Immunohistochemical profile of high-grade ductal carcinoma in situ of the breast

OBJECTIVE: To determine the frequency of the immunohistochemical profiles of a series of high-grade ductal carcinoma in situ of the breast. METHODS: One hundred and twenty-one cases of high-grade ductal carcinoma in situ, pure or associated with invasive mammary carcinoma, were identified from 2003 to 2008 and examined with immunohistochemistry for estrogen receptor, human epidermal growth factor receptor 2, cytokeratin 5, and epidermal growth factor receptor. The tumors were placed into five subgroups: luminal A, luminal B, HER2, basal-like, and “not classified”. RESULTS: The frequencies of the immunophenotypes of pure ductal carcinoma in situ were the following: luminal A (24/42 cases; 57.1%), luminal B (05/42 cases; 11.9%), HER2 (07/42 cases; 16.7%), basal-like phenotype (00/42 cases; 0%), and “not classified” (06/42 cases; 14.3%). The immunophenotypes of ductal carcinoma in situ associated with invasive carcinoma were the following: luminal A (46/79 cases; 58.2%), luminal B (10/79 cases; 12.7%), HER2 (06/79 cases; 7.6%), basal-like (06/79 cases; 7.6%), and “not classified” (11/79 cases; 13.9%). There was no significant difference in the immunophenotype frequencies between pure ductal carcinoma in situ and ductal carcinoma in situ associated with invasive carcinoma (p>;0.05). High agreement was observed in immunophenotypes between both components (kappa=0.867). CONCLUSION: The most common immunophenotype of pure ductal carcinoma in situ was luminal A, followed by HER2. The basal-like phenotype was observed only in ductal carcinoma in situ associated with invasive carcinoma, which had a similar phenotype

Immunoexpression of cell cycle regulators in canine prostate with proliferative lesions

Immunostaining of p21, p27, p53, cyclin D1, c-myc was evaluated in normal canine prostate and prostate with proliferative disorders to verify the interaction between these regulators of cell cycle progression. From 106 samples of canine prostate obtained from a TMA block, 15 were considered normal, 16 diagnosed as benign prostatic hyperplasia (BPH), 30 as proliferative inflammatory atrophy (PIA), 20 as prostatic intraepithelial neoplasia (PIN), and 25 as prostatic carcinoma (PC). There was positive correlation between p21 and p27 for number of stained cells and staining intensity in all conditions and between c-myc and p53 in prostates with PIN. Considering the number of labeled cells, there was positive correlation between p21 and p53 in the normal prostate. Relative to the intensity of staining, there was positive correlation between p21 and p53 in prostate tissue with PIN and between p27 and c-myc in prostates with PIA. A negative correlation between c-myc and cyclin D1 was also identified in the glands with PIN, considering the number of labeled cells, and between p27 and c-myc in the prostates with PC for staining intensity. In conclusion, the expression of p21, p27, p53, cyclin D1 and c-myc varies according to type of proliferative lesion in canine prostate. Taken together, the results indicate low growth potential of the canine PC in the presence of p21 and p27 overexpression, cyclin D1 low expression and regular expression of c-myc, even with the expression of p53 mutant type. Further, it was possible reaffirm the premalignant potential of PIA and PIN in canine prostate

Tissue-Associated Bacterial Alterations in Rectal Carcinoma Patients Revealed by 16S rRNA Community Profiling

Sporadic and inflammatory forms of colorectal cancer (CRC) account for more than 80% of cases. Recent publications have shown mechanistic evidence for the involvement of gut bacteria in the development of both CRC-forms. Whereas, colon and rectal cancer have been routinely studied together as CRC, increasing evidence show these to be distinct diseases. Also, the common use of fecal samples to study microbial communities may reflect disease state but possibly not the tumor microenvironment. We performed this study to evaluate differences in bacterial communities found in tissue samples of 18 rectal-cancer subjects when compared to 18 non-cancer controls. Samples were collected during exploratory colonoscopy (non-cancer group) or during surgery for tumor excision (rectal-cancer group). High throughput 16S rRNA amplicon sequencing of the V4V5 region was conducted on the Ion PGM platform, reads were filtered using Qiime and clustered using UPARSE. We observed significant increases in species richness and diversity in rectal cancer samples, evidenced by the total number of OTUs and the Shannon and Simpson indexes. Enterotyping analysis divided our cohort into two groups, with the majority of rectal cancer samples clustering into one enterotype, characterized by a greater abundance of Bacteroides and Dorea. At the phylum level, rectal-cancer samples had increased abundance of candidate phylum OD1 (also known as Parcubacteria) whilst non-cancer samples had increased abundance of Planctomycetes. At the genera level, rectal-cancer samples had higher abundances of Bacteroides, Phascolarctobacterium, Parabacteroides, Desulfovibrio, and Odoribacter whereas non-cancer samples had higher abundances of Pseudomonas, Escherichia, Acinetobacter, Lactobacillus, and Bacillus. Two Bacteroides fragilis OTUs were more abundant among rectal-cancer patients seen through 16S rRNA amplicon sequencing, whose presence was confirmed by immunohistochemistry and enrichment verified by digital droplet PCR. Our findings point to increased bacterial richness and diversity in rectal cancer, along with several differences in microbial community composition. Our work is the first to present evidence for a possible role of bacteria such as B. fragilis and the phylum Parcubacteria in rectal cancer, emphasizing the need to study tissue-associated bacteria and specific regions of the gastrointestinal tract in order to better understand the possible links between the microbiota and rectal cancer.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Programa Nacional de Apoio à Atenção Oncológica (Pronon)Associacao Beneficiente Alzira Denise Hertzog Silva (ABADHS)CIPE AC Camargo Canc Ctr, Med Genom Lab, Sao Paulo, BrazilUniv Sao Paulo, Inst Quim, Dept Bioquim, Sao Paulo, BrazilUniv Sao Paulo, Cursode Posgrad Bioinformat, Sao Paulo, BrazilAC Camargo Canc Ctr, Dept Pelv Surg, Sao Paulo, BrazilAC Camargo Canc Ctr, Dept Pathol, Sao Paulo, BrazilUniv Fed Sao Paulo, Coll Med, Dept Gynecol, Lab Mol Gynecol, Sao Paulo, BrazilHosp Sirio Libane, Ctr Oncol Mol, Sao Paulo, BrazilUniv Sao Paulo, Food Res Ctr FoRC, Fac Ciencias Farmaceut, Dept Alimentos & Nutr Expt, Sao Paulo, BrazilAC Camargo Canc Ctr, Dept Clin Oncol, Sao Paulo, BrazilAC Camargo Canc Ctr, Lab Computat Biol & Boinformat, Sao Paulo, BrazilVirginia Tech, Biocomplex Inst, Blacksburg, VA USAUniv Sao Paulo, Fac Med, Inst Psychiat, Lab Neurosci LIM Alzira Denise Hertzog Silva 27, Sao Paulo, BrazilLaboratory of Molecular Gynecology, Department of Gynecology, Medicine College, Universidade Federal de São Paulo (UNIFESP), São Paulo, BrazilFAPESP: 2015/01507-7FAPESP: 2013/07914-8CAPES: 88887.062078/2014-00CAPES: 3385/2013PRONON: 25000.055.167/2015-23Web of Scienc

Down-regulation of ANAPC13 and CLTCL1: Early Events in the Progression of Preinvasive Ductal Carcinoma of the Breast

Alterations in the gene expression profile in epithelial cells during breast ductal carcinoma (DC) progression have been shown to occur mainly between pure ductal carcinoma in situ (DCIS) to the in situ component of a lesion with coexisting invasive ductal carcinoma (DCIS-IDC) implying that the molecular program for invasion is already established in the preinvasive lesion. For assessing early molecular alterations in epithelial cells that trigger tumorigenesis and testing them as prognostic markers for breast ductal carcinoma progression, we analyzed, by reverse transcription-quantitative polymerase chain reaction, eight genes previously identified as differentially expressed between epithelial tumor cells populations captured from preinvasive lesions with distinct malignant potential, pure DCIS and the in situ component of DCIS-IDC. ANAPC13 and CLTCL1 down-regulation revealed to be early events of DC progression that anticipated the invasiveness manifestation. Further down-regulation of ANAPC13 also occurred after invasion appearance and the presence of the protein in invasive tumor samples was associated with higher rates of overall and disease-free survival in breast cancer patients. Furthermore, tumors with low levels of ANAPC13 displayed increased copy number alterations, with significant gains at 1q (1q23.1-1q32.1), 8q, and 17q (17q24.2), regions that display common imbalances in breast tumors, suggesting that down-regulation of ANAPC13 contributes to genomic instability in this disease.Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (CEPID/FAPESP) [98/14335]Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (CEPID/FAPESP)CNPqCNPq [142790/2008-7]FAPESP [2009/00669-2, 2009/02457-2]FAPES

Estudo imunoistoquímico comparativo entre os novos anticorpos monoclonais de coelho e anticorpos clássicos para avaliação dereceptores hormonais em câncer de mama usando arrays de tecidos

Exportado OPUSMade available in DSpace on 2019-08-12T16:25:57Z (GMT). No. of bitstreams: 1 rafael_malagoli_rocha.pdf: 3637442 bytes, checksum: 9b8c0eb8d7eb7632b2f1c95a2d8fd14a (MD5) Previous issue date: 31Introdução: A avaliação imunoistoquímica (IIQ) dos receptores hormonais em câncer de mama é atualmente fator preditivo bem estabelecido da resposta terapêutica. No entanto, não há consenso na literatura sobre quais os melhores anticorpos a serem utilizados. Recentemente foi lançada uma nova geração de anticorpos monoclonais de coelho (RabMab) que, segundo os fabricantes, têm altasensibilidade e especificidade. Objetivos: Neste trabalho, comparamos a expressão dos anticorpos clássicos de camundongo e dos novos RabMab antireceptores de estrógeno e progesterona (RE e RP) em arrays de tecidos construídos com um equipamento alternativo e de baixo custo. Metodologia: Utilizou-se equipamento não comercial que consiste numa mini-retífica com agulha de biópsia hepática de 2mm de diâmetro acoplada a bancada com suporte (DremelÒ). Inicialmente preparou-se o bloco receptor fazendo o número de furos desejável (55). Cilindros de tecido foram obtidos com o mesmo dispositivo e colocados nos orifícios do bloco receptor. De cada bloco doador foram obtidosdois cilindros de diferentes áreas representativas do tumor. As secçõeshistológicas obtidas foram submetidas à IIQ empregando-se anticorpos anti-RE (1D5; 6F11; SP1 e B644) e anti-RP (PgR 312; PgR 636; SP2 e B645). A intensidade da coloração IIQ e a coloração inespecífica foram avaliadas semiquantitativamente por um mesmo pesquisador. Os tumores foram considerados positivos quando mais de 10% dos núcleos das células neoplásicas estavam corados independente da intensidade. Resultados e conclusões: O equipamento e técnica de construção do TMA alternativo representam uma opção econômica aos equipamentos comerciais. Cortes histológicos do array mostraramboa preservação tecidual, adequados para avaliação morfológica e suficientes para confirmação diagnóstica. A análise comparativa mostrou que os clones de RabMab anti-RE apresentaram maior sensibilidade comparados ao clone 1D5 e equivalência ao clone 6F11 e representam uma alternativa confiável aos Mab para avaliação IIQ de tumores mamários. RabMab anti-RP foram mais sensíveis que osMab.Introduction: Immunohistochemistry analysis (IHC) for estrogen and progesterone receptors (ER and PR) in breast cancer is a well established predictive factor of anti-estrogen therapy. However, there is a large variable choice of antibodies and no agreement about the best antibodies to be used. A novel generation of rabbit monoclonal antibodies (Rab Mab) has been released recently. Aims: In this study,we compared the performance of the novel RabMab to Mab using an alternative tissue arrayer. Methods: We used non-commercial equipment that consists of a work station (DremelÒ) to which a liver biopsy needle of 2mm of diameter was connected. A receptor block was prepared perforating it until the desired number of rows (55) was reached. Then, the cylinders of tissue were obtained using the same equipment and included in the holes of the receptor block. Two samples were obtained from different tumor areas of each donor block. Histological sections were immunostained using anti-ER Mab (1D5 and 6F11) and RabMab (SP1 and B644), and anti-PR Mab (PgR312 and PgR636) and RabMab (SP2 and B645). The intensity of the reaction and the background were semiquantitatively evaluated and the tumors in which more than 10% of the tumor cell nuclei stained was considered positive. Results and conclusions: The equipment and technique used in the present study represent an economical alternative when compared to commercialequipment. The slides showed fine tissue preservation, adequate for morphologic evaluation, and sufficient to confirm diagnosis. The comparative analysis of the RabMab anti-ER and anti-PR showed more sensibility compared to clone 1D5 and concordance with clone 6F11 and represent a reliable alternative to Mab for IHC evaluation of breast tumors. RabMab anti-PR were more sensitive than Mabs

Sistemas de visualização imuno-histoquímica livres de biotina para avaliação de receptor de estrógeno em câncer de mama: análise empregando digitalização de lâminas e analisador de imagens

Exportado OPUSMade available in DSpace on 2019-08-13T13:01:34Z (GMT). No. of bitstreams: 1 rafael_malagoli_rocha.pdf: 8528447 bytes, checksum: 4c6988a40d2de624b14212ad98959c19 (MD5) Previous issue date: 3Introdução: uma nova geração de sistemas de visualização poliméricos livres de biotina (SPLB) para imuno-histoquímica têm sido desenvolvidos. Objetivo: comparamos os SPLB com os sistemas streptavidina-biotina (SABS) para a avaliação de imuno-reatividade para receptor de estrógeno (RE) em câncer de mama. Material e método: o anticorpo anti-receptor de estrógeno, clone SP1, foi empregado em um micro-arranjo de tecido (TMA) contendo 320 carcinomas mamários. Onze diferentes sistemas de visualização foram utilizados: seis SPLBde segunda geração (Advance, Novolink, SuperPicTure, PicTure Max, Super Sensitive Non-Biotin HRP, e Mouse/Rabbit Polydetector HRP/DAB), um SPLB de primeira geração (EnVision+), e quatro SABS (LSAB+, EasyPath, Super Sensitive, e Mouse/Rabbit Immunodetector HRP/DAB). As lâminas foram digitalizadas usando o Mirax Scanner e as imagens obtidas foram analisadas de forma automatizada e de forma visual adotando o sistema de escore de Allred para marcação nuclear. Marcação citoplasmática foi avaliada de forma semiquantitativa.Resultados: Os SPLB Advance e Novolink mostraram os escoresmais altos na análise visual e ainda detectaram dois casos positivos que foram considerados negativos utilizando outros sistemas de visualização. Estes sistemas, juntamente com o SAB LSAB+, também mostraram intensidade de marcação mais forte pela análise automatizada. SPLB não mostraram marcação citoplasmática, ao contrário dos SABS. Conclusão: os SPLB de segunda geração, especialmente o Advance e o Novolink, garantem sinal imunohistoquímico mais intenso e marcação nuclear mais bem localizada, sem coloração citoplasmática, quando comparados aos SABS. Outros estudos correlacionando estes achados com a condição de resposta terapêutica das pacientes devem ser realizados já que houve discordância quanto à positividade em alguns casos. SPLB representam uma ferramenta de alta qualidade para pesquisa e avaliação clínica do receptor de estrógeno em câncer de mama.Aims: Biotin-free polymeric visualization systems (BFPS) were compared to streptavidin-biotin systems (SABS) in the evaluation of immunoreactivity for estrogen receptor (ER) in breast carcinomas. Methods: The anti-estrogen antibody clone SP1 was employed on a tissue microarray containing 320 breast carcinomas. Eleven different detection systems were used: six BFPS of second generation (Advance, Novolink, SuperPicTure, PicTure Max, Super Sensitive Non-Biotin HRP, and Mouse/Rabbit Polydetector HRP/DAB), one BFPS of first generation (EnVision+), and four SABS (LSAB+, EasyPath, Super Sensitive, andMouse/Rabbit Immunodetector HRP/DAB). The slides were digitalized using the Mirax scanner and the resulting images were analyzed both by an automated method and by visual analysis using the Allred´s score system considering positive nuclear staining. Cytoplasm staining was also separeted evaluated. Results: The BFPS Advance and Novolink showed the highest scores by visual analysis, and additionally detected two positive cases which were considered negative using the other detection systems. Likewise, these systems, together with the SAB LSAB+, showed higher staining intensity by the automated method.BFPS revealed no cytoplasm staining, in opposition to the SABS. Conclusions: The second generation BFPS, especially Advance and Novolink, provide stronger and sharper nuclear immunohistochemical signal as compared to most SABS, without nonspecific cytoplasm staining. As in few instances these detection systems show discordant results in relation to SABS, further studies correlating these findings to therapeutic response are necessary. BFPS may represent a high quality tool both for research and clinical evalutation of estrogen receptor in breast cancer

Predictive factors of breast cancer evaluated by immunohistochemistry Fatores preditivos do câncer de mama avaliados pela imuno-histoqu��mica

Hormone receptor and Her2 protein overexpression evaluated by immunohistochemistry (IHC) is widely validated as a predictive factor in breast cancer. The quality of the IHC reaction is influenced by tissue fixation and processing. Over- and underfixation deeply affect IHC results. Antigen retrieval may improve IHC but it does not recover tissue from autolysis or overfixation. The choice of primary antibody for IHC as to its sensitivity and specificity in relation to therapeutic response represents an important stage. Apart from mouse monoclonal antibodies, new rabbit monoclonal antibodies are commercially available, such as clones anti-ER SP1 and B644, anti-PR SP2 and B645 and anti-Her2 SP3 and 4B5. They represent an alternative to hormone receptor and Her2 evaluation by IHC. New polymeric non-biotinylated detection systems are also available and allow accurate and strong marking with no stromal and no non-specific cytoplasmic staining due to endogenous biotin. The most recommended cut off for estrogen and progesterone receptors (ER and PR) is more than 1% of positive cells with moderate or strong staining intensity (Allred's scoring system). New guidelines for Her2 evaluation by IHC show a cut off of more than 30% of positive cells with strong intensity (3+) that correlates better with gene amplification. The 2+ cases are now considered indeterminate and should be confirmed by fluorescence in situ hybridisation (FISH) or chromogenic in situ hybridisation CISH. A quality control of pre-analytical, analytical and post-analytical phases of IHC is recommended in order to optimize results.<br>A superexpressão de receptores hormonais e Her2 avaliada pela imuno-histoquímica (IHQ) é amplamente validada como fator preditivo em câncer de mama. A qualidade da reação imuno-histoquímica é influenciada pela fixação do tecido e seu processamento. A fixação insuficiente ou demasiada afeta profundamente os resultados da IHQ. A reativação antigênica pode melhorar os resultados da IHQ, porém não recupera tecidos com autólise ou com excessiva fixação. A escolha do anticorpo primário para a IHQ, considerando sua sensibilidade e sua especificidade de acordo com a resposta terapêutica, representa uma importante etapa. Além de anticorpos monoclonais de camundongo, novos anticorpos monoclonais de coelho são comercialmente disponíveis, tais como clones SP1 e B644 anti-RE, SP2 e B645 anti-RP, e SP3 e 4B5 anti-Her2. Eles representam uma alternativa para avaliação de receptores hormonais e Her2 através da IHQ. Novos sistemas de detecção poliméricos não-biotinilados também são disponíveis e permitem marcação exata e forte sem marcação estromal ou citoplasmática inespecífica devido à biotina endógena. O cut off mais recomendado para receptor de estrogênio (RE) e receptor de progesterona (RP) é acima de 1% de células positivas com marcação moderada ou forte (sistema de escore de Allred). Novas recomendações para avaliação de Her2 através da IHQ apontam um cut off de mais de 30% de células positivas com marcação forte (3+), que melhor se relaciona com amplificação gênica. Os casos 2+ são agora considerados indeterminados e devem ser confirmados por hibridação in situ por fluorescência (FISH) ou hibridização in situ colorimétrica (CISH). Um controle de qualidade de fases pré-analítica, analítica e pós-analítica da IHQ é recomendado para a otimização dos resultados

Morphological aspects and immunophenotypic profiles of mammary carcinomas in benign-mixed tumors of female dogs.

Carcinoma in benign-mixed tumor (CBMT) is common in the female canine mammary gland and comprises malignant epithelial between benign mesenchymal elements. This study investigated the morphological aspects of 29 CBMT and their immunophenotypical profiles, by using an immunohistochemistry panel based on five molecular markers—estrogen receptor (ER), progesterone receptor (PR), human epidermal growth factor receptor 2 (HER2), cytokeratin 5 (CK5), and human epidermal growth factor receptor 1 (EGFR). From these, CBMT was classified into four subtypes: luminal A, luminal B, HER2-like, basallike, and normal. “In situ” and invasive carcinomatous components were analyzed and compared. Histological grade I carcinoma was observed in 16 cases (55.2%) of the tumors analyzed, grade II in 10 cases (34.5%), and grade III in three cases (10.3%). The invasive carcinomatous component has shown, more frequently, luminal A (12/29 cases, 41.4%), followed by basal-like phenotype (8/29 cases, 27.6%). There was high concordance between immunophenotypical profiles of the in situ and invasive carcinomatous components (kappa coefficient = 0.816,P < 0.001).We concluded that CBMT predominantly has features of low-grade neoplasms of malignancy. The various immunophenotypic profiles suggest the origin of these lesions in more than one cell type (luminal and myoepithelial)

Noncoding RNA Profiles in Tobacco- and Alcohol-Associated Diseases

Tobacco and alcohol are the leading environmental risk factors in the development of human diseases, such as cancer, cardiovascular disease, and liver injury. Despite the copious amount of research on this topic, by 2030, 8.3 million deaths are projected to occur worldwide due to tobacco use. The expression of noncoding RNAs, primarily microRNAs (miRNAs) and long noncoding RNAs (lncRNAs), is modulated by tobacco and alcohol consumption. Drinking alcohol and smoking cigarettes can modulate the expression of miRNAs and lncRNAs through various signaling pathways, such as apoptosis, angiogenesis, and inflammatory pathways—primarily interleukin 6 (IL-6)/signal transducer and activator of transcription 3 (STAT3), which seems to play a major role in the development of diseases associated with these risk factors. Since they may be predictive and prognostic biomarkers, they can be used both as predictors of the response to therapy and as a targeted therapy. Further, circulating miRNAs might be valuable noninvasive tools that can be used to examine diseases that are related to the use of tobacco and alcohol. This review discusses the function of noncoding RNAs in cancer and other human tobacco- and alcohol-associated diseases

A comparison between the novel rabbit monoclonal antibodies (SP1 and B644) and mouse antibodies for evaluating estrogen receptor in breast tumors Uma comparação entre os novos anticorpos monoclonais de coelho (SP1 e B644) e anticorpos de camundongo para detecção de receptores de estrógeno em carcinomas mamários

BACKGROUND: A novel generation of rabbit monoclonal antibodies has been released recently for estrogen (ER) and progesterone (PR) receptor evaluation in breast cancer by immunohistochemistry. Aims: We compared novel rabbit monoclonal antibodies anti-ER SP1 (LabVision®) and B644 (Cell Marque®) to mouse monoclonal antibodies 1D5 (Dako®) and 6F11 (Novocastra®) using a tissue microarray of breast carcinomas. METHODS: Two cylinders (2 mm diameter) of formalin-fixed paraffin embedded tissue were obtained from 24 invasive breast carcinomas and immunostained by using the anti-ER rabbit and mouse antibodies and the streptavidin-biotin detection system (Biogenex®). Immunostaining was evaluated considering positive those tumors in which more than 10% of the tumor cell nuclei stained. The stain intensity was also evaluated as weak (1), moderate (2), and strong (3). Results: Both rabbit antibodies against ER have similar staining pattern to each other and also to 6F11, but significantly stronger scores compared to mouse 1D5. The rabbit antibodies allow better cost/benefit because of higher working dilutions compared to mouse antibodies using the same procedure. CONCLUSION: The new rabbit antibodies against ER are highly sensitive and reliable in clinical and research immunohistochemical testing of breast carcinomas.<br>INTRODUÇÃO: Uma nova geração de anticorpos monoclonais de coelho tem sido produzida para detecção de receptores de estrógeno (RE) e progesterona (RP) pela imuno-histoquímica em câncer de mama. OBJETIVO: Comparamos os novos anticorpos monoclonais de coelho anti-RE SP1 (LabVision®) e B644 (Cell Marque®) com anticorpos monoclonais de camundongo 1D5 (DAKO®) e 6F11 (Novocastra®) utilizando um tissue microarray de carcinomas mamários. METODOLOGIA: Dois cilindros (2 mm de diâmetro) de tecido fixado em formol e embebido em parafina foram retirados de 24 carcinomas mamários invasivos e corados pela imuno-histoquímica utilizando-se os anticorpos de coelho e de camundongo anti-RE e o sistema de detecção estreptavidina-biotina peroxidase (Biogenex®). A coloração imuno-histoquímica foi avaliada considerando positivos os tumores nos quais mais de 10% dos núcleos das células tumorais estivessem corados. A coloração também foi classificada em fraca (1), moderada (2) e forte (3). RESULTADOS: Ambos os anticorpos monoclonais de coelho contra RE apresentaram intensidade de coloração semelhante àquela pelo anticorpo de camundongo 6F11, porém os anticorpos de coelho apresentaram intensidades de coloração significativamente mais fortes que as do clone de camundongo 1D5. As altas diluições possíveis utilizando anticorpos de coelho permitem melhor custo/benefício quando comparadas com as diluições possíveis utilizando anticorpos de camundongo. CONCLUSÃO: Os novos anticorpos monoclonais de coelho anti-RE são altamente sensíveis e fidedignos para testes imuno-histoquímicos tanto para a clínica quanto para pesquisa de tumores mamários