HyGAnno: hybrid graph neural network-based cell type annotation for single-cell ATAC sequencing data.

Reliable cell type annotations are crucial for investigating cellular heterogeneity in single-cell omics data. Although various computational approaches have been proposed for single-cell RNA sequencing (scRNA-seq) annotation, high-quality cell labels are still lacking in single-cell sequencing assay for transposase-accessible chromatin (scATAC-seq) data, because of extreme sparsity and inconsistent chromatin accessibility between datasets. Here, we present a novel automated cell annotation method that transfers cell type information from a well-labeled scRNA-seq reference to an unlabeled scATAC-seq target, via a parallel graph neural network, in a semi-supervised manner. Unlike existing methods that utilize only gene expression or gene activity features, HyGAnno leverages genome-wide accessibility peak features to facilitate the training process. In addition, HyGAnno reconstructs a reference-target cell graph to detect cells with low prediction reliability, according to their specific graph connectivity patterns. HyGAnno was assessed across various datasets, showcasing its strengths in precise cell annotation, generating interpretable cell embeddings, robustness to noisy reference data and adaptability to tumor tissues.

Epigenetic characterization of housekeeping core promoters and their importance in tumor suppression.

In this research, we elucidate the presence of around 11,000 housekeeping cis-regulatory elements (HK-CREs) and describe their main characteristics. Besides the trivial promoters of housekeeping genes, most HK-CREs reside in promoter regions and are involved in a broader role beyond housekeeping gene regulation. HK-CREs are conserved regions rich in unmethylated CpG sites. Their distribution highly correlates with that of protein-coding genes, and they interact with many genes over long distances. We observed reduced activity of a subset of HK-CREs in diverse cancer subtypes due to aberrant methylation, particularly those located in chromosome 19 and associated with zinc finger genes. Further analysis of samples from 17 cancer subtypes showed a significantly increased survival probability of patients with higher expression of these genes, suggesting them as housekeeping tumor suppressor genes. Overall, our work unravels the presence of housekeeping CREs indispensable for the maintenance and stability of cells.

Intercellular crosstalk in adult dental pulp is mediated by heparin-binding growth factors Pleiotrophin and Midkine.

BACKGROUND: In-depth knowledge of the cellular and molecular composition of dental pulp (DP) and the crosstalk between DP cells that drive tissue homeostasis are not well understood. To address these questions, we performed a comparative analysis of publicly available single-cell transcriptomes of healthy adult human DP to 5 other reference tissues: peripheral blood mononuclear cells, bone marrow, adipose tissue, lung, and skin. RESULTS: Our analysis revealed that DP resident cells have a unique gene expression profile when compared to the reference tissues, and that DP fibroblasts are the main cell type contributing to this expression profile. Genes coding for pleiotrophin (PTN) and midkine (MDK), homologous heparin-binding growth-factors, possessed the highest differential expression levels in DP fibroblasts. In addition, we identified extensive crosstalk between DP fibroblasts and several other DP resident cells, including Schwann cells, mesenchymal stem cells and odontoblasts, mediated by PTN and MDK. CONCLUSIONS: DP fibroblasts emerge as unappreciated players in DP homeostasis, mainly through their crosstalk with glial cells. These findings suggest that fibroblast-derived growth factors possess major regulatory functions and thus have a potential role as dental therapeutic targets.

Multi-omics computational analysis unveils the involvement of AP-1 and CTCF in hysteresis of chromatin states during macrophage polarization.

Macrophages display extreme plasticity, and the mechanisms and applications of polarization and de-/repolarization of macrophages have been extensively investigated. However, the regulation of macrophage hysteresis after de-/repolarization remains unclear. In this study, by using a large-scale computational analysis of macrophage multi-omics data, we report a list of hysteresis genes that maintain their expression patterns after polarization and de-/repolarization. While the polarization in M1 macrophages leads to a higher level of hysteresis in genes associated with cell cycle progression, cell migration, and enhancement of the immune response, we found weak levels of hysteresis after M2 polarization. During the polarization process from M0 to M1 and back to M0, the factors IRFs/STAT, AP-1, and CTCF regulate hysteresis by altering their binding sites to the chromatin. Overall, our results show that a history of polarization can lead to hysteresis in gene expression and chromatin accessibility over a given period. This study contributes to the understanding of de-/repolarization memory in macrophages.

Cyclin-Dependent Kinase 4/6 Inhibitor Outcomes in Patients With Advanced Breast Cancer Carrying Germline Pathogenic Variants in DNA Repair-Related Genes.

PURPOSE: In recent years, unprecedented benefits have been observed with the development of cyclin-dependent kinase (CDK) 4 and 6 inhibitors for the treatment of hormone receptor-positive/human epidermal growth factor receptor 2-negative metastatic breast cancer. However, there is scarce evidence of their value in specific populations, such as patients carrying germline pathogenic variants in DNA repair-related genes. PATIENTS AND METHODS: We retrospectively studied the efficacy of CDK 4/6 inhibitors plus endocrine therapy in patients with hormone receptor-positive/human epidermal growth factor receptor 2-negative advanced breast cancer. Three cohorts were compared, including patients harboring germline pathogenic variants in DNA repair-related genes (gBRCA1/2-ATM-CHEK2 mutated), those tested without these mutations (wild type [WT]), and the nontested subgroup. Relevant prognostic factors including age, metastatic site (visceral v nonvisceral), Eastern Cooperative Oncology Group, and prior treatment with CDK 4/6 inhibitors were stratified by univariate and multivariate Cox regression models. RESULTS: Among the total population (n = 217), 15 (6.9%) patients carried gBRCA1/2 (n = 10)-ATM (n = 4)-CHEK2 (n = 1) pathogenic variants, 45 (20.7%) were WT, and 157 (72.4%) were nontested. Gene pathogenic variant carriers were younger (P < .001). Most patients (164, 75.6%) had not received prior endocrine therapy in the advanced setting. Median progression-free survival was shorter in patients with evaluated germline pathogenic variants (10.2 months [95% CI, 5.7 to 14.7]), compared with WT and nontested patients (15.6 months [95% CI, 7.8 to 23.4], and (17.6 months [95% CI, 12.9 to 22.2]; P = .002). Consistently, a worse median overall survival was observed in the subgroup with germline pathogenic variants than in the WT group (P = .006). Multivariable analysis showed that mutation status was an independent prognostic factor of progression-free survival (P = .020) and overall survival (P = .012). CONCLUSION: In this retrospective real-world study, gBRCA1/2-ATM-CHEK2 pathogenic variants were independently associated with poor outcomes in patients with advanced breast cancer treated with CDK4/6 inhibitors.

Unbiased integration of single cell transcriptome replicates.

Single cell transcriptomic approaches are becoming mainstream, with replicate experiments commonly performed with the same single cell technology. Methods that enable integration of these datasets by removing batch effects while preserving biological information are required for unbiased data interpretation. Here, we introduce Canek for this purpose. Canek leverages information from mutual nearest neighbor to combine local linear corrections with cell-specific non-linear corrections within a fuzzy logic framework. Using a combination of real and synthetic datasets, we show that Canek corrects batch effects while introducing the least amount of bias compared with competing methods. Canek is computationally efficient and can easily integrate thousands of single-cell transcriptomes from replicated experiments.

Valor de la ruptura capsular y extensión extranodal en el ganglio centinela como predictores del estado axilar en pacientes con cáncer de mama T1-T2 / Significance of extracapsular extension in sentinel lymph nodes as a predictor of axillary lymph node status in T1-T2 breast cancer patients

Introducción: Identificar aquellas pacientes con cáncer de mama en estadíos iniciales que no se benefician de la linfadenectomía (LA), a pesar de contar con ganglios centinela positivos, constituye un desafío. El ensayo ACOSOG-Z0011 modificó el paradigma de la cirugía axilar, pero aún no está claro qué efecto tiene la ruptura capsular (RC) y su extensión (EEC) en el compromiso axilar. Material y método: Se incluyeron 214 pacientes intervenidas quirúrgicamente entre 2009-2019 en el Centro mamario del Instituto Alexander Fleming, con cáncer de mama en T1-2, en las que la biopsia de ganglio centinela (BGC) resultó positiva, y se realizó LA. Se realizaron comparaciones entre aquellas pacientes con y sin RC. Las pacientes con RC fueron divididas en dos grupos, según la EEC fuera mayor o igual a 2 mm, o menor a 2 mm. Para los distintos grupos de pacientes, se analizaron variables clínicas y anatomo-patológicas, incluyendo edad, estado menopáusico, subtipo biológico, grado nuclear, tamaño tumoral, invasión linfovascular (ILV) y multicentricidad. Resultados: La RC se asoció a una mayor probabilidad de presentar ganglios no centinela positivos, y en particular a la presencia de 4 o más ganglios positivos. Este grupo de pacientes presentó con más frecuencia ILV. En cuanto a la EEC, no hallamos diferencias significativas de acuerdo a la extensión de la ruptura (EEC<2 mm y EEC≥2 mm), aunque en el análisis uni y multivariado evidenció un mayor riesgo de presentar ≥4 ganglios positivos en el grupo de pacientes con EEC≥2 mm. Discusión: En línea con la bibliografía actual, encontramos que la RC es un hallazgo frecuente y que se asocia a una mayor probabilidad de presentar metástasis ganglionar, en especial 4 o más ganglios positivos. Al separar a las pacientes de acuerdo a la EEC, no hallamos diferencias en cuanto a la proporción de pacientes con ganglios positivos en la LA. Estos resultados difieren de los obtenidos por otros centros, en donde se ha demostrado una mayor probabilidad de contar con ganglios no centinela positivos en el grupo de pacientes con EEC>2mm. Conclusiones: En la bibliografía actual existe consenso en relación al rol de la RC como factor de riesgo, y nuestros resultados apoyan esta hipótesis. Sin embargo, resulta menos claro el papel que juega la magnitud de la EEC. Esto podría deberse, por un lado, a la falta que bibliografía disponible, y por otro, a la falta de consenso para determinar la medición de la EEC En línea con publicaciones recientes que no hallan diferencias significativas en la recurrencia de la enfermedad a largo plazo según la magnitud de la EEC, será fundamental continuar con un futuro análisis que contemple estos aspectos en nuestra población. Al día de hoy, no contamos con evidencia que nos permita afirmar que las pacientes con EEC<2 mm puedan beneficiarse de la omisión de LA

Introduction: The identification of those early breast cancer patients with no clear benefit from axillary lymph node dissection (ALND) in spite of the presence of positive sentinel lymph nodes (SLNs), remains controversial. Although the ACOSOG-Z001 trial has significantly altered management of the axilla, the role played by the extracapsular extension (ECE) is still a subject of debate. Materials and method: In the present study, we analysed 214 early breast cancer patients with positive SLN biopsy, who underwent ALND at Instituto Alexander Fleming between 2009 and 2019. Patients were divided into two categories based on the presence or absence of ECE; those patients with ECE were further divided based on the extent of ECE (ECE<2 mm and ECE≥2 mm). Analysis of clinical-pathological parameters was performed, including age, menopausal status, tumor subtype, nuclear grade, tumor size, lymphovascular invasion (LVI) and multicentricity. Results: ECE was associated with an increased probability of additional positive nodes in the ALND, and these patients were also more likely to have 24 positive nodes. LVI was increased in patients with ECE. Additionally, we found no significant differences regarding the number of positive nodes when comparing patients according to the extent of ECE (ECE<2 mm and ECE≥2 mm). Univariate and multivariate analyses of factors associated with involvement of ≥4 nodes at completion ALND resulted in an increased odds ratio for patients with ECE ≥2 mm. Discussion: In line with recent literature, we found ECE is frequently observed in breast cancer patients and is associated with an increased probability of lymph node metastases, and these patients are also more likely to have 24 positive nodes. We found no significant differences in terms of the proportion of patients with positive lymph nodes in ALND when comparing patients with and without ECE. Our results differ from other studies that showed a higher risk of non-sentinel lymph nodes metastases in patients with ECE>2mm. Conclussions: There is cumulative evidence on the role of ECE as a risk factor in breast cancer patients, and our findings further support this hypothesis. However, the extent of ECE is still a topic of heated debate, and its role in disease progression is less clear, given there are relatively few studies addressing this matter and there are discrepancies in the way the extent of ECE is measured. Considering recent publications where no significant differences were found in terms of longterm disease recurrence when stratifying patients according to the extent of ECE, our future endeavours should focus on the assessment of the course of the disease. To date, we have no evidence supporting the idea that patients with ECE<2mm could actually benefit from omis- sion of ALND.

Lesiones de potencial maligno incierto (B3): nuestra experiencia en el Instituto Alexander Fleming / Lesions of uncertain malignant potential (B3): Our experience at the Alexander Fleming Institute

Objetivo: Revisar la correlación radiopatológica de las lesiones de potencial maligno incierto (B3) de nuestra institución, evaluar la conducta y establecer el porcentaje de subestimación en relación a las lesiones tratadas quirúrgicamente. Material y método: Estudio retrospectivo de la base de datos de procedimientos intervencionistas efectuados en el servicio de diagnóstico por imágenes del Instituto Alexander Fleming entre mayo de 2016 y diciembre de 2019 inclusive. Se incluyeron las pacientes con resultado histológico en la biopsia percutánea de uno o más de los siguientes diagnósticos: atipia epitelial plana (AEP), cicatriz radiada/lesión esclerosante compleja (CR), hiperplasia ductal atípica (HDA), neoplasia lobular clásica (NL), lesión papilar (LP) o tumor phyllodes (TP). Resultados: De 67 pacientes analizadas, el 43.3% se manifestaron en los estudios por imágenes con nódulos y en un 37.3% con microcalcificaciones agrupadas. La LP fue la lesión B3 más frecuente en un 44.8% seguido por la AEP en un 16.4%. El 98.5% de las pacientes presentó adecuada concordancia radiopatológica. Fueron sometidas a cirugía 48 pacientes, las 19 pacientes restantes continuaron con seguimiento clínico radiológico. La anatomía patológica de la pieza quirúrgica reflejó que en un 33.3% hubo subestimación en relación a la biopsia; en más de la mitad de los casos correspondieron a CDIS. Conclusiones: El porcentaje de subestimación con resultado final de CDIS o CDI de bajo grado se encontró dentro de los parámetros hallados en la literatura. Si bien logramos reducir la tasa de cirugías al 71% de pacientes con lesiones B3, una adecuada selección para efectuar exéresis con aguja por sistema de vacío podría reducir aún más el número de cirugías innecesarias y probablemente la tasa de subestimación.

Objective: To review the radiopathological correlation of lesions of uncertain malignant potential (B3) diagnosed in our institution, as well as to evaluate the therapeutic conduct and to establish the percentage of underestimation of the excised lesions. Material and method: This work consists of a retrospective study of the database which in- cludes the interventional procedures performed in the Imaging Department of the Alexander Fleming Institute between May 2016 and December 2019. Patients with a histological outcome in the percutaneous biopsy of one or more of the following diagnosis were included: flat epithelial atypia (FEA), radial scar (RS) /complex sclerosing lesion (CSL), atypical ductal hyperplasia (ADH), classic lobular neo- plasia (LN), papillary lesión (PL) or phyllodes tumor (PT). Results: Out of the 67 analyzed patients, 43.3% were perceived as nodules at imaging examinations and 37.3% as grouped microcalcifications. Papillary lesion was the most frequently diagnosed B3 lesion (44.8%), followed by flat epithelial atypia (16.4%). 98.5% of patients presented an accurate imaging-pathology concordance. 48 patients underwent surgery and the remaining 19 patients continued with clinical and radiological follow-up. The histopathology of the surgical specimen reflected that in 33.3% of the cases there was an underestimation in relation to the percutaneous biopsy; in over half of these cases they corresponded with DCIS. Conclusions: The percentage of underestimation with final diagnosis of DCIS or low grade IDC coincided with the parameters found in current literature. Even though we were able to reduce the surgical rate to 71% of patients with B3 lesions, a proper selection of cases which could be candidates for vacuum assisted excisional biopsy could further reduce the number of unnecessary surgeries and probably the un- derestimation rate as well.

Disección axilar dirigida: Nuestra experiencia con el uso de suspensión de carbón activado / Target axillary dissection: Our experience with the use of charcoal suspension

Objetivo: Determinar la tasa de identificación intra operatoria por el médico cirujano de los ganglios marcados con suspensión de carbón activado previo a la neoadyuvancia. El objetivo secundario es determinar la concordancia entre los ganglios linfáticos marcados con carbón y aquellos considerados ganglios centinelas. Material y método: Es un estudio retrospectivo desde el año 2016 hasta el año 2020. Se incluyeron 27 pacientes con cáncer de mama en estadios T1 - T3 que realizaron quimioterapia neoadyuvante y con axila con estadio N1 y N2. Los ganglios axilares biopsiados con resultado positivo fueron marcados con suspensión de carbón activado, posteriormente las pacientes realizaron quimioterapia neoadyuvante. Se evaluó la tasa de detección y concordancia del ganglio marcado con el ganglio centinela durante el procedimiento quirúrgico. Resultados: Del total de pacientes en 20 casos se realizó efectivamente la identificación por inspección visual de la suspensión de carbón activado en la cavidad axilar durante la cirugía. La tasa de detección fue del 74%. Del total de 20 pacientes en los cuales se identificó carbón visualmente en el acto quirúrgico, 16 se sometieron a biopsia de ganglio centinela. En 81% de los casos hubo una coincidencia entre el ganglio marcado con carbón y el ganglio centinela. Conclusión: En nuestro trabajo la tasa de detección intraoperatoria de los ganglios marcados con carbón está en concordancia con lo publicado en la literatura. Esto catapulta a este método de marcación como una alternativa factible para realizar una disección axilar dirigida asegurándole al médico cirujano la resección de una ganglio positivo de inicio para su análisis anatomopatológico de respuesta. Hemos comprobado que la marcación con carbón no interfiere con la técnica estándar utilizada para la biopsia de ganglio centinela sino que su uso en conjunto mejora la técnica dignóstica.

Objetive: The aim of this study was to determine the rate of identification of activated charcoal suspension during surgery in positive lymph nodes before neadjuvant chemotherapy. The secondary objetive is to determine the rate of concordance between the marked lymph nodes and the sentinel lymph nodes. Material and method: A retrospective study that goes from the year 2016 - 2020. It includes 27 patients with breast cancer (T1 - T3) and positive lymph nodes (N1 - N2). Patients with biopsy - confirmed nodal metatases were marked with activated charcoal suspension in the sampled node. After this procedure patients underwent neoadjuvant chemotherapy and axillary surgery. The rate of detection and the concordance of the marked lymph node with the sentinel lymph nodes was calculated. Results: Of the 27 patients enrolled in this study in 20, the marked node was detected during surgery. The detection rate was of 74%. Of these 20 patientes, 16 had sentinel node biopsy. There was an 81% rate of concordance between the sentinel lymph node and the tattooed lymph node. Conclusions: In our study, the detection rate of marked lymph node is concordant with the numbers publised by other studies. This shows that axillary lymph node tattooing with activated charcoal suspension is a viable, low cost and precise method when performing targeted axillary dissection. We identified that the tattooing procedure does not affect the standard sentinel node biopsy, in fact, when used together it improves its diagnostic performance.

Breast Cancer in Young Women Presents With More Aggressive Pathologic Characteristics: Retrospective Analysis From an Argentine National Database.

PURPOSE: Multiple studies have reported that breast cancer in young patients is associated with aggressive characteristics, and it is suggested that prognosis is worse independently of pathologic variables. PATIENTS AND METHODS: We performed a retrospective analysis of the Breast Cancer Registry of the Argentinian Society of Mastology, including public and private centers. Patients ≤ 40 years of age at diagnosis were classified as "young," and patients ≤ 35 years of age at diagnosis were classified as "very young." Univariate and multivariate analyses were performed to detect differences between groups. RESULTS: Patients ≤ 40 years of age comprised 10.40% (739/7,105) of the participants, with an average age of 35.61 ± 4.04 years. Multivariate analysis showed that human epidermal growth factor receptor 2 (HER2)-positive tumor phenotype (odds ratio [OR], 1.82), nodal involvement (OR, 1.69), histologic grade (grade 3 OR, 1.41), and tumor size (T2 OR, 1.37; T3-T4, 1.47) were independently associated with younger age at diagnosis. Patients ≤ 35 years of age (n = 286), compared with patients 36 to 40 years of age, had a higher proportion of HER2 tumors (24.58% v 16.94%; P = .021), absence of progesterone receptor expression (29.85% v 22.95%; P = .043), and stage 3 cancer (29.34% v 18.52%; P < .001). Fewer breast-conserving surgeries (75.37% v 62.89%; P < .001) and more adjuvant chemotherapy (59.04% v 36.66%; P < 0.001) were reported in patients ≤ 40 years of age. CONCLUSION: In the population studied, breast cancer in young women was associated with aggressive pathologic features and locally advanced disease at the time of diagnosis. Moreover, tumor characteristics in very young patients with breast cancer nested in the population ≤ 40 years of age showed differences in important prognostic factors. More high-quality evidence is needed to improve treatment strategies in these patients.

Los linfocitos estromales intratumorales (tils) como factor pronóstico en tumores primarios de mama Triple Negativos / Tumor infiltrating lymphocytes (tils) in Triple Negative breast cancer as a prognostic factor

Introducción Los tumores de mama se encuentran frecuentemente rodeados por células inflamatorias como signo de interacción entre el tumor y el huésped, siendo esta crítica para el desarrollo y progresión del cáncer. Algunas observaciones sugieren el valor pronóstico de los linfocitos estromales intratumorales (tils). Sin embargo, su evaluación no es rutinaria ya que su relevancia clínica aún no se encuentra consolidada. Objetivos Los objetivos de este trabajo son: • la evaluación de la concordancia interobservador de los linfocitos intratumorales (tils); • su relación con la sobrevida libre de enfermedad (sle); • su valoración como factor pronóstico en cáncer de mama Triple Negativo. Material y método Se seleccionaron retrospectivamente pacientes con tumores de mama Triple Negativos operados en el Instituto Alexander Fleming entre 2010-2016 sin tratamiento neoadyuvante, alcanzando una muestra de 65 pacientes. Resultados El porcentaje mediano de tils fue de 30% (12,5-50), y se consideraron como "Tumores ricos en linfocitos" (Lymphocyte Predominant Breast Cancerlpbc) a los de 19 pacientes (29,2%). Tanto la presencia de tils (p>0,01) como la definición del subtipo de lpbc (p=0,03) presentaron asociación estadísticamente significativa con la recurrencia de enfermedad. En el análisis multivariado, presentaron asociación la histología ductal y el valor de tils. Por cada 10% de aumento, disminuye 31% el riesgo de recaída. El valor de tils estratificado en 3 subgrupos (≤20; 30-40; ≥50%) presentó asociación estadísticamente significativa con la Sobrevida Libre de Enfermedad (Log Rank <0,01). Conclusiones En este trabajo se logró describir una característica tumoral y del huésped reproducible, cuya instrumentación podría generalizarle por el potencial valor pronóstico.

Introduction Breast tumors are frequently surrounded by inflammatory cells as a sign of interaction between the tumor and host, being this relationship critical for cancer development and progression. Present evidence suggests that tumor infiltrating lymphocytes (tils) may provide prognostic information. Nevertheless, tils description is not generalized as its clinical relevance is not consolidated. Objectives • evaluation of interobserver concordance of intratumoral lymphocytes (tils); • its relationship with Disease Free Survival; • its assessment as a prognostic factor in Triple Negative breast cancer. Materials end method Triple Negative breast cancer patients with surgery in Instituto Alexander Fleming, between 2010-2016, without neoadyuvant treatment, were selected retrospectively. 65 patients were selected. Results In the 65 patients selected, tils median percentage was 30% (12.5-50), and 19 (29.2%) were considered Lymphocyte Predominant Breast Cancer (lpbc). tils percentage (p>0.01) and lpbc subtype (p=0.03) presented significant association with disease recurrence. Multivariate analysis showed that ductal histology and tils percentage are associated with disease recurrence. For every 10% increment in tils, there was a 31% reduction of risk of recurrence. High tils value stratified in 3 subgroups (≤20; 30-40; ≥50%) was associated with better Disease Free Survival (Log Rank 0.01). Conclusions Due to its potential prognostic value and its technical reproducibility, we believe that this tumoral and host characteristic must be generalized.

Activated and Micronized Zeolite in the Modulation of Cellular Oxidative Stress in Mexican Smokers: A Randomized Clinical Trial.

BACKGROUND: Activated and micronized zeolites are used as detoxifying agents in humans. Detoxification is attributed to their ability to reduce lipid peroxidation by scavenging free radicals. OBJECTIVE: To evaluate activated and micronized zeolites as modulators of cellular oxidative stress in Mexican smokers without lung diseases. METHODS: Randomized clinical trial. Subjects were randomly divided into three groups: activated and micronized zeolites, n = 29; vitamin E, an accepted antioxidant, n = 29; and maltodextrin as control, n = 27. Each group received the corresponding supplementation, dissolved in water, once a day for 30 days as follows: activated and micronized zeolites, 5.4 g activated and micronized zeolite; vitamin E, 400 mg D-alpha tocopheryl acetate; and maltodextrin, 250 mg of maltodextrin. The thiobarbituric acid reactive substances assay was used to screen for lipid peroxidation. Catalase activity, plasma antioxidant capacity, and hydrogen peroxide levels were also measured. Results were analyzed by a one-way ANOVA and post hoc test of Bonferroni. RESULTS: Subjects administered activated and micronized zeolites had equivalent antioxidant activities as subjects administered vitamin E. CONCLUSIONS: Activated and micronized zeolites may be useful as a modulator of oxidative stress in smokers. However, inclusion of a comparison group of non-smokers would be useful in future studies to assess the degree to which zeolites reverse the oxidant stress.

Rol de la biopsia del ganglio centinela en el carcinoma ductal in situ y en el microinvasor: experiencia del Instituto de Oncología Alexander Fleming / Rol of Sentinel Node Biopsy in Ductal Carcinoma In Situ and Microinvasive Breast Cancer: Instituto Alexander Fleming Experience

Determinar la incidencia de ganglio centinela (GC) positivo en pacientes con Carcinoma ductal in situ (CDIS) y microinvasor (T1mic); y describir las características clinicopatológicas de los mismos en relación con el compromiso axilar. Material y método: Se realizó un estudio retrospectivo en 46 pacientes con diagnóstico de CDIS y en 88 pacientes con T1mic a las cuales se les realizó la biopsia del ganglio centinela (BGC), en el período comprendido entre marzo de 1999 y octubre de 2013. Para el análisis estadístico, se utilizó el programa SPSS 17.0. Resultados: Una paciente de 46 (2,1%) con CDIS presentó una micrometástasis en el estudio diferido. No se completó la linfadenectomía axilar (LA). En 4 de las 88 pacientes (4,5%) con T1mic, el GC fue positivo (2 micrometástasis y 2 macrometástasis). A este grupo se le efectuó linfadenetomía axilar (LA); A este grupo se le efectuó linfadenetomía axilar (LA); una paciente presentó un ganglio positivo (micrometástasis) en los ganglios no centinela (GNC). Cuatro pacientes (4,5%) con T1mic presentaron recidiva en la mama y una (1,1%) a distancia. No hubo recurrencias en la paciente con CDIS. En todos estos casos, el GC había sido negativo. Conclusiones: Nuestros resultados son coincidentes con los de la literatura mundial. Actualmente, en el CDIS, no indicamos la BGC, excepto en CDIS extensos, sospecha de invasión en biopsias con aguja gruesa o cuando la paciente debe ser sometida a una mastectomía. A pacientes con T1mic les realizamos la BGC...

Micrometástasis y células tumorales aisladas en ganglio centinela en pacientes con cáncer de mama: experiencia del Instituto Alexander Fleming / Micrometastases and isolated tumor cells in the centinela node in patients with breast cancer: experience of the Instituto Alexander Fleming

Introducción: el rol del vaciamiento axilar en pacientes con cáncer de mama (CM) con micrometástasis o células tumorales aisladas (CTA) en el ganglio centinella (GC) es controvertido. Objetivos: analizar retrospectivamente pacientes con CM y micrometástasis o CTA en el GC, en términos descriptivos histológicos, terapéuticos y evolución clínica. Métodos: mil veintidós (1.022) biopsias del GC en pacientes con CM (período 1998-2010) fueron evaluadas histológicamente y con inmunohistoquímica. Los tratamientos adyuvantes y los patrones de recurrencia fueron evaluados retrospectivamente de las historias clínicas. Resultados: doscientos treinta y ocho (238) pacientes (23.2%) presentaron GC+. Ciento cuarenta y tres (143) casos (60.0%) fueron macrometástasis, 58 casos (24.3%) micrometástasis y 37 casos (15.5%) CTA. De 58 pacientes con micrometástasis, 75.8% realizó VAG. Veintiocho (28) pacientes (75.6%) de 37 pacientes con CTA no completaron VAG. El porcentaje de GNC+ en las pacientes con micrometástasis y CTA fue 22.7% y 11.0%, respectivamente. Todas las pacientes recibieron tratamiento adyuvante. La mediana de seguimiento fue 54 meses. No hubo recurrencias axilares. El 5% de ambos grupos presentó recurrencias a distancia. La sobrevida libre de eventos es del 94% a 48 meses en ambos grupos. No hubo diferencias estadísticamente significativas para eventos y sobrevida global entre CTA y MIC (p=0.49). Conclusiones: en nuestro estudio las pacientes con micrometástasis y CTA no presentaron recurrencias axilares. No hubo diferencias entre ambos grupos con relación a sobrevida libre de eventos y sobrevida global...