The purpose of this study was to develop and validate a new software, HER2-CONNECT(TM), for digital image analysis of the human epidermal growth factor receptor 2 (HER2) in breast cancer specimens. The software assesses immunohistochemical (IHC) staining reactions of HER2 based on an algorithm evaluating the cell membrane connectivity. The HER2-CONNECT algorithm was aligned to match digital image scorings of HER2 performed by 5 experienced assessors in a training set and confirmed in a separate validation set. The training set consisted of 167 breast carcinoma tissue core images in which the assessors individually and blinded outlined regions of interest and gave their HER2 score 0/1+/2+/3+ to the specific tumor region. The validation set consisted of 86 core images where the result of the automated image analysis software was correlated to the scores provided by the 5 assessors. HER2 fluorescence in situ hybridization (FISH) was performed on all cores and used as a reference standard. The overall agreement between the image analysis software and the digital scorings of the 5 assessors was 92.1% (Cohen's Kappa: 0.859) in the training set and 92.3% (Cohen's Kappa: 0.864) in the validation set. The image analysis sensitivity was 99.2% and specificity 100% when correlated to FISH. In conclusion, the Visiopharm HER2 IHC algorithm HER2-CONNECT(TM) can discriminate between amplified and non-amplified cases with high accuracy and diminish the equivocal category and thereby provides a promising supplementary diagnostic tool to increase consistency in HER2 assessment.

Although the study in general showed a moderate to good inter-observer agreement according to both ICC and Lights Kappa, still major discrepancies were identified in especially the mid-range of observations. Consequently, for now Ki67 estimation is not implemented in the DBCG treatment algorithm.

BackgroundThe three members of the human heterochromatin protein 1 (HP1) family of proteins, HP1α, HP1β, and HPγ, are involved in chromatin packing and epigenetic gene regulation. HP1α is encoded from the CBX5 gene and is a suppressor of metastasis. CBX5 is down-regulated at the transcriptional and protein level in metastatic compared to non-metastatic breast cancer. CBX5 shares a bi-directional promoter structure with the hnRNPA1 gene. But whereas CBX5 expression is down-regulated in metastatic cells, hnRNAP1 expression is constant. Here, we address the regulation of CBX5 in human breast cancer.MethodsTransient transfection and transposon mediated integration of dual-reporter mini-genes containing the bi-directional hnRNPA1 and CBX5 promoter was performed to investigate transcriptional regulation in breast cancer cell lines. Bioinformatics and functional analysis were performed to characterize transcriptional events specifically regulating CBX5 expression. TSA treatment and Chromatin Immunoprecipitation (ChIP) were performed to investigate the chromatin structure along CBX5 in breast cancer cells. Finally, expression of hnRNPA1 and CBX5 mRNA isoforms were measured by quantitative reverse transcriptase PCR (qRT-PCR) in breast cancer tissue samples.ResultsWe demonstrate that an hnRNPA1 and CBX5 bi-directional core promoter fragment does not comprise intrinsic capacity for specific CBX5 down-regulation in metastatic cells. Characterization of transcriptional events in the 20 kb CBX5 intron 1 revealed existence of several novel CBX5 transcripts. Two of these encode consensus HP1α protein but used autonomous promoters in intron 1 by which HP1α expression could be de-coupled from the bi-directional promoter. In addition, another CBX5 transcriptional isoform, STET, was discovered. This transcript includes CBX5 exon 1 and part of intron 1 sequences but lacks inclusion of HP1α encoding exons. Inverse correlation between STET and HP1α coding CBX5 mRNA expression was observed in breast cancer cell lines and tissue samples from breast cancer patients.ConclusionWe find that HP1α is down-regulated in a mechanism involving CBX5 promoter downstream sequences and that regulation through alternative polyadenylation and splicing generates a transcript, STET, with potential importance in carcinogenesis.Electronic supplementary materialThe online version of this article (doi:10.1186/s12885-016-2059-x) contains supplementary material, which is available to authorized users.

PurposeHigh activity of the intracellular phosphatidylinositol-3 kinase (PI3K) pathway is common in breast cancer. Here, we explore differences in expression of important PI3K pathway regulators: the activator, phosphatidylinositol-3-kinase catalytic subunit alpha (PIK3CA), and the tumour suppressor, phosphatase and tensin homolog (PTEN), in breast carcinoma tissue and normal breast tissue. Furthermore, we examine whether expression of PIK3CA and PTEN mRNA and occurrence of PIK3CA mutations are associated with lymph node metastases in patients with primary breast cancer.MethodsPaired tissue samples of breast carcinoma and normal breast tissue were obtained from 175 breast cancer patients at the time of primary surgery, of these 105 patients were lymph node positive. Expression of PIK3CA and PTEN mRNA was quantified with Quantitative Real Time PCR. Somatic mutations in exon 9 and exon 20 of the PIK3CA gene were identified by genotyping.ResultsBoth PIK3CA and PTEN mRNA expression was significantly increased in breast carcinoma tissue compared to normal breast tissue (p = 2 × 10-11) and (p < 0.001), respectively. PIK3CA mutations were present in 68 out of 175 patients (39%), but were not associated with PIK3CA expression (p = 0.59). Expression of PIK3CA and PTEN mRNA, and PIK3CA mutations in breast carcinomas were not associated with presence of lymph node metastases.ConclusionsThe expression of PTEN and PIK3CA mRNA is increased in breast carcinoma tissue compared to normal breast tissue, and PIK3CA mutations are frequent in primary breast carcinoma, however these factors were not associated with lymph node metastases.Electronic supplementary materialThe online version of this article (doi:10.1186/2193-1801-2-464) contains supplementary material, which is available to authorized users.

Visual assessment of immunohistochemically detected estrogen receptor protein is prone to interobserver and intraobserver variation due to its subjective evaluation. The aim of this study was to validate a new image analysis system based on virtual double staining (VDS) by comparing visual and automated scorings of ER in tissue microarrays of breast carcinomas. Tissue microarrays were constructed of 112 consecutive resection specimens of breast carcinomas. Immunohistochemistry assays for ER and pancytokeratin was applied on separate serial sections. ER scoring was visually performed by 5 observers using the histoscore (H-score) method. The Visiopharm ER image analysis protocol (APP) software application using VDS technique was applied separating stromal cells from carcinoma and other epithelial cells based on the pancytokeratin reaction. Using color deconvolution, polynomial filters, and nuclear segmentation the APP determined the percentage of positive cells and their intensity, and calculated the resulting H-score. On the basis of 1% cutoff VDS was perfectly correlated with visual assessment (κ=1). Using H-score, a very high agreement between VDS and visual ER assessment was seen (R=0.950). Image analysis has the attributes to eliminate the shortcomings of visual ER evaluation by generating automated, reproducible, and objective results of ER assessment.

BRISH methods provide an alternative to FISH in evaluating HER2/CEN17 ratio in primary breast carcinomas. Dual ISH showed an almost perfect agreement with FISH and is a fast track method realistic to perform on all breast carcinomas. BRISH provide a permanent result that makes the method eligible for use in internal and external quality assurance.

Testing for amplification of the human EGF receptor 2 (HER2) gene by in situ hybridization is a central principle for the identification of breast cancer patients likely to respond to treatments directed toward HER2. However, its application in clinical routine has been somewhat restricted by the typical use of a visualization system based on fluorescence (FISH), which requires skilled, work-intensive, high-magnification quantitative microscopy. The US FDA has recently approved the HER2 CISH pharmDx™ Kit, which is characterized by employing a chromogenic visualization system that allows quantification of the HER2 gene and centromere 17 reference signals by relatively low-magnification brightfield microscopy. It is indicated as an aid in the assessment of patients for whom Herceptin(®) (trastuzumab) treatment is being considered.

Purpose: In breast cancer, the EGF receptors host an increasing number of therapeutic targets and the interactive mechanisms of actions of the receptors and their ligands justify investigation of the EGF family as an entity. Experimental design: Paired tissue samples of normal breast tissue and primary breast carcinomas were examined in a prospective study of 163 patients. A third sample was obtained from the paired ipsilateral metastatic lymph node from 58 of these patients. The mRNA expression of four EGF receptors (HER1 -HER4) and 11 activating ligands was quantified with real-time RT-PCR. Results: Expression of HER2, HER3, and HER4 mRNA was upregulated in primary carcinomas compared to normal breast tissue while HER1 was downregulated. The mRNA expression of HER3 and HER4 differed between primary breast carcinomas and lymph node metastases whereas there was no difference in the expression of HER1 and HER2. The combination of low HER3 and low HER4 expression in the primary carcinoma was significantly more frequent in lymph node-negative patients as compared to lymph node positive patients. Distinct correlation patterns of the receptors and their corresponding activating ligands appeared in both normal breast tissue and in carcinomas, notably for the HER3 and HER4 receptors and their 3 specific ligands: HB-EGF, NRG2, and NRG4. Conclusion: HER2, HER3, and HER4 showed increased mRNA expression in carcinomas and were positively correlated to each other and to specific activating ligands. Furthermore, low HER3 and HER4 expression in the carcinomas correlated to the absence of lymph node metastases.