The Coronavirus Pandemic and Mental Health Presentations of Young Children.

Children under the age of four are emotionally vulnerable to global disasters, such as the COVID-19 pandemic given the lack of socialization opportunities and coping mechanisms, and susceptibility to heightened caregiver stress. Currently, the extent to which the pandemic impacted the mental health of clinically referred young children is unknown. To evaluate how children's mental health outcomes were impacted during the pandemic, interRAI Early Years assessments (N = 1343) were obtained from 11 agencies across the Province of Ontario, during pre-pandemic and pandemic timepoints. Findings demonstrated that the number of completed assessments declined during the pandemic. Further, children's emotional concerns differed before and during the pandemic, whereby children exhibited greater emotional dysregulation during the pandemic. However, there were no significant differences when examining caregiver distress, parenting strengths, child distractibility/inattention or behavioural issues. Implications for young children and their families, clinicians, and policy makers are discussed.

Cardiotoxicity of BRAF/MEK Inhibitors: A Longitudinal Study Incorporating Contemporary Definitions and Risk Scores.

Background: Rapidly accelerated fibrosarcoma B-type (BRAF) and mitogen-activated extracellular signal-regulated kinase (MEK) inhibitors have revolutionized treatment for patients with BRAF-mutated melanoma. Although left ventricular systolic dysfunction associated with these therapies has been reported in clinical trials, the real-world incidence is poorly defined, as are risk factors for its development. Objectives: This study sought to characterize the incidence, time course, and risk factors for cancer therapy-related cardiac dysfunction (CTRCD) in patients with melanoma receiving BRAF and MEK inhibitors. Methods: Patients with melanoma treated with BRAF and MEK inhibitors at a cancer hospital network between June 1, 2017, and June 30, 2020, were included retrospectively. CTRCD was defined as mild, moderate, or severe according to International Cardio-Oncology Society (ICOS) definitions. Baseline cardiotoxicity risk stratification was performed using the Heart Failure Association/ICOS tool. Results: Of the 63 patients included, 27% developed CTRCD (17% mild and 10% moderate). No patients developed severe CTRCD or symptomatic heart failure. CTRCD occurred most frequently in patients considered to be at "low" and "medium" baseline risk of cardiotoxicity (82%). The baseline left ventricular ejection fraction and global longitudinal strain were not different in patients who developed moderate CTRCD vs those who did not. Left ventricular internal diameters in diastole and systole were larger in patients who developed moderate CTRCD compared with those who did not (left ventricular internal diameter in diastole: 4.9 ± 0.6 cm vs 4.3 ± 0.6 cm; P = 0.023; left ventricular internal diameter in systole: 3.3 ± 0.4 cm vs 2.8 ± 0.5 cm; P = 0.039). Conclusions: BRAF and MEK inhibitor-associated CTRCD is common. The utility of the Heart Failure Association/ICOS risk stratification tool appears limited in this group, and better risk prediction tools are needed. The long-term consequences of CTRCD, particularly mild CTRCD, warrant evaluation in larger prospective studies.

What makes joint assessment procedures attractive to the innovative industry: successes, challenges, and proposed improvements.

Regulatory harmonization and convergence have been identified as the key driver in promoting efficient evaluation of medicines, reducing workload, and supporting earlier access to medicines on the African continent. There has been great progress to date in enhancing regulatory harmonization and convergence on the African continent via the Regional Economic Communities (RECs) and with the establishment of the Africa Medicines Agency (AMA). In this article, the International Federation of Pharmaceutical Manufacturers and Associations (IFPMA) Africa Regulatory Network (ARN) presents its perspective based on the available literature review and results from a survey conducted with innovative biopharmaceutical companies to gather experiences using regional joint assessment procedures (JAPs) in Africa, such as the East African Community Medicines Regulatory Harmonization (EAC-MRH), the West African Medicines Regulatory Harmonization (WA-MRH), and the Southern African Development Community Medicines Regulatory Harmonization (SADC-MRH) initiative through the ZAZIBONA Collaborative Procedure for Medicines Registration (ZaZiBoNa), and provides best practices in this evolving landscape. The article also assesses other collaborative registration pathways available to facilitating registration of pharmaceutical products in African countries, such as WHO Collaborative Registration Procedures (CRP), Swissmedic's Marketing Authorisation for Global Health Products (MAGHP) and EU Medicines for All (EU-M4ALL). Benefits and challenges of each of the existing pathways are discussed in this article. Main benefits include building more expert capacity and improved collaboration amongst experts, as well as shorter review timelines in some cases. Key challenges include the lack of predictability in the adherence to procedural timelines as defined per guidelines, lengthy timeline to achieve national marketing authorization following joint assessment, the lack of dedicated personnel, administrative issues during the submission process as well as additional country-specific requirements on top of JAP-specific requirements. Our recommendations for improvements include harmonization of requirements across countries and regions and with international standards, appropriate resource allocation for JAP activities to ensure adherence to timelines, use of JAPs throughout the entire product lifecycle and all product categories, adequate use of digital technologies, and improved communication and transparency with applicants. These improvements will allow industry to better plan their filing strategies for the region which will lead to overall improved usability of the JAPs in Africa and enable faster patient access.

VA-Based Peritoneal Dialysis Program Feasibility Considerations and Process Outline.

Background: Home dialysis utilization is lower among veterans than in the general US population. Several sociodemographic factors and comorbidities contribute to peritoneal dialysis (PD) underutilization. In 2019, the Veterans Health Administration (VHA) Kidney Disease Program Office convened a PD workgroup to address this concern. Observations: The PD workgroup was explicitly concerned by the limited availability of PD within the VHA, which frequently requires veterans to transition kidney disease care from US Department of Veterans Affairs medical centers (VAMCs) to non-VHA facilities when they progress from chronic kidney disease to end-stage kidney disease, causing fragmentation of care. Since the administrative requirements and infrastructure of VAMCs vary, the workgroup focused its deliberations on synthesizing a standard process for evaluating the feasibility and establishing a new PD program within any individual VAMC. A 3-phased approach was envisioned, beginning with ascertainment of prerequisites, leading to an examination of the clinical and financial feasibility through the process of data gathering and synthesis, culminating in a business plan that translates the previous 2 steps into an administrative document necessary for obtaining VHA approvals. Conclusions: VAMCs can use the guide presented here to improve therapeutic options for veterans with kidney failure by establishing a new or restructured PD program.

Path Forward to Optimise Post-approval Change Management and Facilitate Continuous Supply of Medicines and Vaccines of High Quality Worldwide : Joint Position from EFPIA, IFPMA and Vaccines Europe.

Post-approval changes (PACs) to the registered information of authorised medicinal products are introduced routinely worldwide to enhance the robustness and efficiency of the manufacturing process, ensure timely supply in case of increased demand, improve quality control techniques, respond to changes in regulatory requirements and upgrade to state-of-the-art facilities. These are critical to prevent supply disruption and continuously improve existing medicines and vaccines. Due to the complexity of current PAC systems across markets, a change can take 3 to 5 years to approval globally (Hoath et al in BioProcess Int, 2016) thus hindering innovation and increasing the risk of shortages. The key messages are as follows: 1. Industry believes that global regulatory convergence of post-approval changes to Marketing Authorisations (MAs) using science- and risk-based approaches will enable a more efficient management of quality and supply improvements and will facilitate patients' access to innovative medicines and vaccines of the highest quality. 2. National Regulatory Authorities (NRAs) should establish national or regional guidelines in line with international standards (regarding a risk-based classification of changes and standardisation of requirements) (Guidelines on procedures and data requirements for changes to approved biotherapeutic products, in WHO Technical Report Series, 2018, Guidelines on procedures and data requirements for changes to approved vaccines, in WHO Technical Report Series, 2015), have clear procedural guidance including timelines and implement reliance pathways to accelerate the approval of changes. This paper briefly outlines the challenges for PACs and provides solutions for a more flexible and aligned global system.

UK Dietary Practices for Tyrosinaemias: Time for Change.

In the UK, different dietary systems are used to calculate protein or tyrosine/phenylalanine intake in the dietary management of hereditary tyrosinaemia, HTI, II and III (HT), with no systematic evidence comparing the merits and inadequacies of each. This study aimed to examine the current UK dietary practices in all HTs and, using Delphi methodology, to reach consensus agreement about the best dietary management system. Over 12 months, five meetings were held with UK paediatric and adult dietitians working in inherited metabolic disorders (IMDs) managing HTs. Eleven statements on the dietary system for calculating protein or tyrosine/phenylalanine intake were discussed. Dietitians from 12 of 14 IMD centres caring for HT patients participated, and 7/11 statements were agreed with one Delphi round. Nine centres (three abstentions) supported a 1 g protein exchange system for all foods except fruit and vegetables. The same definitions used in the UK for phenylketonuria (PKU) were adopted to define when to calculate foods as part of a protein exchange system or permit them without measurement. Fruit and vegetables contain a lower amount of tyrosine/phenylalanine per 1 g of protein than animal and cereal foods. The correlation of tyrosine vs. phenylalanine (mg/100 g) for vegetables and fruits was high (r = 0.9). In Delphi round 2, agreement was reached to use the tyrosine/phenylalanine analyses of fruits/vegetables, for their allocation within the HT diet. This allowed larger portion sizes of measured fruits and vegetables and increased the variety of fruit and vegetables that could be eaten without measurement. In HTs, a combined dietary management system will be used: 1 g protein exchanges for cereal and milk protein sources and tyrosine/phenylalanine exchanges for fruit and vegetables. Intensive, systematic communication with IMD dietitians and reappraisal of the evidence has redefined and harmonised HT dietary practice across the UK.

Suitability and Allocation of Protein-Containing Foods According to Protein Tolerance in PKU: A 2022 UK National Consensus.

Introduction: There is little practical guidance about suitable food choices for higher natural protein tolerances in patients with phenylketonuria (PKU). This is particularly important to consider with the introduction of adjunct pharmaceutical treatments that may improve protein tolerance. Aim: To develop a set of guidelines for the introduction of higher protein foods into the diets of patients with PKU who tolerate >10 g/day of protein. Methods: In January 2022, a 26-item food group questionnaire, listing a range of foods containing protein from 5 to >20 g/100 g, was sent to all British Inherited Metabolic Disease Group (BIMDG) dietitians (n = 80; 26 Inherited Metabolic Disease [IMD] centres). They were asked to consider within their IMD dietetic team when they would recommend introducing each of the 26 protein-containing food groups into a patient's diet who tolerated >10 g to 60 g/day of protein. The patient protein tolerance for each food group that received the majority vote from IMD dietetic teams was chosen as its tolerance threshold for introduction. A virtual meeting was held using Delphi methodology in March 2022 to discuss and agree final consensus. Results: Responses were received from dietitians from 22/26 IMD centres (85%) (11 paediatric, 11 adult). For patients tolerating protein ≥15 g/day, the following foods were agreed for inclusion: gluten-free pastas, gluten-free flours, regular bread, cheese spreads, soft cheese, and lentils in brine; for protein tolerance ≥20 g/day: nuts, hard cheeses, regular flours, meat/fish, and plant-based alternative products (containing 5−10 g/100 g protein), regular pasta, seeds, eggs, dried legumes, and yeast extract spreads were added; for protein tolerance ≥30 g/day: meat/fish and plant-based alternative products (containing >10−20 g/100 g protein) were added; and for protein tolerance ≥40 g/day: meat/fish and plant-based alternatives (containing >20 g/100 g protein) were added. Conclusion: This UK consensus by IMD dietitians from 22 UK centres describes for the first time the suitability and allocation of higher protein foods according to individual patient protein tolerance. It provides valuable guidance for health professionals to enable them to standardize practice and give rational advice to patients.

A Systems Thinking approach for the creation of effective competency-based medical education programs.

Successful and sustainable implementation of Competency-based Medical Education (CBME) programs is a significant and daunting challenge facing medical education worldwide. Our manuscript endorses for the first time, Systems Thinking as a concept for transforming and redesigning CBME programs employing the full 7-system elements as advocated by the Biomatrix Systems Theory. The majority of internationally recommended actions and processes for such an endeavor are highlighted, each within its system element. New innovative ideas such as having competency-structured clinical training activities as well as re-writing medical textbooks following a novel competency-based roadmap for their disease monographs etc. are also highlighted. Furthermore, the need for innovative partnerships as well as novel medical rotations that may facilitate the creation of "master clinicians" are also stressed.

Dietetic Management of Adults with Phenylketonuria (PKU) in the UK: A Care Consensus Document.

There is an increasing number of adults and elderly patients with phenylketonuria (PKU) who are either early, late treated, or untreated. The principal treatment is a phenylalanine-restricted diet. There is no established UK training for dietitians who work with adults within the specialty of Inherited Metabolic Disorders (IMDs), including PKU. To address this, a group of experienced dietitians specializing in IMDs created a standard operating procedure (SOP) on the dietetic management of adults with PKU to promote equity of care in IMD dietetic services and to support service provision across the UK. The group met virtually over a period of 12 months until they reached 100% consensus on the SOP content. Areas of limited evidence included optimal blood phenylalanine reporting times to patients, protein requirements in older adults, management of weight and obesity, and management of disordered eating and eating disorders. The SOP does not include guidance on maternal PKU management. The SOP can be used as a tool for training dietitians new to the specialty and to raise the standard of education and care for patients with PKU in the UK.

Mechanisms of obesity in children and adults with phenylketonuria on contemporary treatment.

BACKGROUND & AIMS: Obesity prevalence in people with phenylketonuria (PKU) is comparable to that of the general population but the underlying aetiology remains unknown. To assess body composition, dietary intake, moderate physical activity duration (MPAD) and energy expenditure (MPAEE), resting metabolic rate (RMR), diet-induced thermogenesis (DIT), fasting and postprandial fat (FOx) and carbohydrate oxidation (CHOOx), in PKU people and healthy Controls. METHODS: Participants were PKU people (n = 16) and healthy controls (n = 15). Body composition was measured with stable isotopes using deuterium as tracer, dietary intake from 4-day food diaries, MPAD and MPAEE from 7-day activity counts measured by triaxial accelerometers, calibrated against individual rates of oxygen consumption and carbon dioxide production, RMR, DIT, FOx and CHOOx by indirect calorimetry. RESULTS: Body composition, DIT, FOx, CHOOx and RMR did not differ between the PKU and the Control groups. MPAD (PKU, 73 ± 26 min/week; Control, 152 ± 43 min/week) and MPAEE (PKU, 404 ± 127 kcal/week; Control, 741 ± 153 kcal/week) were lower (P < 0.05) in the PKU than the Control group. Raised phenylalanine levels were inversely related with MPAD and MPAEE. Energy intake and energy provided by protein did not differ between the groups, while energy proportion obtained from carbohydrate was higher (PKU, 60 ± 2%; Control, 51 ± 2%; P < 0.05) and from fat lower (PKU, 24 ± 2%; Control, 35 ± 3%; P < 0.05) in the PKU than in the Control group. CONCLUSION: People with PKU spent less time and expend less energy in moderate physical activity and have a higher intake of energy from CHO which may be involved in the underlying mechanisms of obesity in PKU.

Uniformity of Food Protein Interpretation Amongst Dietitians for Patients with Phenylketonuria (PKU): 2020 UK National Consensus Statements.

In phenylketonuria (PKU), variable dietary advice provided by health professionals and social media leads to uncertainty for patients/caregivers reliant on accurate, evidence based dietary information. Over four years, 112 consensus statements concerning the allocation of foods in a low phenylalanine diet for PKU were developed by the British Inherited Metabolic Disease Dietitians Group (BIMDG-DG) from 34 PKU treatment centres, utilising 10 rounds of Delphi consultation to gain a majority (≥75%) decision. A mean of 29 UK dietitians (range: 18-40) and 18 treatment centres (range: 13-23) contributed in each round. Statements encompassed all foods/food groups divided into four categories based on defined protein/phenylalanine content: (1) foods high in protein/phenylalanine (best avoided); (2) foods allowed without restriction including fruit/vegetables containing phenylalanine ≤75 mg/100 g and most foods containing protein ≤0.5 g/100 g; (3) foods that should be calculated/weighed as an exchange food if they contain protein exchange ingredients (categorized into foods with a protein content of: >0.1 g/100 g (milk/plant milks only), >0.5 g/100 g (bread/pasta/cereal/flours), >1 g/100 g (cook-in/table-top sauces/dressings), >1.5 g/100 g (soya sauces)); and (4) fruit/vegetables containing phenylalanine >75 mg/100 g allocated as part of the protein/phenylalanine exchange system. These statements have been endorsed and translated into practical dietary management advice by the medical advisory dietitians for the National Society for PKU (NSPKU).

Nutritional and Metabolic Characteristics of UK Adult Phenylketonuria Patients with Varying Dietary Adherence.

The nutritional and metabolic characteristics of adult phenylketonuria (PKU) patients in the UK with varying dietary adherence is unknown. In other countries, nutritional and metabolic abnormalities have been reported in nonadherent patients compared to adherent counterparts. A pooled analysis of primary baseline data from two UK multi-centre studies was therefore performed to establish whether this is true from a UK perspective. Adult PKU patients who had provided 3-day food records and amino acid blood samples were included and grouped according to dietary adherence (adherent; n = 16 vs. nonadherent; n = 14). Nonadherent patients consumed greater amounts of natural protein compared to adherent patients (61.6 ± 30.7 vs. 18.3 ± 7.7 g/day; q < 0.001). In contrast, the contribution of protein substitutes to total protein intake was lower in nonadherent compared to adherent patients (3.9 ± 9.2 g/day vs. 58.6 ± 10.2 g/day; q < 0.001). Intakes of iron, zinc, vitamin D3, magnesium, calcium, selenium, iodine, vitamin C, vitamin A and copper were significantly lower in nonadherent compared to adherent patients and were below UK Reference Nutrient Intakes. Similarly, intakes of thiamin, riboflavin, niacin, vitamin B6 and phosphorus were significantly lower in nonadherent compared to adherent patients but met the UK Reference Nutrient Intakes. Phenylalanine concentrations in nonadherent patients were significantly higher than adherent patients (861 ± 348 vs. 464 ± 196 µmol/L; q=0.040) and fell outside of European treatment target ranges. This study shows the nutritional and metabolic consequences of deviation from phenylalanine restriction and intake of PKU protein substitutes in nonadherent adult PKU patients. Collectively, these data further underlie the importance of life-long adherence to the PKU diet.

Improved Eating Behaviour and Nutrient Intake in Noncompliant Patients with Phenylketonuria after Reintroducing a Protein Substitute: Observations from a Multicentre Study.

Noncompliance is widespread in adults with PKU and is associated with adverse metabolic, nutritional and cognitive abnormalities. Returning to the PKU diet is important for this at-risk population, yet for many this is challenging to achieve. Strategies that ease the return to the PKU diet, while offering nutritional and cognitive advantages, are needed. Twelve PKU adults (33.7 ± 2.6 years), who had been noncompliant for 4.5 years (range: 1 to 11 years), took 33 g of a low-volume, nutrient-enriched, protein substitute daily for 28 days. Outcomes of eating behaviour, nutrient intake and mood were assessed at entry (baseline, days 1-3) and after the intervention period (days 29-31). At baseline, intakes of natural protein and estimated phenylalanine were high (66.4 g and 3318.5 mg, respectively) and intakes of calcium, magnesium, iron, zinc, iodine and vitamin D were below country-specific recommendations. With use of the experimental protein substitute, natural protein and estimated phenylalanine intake declined (p = 0.043 for both). Fat and saturated fat intakes also decreased (p = 0.019 and p = 0.041, respectively), while energy and carbohydrate intake remained unchanged. Micronutrient intake increased (p ≤ 0.05 for all aforementioned) to levels well within reference nutrient intake recommendations. Blood vitamin B12 and vitamin D increased by 19.8% and 10.4%, respectively. Reductions in anxiety and confusion were also observed during the course of the study yet should be handled as preliminary data. This study demonstrates that reintroducing a low-volume, nutrient-enriched protein substitute delivers favourable nutritional and possible mood benefits in noncompliant PKU patients, yet longer-term studies are needed to further confirm this. This preliminary knowledge should be used in the design of new strategies to better facilitate patients' return to the PKU diet, with the approach described here as a foundation.

Development of national consensus statements on food labelling interpretation and protein allocation in a low phenylalanine diet for PKU.

BACKGROUND: In the treatment of phenylketonuria (PKU), there was disparity between UK dietitians regarding interpretation of how different foods should be allocated in a low phenylalanine diet (allowed without measurement, not allowed, or allowed as part of phenylalanine exchanges). This led to variable advice being given to patients. METHODOLOGY: In 2015, British Inherited Metabolic Disease Group (BIMDG) dietitians (n = 70) were sent a multiple-choice questionnaire on the interpretation of protein from food-labels and the allocation of different foods. Based on majority responses, 16 statements were developed. Over 18-months, using Delphi methodology, these statements were systematically reviewed and refined with a facilitator recording discussion until a clear majority was attained for each statement. In Phase 2 and 3 a further 7 statements were added. RESULTS: The statements incorporated controversial dietary topics including: a practical 'scale' for guiding calculation of protein from food-labels; a general definition for exchange-free foods; and guidance for specific foods. Responses were divided into paediatric and adult groups. Initially, there was majority consensus (≥86%) by paediatric dietitians (n = 29) for 14 of 16 statements; a further 2 structured discussions were required for 2 statements, with a final majority consensus of 72% (n = 26/36) and 64% (n = 16/25). In adult practice, 75% of dietitians agreed with all initial statements for adult patients and 40% advocated separate maternal-PKU guidelines. In Phase 2, 5 of 6 statements were agreed by ≥76% of respondents with one statement requiring a further round of discussion resulting in 2 agreed statements with a consensus of ≥71% by dietitians in both paediatric and adult practice. In Phase 3 one statement was added to elaborate further on an initial statement, and this received 94% acceptance by respondents. Statements were endorsed by the UK National Society for PKU. CONCLUSIONS: The BIMDG dietitians group have developed consensus dietetic statements that aim to harmonise dietary advice given to patients with PKU across the UK, but monitoring of statement adherence by health professionals and patients is required.

Meaningful components of a community-based exercise program for individuals with disabilities: A qualitative study.

BACKGROUND: Enhanced methods of evaluation are necessary to identify community-based exercise interventions that promote physical activity and improve health and participation for individuals with disabilities. The heterogeneity of the populations served, interventions implemented, and outcome measures used remains a barrier to effectively evaluate programs and generate evidence to inform best practice. OBJECTIVE: To explore goals and benefits of community-based exercise for individuals with disabilities and determine barriers and facilitators to evaluation in a community setting. METHODS: We conducted semi-structured interviews with exercise participants and staff of a community-based exercise program for individuals with disabilities. We then coded responses to interview questions for themes using thematic analysis or deductive content analysis, with codes linked to categories within the International Classification of Functioning, Disability and Health (ICF). RESULTS: Identified goals and benefits spanned the ICF domains of Body Functions and Activities and Participation. Commonly cited goals and benefits included improving strength and endurance, general health, self-efficacy, community participation, and the importance of returning to exercise. Barriers and facilitators to evaluation identified by staff included maintaining a balance between evaluation and services, negative attitudes toward evaluation, access to data, and consistency with scheduling. CONCLUSIONS: These results can be used to enhance evaluation within community-based exercise programs for individuals with disabilities, which may improve both the quality and impact of these programs.

See food diet? Cultural differences in estimating fullness and intake as a function of plate size.

Previous research has suggested that manipulations of plate size can have a direct impact on perception of food intake, measured by estimated fullness and intake. The present study, involving 570 individuals across Canada, China, Korea, and New Zealand, is the first empirical study to investigate cultural influences on perception of food portion as a function of plate size. The respondents viewed photographs of ten culturally diverse dishes presented on large (27 cm) and small (23 cm) plates, and then rated their estimated usual intake and expected fullness after consuming the dish, using 100-point visual analog scales. The data were analysed with a mixed-model ANCOVA controlling for individual BMI, liking and familiarity of the presented food. The results showed clear cultural differences: (1) manipulations of the plate size had no effect on the expected fullness or the estimated intake of the Chinese and Korean respondents, as opposed to significant effects in Canadians and New Zealanders (p < 0.05); (2) Canadian (88.91 ± 0.42) and New Zealanders (90.37 ± 0.41) reported significantly higher estimated intake ratings than Chinese (80.80 ± 0.38) or Korean (81.69 ± 0.44; p < 0.05), notwithstanding the estimated fullness ratings from the Western respondents were comparable or even higher than those from the Asian respondents. Overall, these findings, from a cultural perspective, support the notion that estimation of fullness and intake are learned through dining experiences, and highlight the importance of considering eating environments and contexts when assessing individual behaviours relating to food intake.

Estrogen Receptors and Signaling in Fibroids: Role in Pathobiology and Therapeutic Implications.

Uterine fibroids are the most common gynecologic tumors with a significant medical and financial burden. Several genetic, hormonal, and biological factors have been shown to contribute to the development and growth of fibroid tumors. Of these factors, estrogen is particularly critical since fibroids are considered estrogen dependent because no prepubertal cases have been described in the literature and tumors tend to regress after menopause. Understanding the role of estrogen in fibroids is not only important for understanding the pathobiology of fibroids but also for the development of successful therapeutics. In this review, we discuss the types and structure of estrogen receptors (nuclear and membrane bound, including α and ß receptors and G protein-coupled estrogen receptor 1 GPER1). Estrogen-signaling pathways in fibroids include genomic (direct and indirect) and nongenomic including Ras-Raf-MEK (MAPK/Erk Kinase)-mitogen-activated protein kinase (MAPK) and phosphatidylinositide 3-kinase (PI3K)-phosphatidylinositol-3,4,5-trisphosphate (PIP3)-Akt (Protein kinase B)-mammalian target of rapamycin (mTOR) pathways; shortly Ras-Raf-MEK-MAPK and PI3K-PIP3-Akt-mTOR pathways. Several aberrations in estrogen receptors and signaling pathways are implicated in fibroid pathobiology. Current therapeutic and research agents targeting ERs/signaling include gonadotropin-releasing hormone (GnRH) agonists, GnRH antagonists, aromatase inhibitors, selective ER modulators, gene therapy, and others. Future research can identify potential targets for the development of novel treatments. In particular, epigenomics of estrogen activity and individualized (precision) medicine appear to be attractive areas for future research.