Navigating HER2-Low Testing in Invasive Breast Cancer: Update Recommendations for Pathologists.

The article discusses the importance of accurately distinguishing HER2-low from HER2-negative breast cancer, as novel ADCs have demonstrated activity in a large population of patients with HER2-low-expressing BC. While current guidelines recommend a dichotomous classification of HER2 as either positive or negative, the emergence of the HER2-low concept calls for standardization of HER2 testing in breast cancer, using currently available assays to better discriminate HER2 levels. This review covers the evolution and latest updates of the ASCO/CAP guidelines relevant to this important biomarker in breast cancer, including still-evolving concepts such as HER2 low, HER2 heterogeneity, and HER2 evolution. Our group presents the latest Mexican recommendations for HER2 status evaluation in breast cancer, considering the ASCO/CAP guidelines and introducing the HER2-low concept. In the era of personalized medicine, accurate HER2 status assessment remains one of the most important biomarkers in breast cancer, and the commitment of Mexican pathologists to theragnostic biomarker quality is crucial for providing the most efficient care in oncology.

Nonalcoholic Fatty Liver Disease Severity Is Related to Plasma Pro-Oxidative Biomarkers Rather Than Liver Tissue-Measured Nitrogen Metabolism Biomarkers in Population with Obesity and Metabolic Syndrome.

Background: The metabolic syndrome (MS) is associated with an increased production of nitrogen metabolites and elevated oxidative stress, which favors progression of nonalcoholic fatty liver disease (NAFLD). Subjects with the phenotype known as metabolically unhealthy obese (MUO) meet most of the MS cardiometabolic risk criteria and show a higher risk of advanced NAFLD severity, compared with the so-widely known metabolically healthy obese (MHO). Obese individuals with MS are more susceptible to abnormal lipid accumulation in different tissues, whereas oxidative stress and nitrogen metabolites are increased in MS and/or obesity. This study aimed to explore whether plasma- or liver tissue-determined biomarkers of nitrogen metabolism and oxidative stress relate to NAFLD severity and/or metabolic phenotype. Methods: This cross-sectional study included candidates for bariatric surgery with biopsy-proven NAFLD diagnosis and staging. For comparison, the study population was divided according to NAFLD damage (steatohepatitis F0-F1 vs. steatohepatitis F2-F4) and metabolic phenotype (MHO vs MUO, based on the MS criteria). Hepatic and plasma concentrations of nitrogen metabolites and oxidative stress biomarkers were determined by enzymatic kinetics assays, enzyme-linked immunosorbent assay, and Greiss reaction. Results: The study population (N = 45) was constituted by patients with obesity and higher prevalence of dyslipidemia, diabetes mellitus, and hypertension. According to plasma biomarkers, MUO phenotype was related to higher cardiometabolic risk; meanwhile, advanced NAFLD damage was related to higher glycated hemoglobin (HbA1c) and triglycerides. Elevated hepatic concentrations of ammonium, nitrites, arginine, and citrulline were found in MUO phenotype, but only higher plasma concentration of malondialdehyde was found as specifically related to advanced NAFLD damage. Conclusions: Circulating biomarkers of redox state were selectively related to advanced NAFLD damage, suggesting prognostic and therapeutic targets. Hepatic concentrations of nitrogen metabolism biomarkers may be more related to cardiometabolic risk.

The metabolic phenotype of the patient influences the reduction in carotid intima-media thickness achieved following metabolic surgery.

OBJECTIVES: To determine whether metabolic phenotype is associated with the change in carotid intima-media thickness (CIMT) in patients undergoing bariatric /metabolic surgery (BMS). METHODS: We performed a case-control study of BMS candidates who had metabolically unhealthy obesity (MUO) or metabolically healthy obesity (MHO). We measured the change in CIMT during the 9 months following BMS. The plasma tumor necrosis factor-α, interleukin-1ß, adiponectin, leptin, nitric oxide (NO), vascular endothelial growth factor A (VEGF-A), and malondialdehyde concentrations were determined, adipocyte area was measured histologically, and adipose tissue area was estimated using computed tomography. RESULTS: Fifty-six patients (mean age 44.5 years, mean body mass index 44.9 kg/m2, 53% women, and 53% had MUO) were studied. Nine months following BMS, the MUO phenotype was not associated with a significant reduction in CIMT, and that of the MHO group was larger. In addition, fewer participants achieved a 10% reduction in CIMT in the MUO group. A CIMT reduction was associated with lower VEGF-A and NO in the MUO group, while that in the MHO group was associated with a higher NO concentration. CONCLUSION: The metabolic phenotype of patients may influence their change in CIMT following BMS, probably through circulating vasodilatory and pro-inflammatory molecules.

Identification of adipose tissue-related predictors of the reduction in cardiovascular risk induced by metabolic surgery.

OBJECTIVES: We aimed to determine whether parameters associated with adipose tissue (adipocyte density and the circulating concentrations of markers of adipose tissue pathology) predict cardiovascular risk (CVR) modification after metabolic surgery (MS). METHODS: We performed a case-control study of patients with morbid obesity who were candidates for MS. CVR was defined using flow-mediated dilation (FMD) and carotid intima media thickness (CIMT), which were measured during the 9 months following MS. Subgroups of CVR reduction were defined using the following cut-offs: CIMT 10% and/or a two-fold increase in FMD. RESULTS: We studied 40 patients with morbid obesity (mean age 44.5 years, 75% women, mean body mass index 46.4 kg/m2) and high prevalences of the metabolically unhealthy obesity phenotype, hypertension, and diabetes mellitus. A significant reduction in CVR was associated with lower vascular endothelial growth factor-A concentration (6.20 vs. 1.59 pg/mL, respectively), low adipocyte density in visceral adipose tissue (100 vs. 80 cells/field), low infiltration with CD68+ cells (18 vs. 8 cells/field) and higher concentrations of lipid peroxidation markers and malondialdehyde (313.7 vs. 405.7 ng/mL). CONCLUSION: The characteristics of adipose tissue and the circulating concentrations of markers of adipose pathology might represent useful predictors of the reduction in CVR following MS.Clinical trial registration number: NCT0356198 (https://clinicaltrials.gov).

Enlarged adipocytes from subcutaneous vs. visceral adipose tissue differentially contribute to metabolic dysfunction and atherogenic risk of patients with obesity.

Morphological characteristics and source of adipose tissue as well as adipokines may increase cardiometabolic risk. This study aimed to explore whether adipose tissue characteristics may impact metabolic and atherogenic risks. Subcutaneous Adipose Tissue (SAT), Visceral Adipose Tissue (VAT) and peripheral blood were obtained from obese patients submitted to bariatric surgery. Adipose tissue (morphometry), plasma adiponectin, TNF-α, resistin (multiplexing) and biochemical chemistry were analyzed; as well as endothelial dysfunction (Flow Mediated Dilation, FMD) and atherogenesis (Carotid Intima Media Thickness, CIMT). Subgroups divided by adipocyte size and source were compared; as well as correlation and multivariate analysis. Sixty patients 36.6% males, aged 44 years-old, BMI 46.7 kg/m2 were included. SAT's adipocytes showed a lower range of size expandability than VAT's adipocytes. Independent from their source, larger adipocytes were associated with higher glucose, lower adiponectin and higher CIMT. Particularly, larger adipocytes from SAT were associated with higher blood pressure, lower insulin and HDL-cholesterol; and showed positive correlation with glucose, HbA1c, systolic/diastolic values, and negatively correlated with insulin and adiponectin. VAT's larger adipocytes particularly associated with lower resistin and lower FMD values. Gender and Diabetes Mellitus significantly impacted the relation of adipocyte size/source with the metabolic and atherogenic risk. Multivariable analysis suggested hypertension-resistin-HbA1c interactions associated with SAT's larger adipocytes; whereas potential insulin-adiponectin associations were observed for VAT's larger adipocytes. Adipocyte morphology and source are differentially related with cardiometabolic and atherogenic risk in population with obesity, which are potentially affected by gender and Diabetes Mellitus.

Neutrophil-to-lymphocyte ratio and its relation with pro-inflammatory mediators, visceral adiposity and carotid intima-media thickness in population with obesity.

BACKGROUND: Atherosclerosis represents a cardiovascular risk. Chronic inflammation is a key factor for atherogenic progression. Neutrophil-to-lymphocyte ratio (NLR) has been proposed as a novel biomarker for cardiovascular risks. We aimed to explore whether NLR was related to surrogate pro-atherogenic promoters driving atherogenic progression, as measured by carotid intima-media thickness (CIMT). STUDY DESIGN: Thirty-one patients with obesity candidates for bariatric surgery were recruited from Centro Médico Nacional "20 de Noviembre", ISSSTE, Mexico City. The results are part of the "CROP" study (NCT03561987). NLR was calculated from routine complete blood count, and its relation with plasma pro-inflammatory mediators (hsCRP, TNF-α and IL-1ß), adipokines (adiponectin and leptin), adiposity markers (visceral adipose tissue [VAT] determined from CT scan image and VAT individual adipocyte area at histological sample) and CIMT were determined. RESULTS: Neutrophil-to-lymphocyte ratio correlated with hsCRP (Spearman's r = 0.70 [95% CI 0.46 to 0.85], P < 0.01), TNF-α (r = 0.69 [0.44 to 0.84], P < 0.0001) and adiponectin (r = -0.69 [-0.84 to -0.45], P < 0.03), as well as with VAT individual adipocyte area (r = 0.64 [0.37 to 0.81], P < 0.0001) and with VAT area (r = 0.43; [0.07 to 0.68], P < 0.01). Leptin and adiponectin showed further independent association with higher NLR (multivariate regression analysis OR 7.9 [95% CI 1.1 to 56.2] P = 0.03 and 0.1 [0.01 to 1.0] P = 0.05, respectively). Moreover, NLR distribution significantly varied between subgroups divided according to progressive CIMT (P = 0.05); whereas adiponectin and VAT adipocyte area associated with CIMT > 0.9 mm (univariate analysis OR 0.1 [0.01 to 1.0] P = 0.05 and 13.1 [1.4 to 126.3] P = 0.03, respectively). CONCLUSION: Neutrophil-to-lymphocyte ratio was related to pro-inflammatory, adiposity biomarkers and progressive subclinical atherogenesis.

Eosinophilic gastroenteritis / Gastroenteritis eosinofílica

The eosinophilic gastroenteritis is a disease of unknown etiopathogenesis and rare presentation, with several clinical symptoms, ranging from mild episodes until nonspecific abdominal acute episodes of intestinal obstruction, which some times make it necessary urgent surgical treatment. This wide symptomatic range seems to be conditioned by the degree of eosinophilic infiltration of the intestinal wall and the number of layers involved. This paper reports the case of a patient who, due to the diagnosis difficulties, illustrates in a single patient the intestinal and respiratory anatomo-clinical diversity and the evolution of the eosinophilia both intestinal and peripheral. Patient was sent to our service with diagnoses of bronchial asthma, chronic allergic rhinitis and chronic anemia.

La gastroenteritis eosinofílica es una enfermedad de etiopatogenia no aclarada y manifestación poco frecuente, con síntomas clínicos diversos, abarca desde cuadros leves abdominales inespecíficos hasta episodios agudos de obstrucción intestinal que en ocasiones hacen preciso el tratamiento quirúrgico urgente. Este amplio abanico sintomático parece estar condicionado por el grado de infiltración eosinofílica de la pared intestinal y el número de capas afectadas. Comunicamos un caso que por la dificultad diagnóstica ilustra, en un solo paciente, la diversidad anatomoclínica del cuadro intestinal y respiratorio y la evolución de la eosinofilia intestinal y periférica. La paciente fue enviada a nuestro servicio con los diagnósticos de asma bronquial, rinitis crónica alérgica y anemia crónica persistente.