Carcinoma de mama: novos conceitos na classificação: [revisão] / Breast cancer: new concepts in classification: [review]

O carcinoma de mama é a neoplasia maligna mais comum em mulheres. Estudos moleculares do carcinoma de mama, baseados na identificação do perfil de expressão gênica por meio do cDNA microarray, permitiram definir pelo menos cinco sub-grupos distintos: luminal A, luminal B, superexpressão do HER2, basal e normal breast-like. A técnica de tissue microarray (TMA), descrita pela primeira vez em 1998, permitiu estudar, em várias amostras de carcinoma, os perfis de expressão protéica de diferentes neoplasias. No carcinoma de mama, os TMAs têm sido utilizados para validar os achados dos estudos preliminares, identificando, desta forma, os novos subtipos fenotípicos do carcinoma de mama. Dentre os subtipos classicamente descritos, o grupo basal constitui um dos mais intrigantes subtipos tumorais e é freqüentemente associado com pior prognóstico e ausência de alvos terapêuticos definidos. A classificação histopatológica do carcinoma de mama tem pobre valor preditivo. Portanto, a associação entre o diagnóstico histológico com técnicas moleculares nos laboratórios de anatomia patológica, por meio do estudo imunoistoquímico, pode determinar o perfil molecular do carcinoma de mama, buscando melhorar a resposta terapêutica. Este estudo visou resumir os mais recentes conhecimentos em que se baseiam os novos conceitos da classificação do carcinoma de mama.

Breast cancer is the principal cause of death from cancer in women. Molecular studies of breast cancer, based in the identification of the molecular profiling techniques through cDNA microarray, had allowed defining at least five distinct sub-group: luminal A, luminal B, HER-2-overexpression, basal and " normal" type breast-like. The technique of tissue microarrays (TMA), described for the first time in 1998, allows to study, in some samples of breast cancer, distinguished by differences in their gene expression patterns, which provide a distinctive molecular portrait for each tumor and the basis for and improved breast cancer molecular taxonomy. Another important implication is that genetic profiling may lead to the identification of new target for therapy and better predictive markers are needed to guide difficult treatment decisions. Additionally, the current pathology classification system is suboptimal, since patients with identical tumor types and stage of disease present different responses to therapy and different overall outcomes. Basal breast tumor represents one of the most intriguing subtypes and is frequently associated with poor prognosis and absence of putative therapeutic targets. Then, the purpose of this review was to resume the most recent knowledge about the breast carcinoma classification and characterization.

[Breast cancer: new concepts in classification]. / Carcinoma de mama: novos conceitos na classificação.

Breast cancer is the principal cause of death from cancer in women. Molecular studies of breast cancer, based in the identification of the molecular profiling techniques through cDNA microarray, had allowed defining at least five distinct sub-group: luminal A, luminal B, HER-2-overexpression, basal and 'normal' type breast-like. The technique of tissue microarrays (TMA), described for the first time in 1998, allows to study, in some samples of breast cancer, distinguished by differences in their gene expression patterns, which provide a distinctive molecular portrait for each tumor and the basis for and improved breast cancer molecular taxonomy. Another important implication is that genetic profiling may lead to the identification of new target for therapy and better predictive markers are needed to guide difficult treatment decisions. Additionally, the current pathology classification system is suboptimal, since patients with identical tumor types and stage of disease present different responses to therapy and different overall outcomes. Basal breast tumor represents one of the most intriguing subtypes and is frequently associated with poor prognosis and absence of putative therapeutic targets. Then, the purpose of this review was to resume the most recent knowledge about the breast carcinoma classification and characterization.

HER2 evaluation using the novel rabbit monoclonal antibody SP3 and CISH in tissue microarrays of invasive breast carcinomas.

BACKGROUND: Laboratory methods for HER2 assessment currently include immunohistochemical (IHC) methods (measuring protein overexpression) and fluorescence in situ hybridisation (FISH) (measuring gene amplification). The measure of HER2 protein by IHC is usually assessed by the mouse monoclonal antibody CB11, and polyclonal antibodies (Herceptest) directed against the internal portion of the receptor. Recently, chromogenic in situ hybridisation (CISH), in which HER2 is detected by a peroxidase reaction and the gene amplification can be determined by regular bright-field microscopy, has emerged as an alternative to FISH. AIMS: To evaluate the status of HER2 in tissue microarrays (TMAs) of invasive breast cancer using the novel rabbit monoclonal antibody SP3 directed against the external portion of HER2, and correlate the results with CB11 and CISH. METHODS: IHC was performed with two antibodies (CB11 and SP3) and CISH for HER2 in 10 TMA blocks with 190 formalin-fixed paraffin-embedded cases of invasive breast carcinomas. RESULTS: The correlation between SP3 and CB11 was significant (p<0.001) with an agreement rate of 86.9%. When the staining pattern of the two antibodies was compared, the majority of SP3 immunostainings were assessed more easily, with a strong complete membrane staining pattern without non-specific cytoplasmic staining. There was a good correlation between SP3 and CISH (p<0.001). 23/24 SP3 3+ cases showed gene amplification, 97.3% of the cases without gene amplification were SP3 negative, and 6/7 SP3 2+ were amplified. CONCLUSION: The high level of agreement between SP3, a monoclonal antibody that recognises the extracellular domain of the HER2 receptor, and CB11 and CISH, shows that this novel antibody is a reliable candidate to evaluate the expression of HER2 in breast cancer.

Comparison of manual and automated methods of liquid-based cytology. A morphologic study.

OBJECTIVE: To evaluate the morphologic characteristics of gynecologic samples prepared by 3 different methods of liquid-based cytology. STUDY DESIGN: Cytologic samples from representative cases of each diagnostic category of squamous epithelial lesion, prepared by automated and manual liquid-based systems, were analyzed by 3 laboratories in the United States, Portugal and Brazil. The systems included: ThinPrep (automated, U.S. Food and Drug Administration approved; Cytyc Corp., Boxborough, Massachusetts, U.S.A.), Autocyte PREP (South American system, manual; TriPath Imaging, Inc., Burlington, North Carolina, U.S.A.) and DNACITOLIQ (manual; Digene Brazil, São Paulo, Brazil). A panel of 16 morphologic parameters was evaluated: cellularity, clean background, uniform distribution, artifacts, cellular overlapping, architectural and cytoplasmic distortion, cytoplasmic vacuolization, cellular elongation, imprecise cytoplasmic borders, folded cytoplasmic borders, nuclear hyperchromasia, coarse chromatin, prominent nucleolus, irregular nuclear borders, atypical mitosis and inflammatory infiltrate. Negative, atypical squamous cells of undetermined significance, low grade squamous intraepithelial lesion (LSIL) and high grade squamous intraepithelial lesion (HSIL) cases were included. Cases without biopsies were confirmed by consensus. RESULTS: Cellularity was adequate in all samples. Clean background was observed in the vast majority of samples with all liquid-based systems. Uniform distribution was frequently found in ThinPrep and Autocyte PREP samples but not in DNACITOLIQ. Artifacts were not present in DNACITOLIQ samples, rare in ThinPrep and observed in 8 (34.7%) Autocyte PREP. Cellular overlapping was observed in all 3 system samples: 11 (31.42%) cases in ThinPrep, 16 (69.56%) in Autocyte PREP and 17 (68%) in DNACITOLIQ System. Architectural and cytoplasmic distortion were present in 3 cases of HSIL (13%) and cytoplasmic vacuolization in 2 cases of LSIL and 1 HSIL of Autocyte PREP. Cellular elongation was found in 13 (56.5%) Autocyte PREP and in 5 (20%) DNACITOLIQ samples. Inflammatory infiltrate was found in all 3 system samples but with more frequency in the Autocyte PREP (69.56%) and DNACITOLIQ System (72%). CONCLUSION: This study clearly indicated that in spite of the different methodologies, the 3 methods adequately preserved cellular structure for morphologic evaluation. The choice of method will depend on price, availability and procedures involved.