3-0.4 years in boys (‘persistent’). At one year, more girls than boys had breast tissue present (p=0.010). Most clinical and hormonal markers did not differ in infants with/without persistent breast tissue. However, in those with persistent breast tissue, estradiol (first visit, girls, p=0.034), androstenedione, corticosterone, cortisol (first visit, boys, all p

Background: The average age at thelarche has trended downwards worldwide since 1970s; however, the onset age of "precocious puberty", defined as the lower percentiles of thelarche age, has been rarely reported. This systematic review aims to evaluate secular trends in age at thelarche among Chinese girls. Methods: This systematic review on the age at thelarche during puberty among Chinese girls was conducted via systematic search of both Chinese (Chinese National Knowledge Infrastructure, WanFang Database, and the Chinese Scientific Journals Database) and English (PubMed, Cochrane Library, and Embase) databases. Data were analyzed using the GraphPad Prism v9.0. Results: A total of 16 studies involving 177,886 Chinese girls were synthesized. The QualSyst scores of these studies were high at an average of 21.25. The timing of Tanner breast stage 2 (B2) occurred earlier over time at the P3, P10, and median ages. Weighted analyses revealed that the overall onset age of B2 tended to be younger at P3, P10, and P25. The age of B2 varied across regions and areas. For example, P3, P10, and median age of B2 in years were younger in southern regions than that in northern regions of China (P3: 5.94 vs. 7.3; P10: 6.6 vs. 7.9; median age: 8.26 vs. 9.5), and median age of B2 in urban areas (8.26 years) was earlier than that in rural areas (10.29 years). In addition, median age of B2 from 12 single-center studies was earlier than that from 4 multicenter studies (8.26 vs. 9.18 years). Conclusions: The current findings indicated that pubertal breast development age among Chinese girls presented an advanced trend over the past 20 years, which urges the necessity to revisit and redefine "precocious puberty" and provides useful recommendations for clinical practice. [ABSTRACT FROM AUTHOR]

BackgroundMany common environmental chemicals are mammary gland carcinogens in animal studies, activate relevant hormonal pathways, or enhance mammary gland susceptibility to carcinogenesis. Breast cancer's long latency and multifactorial etiology make evaluation of these chemicals in humans challenging.ObjectiveFor chemicals previously identified as mammary gland toxicants, we evaluated epidemiologic studies published since our 2007 review. We assessed whether study designs captured relevant exposures and disease features suggested by toxicological and biological evidence of genotoxicity, endocrine disruption, tumor promotion, or disruption of mammary gland development.MethodsWe systematically searched the PubMed database for articles with breast cancer outcomes published in 2006-2016 using terms for 134 environmental chemicals, sources, or biomarkers of exposure. We critically reviewed the articles.ResultsWe identified 158 articles. Consistent with experimental evidence, a few key studies suggested higher risk for exposures during breast development to dichlorodiphenyltrichloroethane (DDT), dioxins, perfluorooctane-sulfonamide (PFOSA), and air pollution (risk estimates ranged from 2.14 to 5.0), and for occupational exposure to solvents and other mammary carcinogens, such as gasoline components (risk estimates ranged from 1.42 to 3.31). Notably, one 50-year cohort study captured exposure to DDT during several critical windows for breast development (in utero, adolescence, pregnancy) and when this chemical was still in use. Most other studies did not assess exposure during a biologically relevant window or specify the timing of exposure. Few studies considered genetic variation, but the Long Island Breast Cancer Study Project reported higher breast cancer risk for polycyclic aromatic hydrocarbons (PAHs) in women with certain genetic variations, especially in DNA repair genes.ConclusionsNew studies that targeted toxicologically relevant chemicals and captured biological hypotheses about genetic variants or windows of breast susceptibility added to evidence of links between environmental chemicals and breast cancer. However, many biologically relevant chemicals, including current-use consumer product chemicals, have not been adequately studied in humans. Studies are challenged to reconstruct exposures that occurred decades before diagnosis or access biological samples stored that long. Other problems include measuring rapidly metabolized chemicals and evaluating exposure to mixtures.

Abstract Background Earlier age at menarche is an established risk factor for breast cancer. While age at menarche has been fairly stable over the past half-century, age at breast development (thelarche) has continued to decrease. Recently, earlier age at thelarche and a longer time between thelarche and menarche (pubertal tempo) were shown to be associated with increased breast cancer risk. Our objective was to examine how breast cancer risk was associated with pubertal timing and tempo in a prospective US cohort. Methods Women ages 35–74 years without a history of breast cancer, but who had a sister previously diagnosed with breast cancer, were enrolled in the Sister Study from 2003 to 2009 (N = 50,884). At enrollment, participants reported their ages at thelarche and menarche. Pubertal tempo was age at menarche minus age at thelarche. We estimated adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) for each pubertal milestone and risk of breast cancer (invasive or ductal carcinoma in situ) using Cox proportional hazards regression. We examined whether associations between age at thelarche and breast cancer risk were modified by birth cohort, race/ethnicity, weight at age 10, and extent of breast cancer family history, as characterized by a Bayesian score based on first-degree family structure. Results During follow-up (mean = 9.3 years), 3295 eligible women were diagnosed with breast cancer. Early ages at thelarche (HR = 1.23, 95% CI 1.03–1.46 for

Background: Early age at breast development (thelarche) has been associated with increased breast cancer risk. Average age at thelarche has declined over time, but there are few established risk factors for early thelarche. We examined associations between pre- and postnatal exposures and age at thelarche in a US cohort of women born between 1928 and 1974.Methods: Breast cancer-free women ages 35-74 years who had a sister diagnosed with breast cancer were enrolled in the Sister Study from 2003 to 2009 (N = 50,884). At enrollment, participants reported information on early-life exposures and age at thelarche, which we categorized as early (≤ 10 years), average (11-13 years), and late (≥ 14 years). For each exposure, we estimated odds ratios (ORs) and 95% confidence intervals (CIs) for early and late thelarche using polytomous logistic regression, adjusted for birth cohort, race/ethnicity and family income level in childhood.Results: Early thelarche was associated with multiple prenatal exposures: gestational hypertensive disorder (OR = 1.25, 95% CI 1.09-1.43), diethylstilbestrol use (OR = 1.23, 95% CI 1.04-1.45), smoking during pregnancy (OR = 1.20, 95% CI 1.13-1.27), young maternal age (OR 1.30, 95% CI 1.16-1.47 for < 20 vs. 25-29 years), and being firstborn (OR = 1.25, 95% CI 1.17-1.33). Birthweight < 2500 g and soy formula use in infancy were positively associated with both early and late thelarche.Conclusions: Associations between pre- and postnatal exposures and age at thelarche suggest that the early-life environment influences breast development and therefore may also affect breast cancer risk by altering the timing of pubertal breast development. [ABSTRACT FROM AUTHOR]

Purpose of Review: Radiologic-pathologic concordance is the review of a patient's breast imaging in the context of his/her pathology results and is a critical and unique component of breast imaging and diagnosis. Our goal is to develop a structured curriculum that prepares residents and fellows to analyze radiologic-pathologic concordance critical to patient management and improved patient outcomes. Recent Findings: To our knowledge, there is no formalized academic educational program to teach radiologic-pathologic concordance. To address this gap for our diagnostic radiology residents and fellows, we developed, in coordination with our breast pathology department, a standardized educational curriculum for radiologic-pathologic correlation based on the American College of Radiology and Society of Breast Imaging Resident and Fellowship Training Curriculum Monticciolo DL, Rebner M, Appleton CM, Newell MS, Farria DM, Sickles EA et al. (J Am Coll Radiol 10(3):207–10.e4, 1). This curriculum also includes normal breast development and unique pathology for different patient populations. Summary: The process of evaluating radiologic-pathologic concordance in breast imaging is essential, particularly after minimally invasive breast procedures to identify potentially discordant pathology results that require further action and concordant results that may need further management. Breast imagers traditionally teach residents and fellows this process primarily at the monitor as pathology results return and during periodic joint conferences with pathology colleagues. This leaves potential gaps of knowledge as trainees' experience is dependent on the types of pathology results returning while they are on rotation and if they are available when this process occurs. The absence of a standardized curriculum makes it challenging to learn or review this material and track its acquisition. The creation of a standardized curriculum and an educational journal series should enhance the uniformity of trainees' experiences with regard to this important topic. The purpose of this publication is to introduce the curriculum and describe topics covered in the first module, including normal breast histology, gross anatomy, development, alterations during the menstrual cycle, and the male breast. [ABSTRACT FROM AUTHOR]

The twelfth annual workshop of the European Network for Breast Development and Cancer focused on methods in mammary gland biology and breast cancer, was scheduled to take place on March 26–28, 2020, in Weggis, Switzerland. Due to the COVID-19 pandemic, the meeting was rescheduled twice and eventually happened as a virtual meeting on April 22 and 23, 2021. The main topics of the meeting were branching and development of the mammary gland, tumor microenvironment, circulating tumor cells, tumor dormancy and breast cancer metastasis. Novel and unpublished findings related to these topics were presented, with a particular focus on the methods used to obtain them. Virtual poster sessions were a success, with many constructive and fruitful interactions between researchers and covered many areas of mammary gland biology and breast cancer. [ABSTRACT FROM AUTHOR]

Abstract Background Premature thelarche (PT) is a benevolent ailment affecting young girls. Multiple factors are reported to correlate with this condition, but the mechanisms responsible for the onset of PT have not yet been fully investigated. This study aimed to evaluate the relationship of nutrient intake, insulin resistance and lipid profile with PT. Methods Two hundred sixty-three girls with PT, and 222 healthy girls of similar age were enrolled into this study. Their demographics, Tanner stage of breast development, nutrient intake, insulin resistance and lipid profiles were compared. Results Daily protein and fat intakes, insulin resistance parameters including serum insulin-like growth factor 1, fasting glucose to insulin ratio, quantitative insulin check index and homeostasis model of assessment of insulin resistance, as well as serum levels of triacylglycerol, total cholesterol and low-density lipoprotein, were all significantly altered in PT patients. Daily intake of energy and carbohydrate, and serum level of high-density lipoprotein protein were statistically indistinguishable between PT patients and healthy controls. Conclusion Chinese girls with PT are potentially insulin resistant, which warrants more clinical attention and further investigation to address the underlying etiology.

Abstract According to the life‐history theory, rates of sexual maturation have coevolved with mortality rates so that individuals who mature faster tend to die younger. We used two data sets, providing different markers for the speed of pubertal development to test whether rates of sexual maturation of women predict the age at death of their parents. In the data set of Estonian schoolgirls born between 1936 and 1961, the rate of breast development predicted lifespan of both mothers and fathers (irrespectively of their socio‐economic position), so that parents of rapidly maturing girls died at younger age. This finding supports the view that fast maturation rates in humans have coevolved with short lifespans and that such trade‐offs can be detected as intergenerational phenotypic correlations in modern populations. Menarcheal age of participants of Estonian Biobank (born between 1925 and 1996) did not predict the age of death of their mothers; however, it did predict survival of their fathers, but only in environment where the genetic variation is exposed (families where at least one parent had tertiary education). In such families (where girls also matured 0.2–0.4 years earlier than in poorly educated families), 1‐year delay in daughter's menarche corresponded to 9% lower hazard of father's death. Heritability of menarcheal age was also highest in well‐educated families. The latter findings are consistent with the idea that genetic differences in the rate of pubertal maturation may be expressed most clearly in well‐off families because in such families, the contribution of environmental variance to total phenotypic variance in menarcheal age is smallest. Our findings suggest that with global improvement and equalization of growth conditions, reductions of environmental variation in the rate of maturation increasingly expose the genetic differences in menarcheal age to selection. Under such conditions, selection on menarcheal age has a potential to affect the evolution of lifespan.

Background and objectivesThere is growing evidence of pubertal maturation occurring at earlier ages, with many studies based on cross-sectional observations. This study examined age at onset of breast development (thelarche), and the impact of BMI and race/ethnicity, in the 3 puberty study sites of the Breast Cancer and the Environment Research Program, a prospective cohort of >1200 girls.MethodsGirls, 6 to 8 years at enrollment, were followed longitudinally at regular intervals from 2004 to 2011 in 3 geographic areas: the San Francisco Bay Area, Greater Cincinnati, and New York City. Sexual maturity assessment using Tanner staging was conducted by using standardized observation and palpation methods by trained and certified staff. Kaplan-Meier analyses were used to describe age at onset of breast maturation by covariates.ResultsThe age at onset of breast stage 2 varied by race/ethnicity, BMI at baseline, and site. Median age at onset of breast stage 2 was 8.8, 9.3, 9.7, and 9.7 years for African American, Hispanic, white non-Hispanic, and Asian participants, respectively. Girls with greater BMI reached breast stage 2 at younger ages. Age-specific and standardized prevalence of breast maturation was contrasted to observations in 2 large cross-sectional studies conducted 10 to 20 years earlier (Pediatric Research in Office Settings and National Health and Nutrition Examination Survey III) and found to have occurred earlier among white, non-Hispanic, but not African American girls.ConclusionsWe observed the onset of thelarche at younger ages than previously documented, with important differences associated with race/ethnicity and BMI, confirming and extending patterns seen previously. These findings are consistent with temporal changes in BMI.

Background: Adolescence is accompanied by a variety of changes in young breast development, which greatly affects the adolescent's psychology and socialization. Summary: PubMed, EMBASE, and the Cochrane Library were searched for studies relative to epidemiology, clinical characteristics, diagnosis, and management of all breast disorders in adolescence and their consequences. Development disorders are breast asymmetry, breast atrophy, breast hypoplasia, hypomastia, juvenile breast hypertrophy, and tuberous breast. Breast congenital abnormalities include athelia, amastia, accessory breast tissue, polymastia, polythelia, and congenital disorders of nipples. Breast infections are commonly caused from Gram-positive coccus rather than Gram-negative bacteria. Breast abscess occurs when breast infections are not promptly treated. Nipple discharge is caused by a variety of conditions and should be managed carefully. Fibrocystic changes, cysts, and fibroadenomas are the most common benign masses in adolescence. Primary, secondary, or metastatic breast cancer is extremely rare in adolescence. However, clinicians should include breast cancer in the differential diagnosis of a breast mass in adolescence. Key Messages: Clinicians should be aware of all breast disorders that may occur in adolescence. Early diagnosis and treatment will result in the reassurance of adolescents and their families without any detrimental effect on their psychology, sexual behavior, and socialization. Adolescents with breast disorders may require a multidisciplinary approach by a pediatrician, a gynecologist specializing in pediatric-adolescent gynecology, a plastic surgeon, and a psychologist for the best management of breast disorders. [ABSTRACT FROM AUTHOR]

Context: Breast development is an important outcome for trans women receiving gender affirming hormone therapy (GAHT). Limited breast development has been reported, possibly because of testosterone exposure during puberty. The impact of puberty suppression (PS) on breast development is unclear., Objective: To investigate the impact of PS and timing of PS prior to GAHT on breast volume and satisfaction., Design: Cross-sectional study., Setting: Tertiary gender identity clinic., Participants: 60 trans women (aged 17-57 years) after 4.5±1.7 years of GAHT were included of whom 23 initiated PS early in puberty (Tanner stage G2-3), 17 late in puberty (Tanner stage G4-5), and 20 started GAHT in adulthood without prior PS., Main Outcome Measures: Breast volume measured with a 3D scanner and breast satisfaction measured with a questionnaire. Comparisons of breast volumes were adjusted for fat percentage., Results: Median breast volume was 115ml (IQR 68; 203), i.e. bra cup-size

Purpose: The aim of this study was to assess the accuracy and diagnostic use of shear wave elastography (SWE) in differentiating central precocious puberty (CPP) with breast development and to analyze the correlations between sex hormone levels and SWE parameters., Methods: A total of 227 participants were included in this retrospective case-control study, including 113 girls with genuine precocious puberty breast development (the CPP group) and 114 with non-genuine precocious puberty breast development (the non-CPP group). The participants underwent clinical assessment, hormonal assays, and SWE using advanced ultrasound equipment. Statistical analyses, including t-tests, correlation analysis, logistic regression, and receiver operating characteristic (ROC) analysis, were performed to evaluate the diagnostic value of SWE and sex hormone levels in differentiating CPP with breast development., Results: There were no significant differences in clinical characteristics between the two groups. The sex hormone levels of estradiol, testosterone, luteinizing hormone (LH), follicle-stimulating hormone (FSH), and prolactin in the CPP group were significantly higher than those in the non-CPP group. Shear wave velocity (SWV) Maximum (Max), SWV Minimum (Min), SWV Mean, SWV standard deviation (SD), and SWV coefficient of variation in the CPP group were significantly higher than in the non-CPP group. Correlation analysis demonstrated significant positive correlations between LH, FSH, estradiol, and testosterone levels with various SWE parameters, indicating their clinical relevance. Logistic regression analysis identified substantial predictive potential of sex hormone levels and SWE parameters for genuine precocious puberty breast development. Additionally, the ROC analysis highlighted a high predictive value of the combined model of SWE parameters, with an area under the curve (AUC) of 0.903., Conclusion: The study underscores the correlations between sex hormone levels and SWE parameters. The superior predictive performance of the combined model of SWE parameters emphasizes the value of integrated SWE assessments for improving the accuracy of diagnosing genuine precocious puberty breast development., Competing Interests: None., (AJTR Copyright © 2024.)

Breast development in a girl 3 years of age or younger is a commonly encountered scenario. Nearly all of these cases will either regress or fail to progress during follow-up, confirming a diagnosis of premature thelarche (PT). Studies show that these girls will have onset of true puberty and menses at a normal age. The authors present evidence that laboratory testing, particularly basal and gonadotropin hormone-releasing hormone -stimulated gonadotropin levels, will show overlap between girls with PT and the rare patients with the onset of central precocious puberty before age 3, mainly of whom have hypothalamic hamartomas., Competing Interests: Disclosure The authors have nothing to disclose., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Abstract Background Younger age at onset of breast development, which has been declining in recent decades, is associated with increased breast cancer risk independent of age at menarche. Given the need to study the drivers of these trends, it is essential to validate methods to assess breast onset that can be used in large-scale studies when direct clinical assessment of breast onset is not feasible. Methods Breast development is usually measured by Tanner stages (TSs), assessed either by physical examination or by mother’s report using a picture-based Sexual Maturation Scale (SMS). As an alternative, a mother-reported Pubertal Development Scale (PDS) without pictures has been used in some studies. We compared agreement of SMS and PDS with each other (n = 1022) and the accuracy of PDS with clinical TS as a gold standard for the subset of girls with this measure (n = 282) using the LEGACY cohort. We further compared prediction of breast onset using ROC curves and tested whether adding urinary estrone 1-glucuronide (E1G) improved the AUC. Results The agreement of PDS with SMS was high (kappa = 0.80). The sensitivity of PDS vs clinical TS was 86.6%. The AUCs for PDS alone and SMS alone were 0.88 and 0.79, respectively. Including E1G concentrations improved the AUC for both methods (0.91 and 0.86 for PDS and SMS, respectively). Conclusions The PDS without pictures is a highly accurate, sensitive, and specific method for assessing breast onset, especially in settings where clinical TS is not feasible. In addition, it is comparable to SMS methods with pictures and thus easier to implement in large-scale studies, particularly phone-based interviews where pictures may not be available. Urinary E1G can improve accuracy over than PDS or SMS alone.

Background: Earlier age at menarche is an established risk factor for breast cancer. While age at menarche has been fairly stable over the past half-century, age at breast development (thelarche) has continued to decrease. Recently, earlier age at thelarche and a longer time between thelarche and menarche (pubertal tempo) were shown to be associated with increased breast cancer risk. Our objective was to examine how breast cancer risk was associated with pubertal timing and tempo in a prospective US cohort.Methods: Women ages 35-74 years without a history of breast cancer, but who had a sister previously diagnosed with breast cancer, were enrolled in the Sister Study from 2003 to 2009 (N = 50,884). At enrollment, participants reported their ages at thelarche and menarche. Pubertal tempo was age at menarche minus age at thelarche. We estimated adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) for each pubertal milestone and risk of breast cancer (invasive or ductal carcinoma in situ) using Cox proportional hazards regression. We examined whether associations between age at thelarche and breast cancer risk were modified by birth cohort, race/ethnicity, weight at age 10, and extent of breast cancer family history, as characterized by a Bayesian score based on first-degree family structure.Results: During follow-up (mean = 9.3 years), 3295 eligible women were diagnosed with breast cancer. Early ages at thelarche (HR = 1.23, 95% CI 1.03-1.46 for < 10 vs. 12-13 years) and menarche (HR = 1.10, 95% CI 1.01-1.20 for < 12 vs. 12-13 years) were positively associated with breast cancer risk. Pubertal tempo was not associated with breast cancer risk (HR = 0.99, 95% CI 0.97-1.02 per 1-year longer tempo). When considering early thelarche (< 10 years) and early menarche (< 12 years) jointly, women with both had a 30% greater risk of breast cancer compared with women with neither risk factor (95% CI 1.07-1.57). The association between age at thelarche and breast cancer risk did not significantly vary by birth cohort, race/ethnicity, childhood weight, or Bayesian family history score.Conclusions: Earlier ages at thelarche and menarche may enhance susceptibility to breast carcinogenesis. Age at thelarche is an important risk factor to consider given secular trends towards earlier development. [ABSTRACT FROM AUTHOR]

Several strategies have been proposed to determine onset of puberty without examination by a trained professional. This study sought to evaluate a novel approach to determine onset of puberty in girls. This study used the Cincinnati cohort of the Breast Cancer and the Environment Research Program. Girls were recruited at 6-7 years of age and followed every 6 months in the initial 6 years, and annually thereafter. Breast maturation and foot length were performed at each visit by health professionals certified in those methods. Mothers were asked to provide the age at which they believed that their daughter's shoe size had increased more rapidly. These analyses include 252 participants. Age at increase in shoe size was correlated to age at onset of puberty (r = 0.21) and increase in foot length (r = 0.24). The difference of reported age of increased shoe size was 0.46 years before breast development. Reported increase in shoe size occurred somewhat earlier and was significantly correlated to age of breast development. These preliminary results suggest that mother's report of increase in shoe size appear to be as accurate as reports of other indirect methods of determining onset of puberty, such as self- or maternal estimates of breast development. [ABSTRACT FROM AUTHOR]

Objective: To examine adherence to a Mediterranean-like diet at age 9–10 years in relation to onset of breast development (thelarche) and first menstruation (menarche). Design: We evaluated the associations of adherence to a Mediterranean-like diet (measured by an adapted Mediterranean-like Diet Score, range 0–9) with thelarche at baseline, age at thelarche and time to menarche. Data were collected at baseline during a clinic visit, complemented with a mailed questionnaire and three 24 hour telephone dietary recalls, followed by annual follow-up questionnaires. Multivariable Poisson regression, linear regression and Cox proportional hazards regression were used to evaluate timing of pubertal development in relation to diet adherence. Setting: New Jersey, USA. Participants: Girls aged 9 or 10 years at baseline (2006–2014, n 202). Results: High Mediterranean-like diet adherence (score 6–9) was associated with a lower prevalence of thelarche at baseline compared with low adherence (score 0–3; prevalence ratio = 0·65, 95 % CI 0·48, 0·90). This may have been driven by consumption of fish and non-fat/low-fat dairy. Our models also suggested a later age at thelarche with higher Mediterranean-like diet adherence. Girls with higher Mediterranean-like diet adherence had significantly longer time to menarche (hazard ratio = 0·45, 95 % CI 0·28, 0·71 for high v. low adherence). Further analysis suggested this may have been driven by vegetable and non-fat/low-fat dairy consumption. Conclusions: Consuming a Mediterranean-like diet may be associated with older age at thelarche and menarche. Further research is necessary to confirm our findings in other US paediatric populations and elucidate the mechanism through which Mediterranean-like diet may influence puberty timing. [ABSTRACT FROM AUTHOR]

Background: This study examined predictors of perceived athletic competence and subsequent physical activity in a longitudinal sample of adolescent girls. Methods: A sample of 149 girls was assessed at ages 9, 11, and 13. Perceived athletic competence (PAC) was measured at all ages. Nonaesthetic versus aesthetic sport participation, body fat percentage, and breast development were measured at age 9. Accelerometers were used to measure girls' moderate-to-vigorous physical activity (MVPA) at age 13. Results: Girls who participated in nonaesthetic sports at age 9 reported higher PAC at age 11 than those who participated in only aesthetic sports, while more advanced breast development at age 9 was associated with greater relative declines in PAC between ages 11 and 13. Both age 11 PAC and the relative change in PAC between ages 11 and 13 were significant positive predictors of age 13 MVPA. Results were independent of age 9 socioeconomic status and self-reported physical activity. Conclusion: Perceived athletic competence is a suitable target for intervention efforts designed to increase adolescent girls' physical activity. Particular attention should be focused on girls who are overweight or experiencing puberty. Participation in nonaesthetic sports may be particularly important in the development of PAC. [ABSTRACT FROM AUTHOR]

Background. There is wide variation in normal pubertal timing among various populations. Objectives. To determine the mean age of pubertal stages of breast development and menarche, and the influence of nutrition and ethnicity on pubertal onset in primary school girls in Sokoto, North-Western Nigeria. Methods. A cross-sectional study using a multistage random sampling design was conducted on 994 primary school girls in grades 3 - 6. Weight and height measurements and Tanner breast staging were done. Body mass index (BMI) was calculated, and a BMI-for-age percentile was used to categorise nutritional status. There were four major ethnic groups. P≤0.05 was taken as showing statistical significance. Results. The participants’ mean age was 10.23 years (standard deviation (SD) 1.70, range 6 - 15 years). Of the 994 girls, 628 (63.2%) were pre-pubertal, and 366 (36.8%) were pubertal. Of the latter, 158 (15.9%) were in breast stage 2, while 112 (11.3%), 70 (7.0%) and 26 (2.6%) were in breast stages 3, 4 and 5, respectively. The mean ages (SD; range) of pubertal onset and menarche were 10.50 (1.33; 8 - 13), and 12.67 (1.65; 11 - 15), years, respectively. The overnourished (overweight/obese) and Igbo ethnic group girls had early-normal pubertal onset (p=0.006 and p=0.001, respectively). Conclusion. The mean ages of Tanner breast stages 1 - 5 and menarcheal age of girls in Sokoto, North-Western Nigeria, were within the age ranges reported worldwide. Pubertal onset was influenced by nutrition.

Background: Premature thelarche (PT) is a benevolent ailment affecting young girls. Multiple factors are reported to correlate with this condition, but the mechanisms responsible for the onset of PT have not yet been fully investigated. This study aimed to evaluate the relationship of nutrient intake, insulin resistance and lipid profile with PT. Methods: Two hundred sixty-three girls with PT, and 222 healthy girls of similar age were enrolled into this study. Their demographics, Tanner stage of breast development, nutrient intake, insulin resistance and lipid profiles were compared. Results: Daily protein and fat intakes, insulin resistance parameters including serum insulin-like growth factor 1, fasting glucose to insulin ratio, quantitative insulin check index and homeostasis model of assessment of insulin resistance, as well as serum levels of triacylglycerol, total cholesterol and low-density lipoprotein, were all significantly altered in PT patients. Daily intake of energy and carbohydrate, and serum level of high-density lipoprotein protein were statistically indistinguishable between PT patients and healthy controls. Conclusion: Chinese girls with PT are potentially insulin resistant, which warrants more clinical attention and further investigation to address the underlying etiology. [ABSTRACT FROM AUTHOR]

According to the life‐history theory, rates of sexual maturation have coevolved with mortality rates so that individuals who mature faster tend to die younger. We used two data sets, providing different markers for the speed of pubertal development to test whether rates of sexual maturation of women predict the age at death of their parents. In the data set of Estonian schoolgirls born between 1936 and 1961, the rate of breast development predicted lifespan of both mothers and fathers (irrespectively of their socio‐economic position), so that parents of rapidly maturing girls died at younger age. This finding supports the view that fast maturation rates in humans have coevolved with short lifespans and that such trade‐offs can be detected as intergenerational phenotypic correlations in modern populations. Menarcheal age of participants of Estonian Biobank (born between 1925 and 1996) did not predict the age of death of their mothers; however, it did predict survival of their fathers, but only in environment where the genetic variation is exposed (families where at least one parent had tertiary education). In such families (where girls also matured 0.2–0.4 years earlier than in poorly educated families), 1‐year delay in daughter's menarche corresponded to 9% lower hazard of father's death. Heritability of menarcheal age was also highest in well‐educated families. The latter findings are consistent with the idea that genetic differences in the rate of pubertal maturation may be expressed most clearly in well‐off families because in such families, the contribution of environmental variance to total phenotypic variance in menarcheal age is smallest. Our findings suggest that with global improvement and equalization of growth conditions, reductions of environmental variation in the rate of maturation increasingly expose the genetic differences in menarcheal age to selection. Under such conditions, selection on menarcheal age has a potential to affect the evolution of lifespan. [ABSTRACT FROM AUTHOR]

Background: The aim of this study was to analyse the associations of left-hand digit ratio (2D:4D), digit length and puberty characteristics to show the role of prenatal hormones in development among Chinese girls.Method: A total of 318 Chinese girls aged 8-15 years were recruited using a stratified cluster sampling method. The index finger (2D), ring finger (4D) of the left hand, oestradiol and testosterone were measured, and age at menarche (AAM), breast (high and low) and pubic hair (high and low) development were recorded.Results: Girls who had experienced menarche had longer left digits (2D and 4D) and higher oestradiol, testosterone than those who had not. The high breast group had longer digits (2D and 4D), and higher oestradiol than the low breast group. With regard to pubic hair development, the high group had high 2D:4D, longer 2D and higher oestradiol, testosterone than the low group. After adjusting for oestradiol and testosterone, 4D length was positively related to occurrence of menarche. In addition, 2D and 2D:4D were significantly correlated with pubic hair development after adjusting for oestradiol, respectively.Conclusion: Prenatal hormone level may be related to the development of puberty characteristics among Chinese girls. [ABSTRACT FROM AUTHOR]

The article describes the proposed current clinical classification of breast diseases and pathology in childhood and adolescence. The classification is based on the analysis of data obtained from the examination and follow-up monitoring of 6,126 children for up to 8 years. The clinical classification is recommended for widespread use in the work of primary care physicians who conduct follow-up monitoring. The use of this classification creates groups for referral to specialists for further examination and further treatment and follow-up monitoring. The classification is based on the separation of physiological (normal conditions) and pathological processes, as well as on temporary deviations from normal development (temporary conditions not leading to pathological processes) and anomalies in development of mammary glands and nipple-areolar complex. If any abnormalities are suspected, a patient shall be sent to a mammologist for further examination and US scanning. Control of growth and development of mammary glands in childhood and adolescence ensures early detection of abnormalities and allows necessary remedial measures to protect reproductive health.