GATA3 expression in breast carcinoma: utility in triple-negative, sarcomatoid, and metastatic carcinomas

Targeted DNA Sequencing in Diagnosis of Malignant Phyllodes Tumors With Emphasis on Tumors With Keratin and p63 Expression

The differential diagnosis of malignant spindle cell neoplasms in the breast most frequently rests between malignant phyllodes tumor (MPT) and metaplastic carcinoma (MBC). Diagnosis of MPT can be challenging due to diffuse stromal overgrowth, keratin (CK) and/or p63 immunopositivity, and absent CD34 expression, which can mimic MBC, especially in core biopsies. Distinction of MPT from MBC has clinical implications, with differences in surgical approach, chemotherapy, and radiation. In this study, we evaluated MPTs (78 tumors, 64 patients) for stromal CK, p63, and CD34 expression and profiled a subset (n = 31) by targeted next-generation DNA sequencing, with comparison to MBC (n = 44). Most MPTs (71%) were CK+ and/or p63+, including 32% CK+ (25/77 focal) and 65% p63+ (32/66 focal, 10/66 patchy, and 1/66 diffuse). Thirty percent of MPTs expressed both CK and p63 (20/66), compared with 95% of MBCs (40/42, P < .001). CK and/or p63 were positive in CD34+ and CD34- MPTs. Recurrent genetic aberrations in MPTs involved TERT, TP53, MED12, CDKN2A, chromatin modifiers, growth factor receptors/ligands, and phosphoinositide-3 kinase (PI-3K) and MAPK pathway genes. Only MED12 (39%, 12/31) and SETD2 (13%, 4/31) were exclusively mutated in MPTs and not MBCs (P < .001 and P = .044, respectively), whereas PIK3R1 mutations were only found in MBCs (37%, 13/35, P < .001). Comparative literature review additionally identified ARID1B, EGFR, FLNA, NRAS, PDGFRB, RAD50, and RARA alterations enriched or exclusively in MPTs vs MBCs. MED12 was mutated in MPTs with diffuse stromal overgrowth (53%, 9/17), CD34- MPTs (41%, 7/17), and CK+ and/or p63+ MPTs (39%, 9/23), including 36% of CD34- MPTs with CK and/or p63 expression. Overall, MED12 mutation and/or CD34 expression were observed in 68% (21/31) MPTs, including 61% (14/23) of CK+ and/or p63+ tumors. Our results emphasize the prevalence of CK and p63 expression in MPTs and demonstrate the diagnostic utility of next-generation DNA sequencing, especially in MPTs with confounding factors that can mimic MBC.

Morphofunctional Characteristics of the Vessels of the Subareolar Lymphatic Plexus in Breast Cancer with Metastasis to the Lymph Nodes of the Axillary Lymphatic Collector

The subareolar Sappey's plexus was studied using color lymphography and immunohistochemical methods with a panel of antibodies to podoplanin, smooth muscle actin, low molecular weight cytokeratin AE1/AE3, and GATA3 on archival material obtained during radical mastectomies and sectoral resections with lymph node dissection from 86 patients diagnosed with non-special type breast cancer. At the macro- and microscopic levels, the connection between the subareolar lymphatic plexus and the lymphatic system of the breast parenchyma has been demonstrated. In triple negative breast cancer with metastases to the axillary lymph nodes, the involvement of subareolar lymphatic plexus into lymphogenous metastasis to the lymph nodes of the axillary lymphatic collector was shown.

Invasive Ductal Breast Carcinoma Metastasis to the Uterine Cervix Presenting As Heavy Vaginal Bleeding: A Case Report and a Literature Review

Breast carcinoma metastasis to the uterine cervix is a rare occurrence with diagnostic intricacies. We present a case of a 38-year-old woman diagnosed with bilateral stages IIIA and IIIB invasive ductal carcinoma of the breast who developed heavy vaginal bleeding post-treatment, revealing metastatic involvement of the cervix, confirmed by CT imaging and pathological examination, as the presenting sign of widely metastatic disease. This case underscores the importance of a thorough review of systems and physical exams as well as considering uncommon metastatic sites in breast cancer patients.

Role of SOX10 Immunohistochemical Expression in Diagnosing Triple Negative Breast Cancer and Its Correlation With Clinicopathological Features

BACKGROUND

Triple-negative breast cancer (TNBC) poses a diagnostic challenge for histopathologists due to the reduced frequency of breast-specific markers. SOX10 has emerged as a useful diagnostic marker for TNBC. The aim of our study was to determine the frequency of SOX-10 immunohistochemical (IHC) expression in our cohort and assess its correlation with clinicopathological and histological features.

MATERIALS AND METHODS

We included 72 primary TNBC cases. Specimens included tru-cut biopsies and excision specimens. We stained whole slide sections of these specimens with SOX10 antibody and calculated its frequency (%) of expression and H-score. We applied the chi-square test to assess the correlation between SOX10 expression and clinicopathological and histological features such as the patient's age, specimen type, tumor size, histological type, histological grade, nuclear pleomorphism, mitotic count, tumor-infiltrating lymphocytes (TILs), necrosis, calcification, lymphovascular invasion (LVI), lymph node involvement, T stage, and N stage.

RESULTS

SOX10 expression was observed in 42 (58.3%) cases with a median H-score of 57.5. The expression was significantly higher in tru-cut biopsy specimens as compared to excision specimens (73.5 vs 41.7%) and TILs negative tumors as compared to TILs positive tumors (64.3% vs 27.3). Metaplastic carcinoma showed reduced expression when compared with non-metaplastic tumors (35.7% vs 63.8%), but statistical significance was not achieved. No correlation was observed with the patient's age, tumor size, histological type, histological grade, nuclear pleomorphism, mitotic count, necrosis, calcification, LVI, lymph node involvement, T stage, and N stage.

CONCLUSION

SOX10 was expressed in more than half of the TNBC cases of our study which not only highlights its diagnostic utility but advocated its application in combination with other breast-specific markers. The expression didn't correlate with the majority of clinicopathological and histological features, but correlation with tru-cut biopsy specimens and absence of TILs draws attention towards possible roles of proper fixation and host immunity, respectively.

Immunohistochemical Characterization of a Large Cohort of Triple Negative Breast Cancer

Introduction. Triple negative breast carcinomas are characterized by a lack of hormone receptor and HER2 expression and inconsistent expression of breast-specific immunohistochemical markers. The expression of many site-specific markers in these tumors is largely unknown. The objective of the study was to examine the expression of widely used immunohistochemical markers on a large cohort of triple negative breast cancer. Methods. Sections from tissue microarrays were stained with 47 markers using routine protocols. Most markers were scored using a modified Allred method. ATRX, BAP1, SMAD4, e-cadherin, and beta-catenin were scored as retained or lost. Mammaglobin was considered positive if there was at least moderate intensity staining in any tumor cells. P16 was scored as overexpressed or not overexpressed; p53 was scored as wildtype, overexpressed, null, or cytoplasmic. Results. The cohort consisted of 639 tumors including 601 primary and 32 metastases. Overall, 96% expressed GATA3, mammaglobin, and/or SOX10 while 97% of no special type tumors expressed this panel. Carcinoma of apocrine differentiation demonstrated an AR positive, SOX10 negative, K5 negative/focal immunophenotype. PAX8 (SP348), WT1, Napsin A, and TTF1 (8G7G3/1) were never or rarely expressed while CA9, CDX2, NKX3.1, SATB2 (SATBA410), synaptophysin, and vimentin were variably expressed. Conclusions. Almost all TNBC express at least 1 of the 3 IHC markers: GATA3, mammaglobin, and/or SOX10. Carcinoma of apocrine differentiation is characterized by an AR positive, SOX10 negative, K5 negative or focal immunophenotype. Cautious interpretation of so-called site-specific markers, with knowledge of antibody clones, is required in excluding the diagnosis of triple negative breast cancer.

Potential biomarkers in breast cancer drug development: application of the biomarker qualification evidentiary framework

Breast cancer treatments have evolved rapidly, and clinically meaningful biomarkers have been used to guide therapy. These biomarkers hold utility within the drug development process to increase the efficiency and effectiveness. To this purpose, the US FDA developed an evidentiary framework. Literature searches conducted of literature published between 2016 and 2022 identified biomarkers in breast cancer. These biomarkers were reviewed for drug development utility through the biomarker qualification evidentiary framework. In the breast cancer setting, several promising biomarkers (ctDNA, Ki-67 and PIK3CA) were identified. There is a need for increased transparency regarding the requirements for qualification of specific biomarkers and increased awareness of the processes involved in biomarker qualification.

TRPS1 and GATA3 Expression in Invasive Breast Carcinoma With Apocrine Differentiation

CONTEXT.—

The recently identified immunohistochemical marker TRPS1 is highly sensitive and specific for invasive breast carcinoma, especially triple-negative breast carcinoma. However, TRPS1 expression in special morphologic subtypes of breast cancer is unclear.

OBJECTIVE.—

To investigate the expression of TRPS1 in invasive breast cancer with apocrine differentiation, in comparison to the expression of GATA3.

DESIGN.—

A total of 52 invasive breast carcinomas with apocrine differentiation, comprising 41 triple-negative breast carcinomas and 11 estrogen receptor (ER) and progesterone receptor (PR)-negative, human epidermal growth factor receptor 2 (HER2)-positive cases, along with 11 triple-negative breast carcinomas without apocrine differentiation, were evaluated for TRPS1 and GATA3 expression by immunohistochemistry. All tumors were diffusely positive (>90%) for androgen receptor (AR).

RESULTS.—

Triple-negative breast carcinoma with apocrine differentiation had positive TRPS1 expression in 12% of cases (5 of 41), whereas GATA3 was positive in all cases. Similarly, HER2+/ER- invasive breast carcinoma with apocrine differentiation showed positive TRPS1 in 18% of cases (2 of 11), whereas GATA3 was positive in all cases. In contrast, triple-negative breast carcinoma with strong AR expression but without apocrine differentiation showed both TRPS1 and GATA3 expression in 100% (11 of 11) of cases.

CONCLUSIONS.—

Most ER-/PR-/AR+ invasive breast carcinomas with apocrine differentiation are TRPS1 negative and GATA3 positive, regardless of HER2 status. Therefore, TRPS1 negativity does not exclude breast origin in tumors with apocrine differentiation. A panel of TRPS1 and GATA3 immunostains can be helpful when the tissue origin of such tumors is clinically relevant.

Gene of the month: GATA3

GATA binding protein 3 (GATA3) is a zinc-finger pioneer transcription factor involved in diverse processes. GATA3 regulates gene expression through binding nucleosomal DNA and facilitating chromatin remodelling. Post-translational modifications modulate its activity. During development, GATA3 plays a key role in cell differentiation. Mutations in GATA3 are linked to breast and bladder cancer. GATA3 expression is a feature of the luminal subtype of bladder cancer and has implications for immune status and therapeutic response. It also has clinical relevance in squamous cell carcinomas and soft tissue sarcomas. This paper reviews the structure and function of GATA3, its role in cancer and its use and pitfalls as an immunohistochemical marker.

Current Approach to Undifferentiated Neoplasms, With Focus on New Developments and Novel Immunohistochemical Stains

CONTEXT.—

Workup of the poorly differentiated or undifferentiated tumor remains a significant and challenging entity in the practice of anatomic pathology. Particularly in the setting of small biopsies and limited material, these cases demand a balanced approach that considers the patient's clinical and radiologic presentation, a basic assessment of tumor morphology, a reasonably broad immunohistochemical panel, and diligent preservation of tissue for prognostic and therapeutic studies.

OBJECTIVE.—

To illustrate some of the new and emerging immunohistochemical markers in the evaluation of tumors with undifferentiated or poorly differentiated morphology, with a focus on the workup in limited tissue samples to raise awareness of the issues involved with the pathologic workup in these challenging tumors.

DATA SOURCES.—

A literature review of new ancillary studies that can be applied to cytologic specimens was performed.

CONCLUSIONS.—

Knowledge of the patient's history and communication with the patient's clinical team is essential in formulating a differential diagnosis that can appropriately limit the differential diagnosis based on morphology, especially in small specimens. This information, in conjunction with classifying the tumor morphology (eg, epithelioid, spindled, neuroendocrine, basaloid/biphasic, mixed) gives a logical approach to choosing an initial immunohistochemical panel. Fortunately, immunohistochemistry is evolving quickly in the wake of groundbreaking molecular studies to develop new and better markers to further classify these difficult tumors beyond where we traditionally have been able to go.

Comparative expression of TRPS1, GATA3, SOX10, mammaglobin, and GCDFP-15 in effusion specimens with breast carcinoma

BACKGROUND

Traditional immunohistochemistry (IHC) for breast carcinomas has shown low detection rates of metastatic breast carcinoma (MBC) in effusions. Although GATA3 has enhanced diagnostic accuracy in this realm, its limited utility in detecting triple-negative breast carcinoma (TNBC) has been highlighted. TRPS1 has been introduced as a potentially sensitive and specific marker in detecting MBC on histologic samples. We investigate the utility of TRPS1 as a marker for MBC in effusion specimens and compare its performance to SOX10, GATA3, mammaglobin (MG), and GCDFP-15.

METHODS

A database search identified malignant effusions involved by MBC between 2013 and 2021. Cases from unique patients with sufficient cellularity were evaluated for TRPS1, GATA3, SOX10, MG, and GCDFP-15 IHC. The intensity and extent of tumor cells (TC) were scored by two pathologists. Any discrepancies were jointly reviewed for consensus.

RESULTS

GATA3 showed the highest rate of positivity (98.2%), followed by TRPS1 (89.5%), MG (43.9%), GCDFP-15 (21.1%), and SOX10 (3.5%). All GATA3-positive cases showed intermediate to high expression. Comparatively, TRPS1 showed more variability in staining extent and intensity. In 13 (22.8%) cases, TRPS1 showed extensive background staining of inflammatory and mesothelial cells. Of six TNBCs, GATA3, and TRPS1 were positive in six (100%) and four (66.7%) cases, respectively.

CONCLUSIONS

While TRPS1 shows a lower detection rate for MBC than GATA-3, using a combination of these markers can enhance effusion cytology's performance in detecting MBC. However, variability in TRPS1 staining intensity and high background TRPS1 staining of inflammatory and mesothelial cells can increase difficulty in its evaluation.

TRPS1, a New Promising Marker for Assessment of Distant Metastatic Breast Cancer

This article reviewed the identification of breast cancer in the distant metastatic setting through traditional immunohistochemical markers, such as mammaglobin and GATA3, compared with the novel immunohistochemical stain, Trichorhinophalangeal syndrome-1 (TRPS1). We review previous studies evaluating TRPS1 staining, which were conducted using cytology specimens, as well as our recently conducted study evaluating this stain using surgical tissue samples, both from primary and distant metastatic invasive breast carcinoma. In summary, although no immunohistochemical stain is 100% specific or sensitive, in the metastatic setting where tissue available for ancillary studies is limited, TRPS1 was a reliable and even a standalone marker for breast origin, particularly in cases of triple-negative breast cancer.

Immunohistochemistry in the Diagnosis and Classification of Breast Tumors

CONTEXT.—

In the clinical practice of breast pathology, immunohistochemistry (IHC) of different markers is widely used for the diagnosis and classification of breast lesions.

OBJECTIVE.—

To provide an overview of currently used and recently identified IHC stains that have been implemented in the field of diagnostic breast pathology.

DATA SOURCES.—

Data were obtained from literature review and clinical experience of the authors as breast pathologists.

CONCLUSIONS.—

In the current review, we summarize the common uses of IHC stains for diagnosing different types of breast lesions, especially invasive and noninvasive breast lesions, and benign and malignant spindle cell lesions. In addition, the cutting-edge knowledge of diagnostic carcinoma markers will lead us to further understand the different types of breast carcinoma and differentiate breast carcinomas from other carcinomas of similar morphology. Knowing the strengths and limitations of these markers is essential to the clinical practice of breast pathology.

Diagnostic Pitfalls in Breast Cancer Pathology With an Emphasis on Core Needle Biopsy Specimens

CONTEXT.—

Breast pathology has many mimics and diagnostic pitfalls. Evaluation of malignant breast lesions, particularly in the biopsy setting, can be especially challenging, with diagnostic errors having significant management implications.

OBJECTIVE.—

To discuss the pitfalls encountered when evaluating ductal carcinoma in situ and invasive breast carcinomas, providing histologic clues and guidance for appropriate use and interpretation of immunohistochemistry to aid in the correct diagnosis.

DATA SOURCES.—

Data were obtained from review of pertinent literature of ductal carcinoma in situ and invasive breast carcinomas and from the experience of the authors as practicing breast pathologists.

CONCLUSIONS.—

Awareness of the pitfalls in diagnosing breast cancers is important when creating a differential diagnosis for each breast lesion evaluated. This review will cover some of these scenarios to aid in the diagnostic process.

Metaplastic breast cancer: an all-round multidisciplinary consensus

Metaplastic breast cancer (MpBC) is a rare and aggressive histologic subtype of breast cancer (BC) characterized by the presence of at least two cellular types, commonly epithelial and mesenchymal components. Despite growing evidence that MpBC is a unique entity, it has long been treated as a variant of nonspecial type (NST) BC. MpBC typically shows the phenotype of triple-negative breast cancer (TNBC), but compared to NST-TNBC, it is a relatively chemorefractory tumor associated with worse outcomes. Therefore, there is an urgent need to develop management guidelines specifically for MpBC to improve the prognosis of patients with early MpBC. This expert consensus aims to guide diagnosis and standardize clinical management of early MpBC among treating physicians. We provide guidance on the challenging radiological and pathological diagnosis of MpBC. Evidence on the involvement of genetic predisposition in the development of MpBC is also explored. We emphasize the importance of a multidisciplinary approach for the treatment of patients with early MpBC. The optimal surgery and radiotherapy approach is presented, as well as the opportunity offered by novel therapeutic approaches to increase treatment response in this chemoresistant subtype. Appropriate management of patients with MpBC is critical to reduce the high risk of local and distant recurrence that characterizes this disease.

Fine needle aspiration of pancreatic lesions focusing on secondary tumors with emphasis of metastatic breast cancer: A clinicopathological study with follow-up

BACKGROUND

The data on metastatic tumors to the pancreas diagnosed by fine needle aspiration (FNA) biopsy is limited. We report our experience of FNA of primary and secondary pancreatic tumors emphasizing metastatic breast cancer in the pancreas.

METHOD

Total 274 cases of pancreatic FNA in 10 years were retrospectively reviewed. Literature review of metastatic breast cancers to the pancreas was performed.

RESULTS

Out of the 274 cases, 7 (7/274, 2.6%) cases were non-diagnostic, 46 (46/274, 16.8%) cases were negative for malignancy, and 40 (40/274, 14.6%) cases were under the category of atypical cells. There were 133 (133/274, 48.5%) cases diagnosed as positive for malignancy, 20 (20/274, 7.3%) suspicious for malignancy, and 28 (28/274, 10.2%) cases in the category of neoplastic: other. The most common neoplasm diagnosed was ductal adenocarcinoma (114/274, 41.6%; 114/133, 85.7% in positive for malignancy category). Ten cases (10/274, 3.7%) were diagnosed as metastatic neoplasms to the pancreas, including four breast infiltrating ductal carcinomas (IDC), one endocervical adenocarcinoma, one anal/rectal squamous cell carcinoma, one renal cell carcinoma, one hepatocellular carcinoma, one seminoma and one lung adenocarcinoma. We summarized the biomarkers of the four metastatic breast cancers and conducted literature review on biomarkers of metastatic breast cancers to the pancreas.

CONCLUSIONS

Upon analyzing FNAs of primary and secondary tumors in the pancreas, we have found breast carcinoma is the most common secondary pancreatic neoplasm in our patient population. Triple negative breast ductal carcinoma is the most common tumor among the metastasis of breast carcinomas to the pancreas. To the best of our knowledge, this study is the first report with a literature review focusing on biomarkers of metastatic breast cancer to the pancreas.

In Silico Analysis of Publicly Available Transcriptomic Data for the Identification of Triple-Negative Breast Cancer-Specific Biomarkers

BACKGROUND

Breast cancer is the most common type of cancer among women and is classified into multiple subtypes. Triple-negative breast cancer (TNBC) is the most aggressive subtype, with high mortality rates and limited treatment options such as chemotherapy and radiation. Due to the heterogeneity and complexity of TNBC, there is a lack of reliable biomarkers that can be used to aid in the early diagnosis and prognosis of TNBC in a non-invasive screening method.

AIM

This study aims to use in silico methods to identify potential biomarkers for TNBC screening and diagnosis, as well as potential therapeutic markers.

METHODS

Publicly available transcriptomic data of breast cancer patients published in the NCBI's GEO database were used in this analysis. Data were analyzed with the online tool GEO2R to identify differentially expressed genes (DEGs). Genes that were differentially expressed in more than 50% of the datasets were selected for further analysis. Metascape, Kaplan-Meier plotter, cBioPortal, and the online tool TIMER were used for functional pathway analysis to identify the biological role and functional pathways associated with these genes. Breast Cancer Gene-Expression Miner v4.7 was used to validify the obtained results in a larger cohort of datasets.

RESULTS

A total of 34 genes were identified as differentially expressed in more than half of the datasets. The DEG GATA3 had the highest degree of regulation, and it plays a role in regulating other genes. The estrogen-dependent pathway was the most enriched pathway, involving four crucial genes, including GATA3. The gene FOXA1 was consistently down-regulated in TNBC in all datasets.

CONCLUSIONS

The shortlisted 34 DEGs will aid clinicians in diagnosing TNBC more accurately as well as developing targeted therapies to improve patient prognosis. In vitro and in vivo studies are further recommended to validate the results of the current study.

GATA3 expression in primary lung carcinomas: correlation with histopathologic features and TTF-1, napsin A, and p40 expression

This study assessed the expression of GATA3 in primary lung carcinomas and correlated it with tumor histology and immunostains routinely utilized in the work up of primary lung cancers. Tissue microarrays (TMAs) were constructed from a cohort of 184 non-small cell carcinomas, stained with GATA3, p40, TTF-1, and napsin A, and analyzed semi-quantitatively. All TMA cases with GATA3 expression were further analyzed using corresponding whole slide sections. Positive GATA3 staining was present in 16 cases (9%), including 7 squamous cell carcinomas (SqCCs) (4%), 4 adenocarcinomas (AdCs) (2%), 2 adenosquamous carcinomas (AdSqCs) (1%), 2 large cell carcinomas (LCCs) (1%), and 1 sarcomatoid carcinoma (SC) (<1%). Among tumor histotypes, SqCC was more likely to stain with GATA3 (7/49, 14%), while AdC was less likely (4/111, 4%) (p = 0.04). In GATA3-positive cases, high-level expression was observed in 9 cases (56%), including 5 p40-positive SqCCs (3 were nonkeratinizing), 1 p40-positive AdSqC (negative for TTF-1 and napsin A), and 1 AdC (solid), 1 LCC, and 1 SC, each negative for p40, TTF-1, and napsin A). Low-level GATA3 expression was found in 3 AdCs (1 was lepidic and 2 were acinar predominant), 2 SqCCs (keratinizing), 1 AdSqC, and 1 LCC. These findings indicate that GATA3 expression occurs in a minor but significant proportion of primary non-small cell lung carcinomas, most often involves SqCC, and tends to show increasing levels of expression in more poorly differentiated subtypes. Caution should be exercised when interpreting GATA3 expression, and a panel of immunostains should be utilized when assigning tumor origin.

A Case of GATA3 Positive Pleomorphic Liposarcoma, Epithelioid Variant: A Diagnostic Pitfall

Pleomorphic liposarcoma is a rare malignant adipocytic tumor showing undifferentiated pleomorphic sarcoma morphology with various degrees of epithelioid features. It is sometimes difficult to distinguish from carcinoma metastasis. Immunohistochemical panel is very important for differential diagnosis; however, there is a risk that unexpected staining could lead to misinterpretation. We report a pleomorphic liposarcoma, epithelioid variant, in an 88-year-old man, with tricky-positive staining for GATA3. Histological examination revealed a tumor with epithelioid morphology. The tumor consists of solid sheets of epithelioid tumor cells with focal aggregates of pleomorphic lipoblasts. Immunohistochemically, the adipocytic tumor cell areas were positive for S100 protein, and the epithelioid tumor cells showed CAM 5.2 positivity. GATA3 was diffusely positive. The combination of CAM 5.2 and GATA3 staining suggested the possibility of metastatic cancer, but systemic clinical examinations did not detect any presence of a primary tumor, including urinary bladder, breasts, and salivary glands. The pathological diagnosis of pleomorphic liposarcoma, epithelioid variant, was made because of the presence of malignant lipoblasts. Our report may contribute for differential diagnosis of pleomorphic liposarcoma, epithelioid variant, with unexpected positive immunoreaction for GATA3.

Pitfalls in breast pathology

Accurate pathological diagnosis is the cornerstone of optimal clinical management for patients with breast disease. As non-operative diagnosis has now become the standard of care, histopathologists encounter the daily challenge of making definitive diagnoses on limited breast core needle biopsy (CNB) material. CNB samples are carefully evaluated using microscopic examination of haematoxylin and eosin (H&E)-stained slides and supportive immunohistochemistry (IHC), providing the necessary information to inform the next steps in the patient care pathway. Some entities may be difficult to distinguish on small tissue samples, and if there is uncertainty a diagnostic excision biopsy should be recommended. This review discusses (1) benign breast lesions that may mimic malignancy, (2) malignant conditions that may be misinterpreted as benign, (3) malignant conditions that may be incorrectly diagnosed as primary breast carcinoma, and (4) some IHC pitfalls. The aim of the review is to raise awareness of potential pitfalls in the interpretation of breast lesions that may lead to underdiagnosis, overdiagnosis, or incorrect classification of malignancy with potential adverse outcomes for individual patients.

A pilot study: Comparison of TRPS1 and GATA3 immunoperoxidase staining using cytologic smears in entities reportedly positive for GATA3

BACKGROUND

Metastatic breast carcinoma (mBC) is frequently encountered and may be challenging to diagnose as the tumor cells can morphologically resemble carcinomas of other primary origins. An additional challenge is that direct smears are often the only sample type available for immunostaining studies in cytology. Trichorhinophalangeal syndrome GATA-binding type 1 1 (TRPS1) is a highly sensitive marker for BC compared to the commonly used marker GATA3, especially in triple-negative BC (TNBC), in histologic samples. However, its sensitivity and specificity in mBC and other GATA3-positive tumors have not been studied.

METHODS

The authors identified the following cytology cases: 37 GATA3-positive mBC cases and 19 available cases that were deemed mBC but were GATA3-negative during the original case workup and five cases of each of eight epithelioid entities known to have high rates of GATA3 positivity and commonly seen in cytology practice. Immunostainings of TRPS1 and GATA3 were performed on the chosen smears following standard protocols.

RESULTS

TRPS1 was positive in all 37 GATA3-positive mBC cases and in 18 of the 19 GATA3-negative mBC cases. TRPS1 was negative in all five of the seven frequently GATA3-positive epithelioid entities, with the exception of salivary duct carcinomas where GATA3 was positive in a rate ranging 60%-100% among them.

CONCLUSIONS

TRPS1 is as sensitive as GATA3 in GATA3-positive mBC and is more sensitive than GATA3 in TNBC. TRPS1 is negative in most GATA3-positive nonbreast tumors. Thus, the combination of TRPS1 and GATA3 could be used to differentiate breast primary from others in most situations.

Value of Proline, Glutamic Acid, and Leucine-Rich Protein 1 and GATA Binding Protein 3 Expression in Breast Cancer: An Immunohistochemical study

GATA binding protein 3 was more sensitive than traditional markers such as gross cystic disease fluid protein 15 and mammaglobin for identifying primary and metastatic breast carcinomas, but its significance decreased in triple-negative breast cancer. Recent studies showed a high expression rate of proline glutamic acid and leucine-rich protein in breast cancer and their superiority over GATA3 in triple-negative breast cancer. Our study provided new insights into the diagnostic and prognostic roles of PELP1 and GATA3 in primary and metastatic breast cancer. An immunohistochemical assay was carried out using PELP1 and GATA3 in 60 cases of primary breast cancer and 15 metastatic. Invasive carcinoma of no special type was the predominant type (80%). The majority of cases were grade 3 (68.3%). GATA3 expression was 83.3% positive in primary breast carcinomas and 73.5% positive in metastatic breast carcinomas. In comparison, PELP1 had a 96.7% positive expression rate in primary breast carcinomas and an 86.7% positive expression rate in metastasis. There was a statistically significant agreement between GATA3 and PELP1 in the diagnosis of the cases. PELP1 is a significantly higher proportion of both primary and metastatic breast carcinomas than GATA3. In breast cancer, there was a strong association between favorable prognostic factors and GATA3 expression, with evidence of an inverse association with Ki-67 overexpression.

Utility of TRPS-1 immunohistochemistry in diagnosis of metastatic breast carcinoma in cytology specimens

INTRODUCTION

At present, GATA binding protein 3 (GATA-3) is the most frequently used diagnostic immunohistochemical (IHC) marker for breast carcinoma (BC). However, it is not specific and has very low sensitivity for triple-negative BC (TNBC). SRY-box transcription factor 10 (SOX-10) and trichorhinophalangeal syndrome type 1 (TRPS-1) have been suggested for inclusion in the diagnostic workup of TNBC. TRPS-1 has not been established in cytology specimens as a diagnostic IHC marker for metastatic BC (MBC). Hence, in the present study we evaluated the utility of TRPS-1 in diagnosing MBC in cytology specimens.

MATERIALS AND METHODS

MBC cases diagnosed on cytology specimens from January to October 2020 were included in the present study. Only cases with hormonal status available and ≥20 tumor cells on cell blocks were included in the study. The cell blocks were assessed for TRPS-1, GATA-3, and SOX-10 IHC marker positivity (intensity and percentage of tumor cells). The results were correlated with the specimen type (fine needle aspiration [FNA] versus body fluid) and various BC prognostic subgroups.

RESULTS

We analyzed 61 cases, including 33 body fluid and 28 FNA (13 lymph node, 10 bone, 2 liver, 2 soft tissue, and 1 lung) specimens. TRPS-1 had 97.2% positivity in ER/PR+ (estrogen receptor/progesterone receptor-positive) MBC compared with GATA-3, which had 100% positivity in the same group. TRPS-1 showed high positivity in 35 of 37 cases (94.6%) and intermediate positivity in 1 (2.6%) and was negative/low positive in 1 case (2.7%). In contrast, GATA-3 showed high positivity for all 37 cases (100%). SOX-10 showed positivity in only 1 of 37 cases (2.7%), with intermediate positivity. In the HER2+ (human epidermal growth factor receptor 2-positive) group, TRPS-1 showed high positivity in 5 of 7 cases (71.4%), intermediate positivity in 1 case (14.3%), and negativity in 1 case (14.3%). However, GATA-3 showed high positivity in 6 of 7 cases (85.7%) and negative/low positivity in 1 case (14.3%). SOX-10 was negative in all 7 cases. In TNBC, TRPS-1 showed high positivity in 16 of 17 cases (94%) and intermediate positivity in 1 (5.9%), and GATA-3 showed high positivity in 9 (53%), intermediate positivity in 2 (11.8%), and low positive/negative in 6 of the 17 cases (35.3%). TRPS-1 expression was significantly higher than GATA-3 expression for the number of positive cases (P = 0.07), mean percentage of positive tumor cells (P = 0.005), and intensity of reactivity (P = 0.005). SOX-10 expression was present in only 5 of 17 cases (29%), with a mean percentage of positivity in the tumor cells of 26.5% and intensity of 0.8. No differences were found in the IHC results between the different specimen types (FNA versus fluid) in any group.

CONCLUSIONS

TRPS-1 is a highly sensitive new diagnostic IHC marker for breast carcinoma, with a similar positivity rate in ER/PR+ and HER2+ BC compared with GATA-3 and a higher positivity rate than GATA-3 and SOX-10 in TNBC in cytology specimens. In particular, when only a few clusters of tumor cells are present on the cell block, TRPS-1 can be highly useful, because its mean percentage of positive tumor cells and intensity are higher than those of other IHC markers.

Clinicopathological and Molecular Features of Secondary Cancer (Metastasis) to the Thyroid and Advances in Management

Secondary tumours to the thyroid gland are uncommon and often incidentally discovered on imaging. Symptomatic patients often present with a neck mass. Collision tumours of secondary tumours and primary thyroid neoplasms do occur. Ultrasound-guided fine-needle aspiration, core-needle biopsy, and surgical resection with histological and immunohistochemical analysis are employed to confirm diagnosis as well as for applying molecular studies to identify candidates for targeted therapy. Biopsy at the metastatic site can identify mutations (such as EGFR, K-Ras, VHL) and translocations (such as EML4-ALK fusion) important in planning target therapies. Patients with advanced-stage primary cancers, widespread dissemination, or unknown primary origin often have a poor prognosis. Those with isolated metastasis to the thyroid have better survival outcomes and are more likely to undergo thyroid resection. Systemic therapies, such as chemotherapy and hormonal therapy, are often used as adjuvant treatment post-operatively or in patients with disseminated disease. New targeted therapies, such as tyrosine kinase inhibitors and immune checkpoint inhibitors, have shown success in reported cases. A tailored treatment plan based on primary tumour features, overall cancer burden, and co-morbidities is imperative. To conclude, secondary cancer to the thyroid is uncommon, and awareness of the updates on diagnosis and management is needed.

Lobular Carcinoma of the Breast Metastatic to the Ovary: A Clinicopathologic Study of 38 Cases

We evaluated the clinicopathologic features of 38 cases of metastatic lobular (n=33) or predominantly lobular (n=5) carcinoma involving the ovary. The patients were from 39 to 91 years of age (mean: 53 y). In 2 cases, the breast primary and ovarian metastasis were diagnosed synchronously, and in 5, the breast primary was only discovered after the metastatic carcinoma in the ovary was found. In the majority of cases (79%), both ovaries were involved; the mean ovarian tumor size was 5.9 cm. The ovarian tumors demonstrated a range of architectural patterns including macronodular (71%), diffuse/solid growth (87%), single-cell infiltration (87%), cords (74%), and small nests/clusters (50%). Nine cases demonstrated focal signet ring cell morphology. The associated stromal reaction ranged from none to marked, with almost half of cases demonstrating a marked stromal response, largely prominent sclerosis. A variety of neoplasms, most typically sex cord-stromal tumors, lymphoma/leukemia, and desmoplastic small round cell tumor, may enter the differential. In addition to the obvious help afforded in most cases by the clinical history, a combination of judicious sampling, particularly to unearth the delicate cords or single-cell growth of lobular carcinoma, appropriate consideration of the cytologic features of the neoplastic cells, and immunohistochemistry can resolve the diverse issues in differential diagnosis that may arise.

Impact of immunohistochemistry-based subtyping of GATA3, CK20, CK5/6, and CK14 expression on survival after radical cystectomy for muscle-invasive bladder cancer

Molecular subtyping of muscle-invasive bladder cancer (MIBC) predicts disease progression and treatment response. However, standard subtyping based on transcriptomic analysis is relatively expensive. This study tried to use immunohistochemistry (IHC) to subtype MIBC based on GATA3, CK20, CK5/6, and CK14 protein expression. The IHC-based subtypes in MIBC subtypes were classified as luminal (GATA3⁺ CK5/6⁻, 38.6%), basal (GATA3⁻CK5/6⁺, 12.9%), mixed (GATA3⁺ CK5/6⁺, 37.9%), and double-negative (GATA3⁻CK5/6⁻, 10.6%) in 132 MIBC patients. All individual markers and clinicopathological parameters were analyzed against treatment outcomes after radical cystectomy. The mean patient age was 65.6 years, and the male to female ratio was 6.8:1. Positive IHC expression of GATA3, CK20, CK5/6, and CK14 were 80.3%, 50.8%, 42.4%, and 28.0%, respectively. Only GATA3 and CK5/6 were significantly associated with survival outcome (p values = 0.004 and 0.02). The mixed subtype was significantly better in 5-year OS at 42.8%, whereas the double-negative subtype had the worst prognosis (5-year OS 7.14%). The double-negative subtype had a hazard ratio of 3.29 (95% CI 1.71–6.32). Subtyping using GATA3 and CK5/6 was applicable in MIBCs, and patients with the double-negative subtype were at the highest risk and may require more intensive therapy.

Diagnostic utility of the combined use of HNF4A and GATA3 in distinction between primary and metastatic breast and gastric carcinomas

Sometimes the distinction between gastric adenocarcinomas and breast carcinomas can be challenging. Hepatocyte nuclear factor 4-alpha (HNF4A) has been suggested as a potential marker in these cases. The aim of the present work was to evaluate the role of the combined use of HNF4A and GATA3 as immunohistochemical markers in distinction between primary and metastatic breast and gastric carcinomas. This retrospective study was conducted on (81) cases divided into four groups of cohorts: primary BC (cohort I, n = 25), primary GC (cohort II, n = 23), and metastases derived from both types of tumors designated as metastasis derived from BC (cohort III-A, n = 17) and metastasis derived from GC (cohort III-B, n = 16). We performed immunohistochemistry analysis of HNF4A and GATA3 in all (81) cases. HNF4A expression was seen in 22 of 23 primary gastric adenocarcinomas and was absent in all 25 primary breast carcinomas (sensitivity 95.7%, specificity 100%). HNF4A was seen in 15 of 16 metastatic gastric adenocarcinomas and was absent in all 17 metastatic breast carcinomas (sensitivity 93.8%, specificity 100%). GATA3 showed 92 and 88% sensitivity, and 95.7 and 100% specificity for primary breast carcinomas and metastatic breast carcinomas, respectively. Our data confirmed the potential utility of HNF4A as a diagnostic marker and can be used as an adjunct to GATA3 as an immunohistochemical panel to differentiate between breast and gastric carcinomas.

Chromatin interaction neural network (ChINN): a machine learning-based method for predicting chromatin interactions from DNA sequences

Chromatin interactions play important roles in regulating gene expression. However, the availability of genome-wide chromatin interaction data is limited. We develop a computational method, chromatin interaction neural network (ChINN), to predict chromatin interactions between open chromatin regions using only DNA sequences. ChINN predicts CTCF- and RNA polymerase II-associated and Hi-C chromatin interactions. ChINN shows good across-sample performances and captures various sequence features for chromatin interaction prediction. We apply ChINN to 6 chronic lymphocytic leukemia (CLL) patient samples and a published cohort of 84 CLL open chromatin samples. Our results demonstrate extensive heterogeneity in chromatin interactions among CLL patient samples.

Neuroendocrine Neoplasm of the Breast Presenting as a Liver Metastasis: A Rare Diagnostic Challenge

We present a case of a 58-year-old female who presented initially to an outside institution with abdominal pain and was diagnosed on liver biopsy with a well-differentiated neuroendocrine tumor of an unknown primary source. She was referred to our academic institution for a second opinion after disease progression on the initial chemotherapy regimen. Through additional evaluation, diagnostics, and multi-disciplinary tumor board discussion she was diagnosed with metastases from a well-differentiated neuroendocrine neoplasm of the breast (NENB). Consequently, her treatment plan was modified leading to significant clinical and radiological improvement.

Expression Analysis of Long Non-Coding RNAs Related With FOXM1, GATA3, FOXA1 and ESR1 in Breast Tissues

Breast cancer is the most common neoplasm among females. Estrogen receptor (ESR) signaling has a prominent impact in the pathogenesis of breast cancer. Among the transcription factors associated with ESR signaling, FOXM1, GATA3, FOXA1 and ESR1 have been suggested as a candidate in the pathogenesis of this neoplasm. In the current project, we have designed an in silico approach to find long non-coding RNAs (lncRNAs) that regulate these transcription factors. Then, we used clinical samples to carry out validation of our in silico findings. Our systems biology method led to the identification of APTR, AC144450.1, linc00663, ZNF337.AS1, and RAMP2.AS1 lncRNAs. Subsequently, we assessed the expression of these genes in breast cancer tissues compared with the adjacent non-cancerous tissues (ANCTs). Expression of GATA3 was significantly higher in breast cancer tissues compared with ANCTs (Ratio of mean expressions (RME) = 4.99, P value = 3.12E−04). Moreover, expression levels of APTR, AC144450.1, and ZNF337.AS1 were elevated in breast cancer tissues compared with control tissues (RME = 2.27, P value = 5.40E−03; Ratio of mean expressions = 615.95, P value = 7.39E−19 and RME = 1.78, P value = 3.40E−02, respectively). On the other hand, the expression of RAMP2.AS1 was lower in breast cancer tissues than controls (RME = 0.31, P value = 1.87E−03). Expression levels of FOXA1, ESR1, and FOXM1 and linc00663 were not significantly different between the two sets of samples. Expression of GATA3 was significantly associated with stage (P value = 4.77E−02). Moreover, expressions of FOXA1 and RAMP2.AS1 were associated with the mitotic rate (P values = 2.18E−02 and 1.77E−02, respectively). Finally, expressions of FOXM1 and ZNF337.AS1 were associated with breastfeeding duration (P values = 3.88E−02 and 4.33E−02, respectively). Based on the area under receiver operating characteristics curves, AC144450.1 had the optimal diagnostic power in differentiating between cancerous and non-cancerous tissues (AUC = 0.95, Sensitivity = 0.90, Specificity = 0.96). The combination of expression levels of all genes slightly increased the diagnostic power (AUC = 0.96). While there were several significant pairwise correlations between expression levels of genes in non-tumoral tissues, the most robust correlation was identified between linc00663 and RAMP2.AS1 (r = 0.61, P value = 3.08E−8). In the breast cancer tissues, the strongest correlations were reported between FOXM1/ZNF337.AS1 and FOXM1/RAMP2.AS1 pairs (r = 0.51, P value = 4.79E−5 and r = 0.51, P value = 6.39E−5, respectively). The current investigation suggests future assessment of the functional role of APTR, AC144450.1 and ZNF337.AS1 in the development of breast neoplasms.

TRPS1: a highly sensitive and specific marker for breast carcinoma, especially for triple-negative breast cancer

Currently there is no highly specific and sensitive marker to identify breast cancer-the most common malignancy in women. Breast cancer can be categorized as estrogen receptor (ER)/progesterone receptor (PR)-positive luminal, human epidermal growth factor receptor 2 (HER2)-positive, or triple-negative breast cancer (TNBC) types based on the expression of ER, PR, and HER2. Although GATA3 is the most widely used tumor marker at present to determine the breast origin, which has been shown to be an excellent marker for ER-positive and low-grade breast cancer, but it does not work well for TNBC with sensitivity as low as <20% in metaplastic breast carcinoma. In the current study, through TCGA data mining we identified trichorhinophalangeal syndrome type 1 (TRPS1) as a specific gene for breast carcinoma across 31 solid tumor types. Moreover, high mRNA level of TRPS1 was found in all four subtypes of breast carcinoma including ER/PR-positive luminal A and B types, HER2-positive type, and basal-type/TNBC. We then analyzed TRPS1 expression in 479 cases of various types of breast cancer using immunochemistry staining, and found that TRPS1 and GATA3 had comparable positive expression in ER-positive (98% vs. 95%) and HER2-positive (87% vs. 88%) breast carcinomas. However, TRPS1 which was highly expressed in TNBC, was significantly higher than GATA3 expression in metaplastic (86% vs. 21%) and nonmetaplastic (86% vs. 51%) TNBC. In addition, TRPS1 expression was evaluated in 1234 cases of solid tumor from different organs. In contrast to the high expression of GATA3 in urothelial carcinoma, TRPS1 showed no or little expression in urothelial carcinomas or in other tumor types including lung adenocarcinoma, pancreatic adenocarcinoma, colon and gastric adenocarcinoma, renal cell carcinoma, melanoma, and ovarian carcinoma. These findings suggest that TRPS1 is a highly sensitive and specific marker for breast carcinoma and can be used as a great diagnostic tool, especially for TNBC.

GATA binding protein 3 (GATA3) as a marker for metaplastic spindle cell carcinoma of the breast

Spindle cell lesions of the breast comprise a diverse set of tumors; harboring significant histological and immunohistochemical (IHC) overlap. Accurate diagnosis and classification of spindle cell lesions in the breast remains challenging, especially in core biopsies. In the current study, we evaluated a spectrum of spindle cell lesion of the breast with a panel of IHC antibodies in an effort to differentiate metaplastic spindle cell carcinoma from its benign and malignant mimickers. Our study included 92 patients who underwent breast core biopsies or breast resections at Northwell Health who were diagnosed with benign and malignant tumor/tumor-like spindle cell lesions. Tumors subtypes in this the study included: angiosarcoma, nodular fasciitis, fibromatosis, myofibroblastoma, phyllodes tumors (benign, borderline and malignant), primary sarcomas and metaplastic spindle cell carcinoma. Our biomarker panel included high molecular weight keratin (HMWK), CAM5.2, AE1/AE3, p63, CD34 and GATA3. GATA3 expression was significantly higher in metaplastic carcinomas (88.9 % vs 4.1 %, p < 0.001), when compared to other spindle cell lesions. The sensitivity and specificity for detecting metaplastic carcinomas reached 84.2 % and 97.3 %, respectively. Regarding cytokeratin panels, none of the three individual markers were as sensitive or specific for metaplastic breast carcinoma. GATA3 is the most specific and sensitive marker forfor the identification of metaplastic spindle cell carcinoma of the breast.

GREB1: An evolutionarily conserved protein with a glycosyltransferase domain links ERα glycosylation and stability to cancer

What covalent modifications control the temporal ubiquitination of ERα and hence the duration of its transcriptional activity remain poorly understood. We show that GREB1, an ERα-inducible enzyme, catalyzes O-GlcNAcylation of ERα at residues T553/S554, which stabilizes ERα protein by inhibiting association with the ubiquitin ligase ZNF598. Loss of GREB1-mediated glycosylation of ERα results in reduced cellular ERα levels and insensitivity to estrogen. Higher GREB1 expression in ERα^+ve breast cancer is associated with greater survival in response to tamoxifen, an ERα agonist. Mice lacking Greb1 exhibit growth and fertility defects reminiscent of phenotypes in ERα-null mice. In summary, this study identifies GREB1, a protein with an evolutionarily conserved domain related to DNA-modifying glycosyltransferases of bacteriophages and kinetoplastids, as the first inducible and the only other (apart from OGT) O-GlcNAc glycosyltransferase in mammalian cytoplasm and ERα as its first substrate.

Endosalpingiosis Is Negative for GATA3

CONTEXT.—

Endosalpingiosis is a benign Müllerian inclusion that can mimic metastatic low-grade mammary carcinoma, particularly when encountered in axillary lymph nodes excised for breast cancer staging. Immunohistochemistry can be useful in histologically ambiguous cases, and a targeted immunopanel should include a marker of gynecologic tract origin and a marker of mammary origin. GATA3 is a sensitive immunomarker for breast carcinoma, but the immunoreactivity of GATA3 in endosalpingiosis has not been systematically evaluated.

OBJECTIVE.—

To evaluate whether GATA3 immunohistochemistry could be used to differentiate endosalpingiosis from metastatic mammary carcinoma.

DESIGN.—

Whole slide sections of 15 cases of endosalpingiosis involving nonneoplastic tissues were subjected to GATA3 immunohistochemistry. Nuclear GATA3 labeling was scored as percentage and intensity labeling, with any labeling considered positive; GATA3 labeling was recorded in all cells present in the sections.

RESULTS.—

Half (47%, n = 7 of 15) of the endosalpingiosis cases involved lymph nodes (2 axillary, 5 pelvic) and half (53%, n = 8 of 15) involved pelvic organs or soft tissue (3 myometrial, 2 paratubal, 2 periadnexal soft tissue, and 1 pelvic sidewall). GATA3 immunohistochemistry was negative in all cases of endosalpingiosis, with intact, positive control labeling in lymphocytes. The benign fallopian tube epithelium present on the sections of paratubal endosalpingiosis displayed focal (<5%), weak labeling for GATA3, specifically within the ciliated and secretory cells.

CONCLUSIONS.—

These findings support the diagnostic utility of GATA3 immunohistochemistry and its use in a targeted immunopanel to resolve the differential diagnosis of metastatic low-grade mammary carcinoma (GATA3+) and nodal endosalpingiosis (GATA3-).

Cancer of Unknown Primary: Challenges and Progress in Clinical Management

Simple Summary

Patients with cancer of unknown primary site suffer the burden of an uncertain disease, which is characterized by the impossibility to identify the tissue where the tumor has originated. The identification of the primary site of a tumor is of great importance for the patient to have access to site-specific treatments and be enrolled in clinical trials. Therefore, patients with cancer of unknown primary have reduced therapeutic opportunities and poor prognosis. Advancements have been made in the molecular characterization of this tumor, which could be used to infer the tumor site-of-origin and thus broaden the diagnostic outcome. Moreover, we describe here the novel therapeutic opportunities that are based on the genetic and immunophenotypic characterization of the tumor, and thus independent from the tumor type, which could provide most benefit to patients with cancer of unknown primary.

Abstract

Distant metastases are the main cause of cancer-related deaths in patients with advanced tumors. A standard diagnostic workup usually contains the identification of the tissue-of-origin of metastatic tumors, although under certain circumstances, it remains elusive. This disease setting is defined as cancer of unknown primary (CUP). Accounting for approximately 3–5% of all cancer diagnoses, CUPs are characterized by an aggressive clinical behavior and represent a real therapeutic challenge. The lack of determination of a tissue of origin precludes CUP patients from specific evidence-based therapeutic options or access to clinical trial, which significantly impacts their life expectancy. In the era of precision medicine, it is essential to characterize CUP molecular features, including the expression profile of non-coding RNAs, to improve our understanding of CUP biology and identify novel therapeutic strategies. This review article sheds light on this enigmatic disease by summarizing the current knowledge on CUPs focusing on recent discoveries and emerging diagnostic strategies.

Integrative Generalized Convex Clustering Optimization and Feature Selection for Mixed Multi-View Data

In mixed multi-view data, multiple sets of diverse features are measured on the same set of samples. By integrating all available data sources, we seek to discover common group structure among the samples that may be hidden in individualistic cluster analyses of a single data view. While several techniques for such integrative clustering have been explored, we propose and develop a convex formalization that enjoys strong empirical performance and inherits the mathematical properties of increasingly popular convex clustering methods. Specifically, our Integrative Generalized Convex Clustering Optimization (iGecco) method employs different convex distances, losses, or divergences for each of the different data views with a joint convex fusion penalty that leads to common groups. Additionally, integrating mixed multi-view data is often challenging when each data source is high-dimensional. To perform feature selection in such scenarios, we develop an adaptive shifted group-lasso penalty that selects features by shrinking them towards their loss-specific centers. Our so-called iGecco+ approach selects features from each data view that are best for determining the groups, often leading to improved integrative clustering. To solve our problem, we develop a new type of generalized multi-block ADMM algorithm using sub-problem approximations that more efficiently fits our model for big data sets. Through a series of numerical experiments and real data examples on text mining and genomics, we show that iGecco+ achieves superior empirical performance for high-dimensional mixed multi-view data.

Novel uses of immunohistochemistry in breast pathology: interpretation and pitfalls

Immunohistochemistry is an essential component of diagnostic breast pathology. The emergence of novel assays and applications is accompanied by new interpretation criteria and potential pitfalls. Immunohistochemistry assists in supporting breast origin for primary or metastatic carcinomas and identifying non-mammary metastases to the breast; however, no single immunostain is perfectly sensitive nor specific. GATA3 and Sox10 are particularly useful immunostains to identify triple negative breast carcinoma, which are often negative for other markers of mammary differentiation. Sox10 labeling is a major potential diagnostic pitfall, as Sox10 and S-100 label both triple negative breast carcinoma and metastatic melanoma; a pan-cytokeratin immunostain should always be included for this differential diagnosis. Novel immunohistochemistry serves as surrogates for the molecular alterations unique to several of special-type breast carcinomas, including the use of MYB in adenoid cystic carcinoma, pan-TRK in secretory carcinoma, and mutant IDH2 in tall cell carcinoma with reversed polarity (TCCRP). In addition, PD-L1 immunohistochemistry is an emerging, albeit imperfect, biomarker for breast cancer immunotherapy, with different assay parameters and scoring criteria in breast carcinoma compared to other tumor types. The expanding repertoire of novel immunohistochemistry provides additional diagnostic tools and biomarkers that improve diagnostic breast pathology and patient care.

Coexpress of GATA-3 and ER in Anorectal and Head and Neck Squamous Cell Carcinoma Mimicking Metastatic Breast Cancer

GATA binding protein 3 (GATA-3) is a sensitive marker for breast and urothelial carcinomas. In combination with the estrogen receptor (ER), it is often used for differential diagnosis of metastatic carcinomas of breast origin. In this study, we sought to characterize GATA-3 and ER expression in squamous cell carcinoma (SqCC) of various origins to compare with breast carcinoma. Sixty-four SqCC of anorectum (35), head and neck (15), lung (11), and breast (3) as well as urothelial carcinoma (31) were included. In anorectal and head and neck SqCC, GATA-3, and ER was observed in 23/50 (46.0%) and 18/50 (36.0%) of the cases, respectively. The expression of GATA-3 and ER were present in both male and female patients without significant sex predominance. In 2 metastatic SqCC, the GATA-3 and ER expressed similar immunoreactivity compatible with their anorectal primary. Progesterone receptor was only expressed in 2 anorectal SqCC and none of head and neck SqCC or urothelial carcinomas. None of the lung SqCC expressed GATA-3 or ER (0/11). p16 was expressed in the majority of head and neck (6/12) and anorectal SqCC (26/27). Our study demonstrated that the combination of GATA-3 and ER positivity is not entirely specific for breast carcinomas, since both stains are expressed in SqCC from anorectal and head and neck origins. Clinical workup for metastatic carcinoma of suspicious breast origin should be cognizant of other tumors with a similar immunohistochemical profile (ie, SqCC).

Role of immunohistochemistry in gynec oncopathology including specific diagnostic scenarios with associated treatment implications

Over the years, immunohistochemistry has emerged as a powerful tool for a more precise diagnosis of certain tumors in gynecologic oncopathology and resolving certain diagnostic dilemmas with significant treatment implications. Certain specific immunohistochemical (IHC) markers have been useful in the more correct identification of rare tumors, characterized by specific molecular signatures. Immunohistochemistry has also been useful in the identification of underlying genetic events, characterizing various tumors, as well as precancerous lesions. This review will focus upon the judicious application of various IHC antibody markers in gynec oncopathology, including authors' experience during "sign-outs" and especially during interaction with other oncology colleagues within the institutional disease management group. The updated references were retrieved from PubMed.

Immunohistological expression of oestrogen receptor, progesterone receptor, mammaglobin, human epidermal growth factor receptor 2 and GATA-binding protein 3 in non-small-cell lung cancer

AIMS

Non-small-cell lung cancer (NSCLC) and breast cancer are common entities. Staining for oestrogen receptor (ER), progesterone receptor (PgR), mammaglobin (MAMG) and GATA-binding protein 3 (GATA3) is frequently performed to confirm a mammary origin in the appropriate diagnostic setting. However, comprehensive data on the immunohistological expression of these markers in NSCLC are limited. Therefore, the aim of this study was to analyse a large cohort of NSCLCs and correlate the staining results with clinicopathological variables.

METHODS AND RESULTS

A tissue microarray was stained for ER, PgR, MAMG, human epidermal growth factor receptor 2 (HER2), and GATA3, and included 636 adenocarcinomas (ADCs), 536 squamous cell carcinomas (SqCCs), 65 large-cell-carcinomas, 34 pleomorphic carcinomas, and 20 large-cell neuroendocrine carcinomas. HER2 status was determined for immunohistochemically positive cases with chromogenic in-situ hybridisation. Markers with a proportion of ≥5% positive cases in ADC and SqCC were considered for survival analysis. Among ADCs, 62 (10%), 17 (3%), one (<1%), seven (1%), and 49 (8%) cases were positive for ER, PgR, MAMG, HER2, and GATA3, respectively. Among SqCCs, 10 (2%), 14 (3%), two (<1%) and 109 (20%) cases were positive for ER, PgR, HER2, and GATA3, but none of the samples showed positivity for MAMG. ER positivity was associated with ADC, female sex, smaller tumour size, and lower clinical stage. None of the markers had an impact on survival.

CONCLUSION

We report on ER, PgR, MAMG, HER2 and GATA3 expression in a large cohort of NSCLCs. Interpretation of these markers in the differential diagnostic setting should be based on a multimarker panel.

Sry-related high-mobility-group/HMG box 10 (SOX10) as a sensitive marker for triple-negative breast cancer

AIMS

Confirmation of a breast origin for triple-negative breast cancer (TNBC) is sometimes problematic. The traditional breast markers GATA-binding protein 3 (GATA3), mammaglobin (MGB) and gross cystic disease fluid protein 15 (GCDFP15) have shown limitations in identifying TNBC. Here, we aimed to examine the diagnostic potential of the newly proposed TNBC marker, Sry-related high-mobility-group/HMG box 10 (SOX10).

METHODS AND RESULTS

We analysed and compared SOX10 expression with GATA3, MGB and GCDFP15 expression in a test cohort of 1838 invasive breast cancers (IBCs) by using tissue microarrays. The findings from the test cohort were further examined with a validation cohort of 42 TNBCs in whole sections. The overall expression rates of SOX10, GATA3, MGB and GCDFP15 were 6.9%, 83.1%, 47.0%, and 34.8%, respectively. Among the TNBCs within this cohort, the expression rates of SOX10, GATA3, MGB and GCDFP15 were 31.3%, 34.5%, 27.9%, and 25.2%, respectively. SOX10 was strongly associated with TNBC (P < 0.001), whereas all other traditional markers were associated with non-TNBC (P < 0.001 for all). In addition, SOX10 was more correlated to basal-like breast cancer (BLBC) (P = 0.001) than five-marker-negative subtype among the TNBCs. A high expression rate of SOX10 (81%) was confirmed in the validation cohort. Additionally, SOX10 expression was inversely correlated with GATA3 and GCDFP15 expression, so they may complement each other in TNBC detection. The SOX10-GATA3 combination yielded a sensitivity of 60.3% for TNBC detection in the test cohort.

CONCLUSION

SOX10 is a reliable marker for identifying TNBC, and complements GATA3. The SOX10-GATA3 combination may be used as a sensitive TNBC marker.

A Neural Network Framework for Predicting the Tissue-of-Origin of 15 Common Cancer Types Based on RNA-Seq Data

Sequencing-based identification of tumor tissue-of-origin (TOO) is critical for patients with cancer of unknown primary lesions. Even if the TOO of a tumor can be diagnosed by clinicopathological observation, reevaluations by computational methods can help avoid misdiagnosis. In this study, we developed a neural network (NN) framework using the expression of a 150-gene panel to infer the tumor TOO for 15 common solid tumor cancer types, including lung, breast, liver, colorectal, gastroesophageal, ovarian, cervical, endometrial, pancreatic, bladder, head and neck, thyroid, prostate, kidney, and brain cancers. To begin with, we downloaded the RNA-Seq data of 7,460 primary tumor samples across the above mentioned 15 cancer types, with each type of cancer having between 142 and 1,052 samples, from the cancer genome atlas. Then, we performed feature selection by the Pearson correlation method and performed a 150-gene panel analysis; the genes were significantly enriched in the GO:2001242 Regulation of intrinsic apoptotic signaling pathway and the GO:0009755 Hormone-mediated signaling pathway and other similar functions. Next, we developed a novel NN model using the 150 genes to predict tumor TOO for the 15 cancer types. The average prediction sensitivity and precision of the framework are 93.36 and 94.07%, respectively, for the 7,460 tumor samples based on the 10-fold cross-validation; however, the prediction sensitivity and precision for a few specific cancers, like prostate cancer, reached 100%. We also tested the trained model on a 20-sample independent dataset with metastatic tumor, and achieved an 80% accuracy. In summary, we present here a highly accurate method to infer tumor TOO, which has potential clinical implementation.

High-Grade Endometrioid Carcinoma of the Endometrium With a GATA-3-Positive/PAX8-Negative Immunophenotype Metastatic to the Breast: A Potential Diagnostic Pitfall

This report describes clinicopathologic findings from the case of a patient with a breast mass that was ultimately diagnosed as a metastatic high-grade endometrioid carcinoma of endometrial origin. The breast lesion as well as the solid areas of the endometrial lesion displayed a similar immunoprofile: GATA3-positive; synaptophysin positive; negative for mammaglobin, gross cystic disease fluid protein-15, chromogranin, estrogen receptor, progesterone receptor, and HER2/neu; and intact expression of the DNA mismatch repair proteins MLH1, MSH2, MSH6, and PMS2. The breast lesion was negative for PAX-8, whereas the solid areas of the endometrial lesion showed focal weak positivity. A review of the literature on GATA-3 expression in endometrial carcinomas found a reported frequency of expression that ranged from 0% to 13% of cases, typically in a patchy, focal, and generally restricted pattern. However, GATA-3 may be diffusely expressed in high-grade endometrial carcinomas. Since the potential for PAX-8 expression to be lost in high-grade endometrioid carcinomas is well known, a GATA-3-positive/PAX8-negative immunoprofile may be encountered in high-grade endometrioid carcinomas of the endometrium, and this composite immunoprofile is a potential diagnostic pitfall when such a lesion is being evaluated in a breast metastasis.

GATA3 Expression in Common Gynecologic Carcinomas: A Potential Pitfall

GATA binding protein 3 (GATA3) immunohistochemistry is primarily used as a marker of breast and urothelial differentiation, particularly in metastatic settings. In the gynecologic tract it also serves a robust marker for mesonephric and trophoblastic tumors. However, expression has also been described in more common malignancies of gynecologic tract including ovarian, endometrial, and cervical carcinomas. Data on the distribution of GATA3 expression in gynecologic malignancies is somewhat limited, particularly across different histologic subtypes of ovarian, endometrial, and cervical carcinomas. To assess the rates of GATA3 expression among common gynecologic cancers of various histologic types, 100 ovarian carcinomas, 64 endometrial carcinomas/atypical hyperplasias, 16 cervical squamous cell carcinomas (SCCs), and 14 endocervical adenocarcinomas were evaluated by immunohistochemistry for GATA3 positivity. Eight percent of endometrial carcinomas expressed GATA3, including 2 serous carcinomas, 1 carcinosarcoma, and 1 case of atypical hyperplasia. Six percent of ovarian carcinomas were GATA3-positive including 2 clear cell carcinomas, 2 mucinous adenocarcinomas, and 2 high-grade serous carcinomas. Thirty-eight percent of cervical SCCs showed weak to moderate staining in up to 50% of tumor cells. All endocervical adenocarcinomas were entirely negative for GATA3. In summary, GATA3 shows focal weak to moderate expression in a subset of endometrial and ovarian carcinomas. In contrast, usual-type endocervical adenocarcinomas are typically negative for GATA3, which can be helpful in differentiating them from mesonephric proliferations or carcinomas. A larger proportion of cervical SCCs express GATA3, therefore caution should be exercised when using this stain in the setting of a lower genitourinary carcinomas.

SOX10, GATA3, GCDFP15, Androgen Receptor, and Mammaglobin for the Differential Diagnosis Between Triple-negative Breast Cancer and TTF1-negative Lung Adenocarcinoma

Triple-negative breast cancer (TNBC) patients have an increased risk of developing visceral metastases and other primary nonbreast cancers, particularly lung cancer. The differential diagnosis of TNBC metastases and primary cancers from other organs can be difficult due to lack of a TNBC standard immunoprofile. We analyzed the diagnostic value of estrogen receptor, progesterone receptor, human epidermal growth factor receptor, thyroid transcription factor-1 (TTF1), Napsin A, mammaglobin, gross cystic disease fluid protein 15 (GCDFP15), Sry-related HMg-Box gene 10 (SOX10), GATA-binding protein 3 (GATA3), and androgen receptor in a series of 207 TNBC and 152 primary lung adenocarcinomas (LA). All tested TNBCs were TTF1 and Napsin A-negative. When comparing TNBC and TTF1-positive or negative LA, SOX10 had the best sensitivity (62.3%) and specificity (100%) as a marker in favor of TNBC compared with LA, irrespective of TTF1 status (P<0.0001). GATA3 had moderate sensitivity (30.4%) and excellent specificity (98.7%) and misclassified only 2/152 LA (1.3%). GCDFP15 had a moderate sensitivity (20.8%) and excellent specificity (98%) and misclassified only 3/152 (2%) LA. Mammaglobin and androgen receptor had moderate sensitivities (38.2% and 30%), good specificities (81.6% and 86%), and misclassified 28/152 and 21/152 LAs, respectively. In multivariate analysis, the best markers, enabling the distinction between SOX10-negative TNBC and TTF1 and Napsin A-negative LA were GATA3 (odds ratio=33.5; 95% confidence interval, 7.3-153.5; P<0.0001) and GCDFP15 (odds ratio=31.7; 95% confidence interval, 6.9-145.6; P<0.0001). Only 13/207 (6.3%) TNBC cases did not express any aforementioned marker. On the basis of our results, the best sequential immunohistochemical analysis to differentiate TNBC from TTF1-negative LA is first SOX10 followed by GATA3, and finally GCDFP15. This order is important in the diagnostic workup of small biopsies from lung nodules in women with a previous history of TNBC.

Combined use of SOX10 and GATA3 in mammary carcinoma

The complementary coverage of different subsets of breast cancer by GATA3 and SOX10 makes their use in combination appealing for routine clinical use, but study of these markers has been largely limited to cases with high or absent ER expression. Here we report SOX10 and GATA3 immunostaining in parallel using a tissue microarray containing 246 invasive breast carcinoma cases with a range of ER expression. GATA3 and SOX10 were positive in 93 % (229/246) and 15 % (38/246) of cases overall and in 63 % (24/38) and 74 % (28/38) of triple negative breast carcinomas (TNBC), respectively; SOX10 was positive in 15 of the 17 cases that lacked GATA3 expression (88 %). SOX10 was also positive in 3 % (6/196) of ER + cases, including 50 % of cases with low ER (3/6), 20 % with intermediate ER (3/15), and 0 % with high ER (n = 175), so that ER-low cases more strongly resembled TNBC than those with high ER expression. GATA3 expression was lower in cases that co-expressed SOX10 in comparison to those that were positive for GATA3 alone. Less than 1 % (2/246) of cases were negative for both GATA3 and SOX10. Therefore, SOX10 is a useful adjunct to GATA3 in the detection of TNBC and cases with low ER expression and/or reduced GATA3 intensity relative to that typical of breast cancers with higher ER expression. Moreover, given such high sensitivity, metastatic tumors lacking either GATA3 or SOX10 are unlikely to be of breast origin. Additional study is necessary to determine the extent to which SOX10 may also improve specificity and to characterize its biologic significance in breast cancers with low ER expression.