Reliable microRNA profiling in routinely processed formalin-fixed paraffin-embedded breast cancer specimens using fluorescence labelled bead technology

<p>Abstract</p> <p>Background</p> <p>During the last years the analysis of microRNA expression patterns has led to completely new insights into cancer biology. Furthermore, these patterns are a very promising tool for the development of new diagnostic and prognostic markers. However, most human tumour samples for which long term clinical records are available exist only as formalin-fixed paraffin-embedded specimens. Therefore, the aim of this study was to examine the feasibility of microRNA profiling studies in routinely processed formalin-fixed paraffin-embedded human breast cancer specimens using fluorescence labelled bead technology.</p> <p>Results</p> <p>A statistically highly significant correlation (Spearman r: 0.78 – 0.90, p < 0.0001) was observed for the expression of 319 microRNAs in routinely processed FFPE breast cancer specimens and paired fresh frozen tissue samples (n = 5). Results were confirmed in a larger series analyzing a selection of 10 microRNAs reported to be deregulated in breast cancer (n = 12). The expression pattern of 3 microRNAs was independently validated in this cohort using real-time RT-PCR technology.</p> <p>Conclusion</p> <p>Comprehensive microRNA expression patterns can be reliably derived from routinely processed FFPE breast cancer specimens using fluorescence labelled bead technology.</p

Results of a worldwide survey on the currently used histopathological diagnostic criteria for invasive lobular breast cancer

Invasive lobular carcinoma (ILC) represents the second most common subtype of breast cancer (BC), accounting for up to 15% of all invasive BC. Loss of cell adhesion due to functional inactivation of E-cadherin is the hallmark of ILC. Although the current world health organization (WHO) classification for diagnosing ILC requires the recognition of the dispersed or linear non-cohesive growth pattern, it is not mandatory to demonstrate E-cadherin loss by immunohistochemistry (IHC). Recent results of central pathology review of two large randomized clinical trials have demonstrated relative overdiagnosis of ILC, as only ~60% of the locally diagnosed ILCs were confirmed by central pathology. To understand the possible underlying reasons of this discrepancy, we undertook a worldwide survey on the current practice of diagnosing BC as ILC. A survey was drafted by a panel of pathologists and researchers from the European lobular breast cancer consortium (ELBCC) using the online tool SurveyMonkey®. Various parameters such as indications for IHC staining, IHC clones, and IHC staining procedures were questioned. Finally, systematic reporting of non-classical ILC variants were also interrogated. This survey was sent out to pathologists worldwide and circulated from December 14, 2020 until July, 1 2021. The results demonstrate that approximately half of the institutions use E-cadherin expression loss by IHC as an ancillary test to diagnose ILC and that there is a great variability in immunostaining protocols. This might cause different staining results and discordant interpretations. As ILC-specific therapeutic and diagnostic avenues are currently explored in the context of clinical trials, it is of importance to improve standardization of histopathologic diagnosis of ILC diagnosis

Atlas of Lobular Breast Cancer Models: Challenges and Strategic Directions

Invasive lobular carcinoma (ILC) accounts for up to 15% of all breast cancer (BC) cases and responds well to endocrine treatment when estrogen receptor α-positive (ER+) yet differs in many biological aspects from other ER+ BC subtypes. Up to 30% of patients with ILC will develop late-onset metastatic disease up to ten years after initial tumor diagnosis and may experience failure of systemic therapy. Unfortunately, preclinical models to study ILC progression and predict the efficacy of novel therapeutics are scarce. Here, we review the current advances in ILC modeling, including cell lines and organotypic models, genetically engineered mouse models, and patient-derived xenografts. We also underscore four critical challenges that can be addressed using ILC models: drug resistance, lobular tumor microenvironment, tumor dormancy, and metastasis. Finally, we highlight the advantages of shared experimental ILC resources and provide essential considerations from the perspective of the European Lobular Breast Cancer Consortium (ELBCC), which is devoted to better understanding and translating the molecular cues that underpin ILC to clinical diagnosis and intervention. This review will guide investigators who are considering the implementation of ILC models in their research programs

Microenvironment‐induced restoration of cohesive growth associated with focal activation of P ‐cadherin expression in lobular breast carcinoma metastatic to the colon

Invasive lobular carcinoma (ILC) is a special breast cancer type characterized by noncohesive growth and E‐cadherin loss. Focal activation of P‐cadherin expression in tumor cells that are deficient for E‐cadherin occurs in a subset of ILCs. Switching from an E‐cadherin deficient to P‐cadherin proficient status (EPS) partially restores cell–cell adhesion leading to the formation of cohesive tubular elements. It is unknown what conditions control EPS. Here, we report on EPS in ILC metastases in the large bowel. We reviewed endoscopic colon biopsies and colectomy specimens from a 52‐year‐old female (index patient) and of 18 additional patients (reference series) diagnosed with metastatic ILC in the colon. EPS was assessed by immunohistochemistry for E‐cadherin and P‐cadherin. CDH1 /E‐cadherin mutations were determined by next‐generation sequencing. The index patient's colectomy showed transmural metastatic ILC harboring a CDH1 /E‐cadherin p.Q610* mutation. ILC cells displayed different growth patterns in different anatomic layers of the colon wall. In the tunica muscularis propria and the tela submucosa, ILC cells featured noncohesive growth and were E‐cadherin‐negative and P‐cadherin‐negative. However, ILC cells invading the mucosa formed cohesive tubular elements in the intercryptal stroma of the lamina propria mucosae. Inter‐cryptal ILC cells switched to a P‐cadherin‐positive phenotype in this microenvironmental niche. In the reference series, colon mucosa infiltration was evident in 13 of 18 patients, one of which showed intercryptal EPS and conversion to cohesive growth as described in the index patient. The large bowel is a common metastatic site in ILC. In endoscopic colon biopsies, the typical noncohesive growth of ILC may be concealed by microenvironment‐induced EPS and conversion to cohesive growth

Results of a worldwide survey on the currently used histopathological diagnostic criteria for invasive lobular breast cancer

Invasive lobular carcinoma (ILC) represents the second most common subtype of breast cancer (BC), accounting for up to 15% of all invasive BC. Loss of cell adhesion due to functional inactivation of E-cadherin is the hallmark of ILC. Although the current world health organization (WHO) classification for diagnosing ILC requires the recognition of the dispersed or linear non-cohesive growth pattern, it is not mandatory to demonstrate E-cadherin loss by immunohistochemistry (IHC). Recent results of central pathology review of two large randomized clinical trials have demonstrated relative overdiagnosis of ILC, as only similar to 60% of the locally diagnosed ILCs were confirmed by central pathology. To understand the possible underlying reasons of this discrepancy, we undertook a worldwide survey on the current practice of diagnosing BC as ILC. A survey was drafted by a panel of pathologists and researchers from the European lobular breast cancer consortium (ELBCC) using the online tool SurveyMonkey (R). Various parameters such as indications for IHC staining, IHC clones, and IHC staining procedures were questioned. Finally, systematic reporting of non-classical ILC variants were also interrogated. This survey was sent out to pathologists worldwide and circulated from December 14, 2020 until July, 1 2021. The results demonstrate that approximately half of the institutions use E-cadherin expression loss by IHC as an ancillary test to diagnose ILC and that there is a great variability in immunostaining protocols. This might cause different staining results and discordant interpretations. As ILC-specific therapeutic and diagnostic avenues are currently explored in the context of clinical trials, it is of importance to improve standardization of histopathologic diagnosis of ILC diagnosis

Evidence-based guidelines for managing patients with primary ER+ HER2− breast cancer deferred from surgery due to the COVID-19 pandemic

Many patients with ER+ HER2- primary breast cancer are being deferred from surgery to neoadjuvant endocrine therapy (NeoET) during the COVID-19 pandemic. We have collated data from multiple international trials of presurgical endocrine therapy in order to provide guidance on the identification of patients who may have insufficiently endocrine-sensitive tumors and should be prioritised for early surgery or neoadjuvant chemotherapy rather than NeoET during or in the aftermath of the COVID-19 pandemic for safety or when surgical activity needs to be prioritized. For postmenopausal patients, our data provide strong support for the use of ER and PgR status at diagnosis for triaging of patients into three groups in which (taking into account clinical factors): (i) NeoET is likely to be inappropriate (Allred ER 10%) indicates a higher priority for early surgery. Too few data were available for premenopausal patients to provide a similar treatment algorithm. These guidelines should be helpful for managing patients with early ER+ HER2- breast cancer during and in the aftermath of the COVID-19 crisis

Nuclear Kaiso Expression Is Associated with High Grade and Triple-Negative Invasive Breast Cancer

Kaiso is a BTB/POZ transcription factor that is ubiquitously expressed in multiple cell types and functions as a transcriptional repressor and activator. Little is known about Kaiso expression and localization in breast cancer. Here, we have related pathological features and molecular subtypes to Kaiso expression in 477 cases of human invasive breast cancer. Nuclear Kaiso was predominantly found in invasive ductal carcinoma (IDC) (p = 0.007), while cytoplasmic Kaiso expression was linked to invasive lobular carcinoma (ILC) (p = 0.006). Although cytoplasmic Kaiso did not correlate to clinicopathological features, we found a significant correlation between nuclear Kaiso, high histological grade (p = 0.023), ERα negativity (p = 0.001), and the HER2-driven and basal/triple-negative breast cancers (p = 0.018). Interestingly, nuclear Kaiso was also abundant in BRCA1-associated breast cancer (p<0.001) and invasive breast cancer overexpressing EGFR (p = 0.019). We observed a correlation between nuclear Kaiso and membrane-localized E-cadherin and p120-catenin (p120) (p<0.01). In contrast, cytoplasmic p120 strongly correlated with loss of E-cadherin and low nuclear Kaiso (p = 0.005). We could confirm these findings in human ILC cells and cell lines derived from conditional mouse models of ILC. Moreover, we present functional data that substantiate a mechanism whereby E-cadherin controls p120-mediated relief of Kaiso-dependent gene repression. In conclusion, our data indicate that nuclear Kaiso is common in clinically aggressive ductal breast cancer, while cytoplasmic Kaiso and a p120-mediated relief of Kaiso-dependent transcriptional repression characterize ILC

Results of a worldwide survey on the currently used histopathological diagnostic criteria for invasive lobular breast cancer

Invasive lobular carcinoma (ILC) represents the second most common subtype of breast cancer (BC), accounting for up to 15% of all invasive BC. Loss of cell adhesion due to functional inactivation of E-cadherin is the hallmark of ILC. Although the current world health organization (WHO) classification for diagnosing ILC requires the recognition of the dispersed or linear non-cohesive growth pattern, it is not mandatory to demonstrate E-cadherin loss by immunohistochemistry (IHC). Recent results of central pathology review of two large randomized clinical trials have demonstrated relative overdiagnosis of ILC, as only similar to 60% of the locally diagnosed ILCs were confirmed by central pathology. To understand the possible underlying reasons of this discrepancy, we undertook a worldwide survey on the current practice of diagnosing BC as ILC. A survey was drafted by a panel of pathologists and researchers from the European lobular breast cancer consortium (ELBCC) using the online tool SurveyMonkey (R). Various parameters such as indications for IHC staining, IHC clones, and IHC staining procedures were questioned. Finally, systematic reporting of non-classical ILC variants were also interrogated. This survey was sent out to pathologists worldwide and circulated from December 14, 2020 until July, 1 2021. The results demonstrate that approximately half of the institutions use E-cadherin expression loss by IHC as an ancillary test to diagnose ILC and that there is a great variability in immunostaining protocols. This might cause different staining results and discordant interpretations. As ILC-specific therapeutic and diagnostic avenues are currently explored in the context of clinical trials, it is of importance to improve standardization of histopathologic diagnosis of ILC diagnosis

Lobular breast cancer : molecular basis, mouse and cellular models

Infiltrating lobular breast cancer (ILC) is the most common special breast cancer subtype. With mutational or epigenetic inactivation of the cell adhesion molecule E-cadherin (CDH1) being confined almost exclusively to ILC, this tumor entity stands out from all other types of breast cancers. The molecular basis of ILC is linked to loss of E-cadherin, as evidenced by human CDH1 germline mutations and conditional knockout mouse models. A better understanding of ILC beyond the level of descriptive studies depends on physiologically relevant and functional tools. This review provides a detailed overview on ILC models, including well-characterized cell lines, xenograft tumors and genetically engineered mouse models. We consider advantages and limitations of these models and evaluate their representativeness for human ILC. The still incompletely defined mechanisms by which loss of E-cadherin drives malignant transformation are discussed based on recent findings in these models. Moreover, candidate genes and signaling pathways potentially involved in ILC development and progression as well as anticancer drug and endocrine resistance are highlighted