Systematic Review and Meta-Analyses of Aminopeptidases as Prognostic Biomarkers in Amyotrophic Lateral Sclerosis.

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease characterized by the progressive loss of motor neurons in the spinal cord, brain stem, and cerebral cortex. Biomarkers for ALS are essential for disease detection and to provide information on potential therapeutic targets. Aminopeptidases catalyze the cleavage of amino acids from the amino terminus of protein or substrates such as neuropeptides. Since certain aminopeptidases are known to increase the risk of neurodegeneration, such mechanisms may reveal new targets to determine their association with ALS risk and their interest as a diagnostic biomarker. The authors performed a systematic review and meta-analyses of genome-wide association studies (GWASs) to identify reported aminopeptidases genetic loci associated with the risk of ALS. PubMed, Scopus, CINAHL, ISI Web of Science, ProQuest, LILACS, and Cochrane databases were searched to retrieve eligible studies in English or Spanish, published up to 27 January 2023. A total of 16 studies were included in this systematic review, where a series of aminopeptidases could be related to ALS and could be promising biomarkers (DPP1, DPP2, DPP4, LeuAP, pGluAP, and PSA/NPEPPS). The literature reported the association of single-nucleotide polymorphisms (SNPs: rs10260404 and rs17174381) with the risk of ALS. The genetic variation rs10260404 in the DPP6 gene was identified to be highly associated with ALS susceptibility, but meta-analyses of genotypes in five studies in a matched cohort of different ancestry (1873 cases and 1861 control subjects) showed no ALS risk association. Meta-analyses of eight studies for minor allele frequency (MAF) also found no ALS association for the "C" allele. The systematic review identified aminopeptidases as possible biomarkers. However, the meta-analyses for rs1060404 of DPP6 do not show a risk associated with ALS.

Paraneoplastic or treatment-associated dermatomyositis: a diagnostic challenge.

Dermatomyositis (DM) is a systemic autoimmune disorder characterized by proximal myopathy and dermatological findings. Approximately 15-30% of DM cases emerge as a paraneoplastic syndrome caused by a concomitant malignancy. Although more rare, in cancer patients DM has also been reported as a possible result of toxicity of some antineoplastic agents, such as taxanes and monoclonal antibodies. Herein, we report a 35-year-old woman with metastatic breast cancer who presented with skin lesions after initiation of paclitaxel and anti-HER2 agents. Clinical, laboratory, and histological findings were consistent with the diagnosis of DM.

Poor Perception and Knowledge of Electronic Cigarettes Among Adolescents and Their Parents.

OBJECTIVES: Electronic cigarettes (e-cigs) and vaping are a popular form of substance abuse among adolescents. Studies have shown that adolescents have a poor understanding of e-cigs but little is known about parental understanding. The primary objective was to assess if a discrepancy in perception and knowledge regarding the content and safety profile of e-cigs between adolescents and their parents exists. METHODS: Single-site prospective questionnaire analysis of adolescents (12-21 years) and their parents between November 2018 and March 2019 was performed. Each participant pair received an anonymous, confidential, electronic questionnaire. Data were collected via Research Electronic Data Capture. χ2 and independent t tests were used for comparative analysis. RESULTS: A total of 300 adolescent/parent pairs were included for analysis. The mean age of adolescents was 15.1 years (SD, 2.1), and that of parents was 43.9 years (SD, 8.7). Overall knowledge of e-cigs was inadequate in both adolescents and parents: 93.7% and 88.3%, respectively (P < 0.0001). Less adolescents (49.0%) compared with parents (71.0%) perceived any health risks to smoking e-cigs (P < 0.0001). Among adolescents, 17% admitted to smoking e-cigs compared with 5.4% smoking conventional tobacco cigarettes (P < 0.0001), and they reported using e-cigs (17.0%) more often than any other substance except alcohol (27.3%). Only 49.7% of adolescents reported receiving formal education at school regarding e-cigs. Parents reported discussing e-cigs risks/benefits with adolescents less often than other topics (71.3% vs 79.0% to 84.3%; P < 0.0007). CONCLUSIONS: This analysis suggests that perception and knowledge regarding the content and safety profile of e-cigs are poor among both adolescents and parents. These findings support the need for tighter federal regulation and an increase in public health awareness programs.

Toxic erythema of chemotherapy induced by liposomal doxorubicin, a clinical case.

A 76-year-old woman presented to the medical oncology outpatient clinic with painful, burning, pruritic erythematous plaques involving both palms and axillae that had suddenly appeared five days before. Examination revealed no additional relevant findings and laboratory studies did not show any alteration. The patient had been recently diagnosed with a high-grade angiosarcoma of the breast (probably radiation induced) and after frequent local recurrences, was being treated with liposomal doxorubicin (three cycles were administered, the last of which was seven days before the appearance of the mentioned lesions). Oral corticosteroids were started, treatment with liposomal doxorubicin was stopped, and cutaneous biopsies performed that revealed features compatible with toxic erythema of chemotherapy induced by liposomal doxorubicin. Complete resolution of the cutaneous lesions was verified one month after. No signs of recurrence of angiosarcoma were documented at follow-up three months later.

Intense craving for appetizing foods: validation and standardization of the Food Cravings Questionnaire-Trait in Mexico.

INTRODUCTION: Food craving is a motivational and physiological response for eating specific foods, mainly with high caloric content. To assess food craving, self-reports, inventories and questionnaires are used. The Food Cravings Questionnaire-Trait is multi-dimensionally structured and has been validated in several countries, since it is sensitive and adaptable to contextual-cultural changes. OBJECTIVES: To validate and standardize the Food Cravings Questionnaire-Trait in adults of Mexico City. METHOD: Non-experimental, cross-sectional, randomized study of 1059 subjects of both genders, between 18 and 84 years of age; 71.86 % of the female gender. Psychometric properties were examined with exploratory and confirmatory factor analyses. RESULTS: The domains of the questionnaire were reduced and the items were reorganized differently from the original version. The confirmatory factor analysis showed an adequate fit and acceptable standardization of factors. High internal consistency was found for the global questionnaire (a = 0.973 and rho = 0.975) for each one of the domains. CONCLUSION: This study determines the viability of the Food Cravings Questionnaire for the population of Mexico City.

INTRODUCCIÓN: El food craving o "ansia por comer" es una respuesta motivacional y fisiológica por comer alimentos específicos, principalmente con alto contenido calórico. Para evaluarlo se usa, entre otros, el Food Craving Questionnaire Trait, estructurado multidimensionalmente y validado en diversos países, el cual ha mostrado ser sensible y adaptable a los cambios contextuales-culturales. OBJETIVOS: Validar y estandarizar el Food Craving Questionnaire-Trait en adultos de la Ciudad de México. MÉTODO: Estudio no experimental, transversal y aleatorizado de 1059 sujetos de uno y otro sexo, entre 18 y 84 años; 71.86 % del sexo femenino. Se examinaron propiedades psicométricas con análisis factoriales exploratorios y confirmatorios. RESULTADOS: Se redujeron los factores del cuestionario y los ítems se reorganizaron de forma diferente al original. El análisis factorial confirmatorio mostró ajuste adecuado y estandarización aceptable de los factores. Se encontró alta consistencia interna para el cuestionario global (a = 0.973 y rho = 0.975) para cada uno de los factores. CONCLUSIÓN: Este estudio determina la viabilidad del Food Craving Questionnaire para población de la Ciudad de México.

Cervical Spine Motion During Airway Management Using Two Manual In-line Immobilization Techniques: A Human Simulator Model Study.

OBJECTIVE: The aim of this study is to evaluate cervical spine motion using 2 manual inline immobilization techniques with the use of a human simulator model. METHODS: Medical students, pediatric and family practice residents, and pediatric emergency medicine fellows were recruited to maintain cervical manual in line immobilization above the head of the bed and across the chest of a human simulator while orotracheal intubation was performed. Participants were then instructed on appropriate holding techniques after the initial session took place. Orotracheal intubation followed. A tilt sensor measured time to intubation and cervical extension and rotation angle. RESULTS: Seventy-one subjects participated in a total of 284 successful orotracheal intubations. No change in cervical spine movement or time to intubation was observed when using 2 different inline manual immobilization techniques with no training. However, a statistically significant difference with assistants above the head versus across the chest was observed after training in: extension 2.1° (95% confidence interval [95% CI], 1.15 to 3.00; P < 0.0001); rotation 0.7° (95% CI, 0.26 to 1.19; P = 0.003) and intubation time of -1.9 seconds (95% CI, -3.45 to -0.13; P = 0.035) after training. CONCLUSIONS: Cervical spine movement did not change when maintaining cervical spine immobilization from above the head versus across the chest before training. There was a statistically significant change in extension and rotation when assistants were above the head and in time to intubation when assistants were across the chest after training. The clinical significance of these results is unclear.

Anaphylaxis knowledge and practice preferences of pediatric emergency medicine physicians: a national survey.

OBJECTIVES: To assess the knowledge and practice preferences of anaphylaxis in pediatric emergency medicine (PEM) physicians by practice setting, and to identify factors associated with intramuscular (IM) epinephrine administration and admission of patients with anaphylaxis. STUDY DESIGN: The cohort was a cross-sectional convenience sample; potential participants were recruited using contact information obtained from the American Board of Pediatrics and American Board of Medical Specialties membership databases and were asked to complete a 12 item survey. Board-certified PEM physicians were categorized by practice setting: university hospital, non-university hospital with a residency training program, or community hospital with no residency training program. Management practices based on practice setting are presented as proportions. Multivariate logistic regression identified factors associated with IM epinephrine administration and admission of patients with anaphylaxis for observation. RESULTS: Of the 1114 PEM physicians solicited, 620 (56%) completed the survey. The majority (93.5%) correctly identified epinephrine as the treatment of choice for anaphylaxis, yet only 66.9% used the IM route of administration, and only 37.4% admitted affected patients for observation. Factors associated with the use of IM epinephrine included the presence of a residency program at the site of care (OR, 2.28, 95% CI, 1.3-4.04) and higher volume of anaphylaxis cases (OR, 1.21; 95% CI, 1.06-1.38). Increasing anaphylaxis case volume was associated with decreased likelihood of admission of patients with anaphylaxis (OR, 0.81; 95% CI, 0.72-0.92). CONCLUSION: Even though the majority of PEM physicians correctly report using epinephrine in pediatric anaphylaxis, not all use the preferred administration route, and many discharge patients home after an abbreviated period.

Accuracy of laceration length estimation in a pediatric emergency department and its impact on billing practices.

OBJECTIVES: This study aimed to determine the accuracy of laceration length estimation in a pediatric emergency department among health care providers of varying levels of training and its impact on billing practices. METHODS: This study involves a prospective case series. Children younger than 21 years with lacerations evaluated and repaired in the pediatric emergency department between January 1 and April 30, 2012, were eligible for enrollment. Each laceration was evaluated by a trainee/midlevel provider (frontline provider) and by an attending physician; each one offered an estimated laceration length. The true measurement was then documented by 1 of 6 pediatric emergency medicine fellows on shift. Data were analyzed using descriptive statistics. The mean error of estimation (the absolute differences between the estimated and the true laceration length) of attending physicians and frontline providers were determined and compared. The proportions of lacerations whose estimated length was in a different billing category were compared using χ(2). Cost analysis was documented. RESULTS: One hundred ninety patients were enrolled. The mean age was 5.9 years. A total of 119 patients (62.6%) were male, and 134 lacerations (70.5%) were located on the face. Most repairs were simple (79%). There was no difference between the estimated and measured length among attendings and frontline providers (P = 0.583). An average of 8.2% of lacerations were misclassified and billed incorrectly with 20% (4/20) of facial lacerations up-coded. The mean overcharge was $12.04. Of 11 lacerations elsewhere on the body, 3 (27%) were down-coded, with an average difference of $6.97 for simple and $38.51 for layered repairs. CONCLUSIONS: Pediatric emergency medicine practitioners are accurate estimators of laceration length. Eight percent of lacerations are misclassified and billed incorrectly. Physicians should be required to report measured lengths for billing.

Specialized Care Resources for Diagnosis and Management of Patients Who Have Suffered Falls: Results of a National Survey in Geriatric Units.

INTRODUCTION: Clinical guidelines recommend comprehensive multifactorial assessment and intervention to prevent falls and fractures in older populations. METHODS: A descriptive study was conducted by the Falls Study Group of the Spanish Geriatric Medicine Society (SEMEG) to outline which types of healthcare-specific resources were assigned for fall assessment in Spanish geriatric departments. A self-reported seven-item questionnaire was delivered from February 2019 to February 2020. Where geriatric medicine departments were not available, we tried to contact geriatricians working in those areas. RESULTS: Information was obtained regarding 91 participant centers from 15 autonomous communities, 35.1% being from Catalonia and 20.8% from Madrid. A total of 21.6% reported a multidisciplinary falls unit, half of them in geriatric day hospitals. Half of them reported fall assessment as part of a general geriatric assessment in general geriatric outpatient clinics (49.5%) and, in 74.7% of cases, the assessment was based on functional tests. A total of 18.7% reported the use of biomechanical tools, such as posturography, gait-rides or accelerometers, for gait and balance analysis, and 5.5% used dual X-ray absorptiometry. A total of 34% reported research activity focused on falls or related areas. Regarding intervention strategies, 59% reported in-hospital exercise programs focused on gait and balance improvement and 79% were aware of community programs or the pathways to refer patients to these resources. CONCLUSIONS: This study provides a necessary starting point for a future deep analysis. Although this study was carried out in Spain, it highlights the need to improve public health in the field of fall prevention, as well as the need, when implementing public health measures, to verify that these measures are implemented homogeneously throughout the territory. Therefore, although this analysis was at the local level, it could be useful for other countries to reproduce the model.

[An opportunity to identify and prevent frailty through falls intervention.] / Oportunidad para la detección y manejo precoz de la fragilidad a través del abordaje de las caídas.

Falls are one of the classic giant geriatric syndromes with a multifactorial etiopathogenesis and closely related to frailty, being this relationship bidirectional. The Consensus Document on the Prevention of Frailty and Falls approved by the Interterritorial Council of the National Health System in 2014 provides recommendations for the screening of frailty and falls in all older adults in order to develop a management plan in high risk older adults so to prevent disability. This review describes the intrinsic relationship between frailty and falls, falls assessment and screening instruments to use and detect frailty and finally gives evidence-based recommendations to reduce falls impact.

Las caídas son uno de los grandes síndromes geriátricos, con una etiopatogenia multifactorial y con una estrecha relación con la fragilidad, siendo esta relación bidireccional. El Documento de Consenso sobre Prevención de Fragilidad y Caídas aprobado por el Consejo Interterritorial del Sistema Nacional de Salud en 2014, propone un cribado universal de fragilidad y riesgo de caídas, con el objetivo de intervenir en aquellos ancianos de alto riesgo y por tanto prevenir discapacidad. Esta revisión evalúa la relación intrínseca entre caídas y fragilidad, describe las herramientas de valoración del paciente que presenta caídas, incidiendo en aquellos aspectos que detectan fragilidad y finalmente propone intervenciones que han demostrado reducir su impacto.

Prostate Ewing Sarcoma/PNET: A case of long survival in a highly aggressive malignancy.

Prostate Ewing sarcoma/peripheral primitive neuroectodermal tumor (ES/PNET) is extremely rare. Currently, a multimodal approach is recommended, although there is no standard treatment. Nevertheless, this tumor has a very poor prognosis, with the longest reported survival of 24 months. We present a case of locally advanced prostate ES/PNET in a 29-year-old male who was treated with a multimodal approach. The patient is alive and disease free, with a seven year follow-up, with very good quality of life. This exceptionally long survival may be the result of the very aggressive multimodal treatment chosen and described herein.

Association Between Pulmonary Embolism and COVID-19 in Emergency Department Patients Undergoing Computed Tomography Pulmonary Angiogram: The PEPCOV International Retrospective Study.

BACKGROUND: There have been reports of procoagulant activity in patients with COVID-19. Whether there is an association between pulmonary embolism (PE) and COVID-19 in the emergency department (ED) is unknown. The aim of this study was to assess whether COVID-19 is associated with PE in ED patients who underwent a computed tomographic pulmonary angiogram (CTPA). METHODS: A retrospective study in 26 EDs from six countries. ED patients in whom a CTPA was performed for suspected PE during a 2-month period covering the pandemic peak. The primary endpoint was the occurrence of a PE on CTPA. COVID-19 was diagnosed in the ED either on CT or reverse transcriptase-polymerase chain reaction. A multivariable binary logistic regression was built to adjust with other variables known to be associated with PE. A sensitivity analysis was performed in patients included during the pandemic period. RESULTS: A total of 3,358 patients were included, of whom 105 were excluded because COVID-19 status was unknown, leaving 3,253 for analysis. Among them, 974 (30%) were diagnosed with COVID-19. Mean (±SD) age was 61 (±19) years and 52% were women. A PE was diagnosed on CTPA in 500 patients (15%). The risk of PE was similar between COVID-19 patients and others (15% in both groups). In the multivariable binary logistic regression model, COVID-19 was not associated with higher risk of PE (adjusted odds ratio = 0.98, 95% confidence interval = 0.76 to 1.26). There was no association when limited to patients in the pandemic period. CONCLUSION: In ED patients who underwent CTPA for suspected PE, COVID-19 was not associated with an increased probability of PE diagnosis. These results were also valid when limited to the pandemic period. However, these results may not apply to patients with suspected COVID-19 in general.

Predictors of airway and respiratory adverse events with ketamine sedation in the emergency department: an individual-patient data meta-analysis of 8,282 children.

STUDY OBJECTIVE: Although ketamine is one of the most commonly used sedatives to facilitate painful procedures for children in the emergency department (ED), existing studies have not been large enough to identify clinical factors that are predictive of uncommon airway and respiratory adverse events. METHODS: We pooled individual-patient data from 32 ED studies and performed multiple logistic regressions to determine which clinical variables would predict airway and respiratory adverse events. RESULTS: In 8,282 pediatric ketamine sedations, the overall incidence of airway and respiratory adverse events was 3.9%, with the following significant independent predictors: younger than 2 years (odds ratio [OR] 2.00; 95% confidence interval [CI] 1.47 to 2.72), aged 13 years or older (OR 2.72; 95% CI 1.97 to 3.75), high intravenous dosing (initial dose > or =2.5 mg/kg or total dose > or =5.0 mg/kg; OR 2.18; 95% CI 1.59 to 2.99), coadministered anticholinergic (OR 1.82; 95% CI 1.36 to 2.42), and coadministered benzodiazepine (OR 1.39; 95% CI 1.08 to 1.78). Variables without independent association included oropharyngeal procedures, underlying physical illness (American Society of Anesthesiologists class >or = 3), and the choice of intravenous versus intramuscular route. CONCLUSION: Risk factors that predict ketamine-associated airway and respiratory adverse events are high intravenous doses, administration to children younger than 2 years or aged 13 years or older, and the use of coadministered anticholinergics or benzodiazepines.

Predictors of emesis and recovery agitation with emergency department ketamine sedation: an individual-patient data meta-analysis of 8,282 children.

STUDY OBJECTIVE: Ketamine is widely used in emergency departments (EDs) to facilitate painful procedures; however, existing descriptors of predictors of emesis and recovery agitation are derived from relatively small studies. METHODS: We pooled individual-patient data from 32 ED studies and performed multiple logistic regression to determine which clinical variables would predict emesis and recovery agitation. The first phase of this study similarly identified predictors of airway and respiratory adverse events. RESULTS: In 8,282 pediatric ketamine sedations, the overall incidence of emesis, any recovery agitation, and clinically important recovery agitation was 8.4%, 7.6%, and 1.4%, respectively. The most important independent predictors of emesis are unusually high intravenous (IV) dose (initial dose of > or =2.5 mg/kg or a total dose of > or =5.0 mg/kg), intramuscular (IM) route, and increasing age (peak at 12 years). Similar risk factors for any recovery agitation are low IM dose (<3.0 mg/kg) and unusually high IV dose, with no such important risk factors for clinically important recovery agitation. CONCLUSION: Early adolescence is the peak age for ketamine-associated emesis, and its rate is higher with IM administration and with unusually high IV doses. Recovery agitation is not age related to a clinically important degree. When we interpreted it in conjunction with the separate airway adverse event phase of this analysis, we found no apparent clinically important benefit or harm from coadministered anticholinergics and benzodiazepines and no increase in adverse events with either oropharyngeal procedures or the presence of substantial underlying illness. These and other results herein challenge many widely held views about ED ketamine administration.

Heelys injuries: a review of the National Electronic Injury Surveillance System data.

OBJECTIVE: The purpose of this study was to describe the types and severity of Heelys-related injuries reported to the National Electronic Injury Surveillance System (NEISS). Strategies for prevention of these injuries may be developed using this information. METHODS: We performed a retrospective analysis of the NEISS data of the US Consumer Safety Product Commission between 2002 and 2006. RESULTS: The NEISS had 131 reported Heelys injuries in children. The mean age was 10.02 years. The upper extremity was most commonly injured, accounting for 75 (57.3%) of the 131 injuries. Fractures were the most common injuries, accounting for 66 (50.4%) of the 131 injuries. Children younger than 12 years were more likely to sustain fractures than their older counterparts (P = 0.001). Children 12 years or older were more likely to sustain sprains than the younger children (P ≤ 0.001). There was no difference in injury patterns between the sexes (P = not significant). Six children required hospital admission. There was 1 reported death. CONCLUSIONS: Most injuries sustained from Heelys use are orthopedic injuries. However, a wide variety of other injuries occur with Heelys use. Children can sustain injuries serious enough to require hospital admission. Parents and children should be educated about the importance of protective gear use while "heeling."

Simple febrile seizures: are the AAP guidelines regarding lumbar puncture being followed?

BACKGROUND: In 1996, the American Academy of Pediatrics (AAP) published a practice parameter recommending that lumbar puncture (LP) be strongly considered in infants younger than 12 months presenting with a first febrile seizure. OBJECTIVE: We sought: (1) to determine if the recommendations of the AAP are being followed by pediatric emergency medicine-trained physicians at our institution; (2) to describe the rate of meningitis among patients with febrile seizure who underwent LP; and (3) to determine if there were differences in performance of LP if children were younger or pretreated with antibiotics. METHODS: A retrospective chart review of patients aged 6 to 12 months presenting with first simple febrile seizure to the emergency department (ED) at Miami Children's Hospital was conducted between January 2001 and November 2005. RESULTS: A total of 242 ED records with a discharge diagnosis including the term "febrile seizure," "seizure," or "meningitis" were identified. Of those, 56 met inclusion criteria for first simple febrile seizure. Lumbar puncture was performed in 28 patients (50%) that met inclusion criteria. Younger patients were no more likely to have LP performed than older patients (P = 0.15). Ten children (17.8%) received antibiotics before the ED visit; of these, 4 (40%) underwent LP in the ED. Children who presented with first simple febrile seizure to our institution who were pretreated with antibiotics were no more likely to have LP performed than those who were not receiving antibiotics (P = 0.48). All cerebrospinal fluid cultures were sterile. CONCLUSION: The AAP recommendations regarding LP in patients 6 to 12 months of age with first simple febrile seizure are not being strictly adhered to. The AAP recommendations regarding simple febrile seizures were conceived in a different epidemiologic era of disease pathology with data not representative of current prevalence and etiologic issues and need to be revisited.

False-positive colorimetric capnometry after ingestion of carbonated beverages.

STUDY OBJECTIVE: To investigate the potential for false-positive colorimetric capnometric readings during esophageal intubation after ingestion of carbonated beverages. METHODS: The study was conducted in the human patient simulation laboratory of a tertiary care pediatric hospital. The sole outcome measurement was the capnometric indicator membrane color after expiration for 10 breaths. Readings were recorded for scenarios simulating 8 different models. RESULTS: For all carbonated beverage trials with a cuffed endotracheal tube (ETT) and those with 2 and 6 oz of beverage in the gastric sac with an uncuffed ETT, a false-positive result was observed on the capnometer's indicator for breaths 1 through 10. The sensitivity of the capnometer for the detection of CO2 after full exhalation of breath 6 for these trials was 100%. For trials containing 12 oz in the gastric sac and an uncuffed ETT, yellow was observed on the capnometer indicator for breaths 1 through 3, tan for breaths 4 through 6, and purple for breath 7. The sensitivity of the capnometer for the detection of adequate CO2 after full exhalation of breath 6 for these trials was 0%. The overall sensitivity of the capnometer for the carbonated beverage models with a cuffed ETT was 100%, whereas the combined sensitivity for the trials with an uncuffed ETT was 67%. CONCLUSIONS: Under proper circumstances, a significant potential exists for false-positive colorimetric capnometric results in the presence of even small amounts of carbonated beverages.

The Ras-related gene ERAS is involved in human and murine breast cancer.

Although Ras genes are frequently mutated in human tumors, these mutations are uncommon in breast cancer. However, many breast tumors show evidences of Ras pathway activation. In this manuscript, we have analyzed and characterized mouse mammary tumors generated by random Sleeping Beauty transposon mutagenesis and identify ERAS -a member of the RAS family silenced in adult tissues- as a new gene involved in progression and malignancy of breast cancer. Forced expression of ERAS in human non-transformed mammary gland cells induces a process of epithelial-to-mesenchymal transition and an increase in stem cells markers; these changes are mediated by miR-200c downregulation. ERAS expression in human tumorigenic mammary cells leads to the generation of larger and less differentiated tumors in xenotransplant experiments. Immunohistochemical, RT-qPCR and bioinformatics analysis of human samples show that ERAS is aberrantly expressed in 8-10% of breast tumors and this expression is associated with distant metastasis and reduced metastasis-free survival. In summary, our results reveal that inappropriate activation of ERAS may be important in the development of a subset of breast tumors. These findings open the possibility of new specific treatments for this subset of ERAS-expressing tumors.