Testing for her2 in breast cancer: current pathology challenges faced in Canada

Pigment epithelium-derived factor downregulation in oestrogen receptor positive breast cancer bone metastases is associated with menopause

Pigment epithelium-derived factor (PEDF) has a critical role in bone development and anti-tumour function in breast cancer (BC). As the expression and role of PEDF in BC bone metastases is unknown, we aimed to characterise PEDF in primary and metastatic BC. Subcellular PEDF localisation was semi-quantitatively analysed via immunohistochemistry in patient-matched, archived formalin-fixed paraffin-embedded primary BC and liver, lung, and decalcified bone metastases specimens. PEDF localisation was evaluated in 23 metastatic BC patients diagnosed with ER+, human epidermal growth factor receptor-2 (HER2) negative BC or TNBC. Cytoplasmic (p = 0.019) and membrane (p = 0.048) PEDF was lower in bone metastases compared to primary ER+/HER2- BC. In contrast, nuclear PEDF scores were higher in metastases compared to primary TNBC (p = 0.027), and increased membrane PEDF in metastatic tissue had improved disease-free interval (p = 0.016). Nuclear PEDF was decreased in bone metastases compared to primary ER+//HER2- BC in post-menopausal patients (p = 0.029). These novel findings indicate PEDF plays a role in clinical BC metastasis. Significantly lower PEDF levels in the post-menopausal compared to pre-menopausal setting suggests future PEDF research may have greater clinical importance in the post-menopausal ER+/HER2- BC population.

Pathological Diagnosis, Work-Up and Reporting of Breast Cancer 1st Central-Eastern European Professional Consensus Statement on Breast Cancer

This text is based on the recommendations accepted by the 4th Hungarian Consensus Conference on Breast Cancer, modified on the basis of the international consultation and conference within the frames of the Central-Eastern European Academy of Oncology. The recommendations cover non-operative, intraoperative and postoperative diagnostics, determination of prognostic and predictive markers and the content of cytology and histology reports. Furthermore, they address some specific issues such as the current status of multigene molecular markers, the role of pathologists in clinical trials and prerequisites for their involvement, and some remarks about the future.

Determining HER2 (ERBB2) amplification status in women with breast cancer: final results from the Australian in situ hybridisation program

Appropriate and accurate determination of HER2 status in women with breast cancer is critical for stratifying anti-HER2 therapies, and for access to subsidised treatment in the Australian setting. We conducted a regulated, nationwide program providing HER2 in situ hybridisation (ISH) testing for patients with newly diagnosed breast cancer. Cases with equivocal or non-diagnostic ISH test results at the local laboratory were sent to a high volume central testing laboratory for analysis using fluorescence ISH (FISH). We tested 78,408 early breast cancers and 3469 metastatic cancers using ISH. Of these, 12,405 early breast cancers (15.8%) and 798 metastatic cancers (23.0%) were HER2 positive. During the testing period, the proportion of core biopsy samples increased, the number of repeat tests remained stable and testing turnaround time declined. Discordant 3+ IHC, ISH negative results dropped from 20% to 13% in early breast cancers and from 35% to 8% among metastatic breast cancers. Following central laboratory FISH testing only 87 samples remained non-diagnostic (1.9% of FISH-tested samples, 0.1% of the whole cohort), most being decalcified specimens. This is a successful story of a cohesive service determining HER2 status in women with breast cancer in a 'real-world' setting.

An Improved Immunostaining and Imaging Methodology to Determine Cell and Protein Distributions within the Bone Environment

Bone is a dynamic tissue that undergoes multiple changes throughout its lifetime. Its maintenance requires a tight regulation between the cells embedded within the bone matrix, and an imbalance among these cells may lead to bone diseases such as osteoporosis. Identifying cell populations and their proteins within bone is necessary for understanding bone biology. Immunolabeling is one approach used to visualize proteins in tissues. Efficient immunolabeling of bone samples often requires decalcification, which may lead to changes in the structural morphology of the bone. Recently, methyl-methacrylate embedding of non-decalcified tissue followed by heat-induced antigen retrieval has been used to process bone sections for immunolabeling. However, this technique is applicable for bone slices below 50-µm thickness while fixed on slides. Additionally, enhancing epitope exposure for immunolabeling is still a challenge. Moreover, imaging bone cells within the bone environment using standard confocal microscopy is difficult. Here we demonstrate for the first time an improved methodology for immunolabeling non-decalcified bone using a testicular hyaluronidase enzyme-based antigen retrieval technique followed by two-photon fluorescence laser microscopy (TPLM) imaging. This procedure allowed us to image key intracellular proteins in bone cells while preserving the structural morphology of the cells and the bone.

Physicians' Considerations for Repeat Biopsy in Patients With Recurrent Metastatic Breast Cancer

BACKGROUND

A strong recommendation has been made to perform repeat biopsy for recurrent metastatic breast cancer (RMBC), to reconfirm the histologic features, and to assess for possible changes in hormone receptors (HRs) or human epidermal growth factor receptor 2 (HER2) status. The present study was undertaken to assess the documented and nondocumented factors affecting physicians' decisions to perform a repeat biopsy in patients with RMBC.

PATIENTS AND METHODS

We reviewed the medical records of 410 patients with RMBC for whom recurrence had developed between January 2000 and August 2014. The demographic data and characteristics regarding early and metastatic disease were recorded. The written follow-up records were examined, seeking considerations for or against repeat biopsy. Multivariate analysis was performed using logistic regression to determine the nondocumented reasons for repeat biopsy.

RESULTS

A new biopsy was performed in 295 of 410 patients (72%). However, only 88 of the 295 patients (30%) had a documented reason for rebiopsy. The reason for not performing repeat biopsy was documented for only 1 of the 115 patients. The main documented consideration for rebiopsy was to obtain a new receptor status (recorded in 47 of 88 patients; 53%). The other recorded reasons were suspicion of a second primary, differential diagnosis of metastasis from a second primary, the time from early diagnosis, and patient desire. Significant, but undocumented, considerations for repeat biopsy were low stage at early diagnosis, year of recurrence, interval to recurrence, and site of recurrence. Only for 165 of 295 patients (56%) was the full HR and HER2 status from the new biopsy specimen obtained.

CONCLUSION

Nondocumented factors influence physicians' decisions for referring patients for rebiopsy. This might reflect a low rate of patient involvement in their disease management and decision making.

Highly sensitive single domain antibody-quantum dot conjugates for detection of HER2 biomarker in lung and breast cancer cells

Despite the widespread availability of immunohistochemical and other methodologies for screening and early detection of lung and breast cancer biomarkers, diagnosis of the early stage of cancers can be difficult and prone to error. The identification and validation of early biomarkers specific to lung and breast cancers, which would permit the development of more sensitive methods for detection of early disease onset, is urgently needed. In this paper, ultra-small and bright nanoprobes based on quantum dots (QDs) conjugated to single domain anti-HER2 (human epidermal growth factor receptor 2) antibodies (sdAbs) were applied for immunolabeling of breast and lung cancer cell lines, and their performance was compared to that of anti-HER2 monoclonal antibodies conjugated to conventional organic dyes Alexa Fluor 488 and Alexa Fluor 568. The sdAbs-QD conjugates achieved superior staining in a panel of lung cancer cell lines with differential HER2 expression. This shows their outstanding potential for the development of more sensitive assays for early detection of cancer biomarkers.

The human epidermal growth factor receptor 2 screening tests for breast cancer suggested by the new updated recommendation of the american society of clinical oncology/college of american pathologists will involve a rise of the in-situ hybridization tests for the European laboratories of pathology

Aims. The differences between the 2007 and the 2013 ASCO/CAP HER2 guidelines have been compared. We also discussed the potential consequences in our pathological practice. Material and Methodology. 189 HER2 fluorescence in situ hybridisation (FISH) tests were performed from 1016 preliminary HER2 immunohistochemical tests (IHC). All cases were reviewed and reclassed following the 2007 and 2013 ASCO/CAP recommendations. Results. The 2013 version decreased false-negative IHC (3/118 versus 1/54, P = ns) and created more 2+ IHC (40/186 versus 89/186, P = 0.001) or more 3+ IHC (9/186 versus 39/186, P = 0.001). One false-positive IHC was described for the 2013 version (0/9 versus 1/39, P = ns). Equivocal FISH was reduced (8/186 versus 2/186, P = ns). An estimation based on our data for 1000 patients showed a rise of our FISH tests for the control of 2+ IHC (180 tests for the 2007 version versus 274 tests for the 2013 version or FISH work overflow is +52%) and for the control of 2+/3+ IHC (300 for the 2007 version versus 475 for the 2013 version or FISH work overflow is +58%). Conclusions. The new 2013 ASCO/CAP guidelines have detected more HER2 positive cases but have increased the number of FISH tests.