Clinical Implications of Transcriptomic Changes After Neoadjuvant Chemotherapy in Patients with Triple-Negative Breast Cancer.

BACKGROUND: Pathological response to neoadjuvant chemotherapy (NAC) is critical in prognosis and selection of systemic treatments for patients with triple-negative breast cancer (TNBC). The aim of this study is to identify gene expression-based markers to predict response to NAC. PATIENTS AND METHODS: A survey of 43 publicly available gene expression datasets was performed. We identified a cohort of TNBC patients treated with NAC (n = 708). Gene expression data from different studies were renormalized, and the differences between pretreatment (pre-NAC), on-treatment (post-C1), and surgical (Sx) specimens were evaluated. Euclidean statistical distances were calculated to estimate changes in gene expression patterns induced by NAC. Hierarchical clustering and pathway enrichment analyses were used to characterize relationships between differentially expressed genes and affected gene pathways. Machine learning was employed to refine a gene expression signature with the potential to predict response to NAC. RESULTS: Forty nine genes consistently affected by NAC were involved in enhanced regulation of wound response, chemokine release, cell division, and decreased programmed cell death in residual invasive disease. The statistical distances between pre-NAC and post-C1 significantly predicted pathological complete response [area under the curve (AUC) = 0.75; p = 0.003; 95% confidence interval (CI) 0.58-0.92]. Finally, the expression of CCND1, a cyclin that forms complexes with CDK4/6 to promote the cell cycle, was the most informative feature in pre-NAC biopsies to predict response to NAC. CONCLUSIONS: The results of this study reveal significant transcriptomic changes induced by NAC and suggest that chemotherapy-induced gene expression changes observed early in therapy may be good predictors of response to NAC.

Stromal cell expression of caveolin-1 predicts outcome in breast cancer.

Caveolin-1 has been linked to tumor progression and clinical outcome in breast cancer, but a clear resolution of its role as a prognostic marker is lacking. We assessed caveolin-1 levels in normal breast tissue and two breast cancer cohorts for which outcome data were available. We found that caveolin-1 was not expressed in normal breast luminal epithelium but was present in the epithelial compartment of some tumors. We found no association between caveolin-1 expression in the epithelial compartment and clinical outcome. However, high levels of caveolin-1 in the stromal tissue surrounding the tumor, rather than within tumor cells, associated strongly with reduced metastasis and improved survival (P < 0.0001). The onset of mammary tumors driven by Her2/neu overexpression was accelerated in mice lacking caveolin-1, thereby supporting the observation that the presence of caveolin-1 in the tumor microenvironment modulates tumor development. These studies suggest that stromal caveolin-1 expression may be a potential therapeutic target and a valuable prognostic indicator of breast cancer progression.

Simultaneous analysis of the methylation profile of 26 cancer related regions in invasive breast carcinomas by MS-MLPA and drMS-MLPA.

Genetic and epigenetic events play a critical role in the tumorigenic process of breast cancer. The more genes are studied, the more accurate the epigenetic "signature" can be established. The aim of our work has been to apply the technique Methylation-Specific Multiplex Ligation dependent Probe Amplification (MS-MLPA) to study the methylation profile of 26 cancer related gene regions in breast cancers. Secondly, we aimed to establish if the epigenetic "signature" could serve to detect circulating tumor DNA (ctDNA) in breast cancer patients. The MS-MLPA was successfully setup and allowed to establish which regions were preferentially associated with the tumor process. The analysis permitted also to detect significant concurrent methylation between some genes. The detection of ctDNA could be performed by a "double-round" MS-MLPA (drMS-MLPA) approach and nested-Methyl Specific PCR (Nested-MSP). This development is an important novelty and served to detect a small amount of tumor DNA shaded into the blood stream of breast cancer patients. We conclude that MS-MLPA is an excellent assay to analyze the methylation profile of a tumor. The 82 studied samples presented a specific methylation "mark". These studies serve to enhance the knowledge of the role of epigenetic alterations in breast tumors and can contribute to the development of personalized diagnosis, surveillance and treatment strategies.

Working together for the family: determination of HER oncogene co-amplifications in breast cancer.

HER2 is a well-studied tyrosine kinase (TK) membrane receptor which functions as a therapeutic target in invasive ductal breast carcinomas (IDC). The standard of care for the treatment of HER2-positive breast is the antibody trastuzumab. Despite specific treatment unfortunately, 20% of primary and 70% of metastatic HER2 tumors develop resistance. HER2 belongs to a gene family, with four members (HER1-4) and these members could be involved in resistance to anti-HER2 therapies. In this study we designed a probemix to detect the amplification of the four HER oncogenes in a single reaction. In addition, we developed a protocol based on the combination of MLPA with ddPCR to detect the tumor proportion of co-amplified HERs. On 111 IDC, the HER2 MLPA results were validated by FISH (Adjusted r 2 = 0,91, p < 0,0001), CISH (Adjusted r 2 = 0,938, p < 0,0001) and IHC (Adjusted r 2 = 0,31, p < 0,0001). HER1-4 MLPA results were validated by RT-qPCR assays (Spearman Rank test p < 0,05). Of the 111 samples, 26% presented at least one HER amplified, of which 23% showed co-amplifications with other HERs. The percentage of cells with HER2 co-amplified varied among the tumors (from 2-72,6%). Independent in-silico findings show that the outcome of HER2+ patients is conditioned by the status of HER3 and HER4. Our results encourage further studies to investigate the relationship with patient's response to single or combined treatment. The approach could serve as proof of principle for other tumors in which the HER oncogenes are involved.

TP73 DNA methylation and upregulation of ΔNp73 are associated with an adverse prognosis in breast cancer.

AIM: Accumulated evidence suggests that aberrant methylation of the TP73 gene and increased levels of ΔNp73 in primary tumours correlate with poor prognosis. However, little is known regarding the transcriptional and functional regulation of the TP73 gene in breast cancer. The aim of the present study was to determine the expression of the ΔNp73 isoform, its relationship with DNA methylation of TP73 and their clinical prognostic significance in breast cancer patients. METHODS: TP73 gene methylation was studied in TCGA datasets and in 70 invasive ductal breast carcinomas (IDCs). The expression of p73 isoforms was evaluated by immunohistochemistry (IHC) and Western blot and correlated with clinicopathological variables and clinical outcome. RESULTS: We observed that the methylation of diverse CpG islands of TP73 differed significantly between molecular subtypes. An inverse correlation was found between p73 protein expression and the methylation status of the TP73 gene. The expression of exon 3' of p73 (only expressed in ΔNp73) was significantly higher in patients with wild-type p53. Immunohistochemical analysis revealed that all p73 isoforms were localised in both the nuclear and cytoplasmic compartments. We confirmed a positive association between the expression of ∆Np73 and high histological grade. CONCLUSIONS: Our findings suggest that high expression of ΔNp73 could be used to determine the aggressiveness of IDCs and could be incorporated in the pathologist's report.

Co-expression of steroid hormone receptors (estrogen receptor alpha and/or progesterone receptors) and Her2/neu (c-erbB-2) in breast cancer: clinical outcome following tamoxifen-based adjuvant therapy.

In breast cancer patients, the expression of steroid hormone receptors (HR:ERalpha/PR) appears inversely correlated with Her2/neu (not all reports agree on this negative correlation). Moreover, some but not all studies suggest that HR+/Her2/neu+ patients have a poor response to endocrine therapy, making this special group a matter of debate. In this prospective study we have analyzed the clinical outcome of our HR+/Her2/neu+ patients (n=51) selected from 516 consecutive stages I-II cases, with a follow-up 5-10 years (mean 7.3), treated with standard adjuvant therapy with tamoxifen (TAM) (TAM alone or TAM after chemotherapy). This group was compared with the HR+/Her-2/neu- patients (n=129) treated also with TAM. The tumor biopsies were studied by immunohistochemistry. We found that the association HR+/Her2/neu- was 2.5 times higher than the association HR+/Her2/neu+ (25% versus 9.9%, respectively). Our study also showed that the disease free survival (DFS) of the patients co-expressing HR and Her2/neu was significantly lower than those expressing HR but lacking of Her2/neu (p<0.001). A similar result was obtained when the overall survival (OS) was evaluated (p=0.001). All of these patients received hormone therapy with TAM, alone or after chemotherapy. When the analysis was performed in the patients treated with TAM alone, again the expression of Her-2/neu had a negative impact on both the DFS and the OS (p<0.05).

Co-expression of steroid receptors (estrogen receptor alpha and/or progesterone receptors) and Her-2/neu: Clinical implications.

The response of breast cancer patients to endocrine therapy is guided by the expression of two steroid hormone receptors (HR): estrogen receptor alpha (ERalpha) and/or progesterone receptors (PR). In most laboratories the expression of these predictive markers is studied by immunohistochemistry (IHC) in the breast cancer biopsy samples. Another molecular marker that is being increasingly examined in breast cancer is the oncoprotein Her-2/neu, whose expression/amplification predicts the response to anti-Her-2/neu immunotherapy. The co-expression of HR with that of Her-2/neu is infrequent (most reports agree on this), however, there are some conflicting reports about the clinical implications in term of response to endocrine therapy in the patients that co-express HR and Her-2/neu. We have examined these molecular markers for a number of years in our tumor bank, in this dissertation we will present the method and cut-off to study these markers, the correlations between their expression, and the follow-up of the patients that received tamoxifen-based endocrine therapy, alone or following chemotherapy. We confirmed that the co-expression of HR with Her-2/neu is infrequent, and that these patients presented both a shorter disease free survival and overall survival. Our results will be compared with others related recently published. For example, the aromatase inhibitor anastrozole appears to be an effective endocrine treatment in HR+ patients, irrespective of the Her-2/neu status. We will present data on the molecular mechanisms that could explain the relatively poor outcome of these patients. Heregulin has been found to be a potent inducer of heat shock factor 1 (HSF1) activity and of heat shock protein (Hsp) synthesis in breast cancer cells and HSF1 activation plays a role in the tumorigenic changes induced by heregulin, heregulin exerts its tumorigenic changes through the cell surface tyrosine kinase receptors c-erbB-3 and c-erbB-4 which are able to form dimers with the "ligandless" Her-2/neu. We found that HSF1 associates with metastasis associated protein 1 (MTA1) on the promoters of genes as well as other molecules involved in gene repression (HDAC1, HDAC2) in a manner that is enhanced by either heregulin exposure or heat shock. ERs, although promoting the growth of breast cancer cells are less associated with invasion/metastasis and ER-induced gene expression is involve in this effect. Heregulin can overcome the protective effects of ER and at least a component of this appears to be due to MTA1 repression of ERE dependent transcription, HSF1 and MTA1 cooperate in gene repression. The co-expression of HSF1 and MTA1 was confirmed by IHC in human breast cancer biopsy samples.

Asymmetric Cancer Hallmarks in Breast Tumors on Different Sides of the Body.

During the last decades it has been established that breast cancer arises through the accumulation of genetic and epigenetic alterations in different cancer related genes. These alterations confer the tumor oncogenic abilities, which can be resumed as cancer hallmarks (CH). The purpose of this study was to establish the methylation profile of CpG sites located in cancer genes in breast tumors so as to infer their potential impact on 6 CH: i.e. sustained proliferative signaling, evasion of growth suppressors, resistance to cell death, induction of angiogenesis, genome instability and invasion and metastasis. For 51 breast carcinomas, MS-MLPA derived-methylation profiles of 81 CpG sites were converted into 6 CH profiles. CH profiles distribution was tested by different statistical methods and correlated with clinical-pathological data. Unsupervised Hierarchical Cluster Analysis revealed that CH profiles segregate in two main groups (bootstrapping 90-100%), which correlate with breast laterality (p = 0.05). For validating these observations, gene expression data was obtained by RealTime-PCR in a different cohort of 25 tumors and converted into CH profiles. This analyses confirmed the same clustering and a tendency of association with breast laterality (p = 0.15). In silico analyses on gene expression data from TCGA Breast dataset from left and right breast tumors showed that they differed significantly when data was previously converted into CH profiles (p = 0.033). We show here for the first time, that breast carcinomas arising on different sides of the body present differential cancer traits inferred from methylation and expression profiles. Our results indicate that by converting methylation or expression profiles in terms of Cancer Hallmarks, it would allow to uncover veiled associations with clinical features. These results contribute with a new finding to the better understanding of breast tumor behavior, and can moreover serve as proof of principle for other bilateral cancers like lung, testes or kidney.

Análisis comparativo del Carcinoma Lobulillar Invasor versus Carcinoma Ductal Invasor: ¿entidades clínica o biológicamente diferentes? / Comparative analysis of Invasive Lobular Carcinoma versus Invasive Ductal Carcinoma: clinically or biologically different entities?

Introducción El Carcinoma Lobulillar Invasor (cli) es el tipo histológico especial más común del cáncer de mama. Presenta características histopatológicas asociadas a buen pronóstico, pero algunos estudios sugieren que los resultados a largo plazo pueden ser peores que los del Carcinoma Ductal Invasor (cdi). Objetivo Los objetivos principales del estudio fueron evaluar las características clínico-patológicas del cli y establecer el valor pronóstico. Material y método Se seleccionaron 244 pacientes con cli y se utilizó como grupo control a 524 pacientes con cdi, comparándolas con relación 2 a 1. Resultados No se observaron diferencias en edad, estado menopáusico, motivo de consulta e invasión linfovascular. Fueron más frecuentemente multifocales, multicéntricos, de mayor tamaño, bajo grado histológico y her2 negativo. La cirugía conservadora se realizó con menos frecuencia. No hubo diferencias significativas en recaída a distancia, cáncer de mama contralateral, sobrevida libre de enfermedad y global. Conclusiones Las pacientes con cli no tuvieron mejores resultados a pesar de un fenotipo biológico más favorable. La histología ductal o lobulillar no debería ser un factor en el manejo de la patología, y no debería considerarse un factor pronóstico o predictivo determinante al momento del diagnóstico

Introduction Invasive Lobular Carcinoma (ilc) is the second most common histologic type of breast cancer. Typically, displays features associated with a good prognosis, but some studies suggest that outcomes of ilc may be worse than for Invasive Ductal Carcinoma (idc). Objective The main purpose of this study was to evaluate the clinical-pathological characteristics of Lobular Breast Carcinoma and establish his prognostic value. Materials and method We selected a group of 244 patients with ilc and compared with 524 patients whit idc in relation 2:1. Results There were no differences in age, menopausal status, symptoms at time of diagnosis, and lymph vascular invasion. ilc were larger, low histological grade and her2 negative, more often mulfifocal and multicentric. Breast-preservation therapy was less frequent for Invasive Lobular Carcinoma. Distant relapse, contralateral cancer, overall survival, disease-free survival, did not differ between idc and ilc. Conclusions Women with ilc do not have better clinical outcomes than patients with idc, despite the fact that the biologic phenotype of ilc is quite favorable. The ductal or lobular histology should not be a factor in the therapeutic decision-making process, and should not be considered an important prognostic or predictive factor at diagnosis

Epigenetic variations in breast cancer progression to lymph node metastasis.

Breast cancer is a heterogeneous disease characterized by the accumulation of genetic and epigenetic alterations that contribute to the development of regional and distant metastases. Lymph node metastasis (LNM) status is the single most important prognostic factor. Metastatic cancer cells share common molecular alterations with those of the primary tumor, but in addition, they develop distinct changes that allow the cancer to progress. There is an urgent need for molecular studies which focus on identifying genomic and epigenomic markers that can predict the progression to metastasis. The objective of this study was to identify epigenetic similarities and differences between paired primary breast tumor (PBT) and LNM. We employed Methylation-Specific-MLPA (Multiplex ligation-dependent probe amplification) to assess the methylation status of 33 cancer-related genes in a cohort of 50 paired PBT and LNM specimens. We found that the methylation index, which represents the degree of aberrantly methylated genes in a specimen, was maintained during the progression to LNM. However, some genes presented differential methylation profiles. Interestingly, PAX6 presented a significant negative correlation between paired PBT and LNM (p = 0.03), which indicated a switch from methylated to unmethylated status in the progression from PBT to LNM. We further identified that the methylation status of PAX6 on the identified CpG site functionally affected the expression of PAX6 at the mRNA level. Our study unraveled significant epigenetic changes during the progression from PBT to LNM, which may contribute to improved prognosis, prediction and therapeutic management of metastatic breast cancer patients.

HER2 and ß-catenin protein location: importance in the prognosis of breast cancer patients and their correlation when breast cancer cells suffer stressful situations.

In human breast cancer, ß-catenin localization has been related with disease prognosis. Since HER2-positive patients are an important subgroup, and that in breast cancer cells a direct interaction of ß-catenin/HER2 has been reported, in the present study we have explored whether ß-catenin location is related with the disease survival. The study was performed in a tumor bank from patients (n = 140) that did not receive specific anti-HER2 therapy. The proteins were detected by immunohistochemistry in serial sections, 47 (33.5%) patients were HER2-positive with a long follow-up. HER2-positive patients that displayed ß-catenin at the plasma membrane (completely surrounding the tumour cells) showed a significant better disease-free survival and overall survival than the patients showing the protein on other locations. Then we explored the dynamics of the co-expression of ß-catenin and HER2 in human MCF-7 and SKBR3 cells exposed to different stressful situations. In untreated conditions MCF-7 and SKBR3 cells showed very different ß-catenin localization. In MCF-7 cells, cadmium administration caused a striking change in ß-catenin localization driving it from plasma membrane to cytoplasmic and perinuclear areas and HER2 showed a similar localization patterns. The changes induced by cadmium were compared with heat shock, H2O2 and tamoxifen treatments. In conclusion, this study shows the dynamical associations of HER2 and ß-catenin and their changes in subcellular localizations driven by stressful situations. In addition, we report for the first time the correlation between plasma membrane associated ß-catenin in HER2-positive breast cancer and survival outcome, and the importance of the protein localization in breast cancer samples.

Prognostic implication of HSPA (HSP70) in breast cancer patients treated with neoadjuvant anthracycline-based chemotherapy.

Neoadjuvant chemotherapy is used in patients with locally advanced breast cancer to reduce tumor size before surgery. Unfortunately, resistance to chemotherapy may arise from a variety of mechanisms. Heat shock proteins (HSPs), which are highly expressed in mammary tumor cells, have been implicated in anticancer drug resistance. In spite of the widely described value of HSPs as molecular markers in cancer, their implications in breast tumors treated with anthracycline-based neoadjuvant chemotherapy has been poorly explored. In this study, we have evaluated, by immunohistochemistry, the expression of HSP27 (HSPB1) and HSP70 (HSPA) in serial biopsies from locally advanced breast cancer patients (n = 60) treated with doxorubicin (DOX)- or epirubicin (EPI)-based monochemotherapy. Serial biopsies were taken at days 1, 3, 7, and 21, and compared with prechemotherapy and surgical biopsies. After surgery, the patients received additional chemotherapy with cyclophosphamide, methotrexate, and 5-fluorouracil. High nuclear HSPB1 and HSPA expressions were found in invasive cells after DOX/EPI administration (P < 0.001), but the drug did not affect the cytoplasmic expression of the HSPs. Infiltrating lymphocytes showed high nuclear HSPA (P < 0.01) levels at postchemotherapy. No correlations were found between HSPs expression and the clinical and pathological response to neoadjuvant therapy. However, in postchemotherapy biopsies, high nuclear (>31 % of the cells) and cytoplasmic HSPA expressions (>11 % of the tumor cells) were associated with better DFS (P = 0.0348 and P = 0.0118, respectively). We conclude that HSPA expression may be a useful prognostic marker in breast cancer patients treated with neoadjuvant DOX/EPI chemotherapy indicating the need to change the administered drugs after surgery for overcoming drug resistance.

In MMTV-Her-2/neu transgenic mammary tumors the absence of caveolin-1-/- alters PTEN and NHERF1 but not ß-catenin expression.

In a recent study, we have shown that in mammary tumors from mice lacking the Cav-1 gene, there are alterations in specific heat shock proteins as well as in tumor development. With this in mind, we have now investigated other proteins in the same mammary mouse tumor model (Her-2/neu expressing mammary tumors from Cav-1 wild type and Cav-1 null mice), to further comprehend the complex tumor-stroma mechanisms involved in regulating stress responses during tumor development. In this tumor model the cancer cells always lacked of Cav-1, so the KO influenced the Cav-1 in the stroma. By immunohistochemistry, we have found a striking co-expression of ß-catenin and Her-2/neu in the tumor cells. The absence of Cav-1 in the tumor stroma had no effect on expression or localization of ß-catenin and Her-2/neu. Both proteins appeared co-localized at the cell surface during tumor development and progression. Since Her-2/neu activation induces MTA1, we next evaluated MTA1 in the mouse tumors. Although this protein was found in numerous nuclei, the absence of Cav-1 did not alter its expression level. In contrast, significantly more PTEN protein was noted in the tumors lacking Cav-1 in the stroma, with the protein localized mainly in the nuclei. P-Akt levels were relatively low in tumors from both Cav-1 WT and Cav-1 KO mice. There was also an increase in nuclear NHERF1 expression levels in the tumors arising from Cav-1 KO mice. The data obtained in the MMTV-neu model are consistent with a role for Cav-1 in adjacent breast cancer stromal cells in modulating the expression and localization of important proteins implicated in tumor cell behavior.

DNA methylation index and methylation profile of invasive ductal breast tumors.

Breast carcinogenesis is a multistep process that involves both genetic and epigenetic alterations. Identification of aberrantly methylated genes in breast tumors and their relation to clinical parameters can contribute to improved diagnostic, prognostic, and therapeutic decision making. Our objective in the present study was to identify the methylation status of 34 cancer-involved genes in invasive ductal carcinomas (IDC). Each of the 70 IDC cases analyzed had a unique methylation profile. The highest methylation frequency was detected in the WT1 (95.7%) and RASSF1 (71.4%) genes. Hierarchical cluster analysis revealed three clusters with different distribution of the prognostic factors tumor grade, lymph node metastasis, and proliferation rate. Methylation of TP73 was associated with high histological grade and high proliferation rate; methylation of RARB was associated with lymph node metastasis. Concurrent methylation of TP73 and RARB was associated with high histological grade, high proliferation rate, increased tumor size, and lymph node metastasis. Patients with more than six methylated genes had higher rates of relapse events and cancer deaths. In multivariate analysis, TP73 methylation and the methylation index were associated with disease outcome. Our results indicate that methylation index and methylation of TP73 and/or RARB are related to unfavorable prognostic factors in patients with IDC. These epigenetic markers should be validated in further studies to improve breast cancer management.

Aberrant DNA methylation of cancer-related genes in giant breast fibroadenoma: a case report.

INTRODUCTION: Giant fibroadenoma is an uncommon variant of benign breast lesions. Aberrant methylation of CpG islands in promoter regions is known to be involved in the silencing of genes (for example, tumor-suppressor genes) and appears to be an early event in the etiology of breast carcinogenesis. Only hypermethylation of p16INK4a has been reported in non-giant breast fibroadenoma. In this particular case, there are no previously published data on epigenetic alterations in giant fibroadenomas. Our previous results, based on the analysis of 49 cancer-related CpG islands have confirmed that the aberrant methylation is specific to malignant breast tumors and that it is completely absent in normal breast tissue and breast fibroadenomas. CASE PRESENTATION: A 13-year-old Hispanic girl was referred after she had noted a progressive development of a mass in her left breast. On physical examination, a 10 × 10 cm lump was detected and axillary lymph nodes were not enlarged. After surgical removal the lump was diagnosed as a giant fibroadenoma. Because of the high growth rate of this benign tumor, we decided to analyze the methylation status of 49 CpG islands related to cell growth control. We have identified the methylation of five cancer-related CpG islands in the giant fibroadenoma tissue: ESR1, MGMT, WT-1, BRCA2 and CD44. CONCLUSION: In this case report we show for the first time the methylation analysis of a giant fibroadenoma. The detection of methylation of these five cancer-related regions indicates substantial epigenomic differences with non-giant fibroadenomas. Epigenetic alterations could explain the higher growth rate of this tumor. Our data contribute to the growing knowledge of aberrant methylation in breast diseases. In this particular case, there exist no previous data regarding the role of methylation in giant fibroadenomas, considered by definition as a benign breast lesion.

P-cadherin and beta-catenin are useful prognostic markers in breast cancer patients; beta-catenin interacts with heat shock protein Hsp27.

The cadherin-catenin proteins have in common with heat shock proteins (HSP) the capacity to bind/interact proteins of other classes. Moreover, there are common molecular pathways that connect the HSP response and the cadherin-catenin protein system. In the present study, we have explored whether in breast cancer the HSP might interact functionally with the cadherin-catenin cell adhesion system. Beta-catenin was immunoprecipitated from breast cancer biopsy samples, and the protein complexes isolated in this way were probed with antibodies against HSP family members. We are thus the first to demonstrate a specific interaction between beta-catenin and Hsp27. However, beta-catenin did not bind Hsp60, Hsp70, Hsp90, gp96, or the endoplasmic reticulum stress response protein CHOP. To confirm the finding of Hsp27-beta-catenin interaction, the 27-kDa immunoprecipitated band was excised from one-dimensional polyacrylamide gel electrophoresis gels and submitted to liquid chromatography-tandem mass spectrometry with electrospray ionization, confirming a role for Hsp27. In addition, beta-catenin interacted with other proteins including heat shock transcription factor 1, P-cadherin, and caveolin-1. In human breast cancer biopsy samples, beta-catenin was coexpressed in the same tumor areas and in the same tumor cells that expressed Hsp27. However, this coexpression was strong when beta-catenin was present in the cytoplasm of the tumor cells and not when beta-catenin was expressed at the cell surface only. Furthermore, murine breast cancer cells transfected with hsp25 showed a redistribution of beta-catenin from the cell membrane to the cytoplasm. When the prognostic significance of cadherin-catenin expression was examined by immunohistochemistry in breast cancer patients (n = 215, follow-up = >10 years), we found that the disease-free survival and overall survival were significantly shorter for patients expressing P-cadherin and for patients showing expression of beta-catenin in the cytoplasm only (not at the cell surface). The interactions of beta-catenin with Hsp27 and with HSF1 may explain some of the molecular pathways that influence tumor cell survival and the clinical significance in the prognosis of the breast cancer patients.

Prognostic value of Bcl-2 in breast cancer patients treated with neoadjuvant anthracycline based chemotherapy.

We have analyzed the predictive/prognostic value of Bcl-2 protein in breast cancer patients treated with neoadjuvant chemotherapy. One hundred and ten patients were submitted to two different chemotherapeutic regimens: a) 5-fluorouracil, adriamycin or epirubicin, and cyclophosphamide (FAC/FEC) during 2-6 cycles before surgery and 3 or 4 additional cycles of FAC/FEC after surgery (n=40) and b) doxorubicin (D) 75 mg/m(2) or epirubicin (E) 120 mg/m(2) during 4 cycles before surgery, and 6 cycles of cyclophosphamide, methotrexate, and 5-fluorouracil (CMF) after surgery (n=70). Bcl-2 expression, evaluated by immunohistochemistry, did not change significantly after chemotherapy and was not related to clinical/pathological response. In FAC/FEC group, Bcl-2 positive expression after chemotherapy correlated with better disease free survival (DFS) and overall survival (OS) (P=0.008 and P=0.001). In D/E group, Bcl-2 also correlated with better DFS and OS (P=0.03 and P=0.054) in the post-chemotherapy biopsies. An unusual nuclear localization of Bax was observed in some biopsies, but this localization did not correlate with the tumor response or outcome of the patients. We found that a high Bcl-2 expression had no predictive value but had prognostic value in breast cancer patients treated with neoadjuvant anthracycline based chemotherapy.

Caracterización del cáncer de mama en mujeres de la Argentina. Grupo Colaborativo para el Estudio del Cáncer de Mama en la Argentina. PROYCAM2012 / Characterization of breas cancer in woman of Argentina. Collaborative Group for the Study of Breast Cancer in Argentina. PROYCAM2012

En la Argentina el cáncer de mama con un 25 por ciento del total es la neoplasia maligna más común en las mujeres. El objetivo del presente trabajo es describir el perfil epidemiológico, clínico y patológico de mujeres con cáncer de mama concurrentes a centros asistenciales, públicos y privados del país, adheridos voluntariamente al Grupo Colaborativo durante el período 2012-2013. De los 607 casos reportados corresponden un 27 por ciento al sector público y un 73 por ciento al privado. Según subsectores: de obra social, 63.7 por ciento; sin cobertura, 19.7 por ciento; sistema prepago, 14.2 por ciento y mutal, 2.2 por ciento. Los casos por jurisdicciones fueron: Mendoza, 20.5 por ciento; CABA, 19.9 por ciento; Buenos Aires, 13.6 por ciento; Tucumán, 10.8 por ciento; Córdoba, 6.9 por ciento ; Río Negro, 4.9 por ciento y el resto del país, 23 por ciento. Edad de presentación promedio fue de 57.5 años, Con un rango de 63.4 (90.6-27.9). La mayor frecuencia se dio entre los 50-59 años con un 27.2 por ciento. Estadios: El pTNM de presentación en 506 casos fue: estadio 0: 5.9 por ciento; I: 37.7 por ciento; II: 35.7 por ciento; III: 18.8 por ciento y IV: 1.5 por ciento. Un estudio epidemiológico colaborativo sobre el cáncer de mama brinda información sobre las características biológicas y epidemiológicas en un breve lapso, considerando diferencias geográficas, socio-demográficas, biológicas e institucionales subyacentes en la prevención y el diagnóstico de esta patología.

In Argentina breast cancer with 25 percent of the total is the most common malignancy in women. The aim of this paper is to describe the epidemiological, clinical and pathologic women attending breast cancer care centers, public an private, voluntarily adhered to a Collaborative Group for the period 2012-2013. Of the 607 cases reported 27 percent are from the public and 73 percent from private sector. According to the subsectors they were from : social work, 63.7 percent; uninsured, 19.7 percent; prepaid system, 14.2 percent and mutual, 2.2 percent. Cases by jurisdictions were: Mendoza, 20.5 percent; CABA, 19.9 percent; Buenos Aires, 13.6 percent; Tucumán, 10.8 percent; Córdoba, 6.9 percent ; Río Negro, 4.9 percent and rest of the country, 23 percent. Average age at presentation was 57.5 years, with a range 63.4 years (90.6-27.9). The highest frequency was between 50-59 years with 27.2 percent. The pTNM of 506 cases was: stage 0: 5.9 percent; I: 37.7 percent; II: 35.7 percent; III: 18.8 percent and IV: 1.5 percent. A colaborative epidemiology study on breast cancer provides information on the biological and epidemiology in a short time, considering geographical, socio-demographic, biological and institutional differences underlying the prevention and diagnosis of this pathology.

Interpretación clínica de la mastalgia / Clinic interpretation of mastalgia

En los consultorios de la especialidad, el motivo más frecuente de consulta es el dolor mamario, y en virtud que las clasificaciones vigentes en cuanto a patología benigna generalmente no conllevan una orientación clínica, creímos oportuno poner a consideración una clasificación, que a nuestro entender, permite la interpretación de la mastalgia, en la certeza que existe un dolor que tiene origen en la mama (mastalgia genuina), y otro, que a pesar de estar referido a la mama es la expresión de patologías extraglandulares (mastalgia refleja). Dentro de las "mastalgias genuinas", hay dolores que tienen un comportamiento cíclico (mastalgias genuinas cíclicas), dentro de ellas, algunas "fisiológicas" (mastalgia premenstrual) y otras "patológicas". Estas últimas clínicamente se pueden acompañar de induraciones difusas (parcial o total), o pueden ser nodulares (macro o micronodulares). Existen, en cambio, "mastalgias genuinas no cíclicas", con variantes también "fisiológicas" (en el embarazo y la lactancia), y "patológicas" (traumatismos, infecciones, tumores). Entendemos por "mastalgias reflejas" los dolores referidos a la cara anterolateral del tórax, que pueden manifestarse como verdaderas mastalgias, pero que obedecen etiológicamente a diversas causas extramamarias (patología del raquis cérvico-dorsal, traumatismos, neuralgias, mialgias, flebitis, hiperuricemias, síndrome de Pancoast, herpes-zoster, síndrome de Tietze). Creemos que esta orientación clínica de las mastalgias permitirá un adecuado diagnóstico y por ende la terapéutica adecuada.

La importancia del derrame por pezón / Importance of the discharge by nipple

El derrame por pezón es uno de los síntomas más frecuentes de la patología mamaria, pudiendo ser un signo precoz de la enfermedad neoplásica. Por lo cual es importante pesquisar el mismo, conocer los diferentes tipos y sus características, correlacionándolo con las diversas patologías que lo pueden presentar; el que debe ser estudiado siguiendo una metodología que presentamos en este trabajo. Sobre 3.280 consultas de primera vez, 157 pacientes presentaron derrame por pezón, realizándose un estudio clínico, radiológico, citológico, termográfico e histopatológico. Una de las consideraciones más importantes que hemos hallado es que ningún tipo de derrame es patognomónico de determinada patología