Will molecular classification replace traditional breast pathology?

Receptor subtype and outcome of breast cancer - Single-center experience from North India

AIMS/OBJECTIVES

In resource-limited settings, data regarding the impact of molecular/receptor subtypes on breast cancer (BC) are sparse. In this single-center retrospective study from north India, we analyze the outcomes of various molecular subtypes of BC.

MATERIALS AND METHODS

Females with biopsy-proven BC who were treated at our State Cancer Institute from 2014-2018 were included. Data regarding clinicopathological parameters and follow-up details were evaluated. For data analysis, cancers were categorized into 4 subtypes: HR+HER2-, HR+HER2+, HR-HER2+, and HR-HER2-.

RESULTS

Among 944 patients included, HR+HER2- (49.1%) and HR+HER2+ (13.1%) were the most and least common subtypes, respectively. The receptor subtype significantly impacted overall survival (OS). HR+HER2- cancers had the best outcomes while HR-HER2- cancers fared worst (3-yr OS of 94.3% and 69.1%, respectively). On subgroup analysis, the molecular subtype continued to significantly impact OS in patients with tumor grades II and III, disease stages II and III, and age groups of <40 and 40-60 years, respectively (HR-HER2- cancers had the lowest cumulative survival in each subgroup). In patients with metastatic BC, all molecular subtypes except HR+HER2- had a dismal prognosis.

CONCLUSIONS

Overall and across various subgroups, patients with triple-negative BC had the poorest outcomes. Ensuring optimal treatment utilization including affordable access to personalized tailored therapy is the need of the hour to improve long-term outcomes in these patients.

PI3K-AKT-Targeting Breast Cancer Treatments: Natural Products and Synthetic Compounds

Breast cancer is the most commonly diagnosed cancer in women. The high incidence of breast cancer, which is continuing to rise, makes treatment a significant challenge. The PI3K-AKT pathway and its downstream targets influence various cellular processes. In recent years, mounting evidence has shown that natural products and synthetic drugs targeting PI3K-AKT signaling have the potential to treat breast cancer. In this review, we discuss the role of the PI3K-AKT signaling pathway in the occurrence and development of breast cancer and highlight PI3K-AKT-targeting natural products and drugs in clinical trials for the treatment of breast cancer.

A Clinical Cognizance of Molecular and Pathological Diagnostic Approach of TNBC

Genetic, transcriptional, and clinical heterogeneity of disease has remained to be a prominent obstacle to the development of a targeted therapeutic approach against TNBC. So far, based on tumor size, lymph node status, and histologic features TNBC subtypes were stratified. Insights into inter and intratumoral heterogeneity of TNBC were gained by next-generation sequencing, genomic, transcriptomic, proteomic, and clinicopathological characterization. To depict tumor response to neoadjuvant chemotherapy, radiological characterization may also a play significant role. Biomarkers for subtyping TNBC were highly needed to depict the survival outcome. This chapter discussed the available and possible molecular and pathological diagnostic approaches to TNBC. Furthermore, the integration of morphological and genomic data may emerge as a promising approach for the identification of new therapeutic and prognostic markers to predict the likely outcome of the disease. This chapter aims to highlight the molecular and pathological diagnostic approaches to depict both metastatic and non-metastatic TNBC.&nbsp;<br>

Molecular Classification of Breast Cancer: Relevance and Challenges

CONTEXT.—

Appropriate patient management requires precise and meaningful tumor classification. Breast cancer classification continues to evolve from traditional morphologic evaluation to more sophisticated systems with the integration of new knowledge from research being translated into practice. Breast cancer is heterogeneous at the molecular level, with diversified patterns of gene expression, which is presumably responsible for the difference in tumor behavior and prognosis. Since the beginning of this century, new molecular technology has been gradually applied to breast cancer research on issues pertinent to prognosis (prognostic signature) and therapeutic prediction (predictive signature), and much progress has been made.

OBJECTIVE.—

To summarize the current state and the prospective future of molecular classification of breast cancer.

DATA SOURCES.—

Sources include recent medical literature on molecular classification of breast cancer.

CONCLUSIONS.—

Identification of intrinsic tumor subtypes has set a foundation for refining the breast cancer molecular classification. Studies have explored the genetic features within the intrinsic cancer subtypes and have identified novel molecular targets that led to the innovation of clinical assays to predict a patient's prognosis and to provide specific guidelines for therapeutic decisions. With the development and implication of these molecular tools, we have remarkably advanced our knowledge and enhanced our power to provide optimal management to patients. However, challenges still exist. Besides accurate prediction of prognosis, we are still in urgent need of more molecular predictors for tumor response to therapeutic regimes. Further exploration along this path will be critical for improving a patient's prognosis.

Patients with Invasive Lobular Carcinoma Show a Significant Increase in IRS-4 Expression Compared to Infiltrative Ductal Carcinoma—A Histopathological Study

Background and Objectives: Breast cancer (BC) is the first diagnosed type of cancer and the second leading cause of cancer-related mortality in women. In addition, despite the improvement in treatment and survival in these patients, the global prevalence and incidence of this cancer are rising, and its mortality may be different according to the histological subtype. Invasive lobular carcinoma (ILC) is less common but entails a poorer prognosis than infiltrative ductal carcinoma (IDC), exhibiting a different clinical and histopathological profile. Deepening study on the molecular profile of both types of cancer may be of great aid to understand the carcinogenesis and progression of BC. In this sense, the aim of the present study was to explore the histological expression of Insulin receptor substrate 4 (IRS-4), cyclooxygenase 2 (COX-2), Cyclin D1 and retinoblastoma protein 1 (Rb1) in patients with ILC and IDC. Patients and Methods: Thus, breast tissue samples from 45 patients with ILC and from 45 subjects with IDC were analyzed in our study. Results: Interestingly, we observed that IRS-4, COX-2, Rb1 and Cyclin D1 were overexpressed in patients with ILC in comparison to IDC. Conclusions: These results may indicate a differential molecular profile between both types of tumors, which may explain the clinical differences among ILC and IDC. Further studies are warranted in order to shed light onto the molecular and translational implications of these components, also aiding to develop a possible targeted therapy to improve the clinical management of these patients.

Prognostic value of cytokines in breast cancer: Correlation with positive hormonal status and obesity

Background

The relation of interleukin 6 (IL6) and molecular subtypes as well as body mass index is not well settled. Little is known about interferon gamma (IFγ) and prognosis of breast cancer.

Patient and methods

Serum level of IL6 and IFγ was assessed by enzyme-linked immunosorbent assay (ELISA) and correlated with the TNM staging, molecular subtypes, and body mass index.

Results

Among 78 patients, the median age was 54 years. The majority of the cases were T2 (62.8%), N1 (38.5%), and M0 (89.74%) with stage II being the most common (47.4%). Most females were estrogen receptor (97.9%) and progesterone receptor positive (96.9%) with high Ki67 ≥ 20 (61.5%). Her2 neu positive presented 16.7%. Luminal A and luminal B presented 29.5% and 53.8%, respectively. Obese patients presented by far the majority (82.1%).

The median level of IL6 and IFγ was 56.20 ± 28.715 and 76.37 ± 41.54, respectively. IL6 was significantly correlated with tumor size (P = 0.001), nodal involvement (P = >0.0001), the presence of metastasis (P = 0.008), and the stage (P = >0.0001). High level of IL6 was associated with positive estrogen receptor, Her2 neu positive, luminal A, and being obese (P = 0.09, 0.07, 0.06, and 0.05, respectively).

High IFγ was only associated with lower nodal burden being significantly higher in N1 than in N3 (118.15 ± 31.07 vs 76.37 ± 44.46, P = 0.01) and early stage (P = 0.02).

Conclusion

IL6 level was correlated to the initial staging, hormonal status, being Her2 positive, and obesity. The IFγ level was inversely correlated IL6 regarding the nodal status (P = 0.05).

Diagnostic and Predictive Values of Strain Ratios in the Regions of Interests in Reference Tissue for Breast Tumor

PURPOSE

To investigate the diagnostic and predictive value of strain ratios in the regions of interests (ROIs) in reference tissue for breast tumor.

PATIENTS AND METHODS

A total of 707 lesions in 665 consecutive patients were examined with B-mode Breast Imaging-Reporting and Data System (BI-RADS) and Ultrasonic elastography (UE). Elasticity score (ES) and strain ratio (SR) in each lesion were calculated. Receiver operating characteristic (ROC) curves were used to assess the diagnostic value of BI-RADS, ES, SR1, SR2, BI-RADS combined with ES (BI-RADS+ES), BI-RADS combined with SR1 (BI-RADS+SR1), and BI-RADS combined with SR2 (BI-RADS+SR2). The sensitivity, specificity, and areas under the ROC curves (Az) were obtained. Scatter plots were generated to demonstrate the correlation between SR1 and SR2. Kruskal-Walls H-test, Mann-Whitney U-test and one-way ANOVA were performed to evaluate SRs and tumor-related variables. Multiple linear regression analysis was carried out to determine variables independently associated with SRs.

RESULTS

BI-RADS had high sensitivity and low specificity in the diagnosis of breast tumor. The specificity of BI-BADS combined with ES or SR was even higher. The Az value of BI-RADS+ES or BI-RADS+SRs was higher than that of BI-RADS (P < 0.001). The Az value of ES was higher than those of SR1 and SR2 (P < 0.001), and those of SR1 and SR2 were similar. SR1 and SR2 were highly positively correlated. There was no statistical difference between Az values of BI-RADS+ES, BI-RADS+SR1, and BI-RADS+SR2. Indistinct margin, high histologic grade, histological type, and negative human epidermal growth factor receptor (Her-2) were associated with SR1 and SR2. Progesterone receptor (PR) status and molecular subtype were associated with SR2. Histologic grade and tumor margin were significantly associated with SR1, and tumor margin was associated with SR2.

CONCLUSION

SRs in different ROIs in the reference tissue at the same depth showed no different diagnostic value for breast tumor. Both SR1 and SR2 could be useful in assessing the biological characteristics of invasive breast carcinoma.

Identification of MicroRNAs as Diagnostic Biomarkers for Breast Cancer Based on the Cancer Genome Atlas

Breast cancer is the most common cancer among women worldwide. MicroRNAs (miRNAs or miRs) play an important role in tumorigenesis, and thus, they have been identified as potential targets for translational research with diagnostic, prognostic, and therapeutic markers. This study aimed to identify differentially expressed (DE) miRNAs in breast cancer using the Cancer Genome Atlas. The miRNA profiles of 755 breast cancer tissues and 86 adjacent non-cancerous breast tissues were analyzed using Multi Experiment Viewer; miRNA–mRNA network analyses and constructed KEGG pathways with the predicted target genes were performed. The clinical relevance of miRNAs was investigated using area under the receiver operating characteristic curve (AUC) analysis, sensitivity, and specificity. The analysis identified 28 DE miRNAs in breast cancer tissues, including nine upregulated and 19 downregulated miRNAs, compared to non-cancerous breast tissues (p < 0.001). The AUC for each DE miRNA, miR-10b, miR-21, miR-96, miR-99a, miR-100, miR-125b-1, miR-125b-2, miR-139, miR-141, miR-145, miR-182, miR-183, miR-195, miR-200a, miR-337, miR-429, and let-7c, exceeded 0.9, indicating excellent diagnostic performance in breast cancer. Moreover, 1381 potential target genes were predicted using the prediction database tool, miRNet. These genes are related to PD-L1 expression and PD-1 checkpoint in cancer, MAPK signaling, apoptosis, and TNF pathways; hence, they regulate the development, progression, and immune escape of cancer. Thus, these 28 miRNAs can serve as prospective biomarkers for the diagnosis of breast cancer. Taken together, these results provide insight into the pathogenic mechanisms and potential therapies for breast cancer.

The Regulatory Role of Mitochondrial MicroRNAs (MitomiRs) in Breast Cancer: Translational Implications Present and Future

Simple Summary

Mitochondrial microRNAs (mitomiRs) are an emerging field of study in a wide range of tumours including breast cancer. By targeting mitochondrial, or non-mitochondrial products, mitomiRs are able to regulate the functions of this organelle, thus controlling multiple carcinogenic processes. The knowledge of this system may provide a novel approach for targeted therapies, as potential biomarkers or helping in the diagnosis of such a complex malignancy.

Abstract

Breast cancer is the most prevalent and incident female neoplasm worldwide. Although survival rates have considerably improved, it is still the leading cause of cancer-related mortality in women. MicroRNAs are small non-coding RNA molecules that regulate the posttranscriptional expression of a wide variety of genes. Although it is usually located in the cytoplasm, several studies have detected a regulatory role of microRNAs in other cell compartments such as the nucleus or mitochondrion, known as “mitomiRs”. MitomiRs are essential modulators of mitochondrion tasks and their abnormal expression has been linked to the aetiology of several human diseases related to mitochondrial dysfunction, including breast cancer. This review aims to examine basic knowledge of the role of mitomiRs in breast cancer and discusses their prospects as biomarkers or therapeutic targets.

Signal Transduction Pathways in Breast Cancer: The Important Role of PI3K/Akt/mTOR

Breast cancer is the cancer with the highest prevalence in women and is the number-one cause of cancer mortality worldwide. Cell transduction is a fundamental process in the development and progression of cancer. Modifications in various cell signalling pathways promote tumour cell proliferation, progression, and survival. The PI3K/Akt/mTOR pathway is an example of that, and it is involved in growth, proliferation, survival, motility, metabolism, and immune response regulation. Activation of this pathway is one of the main causes of cancer cell resistance to antitumour therapies. This makes PI3K/Akt/mTOR signalling a crucial object of study for understanding the development and progression of this disease. Thus, this pathway may have a role as a potential therapeutic target, as well as prognostic and diagnostic value, in patients with breast cancer. Despite the existence of selective PI3K/Akt/mTOR pathway inhibitors and current clinical trials, the cellular mechanisms are not yet known. The present review aims to understand the current state of this important disease and the paths that must be forged.

Pathology in the era of "Personalized Medicine": The need to learn how to integrate multivariate immunohistochemical and "omics" data with clinicopathologic information in a clinically relevant way"

"Personalized medicine" has been proposed as a new paradigm for patient care that, based on the integration of genomics and other "omics" data with clinical and other multidisciplinary information, promises early disease detection, improved outcomes and reduced side effects to therapies. Pathologists have become important participants in this new approach as the guardians of tissues and experts in the performance of molecular and other laboratory tests. Large amounts of new laboratory data in multiple neoplasms and other entities are being reported but there has been limited discussion about how best to evaluate the clinical significance of this information and how to integrate it into currently available diagnostic and therapeutic modalities. This article introduces a variety of epistemological problems presented by the "personalized medicine" paradigm and briefly discusses various topics that will be evaluated in further detail in future articles of this new series on Evidence-Based Pathology.

Triple negative breast cancer: shedding light onto the role of pi3k/akt/mtor pathway

Breast cancer is one of the most widespread carcinoma and one of the main causes of cancer-related death worldwide, especially in women aged between 35 and 75 years. Among the different subtypes, triple negative breast cancer (TNBC) is characterized by the total absence of the estrogen-receptor (ER) and progesteron-receptor (PR) expression as well as the lack of human epidermal growth factor receptor 2 (HER2) overexpression or gene amplification. These biological characteristics confer to TNBC a higher aggressiveness and relapse risk along with poorer prognosis compared to other subtypes. Indeed, 5-years survival rate is still low and almost all patients die, despite any adjuvant treatment which at moment represents the heading pharmacological approach. To date, several clinical trials have been designed to investigate the potential role of some molecular markers, such as VEGF, EGFR, Src and mTOR, for targeted treatments in TNBC. In fact, many inhibitors of the PI3K/AKT/mTOR pathway, frequently de-regulated in TNBC, are acquiring a growing interest and several inhibitors are in preclinical development or already in early phase clinical trials. In this Review, we investigated the role of the PI3K/AKT/mTOR pathway in TNBC patients, by summarizing the molecular features that led to the distinction of different histotypes of TNBC. Furthermore, we provided an overview of the inhibition mechanisms of the mTOR and PI3K/AKT signaling pathways, highlighting the importance of integrating biological and clinical data for the development of mTOR inhibitors in order to implement targeted therapies for TNBC patients.

Diversity of Breast Carcinoma: Histological Subtypes and Clinical Relevance

Mammary carcinoma is the most common malignant tumor in women, and it is the leading cause of mortality, with an incidence of >1,000,000 cases occurring worldwide annually. It is one of the most common human neoplasms, accounting for approximately one-quarter of all cancers in females worldwide and 27% of cancers in developed countries with a Western lifestyle. They exhibit a wide scope of morphological features, different immunohistochemical profiles, and unique histopathological subtypes that have specific clinical course and outcome. Breast cancers can be classified into distinct subgroups based on similarities in the gene expression profiles and molecular classification.

Molecular Classification of Breast Carcinoma: From Traditional, Old-Fashioned Way to A New Age, and A New Way

Breast carcinoma comprises a group of diseases with specific clinical, histopathologic and molecular properties. Traditional classification use morphology to divide tumors into separate categories with differing behavior and prognosis. However, there are limitations of traditional classification systems, and new molecular methods are expected to improve classification systems. Molecular subtypes of breast carcinomas have been characterized in the last 11 years, and have been studied extensively. Much of the information accumulated in recent years, and molecular taxonomy seems to be still developing and undergoing change. The main question is whether new molecular techniques such as gene expression profiling will be accepted as gold standard in determining breast cancer subtypes, and whether molecular classification is useful in specific subtypes of breast cancer as it is in ductal carcinoma (nonspecific type). In addition, critical review of the literature reveals major problems such as poor definition, lack of reproducibility and lack of quality control in current molecular techniques and classifications. Therefore, current molecular approaches are not yet used in routine clinical practice and treatment guidance since they are immature and can even lead to incorrect assessment.

The histone chaperone HJURP is a new independent prognostic marker for luminal A breast carcinoma

BACKGROUND

Breast cancer is a heterogeneous disease with different molecular subtypes that have varying responses to therapy. An ongoing challenge in breast cancer research is to distinguish high-risk patients from good prognosis patients. This is particularly difficult in the low-grade, ER-positive luminal A tumors, where robust diagnostic tools to aid clinical treatment decisions are lacking. Recent data implicating chromatin regulators in cancer initiation and progression offers a promising avenue to develop new tools to help guide clinical decisions.

METHODS

Here we exploit a published transcriptome dataset and an independent validation cohort to correlate the mRNA expression of selected chromatin regulators with respect to the four intrinsic breast cancer molecular subtypes. We then perform univariate and multivariate analyses to compare the prognostic value of a panel of chromatin regulators to Ki67, a currently utilized proliferation marker.

RESULTS

Unsupervised hierarchical clustering revealed a gene cluster containing several histone chaperones and histone variants highly-expressed in the proliferative subtypes (basal-like, HER2-positive, luminal B) but not in the luminal A subtype. Several chromatin regulators, including the histone chaperones CAF-1 (subunits p150 and p60), ASF1b, and HJURP, and the centromeric histone variant CENP-A, associated with local and metastatic relapse and poor patient outcome. Importantly, we find that HJURP can discriminate favorable and unfavorable outcome within the luminal A subtype, outperforming the currently utilized proliferation marker Ki67, as an independent prognostic marker for luminal A patients.

CONCLUSIONS

The integration of chromatin regulators as clinical biomarkers, in particular the histone chaperone HJURP, will help guide patient substratification and treatment options for low-risk luminal A breast carcinoma patients.

Medullary carcinoma of the thyroid metastatic to the breast: a case report and literature review

Breast malignancies, apart from skin cancer, are the leading cause of cancer from cancer among the female population. Unlike the high prevalence of primary mammary malignancies, metastases to the breast are uncommon, and account for only 0.2-2.7% of all malignancies affecting this organ. We report the case of a 35-year-old woman who sought medical care because of a breast lump. A mammogram suggested a breast tumor, which was biopsied. The histopathological workup resulted in the diagnosis of a metastasis from a medullary thyroid cancer. The authors review the most useful clinical, radiological, histological, and immunohistochemical features concerning extramammary malignancy to the breast.