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.

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.

Quimioterapia neoadyuvante: indicaciones y resultados. Experiencia de 15 años en el Instituto Alexander Fleming / Neoadjuvant chemotherapy: indications and results. Fifteen years of experience at Instituto Alexander Fleming

Introducción Existe consenso sobre los subgrupos de pacientes con más probabilidades de beneficiarse del tratamiento neoadyuvante, pero su utilización en la práctica clínica es variable. Las pacientes con cáncer de mama en etapa temprana susceptibles de requerir quimioterapia adyuvante podrían considerarse para realizar quimioterapia neoadyuvante (qtna). Objetivos Evaluar las tasas de cirugía conservadora en pacientes con cáncer de mama que reciben qtna y describir las tendencias de respuestas clínica, imagenológica y patológica en la mama y la axila. Material y método Se realizó una evaluación retrospectiva de 125 pacientes con cáncer de mama invasor (Estadios IB-IIA/B-IIIA), operadas en el Instituto Alexander Fleming en el período 2002-2018. Resultados Las tasas más altas de respuesta patológica completa (pcr) se obtuvieron en los tumores her2, tn y Luminal B-her2, representando el 56%, 55% y 40% respectivamente. En la respuesta patológica completa ganglionar, las tasas más altas se obtuvieron en los Luminal B-her2 82%, los tn 80% y los her2 70%. Las tasas de cirugía conservadora fueron: para Luminal A 44%, para Luminal B 58%, para Luminal B-her2 54%, para her2 76% y para tn 59%. Conclusiones Concordante con trabajos publicados, se describen altas tasas de cirugía conservadora y altas tasas de pcr en tumores her2 y tn

Introduction Even though there is evidence about better outcomes after neoadjuvant chemotherapy (nac) for breast cancer (bc), it is unclear who are the indicated patients and what are the correct indications for using it. Our hypothesis is that early stage bc patients, who are identified as susceptible for adjuvant chemotherapy, could be the most benefited of receiving nac. Objectives We aimed to study the number of patients who received nac and breast conserving surgery (bcs) assessing clinical, pathological and radiological response in both, breast and axilla. Materials and method We carried out a retrospective study of 125 patients newly diagnosed of bc (Stage IB-IIA-B and IIIA) who received nat and bcs in our institution, "Instituto Alexander Fleming", during the 2002-2018 period Results We obtained the higher rates of pathological complete response (pcr) in her2 being 56%; for tn was 55% and 40% for Luminal B-her2. The highest rates of complete pathological lymph node response were obtained in Luminal B-her2 82%, tn 80% and her2 70%. The rates for bcs where 44%, 58%, 54% and 76% for Luminal A, Luminal B, Luminal B-her2 and her2 respectively. Conclusions There is current data available supporting our findings, having similar results for bcs and pcr performing bcs after nat

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.

Predictive Factors for Non-Sentinel Lymph Node Metastasis in Patients with ACOSOG Z0011 Criteria.

BACKGROUND: Nodal staging constitutes an element of great importance in the treatment planning for early breast cancer. The ACOSOG Z0011 trial demonstrated that sentinel lymph node (SLN) biopsy alone results in rates of local control, disease-free survival, and overall survival equivalent to those seen after axillary lymph node dissection. The purpose of this study was to determine the rate of patients that fulfill the ACOSOG Z0011 inclusion criteria and to define predictive factors for non-SLN positivity. METHODS: A retrospective analysis of the breast surgery database of the Argentinian Society of Mastology was carried out. Patients were selected if they fulfilled the ACOSOG Z0011 inclusion criteria. The association of clinical and pathological factors with non-SLN positivity was evaluated in univariate and multivariate analysis. RESULTS: Among 8,262 patients, 973 had positive SLN, and 348 satisfied the inclusion criteria. Histological grade (G3 vs. G1-2, odds ratio (OR) 1.81; p = 0.024), tumor size (T2 vs. T1, OR 2.39; p = 0.001), and age (>50 vs. <50 years, OR 1.95; p = 0.007) were associated with non-SLN positivity in multivariate analysis. CONCLUSION: Although the clinical relevance of our data is not established, older women with tumors bigger than 2 cm and/or high histological grade are at greater risk of having metastatic disease in the lymph nodes if axillary lymph node dissection is avoided. This subgroup of patients represents only 30% of the trial population.

High Histologic Grade and High Ki-67 Expression Predict Phenotypic Alterations in Node Metastasis in Primary Breast Cancers.

PURPOSE: Several studies have shown that estrogen receptor (ER) and progesterone receptor (PR) expression and human epidermal growth factor receptor 2 (HER2) expression may vary during tumoral progression. We aimed to describe and compare ER, PR, and HER2 expressions in primary breast tumors and synchronic axillary nodal metastases, and evaluate phenotypic correlations between them. METHODS: Patients were identified prospectively through surgical procedures between September 2013 and July 2016. The status of ER, PR, HER2, and Ki-67 were pathologically analyzed in breast cancers and axillary nodal metastases; these patients were classified based on the breast cancer phenotypes into five subgroups. RESULTS: Synchronic axillary nodal metastases were observed in 127 patients. In breast cancers and nodal metastases, correlation analyses of ER, PR, and Ki-67 expression showed a statistical dependence and concordance between these samples was unambiguously demonstrated through Bland-Altman plots for each determination. Primary breast tumors were classified as follows: luminal A, 41.6%; luminal B, 40.0%; luminal B/HER2, 9.6%; HER2, 2.4%; triple negative, 6.4%. Alterations in phenotype were observed in 28% of patients. The most frequent phenotypic alteration was from luminal B to A (36.4%). Ten cases (30.3%) showed alterations with therapeutic implications; six gained HER2 overexpression, and four, hormonal receptor (HR) expression. A moderate strength of agreement (Cohen's κ coefficient, 0.59; 95% confidence interval, 0.48-0.71) was observed. In multivariate analyses, high histologic grade (odds ratio [OR], 2.79; p<0.047) and high Ki-67 expression (OR, 1.05; p<0.037) were independent factors predictive of phenotypic alterations. CONCLUSION: Strong correlations were observed in HR and Ki-67 expressions between primary breast tumors and axillary nodal metastases, and a moderate concordance was observed in their phenotypical characteristics. Nevertheless, alterations did exist, and one-third of these changes may have therapeutic implications. The nodal metastases of tumors with high grade and high Ki-67 expression may need to be analyzed, to obtain complete therapeutic information.

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...

Overexpression of CD85j in TNBC patients inhibits Cetuximab-mediated NK-cell ADCC but can be restored with CD85j functional blockade.

Clinical studies suggest that triple negative breast cancer (TNBC) patients with epidermal growth factor receptor (EGFR)-expressing tumors could benefit from therapy with Cetuximab, which targets EGFR. NK cells are the primary effectors of antibody (Ab)-dependent cell-mediated cytotoxicity (ADCC) and thus play a role in Ab-based therapies. We have previously described diminished levels of Cetuximab-mediated ADCC in vitro in patients with advanced breast cancer. Here, we investigated the potential causes of this NK-cell functional deficiency. We characterized NK-cell activating/inhibitory receptors in the peripheral blood of breast cancer patients and found CD85j inhibitory receptor overexpression. The capacity of NK cells to perform Cetuximab-triggered ADCC against TNBC cells correlated inversely with CD85j expression, even in the presence of the stimulatory cytokines IL-2 or IL-15. Hence, patients expressing high levels of CD85j had an impaired ability to lyse TNBC cells in the presence of Cetuximab. We also found that CD85j overexpression was associated with HLA-I and soluble HLA-G expression by tumors. A CD85j functional blockade with a CD85j antagonist Ab restored ADCC levels in breast cancer patients and reverted this negative effect. Our data suggest that strategies that overcome the hurdles of immune activation could improve Cetuximab clinical efficacy.

IL-2- or IL-15-activated NK cells enhance Cetuximab-mediated activity against triple-negative breast cancer in xenografts and in breast cancer patients.

Triple-negative breast cancer (TNBC) patients do not benefit from target-specific treatments and is associated with a high relapse rate. Epidermal growth factor receptor is frequently expressed in TNBC and is a candidate for new therapies. In this work, we studied Cetuximab-mediated immune activity by NK cells. Thirteen activating/inhibitory receptors were examined on peripheral blood and tumor infiltrating NK cells. NK-cell functionality was evaluated using as effectors tumor-modulated NK cells and NK cells from patients. We evaluated the treatment with Cetuximab plus IL-2 or IL-15 in vivo in TNBC xenografts. Tumor NK-cells receptor profile showed upregulation of inhibitory receptors and downregulation of activating ones. Tumor-modulated NK cells were less cytotoxic. They could perform antibody-dependent cellular cytotoxicity (ADCC) triggered by Cetuximab, although impaired, it could still be restored by stimulation with IL-2 or IL-15. Patients with advanced disease displayed diminished levels of ADCC compared to healthy volunteers. ADCC was restored and potentiated with both cytokines, which were also effective in enhancing the therapeutic activity of Cetuximab in vivo. The combination of Cetuximab with IL-15 and IL-2 may be considered an attractive therapeutic approach to enhance the clinical efficacy of Cetuximab in TNBC.

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...

Identification of network topological units coordinating the global expression response to glucose in Bacillus subtilis and its comparison to Escherichia coli.

BACKGROUND: Glucose is the preferred carbon and energy source for Bacillus subtilis and Escherichia coli. A complex regulatory network coordinates gene expression, transport and enzymatic activities, in response to the presence of this sugar. We present a comparison of the cellular response to glucose in these two model organisms, using an approach combining global transcriptome and regulatory network analyses. RESULTS: Transcriptome data from strains grown in Luria-Bertani medium (LB) or LB+glucose (LB+G) were analyzed, in order to identify differentially transcribed genes in B. subtilis. We detected 503 genes in B. subtilis that change their relative transcript levels in the presence of glucose. A similar previous study identified 380 genes in E. coli, which respond to glucose. Catabolic repression was detected in the case of transport and metabolic interconversion activities for both bacteria in LB+G. We detected an increased capacity for de novo synthesis of nucleotides, amino acids and proteins. A comparison between orthologous genes revealed that global regulatory functions such as transcription, translation, replication and genes relating to the central carbon metabolism, presented similar changes in their levels of expression. An analysis of the regulatory network of a subset of genes in both organisms revealed that the set of regulatory proteins responsible for similar physiological responses observed in the transcriptome analysis are not orthologous. An example of this observation is that of transcription factors mediating catabolic repression for most of the genes that displayed reduced transcript levels in the case of both organisms. In terms of topological functional units in both these bacteria, we found interconnected modules that cluster together genes relating to heat shock, respiratory functions, carbon and peroxide metabolism. Interestingly, B. subtilis functions not found in E. coli, such as sporulation and competence were shown to be interconnected, forming modules subject to catabolic repression at the level of transcription. CONCLUSION: Our results demonstrate that the response to glucose is partially conserved in model organisms E. coli and B. subtilis, including genes encoding basic functions such as transcription, translation, replication and genes involved in the central carbon metabolism.

Regulatory network of Escherichia coli: consistency between literature knowledge and microarray profiles.

The transcriptional network of Escherichia coli may well be the most complete experimentally characterized network of a single cell. A rule-based approach was built to assess the degree of consistency between whole-genome microarray experiments in different experimental conditions and the accumulated knowledge in the literature compiled in RegulonDB, a data base of transcriptional regulation and operon organization in E. coli. We observed a high and statistical significant level of consistency, ranging from 70%-87%. When effector metabolites of regulatory proteins are not considered in the prediction of the active or inactive state of the regulators, consistency falls by up to 40%. Similarly, consistency decreases when rules for multiple regulatory interactions are altered or when "on" and "off" entries were assigned randomly. We modified the initial state of regulators and evaluated the propagation of errors in the network that do not correlate linearly with the connectivity of regulators. We interpret this deviation mainly as a result of the existence of redundant regulatory interactions. Consistency evaluation opens a new space of dialogue between theory and experiment, as the consequences of different assumptions can be evaluated and compared.

La biopsia del ganglio centinela en el cáncer de la mama, resultados de un estudio de 106 pacientes / Sentinel node biopsy in breast cancer. Results of a study of 106 patients

Introducción: La linfadenectomía axilar es parte fundamental del tratamiento quirúrgico del cáncer de mama (CM).Ultimamente su aplicación rutinaria es cuestionada debido a su morbilidad, al hecho que la mayoría de los pacientes tienen axila negativa y a que las terapias adyuvantes se basan cada vez máa en las características del tumor primario. La biopsia del ganglio centinela (BGC), un test mínimamente invasor, ha sido propuesta en su reemplazo en pacientes con axila negativa. Recientes estudios han demostrado que el ganglio centinela (GC) predice en forma confiable el estado del resto de los ganglios axilares (RGA). Objetivos: comprobar la factibilidad de identificar el GC y si suestado refleja el del RGA. Pacientes: pacientes con CM temprano que iban a recibir tratamiento qirúrgico primario. Métodos: El GC fue identificado a través de un colorante vital, patent blue, en 106 pacientes combinado con un radioisótopo, cloide sulfúrico de Tc99, en 46 pacientes. Luego de la BGC se efectuó vaciamiento axilar completo en todas las pacientes. Resultados: Se realizaron 107 BGC (106 pacientes, 1 bilateral). Identificamos el GC en 94/107 biopsias (88 por ciento). Hubo 61/94 GC negativos; en 59/61 coincidió con el estado del RGA (valor de predicción negativo: 97 por ciento); en 2 (3 por ciento), no hubo coincidencia (2 falsos negativos). 33/94GC fueron positivos; en 24 (73 por ciento) coincidieron con el estado de RGA;, 9(27 por ciento) fueron únicos positivos. Conclusión: nuestro estudio confirma la factibilidad técnica de la BGC en pacientes con CM. Su resultado negativo permite predecir con alto grado de confiabilidad el estado del RGA... (AU)

La biopsia del ganglio centinela en el cáncer de la mama, resultados de un estudio de 106 pacientes / Sentinel node biopsy in breast cancer. Results of a study of 106 patients

Introducción: La linfadenectomía axilar es parte fundamental del tratamiento quirúrgico del cáncer de mama (CM).Ultimamente su aplicación rutinaria es cuestionada debido a su morbilidad, al hecho que la mayoría de los pacientes tienen axila negativa y a que las terapias adyuvantes se basan cada vez máa en las características del tumor primario. La biopsia del ganglio centinela (BGC), un test mínimamente invasor, ha sido propuesta en su reemplazo en pacientes con axila negativa. Recientes estudios han demostrado que el ganglio centinela (GC) predice en forma confiable el estado del resto de los ganglios axilares (RGA). Objetivos: comprobar la factibilidad de identificar el GC y si suestado refleja el del RGA. Pacientes: pacientes con CM temprano que iban a recibir tratamiento qirúrgico primario. Métodos: El GC fue identificado a través de un colorante vital, patent blue, en 106 pacientes combinado con un radioisótopo, cloide sulfúrico de Tc99, en 46 pacientes. Luego de la BGC se efectuó vaciamiento axilar completo en todas las pacientes. Resultados: Se realizaron 107 BGC (106 pacientes, 1 bilateral). Identificamos el GC en 94/107 biopsias (88 por ciento). Hubo 61/94 GC negativos; en 59/61 coincidió con el estado del RGA (valor de predicción negativo: 97 por ciento); en 2 (3 por ciento), no hubo coincidencia (2 falsos negativos). 33/94GC fueron positivos; en 24 (73 por ciento) coincidieron con el estado de RGA;, 9(27 por ciento) fueron únicos positivos. Conclusión: nuestro estudio confirma la factibilidad técnica de la BGC en pacientes con CM. Su resultado negativo permite predecir con alto grado de confiabilidad el estado del RGA...

Presente y futuro de la disección axilar / Disection axillary present and future

El tratamiento conservador de la mama ha demostrado definitivamente su valor en los últimos lustros. Si bien no mejora la supervivencia, su difusión y aplicación permitió una mejor calidad de vida. Al valor indiscutible de la conservación de la mama, a pesar de la sombra de las recurrencias locales, se agrega una menor morbilidad del vaciamiento axilar por varios motivos: en muchos centros sólo se realiza la disección del 1er y 2º nivel ganglionar, y aun cuando se realicen vaciamientos completos, no se incluye la adventicia de la vena axilar, se respetan los nervios del dorsal ancho y del serrato mayor, y no se realiza una irradiación indiscriminada de la axila, sino en casos muy seleccionados. Pero no obstante la linfadenectomía axilar sigue siendo el "talón de Aquiles" de la cirugía oncológica mamaria, ya que sus complicaciones siguen representando la causa más frecuente de la mortalidad del tratamiento conservador. Por ese motivo, el objetivo actual de la cirugía del cáncer de mama es evitar el vaciamiento axilar. Para alcanzar dicho objetivo, el cirujano debe estar seguro de respetar los fundamentos del tratamiento locorregional del cáncer de mama: 1. dar suficiente información pronóstica, y 2. controlar la enfermedad locorregional