Cytokeratin 7: a re‐evaluation of the ‘tried and true’ in triple‐negative breast cancers

Davion S M, Siziopikou K P & Sullivan M E
(2012) Histopathology  61, 660–666 Cytokeratin 7: a re‐evaluation of the ‘tried and true’ in triple‐negative breast cancers Aims: Triple‐negative breast cancers (TNBCs) are often poorly differentiated tumours that can present clinically as metastases of an unknown primary. Immunohistochemical panels are frequently used to determine the likelihood of a breast primary, but in this tumour subset cytokeratin (CK)7 may be the only positive finding. In this study we aimed to evaluate a commonly employed immunohistochemical panel using a large group of TNBCs (both basal‐like and unclassified), and to analyse the CK7 staining patterns. Methods and results: Tissue microarrays containing 138 TNBCs were stained with antibodies against CK7, CK20, gross cystic disease fluid protein 15 (GCDFP‐15), and mammaglobin. CK5/6 staining was used to identify basal‐like tumours. CK7 staining was notably heterogeneous, with 14.5% of all cases demonstrating ≤20% tumour cell staining. A greater proportion of basal‐like TNBCs than of unclassified TNBCs showed focal staining. GCDFP‐15 and mammaglobin were not expressed in the majority of TNBCs, and were less frequently positive in basal‐like than in unclassified TNBCs. Conclusions: TNBCs are commonly negative for most immunomarkers indicative of breast origin, with the exception of CK7. As about one in five TNBCs showed only focal CK7 positivity, use of this marker must be interpreted with caution, especially in small samples, so that the possibility of a breast primary is not overlooked.     

Diagnostic utility of mammaglobin and GCDFP‐15 in the identification of metastatic breast carcinoma in fluid specimens

Morphologic differentiation of breast carcinoma from nonmammary malignancies in fluid specimens can be a diagnostic challenge. Immunocytochemistry is often employed in the differential diagnosis. In this study, we evaluated the expression of mammoglobin (MGB1) in body‐cavity fluid specimens and compared its efficacy as a marker for metastatic breast carcinomas with that of gross cystic disease fluid protein‐15 (GCDFP‐15). Cell blocks from 40 fluid specimens were immunostained with monoclonal antibodies against MGB1 and GCDFP‐15. They included 15 breast carcinomas and 25 nonmammary carcinomas (10 lungs, 10 ovaries, 3 gastrointestinal tracts, 1 kidney, and 1 urinary bladder). Positivity was defined as the presence of cytoplasmic staining in 10% or more carcinoma cells. Thirteen (87%) and seven (47%) breast carcinomas showed positive staining with MGB1 and GCDFP‐15, respectively. Three (12%) nonmammary carcinomas (2 ovarian and 1 colonic) showed positive MGB1 staining; one (3%) nonmammary carcinoma demonstrated positive GCDFP‐15 staining. The differences of MGB1 and GCDFP‐15 staining between breast and nonmammary carcinomas were statistically significant (P < 0.05). Both MGB1 and GCDFP‐15 are specific markers for metastatic breast carcinomas in cell block fluid specimens (88 vs. 96%). However, MGB1 is more sensitive than GCDFP‐15 as a marker for metastatic breast carcinoma (87 vs. 46%). Diagn. Cytopathol. 2009. © 2009 Wiley‐Liss, Inc.     

Secondary breast cancer: a 5‐year population‐based study with review of the literature

Secondary tumours in the breast are rare. Based on literature, an incidence of 0.4–2% is reported. In this population‐based study, secondary breast tumours from a 5‐year period (2001–2005), not including metastasis from contralateral breast carcinoma, were reviewed (Vestfold County, Norway). A total of 722 patients with breast malignancies were found in this population (89.3% from Vestfold County Hospital). Ten of these, approximately 1.4%, were metastatic tumours, representing four cutaneous melanomas, three pulmonary carcinomas and three malignant lymphomas. The tumours were often solitary, palpable and close to the skin. Radiologically, the lesions mostly resembled primary carcinomas by mammography and ultrasound, which differs from other studies. Comparison with a known primary tumour and use of immunohistochemical profiling is of crucial importance. Melanoma markers (Melan‐A, HMB‐45, S‐100 protein), lung cancer markers (Cytokeratins, TTF1, Chromogranin, Synapthophysin) and lymphoid markers (CD3, CD20) usually help to confirm a secondary breast tumour diagnosis. This approach is especially indicated in diffusely growing tumours with lack of glandular structure and high‐grade cytological features, and staining for ER and GCDFP15 may be helpful. Thus, the diagnosis of a breast metastasis may be suspected by careful mammography and ultrasound imaging, although some cases have atypical radiological features, and histological examination might be necessary to ensure a correct diagnosis and appropriate treatment.     

Evaluation of androgen receptor and GATA binding protein 3 as immunohistochemical markers in the diagnosis of metastatic breast carcinoma to the lung

Differentiating metastatic breast carcinoma in the lungs from primary lung tumors and mesotheliomas is important for determining prognosis and treatment. We evaluated novel breast specific markers, androgen receptor (AR) and GATA binding protein 3 (GATA3) immunohistostaining, for this differential, and compare to other traditional markers. The specimens comprised 33 metastatic breast carcinomas to the lung, 566 primary lung tumors (170 adenocarcinomas, 157 squamous cell carcinomas, 31 pleomorphic carcinomas, 115 large cell neuroendocrine carcinomas, 43 small cell carcinomas, and 49 typical carcinoids) and 42 malignant mesotheliomas. They were analyzed by immunohistochemistry using antibodies to AR, GATA3, estrogen receptor (ER), progesterone receptor (PgR), mammaglobin, gross cystic disease fluid protein‐15 (GCDFP‐15). Of the metastatic breast carcinomas, immunohistostaining of AR, GATA3, ER, PgR, mammaglobin, GCDFP‐15 were positive in 27 cases (81.8%), 24 cases (72.7%), 26 cases (78.8%), 13 cases (39.4%), 12 cases (36.4%), 9 cases (27.3%), respectively. Of primary lung tumors and mesotheliomas, staining of AR, GATA3, ER, PgR, mammaglobin, GCDFP‐15 were positive in 18 cases (3%), 3 cases (0.5%), 4 cases (0.7%), 2 cases (0.3%), 0 case (0%), 2 cases (0.3%), respectively. Immunohistochemistry of AR and GATA3 are reliable for differentiating metastatic breast carcinoma from primary lung tumors and mesotheliomas.     

Metastatic metaplastic breast carcinoma mimicking pulmonary squamous cell carcinoma on fine‐needle aspiration

Metaplastic squamous cell carcinoma (SCC) of the breast is a rare type of breast cancer. Metastases to the lung, which can be a major site of second primary tumor development among breast cancer patients, are difficult to distinguish from primary SCC of the lung and present a unique challenge for pathologists. There are few available discriminating immunohistochemical markers as squamous differentiation typically leads to loss of expression of characteristic primary epithelial cell markers of both breast and lung origin. GATA protein binding 3 (GATA‐3) is a useful marker of breast origin in metastatic ductal and lobular carcinomas including poorly differentiated triple‐negative carcinomas and some metaplastic carcinomas. Here, we present a case of metastatic SCC presenting as a solitary lung mass with regional lymph node metastases and a single satellite lesion in a patient with a history of metaplastic SCC of the breast. In addition to the routine markers of squamous differentiation, the metastases were also positive for estrogen receptor (ER) and GATA‐3 on cytologic material obtained by transbronchial FNA. This suggests that immunoreactivity for ER and GATA‐3 may support a diagnosis of metastatic SCC in the context of a prior metaplastic SCC of the breast. Diagn. Cytopathol. 2015;43:844–849. © 2015 Wiley Periodicals, Inc.     

Insulin growth factor receptor‐1 expression and loss of PTEN protein predict early recurrence in triple‐negative breast cancer

Iqbal J, Thike A A, Cheok P Y, Tse G M‐K & Tan P H
(2012) Histopathology  61, 652–659 Insulin growth factor receptor‐1 expression and loss of PTEN protein predict early recurrence in triple‐negative breast cancer Aims: Insulin‐like growth factor receptor‐1 (IGFR‐1) and its signalling axis promote tumorigenesis, metastasis, and resistance to existing forms of cancer therapy, and have become a major focus for the development of anticancer drugs. As oncological management options for triple‐negative breast cancers (TNBCs) are limited, there is potential for the rapid development of novel selective anticancer agents specifically targeting components of the PTEN–phosphoinositide 3‐kinase–AKT pathway, including the phosphorylated form of AKT (pAKT) and the tumour suppressor molecule PTEN. The aim of this study was to conduct immunohistochemical analyses to examine the levels of PTEN, IGFR‐1 and pAKT expression in TNBCs, and determine whether these levels correlated with poor prognosis in this subset of aggressive breast cancers. Methods and results: Immunohistochemistry was performed on paraffin‐embedded tumour tissues from a consecutive cohort of 144 female patients diagnosed with TNBC. Associations of IGFR‐1, PTEN and pAKT expression with clinicopathological parameters, disease‐free survival (DFS) and overall survival (OS) were evaluated. There were significant increases in IGFR‐1 expression (99%) and pAKT expression (92%) with concomitant loss of PTEN expression in the majority of cases (63%). Increased IGFR‐1 expression and loss of PTEN expression were associated with reduced OS and DFS, respectively. pAKT expression showed a strong correlation with basal‐like expression. Combinatorial immunophenotypic analyses showed that loss of PTEN expression with concomitant IGFR‐1 expression correlated with poor DFS. Conclusions: A high percentage of PTEN loss with overexpression of IGFR‐1 and pAKT in TNBC indicates the potential of these molecules for predicting early recurrence and/or as targets in the formulation of effective alternative therapy regimens.     

P‐cadherin functional role is dependent on E‐cadherin cellular context: a proof of concept using the breast cancer model

P‐cadherin overexpression is associated with worse breast cancer survival, being a poor prognostic marker as well as a putative therapeutic target for the aggressive triple‐negative and basal‐like carcinomas (TNBCs). Previously, we have shown that P‐cadherin promotes breast cancer invasion of cells where membrane E‐cadherin was maintained; however, it suppresses invasion in models without endogenous cadherins, like melanomas. Here, we investigated if P‐cadherin expression would interfere with the normal adhesion complex and which were the cellular/molecular consequences, constituting, in this way, a new mechanism by which E‐cadherin invasive‐suppressor function was disrupted. Using breast TNBC models, we demonstrated, for the first time, that P‐cadherin co‐localizes with E‐cadherin, promoting cell invasion due to the disruption caused in the interaction between E‐cadherin and cytoplasmic catenins. P‐cadherin also induces cell migration and survival, modifying the expression profile of cells expressing wild‐type E‐cadherin and contributing to alter their cellular behaviour. Additionally, E‐ and P‐cadherin co‐expressing cells significantly enhanced in vivo tumour growth, compared with cells expressing only E‐ or only P‐cadherin. Finally, we still found that co‐expression of both molecules was significantly correlated with high‐grade breast carcinomas, biologically aggressive, and with poor patient survival, being a strong prognostic factor in this disease. Our results show a role for E‐ and P‐cadherin co‐expression in breast cancer progression and highlight the potential benefit of targeting P‐cadherin in the aggressive tumours expressing high levels of this protein. Copyright © 2012 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.     

αB-crystallin is a useful marker for triple negative and basal breast cancers

Tsang J Y S, Lai M W H, Wong K H Y, Chan S‐K, Lam C C F, Tsang A K H, Yu A M C, Tan P‐H & Tse G M
(2012) Histopathology  61, 378–386 αB‐crystallin is a useful marker for triple negative and basal breast cancers Aims: Basal‐like breast cancers (BLBCs), a breast cancer subtype with triple‐negative status, pose significant problems in clinical management because of their aggressive behaviour. Recently, an association between αΒ‐crystallin expression and BLBCs has been suggested, and we therefore investigated whether αΒ‐crystallin could be a putative marker allowing BLBCs to be identified more accurately. Methods and results: We evaluated the expression of αB‐crystallin and other biomarkers in 395 cases of breast carcinoma by immunohistochemistry, analysed the correlation of their expression with different breast cancer subtypes, and compared their sensitivity as well as specificity in identifying BLBCs. αΒ‐crystallin expression was found to be correlated positively with basal markers and histological subtypes associated with BLBCs. A significant positive correlation of αΒ‐crystallin expression was also found with triple‐negative breast cancers (TNBC) (C = 0.409, P < 0.001) and BLBCs (C = 0.393, P < 0.001). Comparing αΒ‐crystallin with other basal markers, only αΒ‐crystallin demonstrated both high sensitivity (48.6%) and specificity (93.8%) as a TNBC marker. All other markers showed either a lower sensitivity of <40% or a lower specificity of <90%. αΒ‐crystallin also demonstrated a high specificity (92.9%) and an even higher sensitivity (56.5%) for BLBCs. Conclusions: The findings indicated that αB‐crystallin was a highly sensitive and specific marker for TNBCs and BLBCs.     

Microglandular adenosis associated with triple‐negative breast cancer is a neoplastic lesion of triple‐negative phenotype harbouring TP53 somatic mutations

Microglandular adenosis (MGA) is a rare proliferative lesion of the breast composed of small glands lacking myoepithelial cells and lined by S100‐positive, oestrogen receptor (ER)‐negative, progesterone receptor (PR)‐negative, and HER2‐negative epithelial cells. There is evidence to suggest that MGA may constitute a non‐obligate precursor of triple‐negative breast cancer (TNBC). We sought to define the genomic landscape of pure MGA and of MGA, atypical MGA (AMGA) and associated TNBCs, and to determine whether synchronous MGA, AMGA, and TNBCs would be clonally related. Two pure MGAs and eight cases of MGA and/or AMGA associated with in situ or invasive TNBC were collected, microdissected, and subjected to massively parallel sequencing targeting all coding regions of 236 genes recurrently mutated in breast cancer or related to DNA repair. Pure MGAs lacked clonal non‐synonymous somatic mutations and displayed limited copy number alterations (CNAs); conversely, all MGAs (n = 7) and AMGAs (n = 3) associated with TNBC harboured at least one somatic non‐synonymous mutation (range 3–14 and 1–10, respectively). In all cases where TNBCs were analyzed, identical TP53 mutations and similar patterns of gene CNAs were found in the MGA and/or AMGA and in the associated TNBC. In the MGA/AMGA associated with TNBC lacking TP53 mutations, somatic mutations affecting PI3K pathway‐related genes (eg PTEN, PIK3CA, and INPP4B) and tyrosine kinase receptor signalling‐related genes (eg ERBB3 and FGFR2) were identified. At diagnosis, MGAs associated with TNBC were found to display subclonal populations, and clonal shifts in the progression from MGA to AMGA and/or to TNBC were observed. Our results demonstrate the heterogeneity of MGAs, and that MGAs associated with TNBC, but not necessarily pure MGAs, are genetically advanced, clonal, and neoplastic lesions harbouring recurrent mutations in TP53 and/or other cancer genes, supporting the notion that a subset of MGAs and AMGAs may constitute non‐obligate precursors of TNBCs. Copyright © 2016 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.     

Angiopoietin‐2 mediates blood–brain barrier impairment and colonization of triple‐negative breast cancer cells in brain

Although the incidence of breast cancer metastasis (BCM) in brain has increased significantly in triple‐negative breast cancer (TNBC), the mechanisms remain elusive. Using in vivo mouse models for BCM in brain, we observed that TNBC cells crossed the blood–brain barrier (BBB), lodged in the brain microvasculature and remained adjacent to brain microvascular endothelial cells (BMECs). Breaching of the BBB in vivo by TNBCs resulted in increased BBB permeability and changes in ZO‐1 and claudin‐5 tight junction (TJ) protein structures. Angiopoietin‐2 expression was elevated in BMECs and was correlated with BBB disruption. Secreted Ang‐2 impaired TJ structures and increased BBB permeability. Treatment of mice with the neutralizing Ang‐2 peptibody trebananib prevented changes in the BBB integrity and BMEC destabilization, resulting in inhibition of TNBC colonization in brain. Thus, Ang‐2 is involved in initial steps of brain metastasis cascade, and inhibitors for Ang‐2 may serve as potential therapeutics for brain metastasis. Copyright © 2013 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.     

Mesothelial markers in high-grade breast carcinoma

Duhig E E, Kalpakos L, Yang I A & Clarke B E
(2011) Histopathology 59 , 957–964 Mesothelial markers in high‐grade breast carcinoma Aims: Advances in molecular profiling have subdivided breast carcinomas into distinct subtypes. Basal carcinomas are generally oestrogen receptor (ER)?progesterone receptor (PR)?/human epidermal growth factor receptor 2 (HER2)?, and cytokeratin (CK)5/6+. This profile overlaps with that of mesothelial cells. This study of high‐grade breast carcinomas was undertaken to determine the expression of mesothelial markers. Methods and results: Immunohistochemistry was performed on 23 basal‐like breast carcinomas and 30 high‐grade breast carcinomas with variable ER, PR and HER2 expression. The incidence of staining of CK5/6, CK14, calretinin, Wilms’ tumour 1 (WT1), thrombomodulin and epithelial membrane antigen was assessed statistically. CK14 staining was more specifically associated with triple‐negative tumours than CK5/6. Calretinin positivity was statistically associated with basal‐like carcinomas. WT1 and thrombomodulin expression was infrequent and limited to a small number of non‐basal carcinomas. Conclusions: There is an overlap between the immunophenotype of mesothelial cells and that of basal‐like carcinomas of breast. Positive calretinin and CK5/6 are not specific, and may be seen in both mesothelial cells and basal‐like breast carcinomas. Negative ER and PR of basal carcinomas may also bias the observer against a breast origin. However, other negative mesothelial markers, such as WT1 and thrombomodulin, may help point to the correct diagnosis.     

Prostate‐specific membrane antigen expression in tumor‐associated vasculature of breast cancers

Prostate‐specific membrane antigen (PSMA) has been found to be expressed in the tumor‐associated neovasculature of multiple solid tumor types including breast cancers. However, thus far, the number of cases studied from some tumor types has been limited. In this study, we set out to assess PSMA expression in the tumor‐associated vasculature associated with invasive breast carcinomas in a sizable cohort of patients. One hundred and six patients with AJCC stage 0‐IV breast cancer were identified. Ninety‐two of these patients had primary breast cancer [invasive breast carcinoma with or without co‐existing ductal carcinoma in situ (DCIS) (74) or DCIS alone (18)]. In addition, 14 patients with breast cancer metastases to the brain were identified. Immunohistochemical staining for PSMA and CD31 was performed on parallel representative tumor sections in each case. Tumor‐associated vascular endothelial cell PSMA immunoreactivity was semi‐quantitatively assessed based on two parameters: overall percent of endothelial positivity and staining intensity. PSMA expression for tumor‐associated vascular endothelial cells was scored 0 if there was no detectable PSMA expression, 1 if PSMA staining was detectable in 5–50%, and 2 if PSMA expression was positive in >50% of microvessels. CD 31 staining was concurrently reviewed to confirm the presence of vasculature in each case. Tumor‐associated vasculature was PSMA‐positive in 68/92 (74%) of primary breast cancers and in 14/14 (100%) of breast cancers metastatic to brain. PSMA was not detected in normal breast tissue or carcinoma cells. All but 2 cases (98%) showed absence of PSMA expression in normal breast tissue‐associated vasculature. The 10‐year overall survival was 88.7% (95% CI = 80.0%, 93.8%) in patients without brain metastases. When overall survival (OS) was stratified based on PSMA score group, patients with PSMA scores of 0, 1, and 2 had 10‐year OS of 95.8%, 96.0%, and 79.7%, respectively (p = 0.12). When PSMA scores of 0 and 1 were compared with 2, there was a statistically significant difference in OS (96.0% vs 79.7%, respectively, p = 0.05). Patients with a PSMA score of 2 had a significantly higher median tumor size compared with patients in the lower PSMA score groups (p = 0.04). Patients with higher nuclear grade were more likely to have a PSMA score of 2 compared with patients with lower nuclear grade (p < 0.0001). Patients with a PSMA score of 2 had a significantly higher median Ki‐67 proliferation index compared with patients in the lower PSMA score groups (p < 0.0001). Patients with estrogen receptor (ER)‐negative tumors were more likely to have a PSMA score of 2 compared with patients with ER‐positive tumors (p < 0.0001). Patients with progesterone receptor (PR)‐negative tumors were more likely to have a PSMA score of 2 compared with patients with PR‐positive tumors (p = 0.03). No significant association was observed between PSMA score group status and lymph node involvement (p = 0.95). Too little variability was present in Human epidermal growth factor receptor‐2 (Her2/neu) amplified tumors to correlate with PSMA score group status. To date, this is the first detailed assessment of PSMA expression in the tumor‐associated vasculature of primary and metastatic breast carcinomas. Further studies are needed to evaluate whether PSMA has diagnostic and/or potential therapeutic value.     

Expression of calretinin by breast carcinoma and the potential for misdiagnosis of mesothelioma

Powell G, Roche H & Roche W R
(2011) Histopathology 59 , 950–956 Expression of calretinin by breast carcinoma and the potential for misdiagnosis of mesothelioma Aims: Calretinin and cytokeratin (CK)5/6 are frequently used to differentiate between metastatic breast cancer and primary malignant mesothelioma in pleural biopsies, but both tumours may express these markers. This study was aimed at evaluating the frequency of calretinin expression in primary breast carcinomas, and assessing the characteristics of the calretinin‐positive tumours. Methods and results: Fifty‐three primary breast adenocarcinomas were analysed for immunohistochemical expression of calretinin. CK5/6 and epidermal growth factor receptor (EGFR) immunostaining were performed on the calretinin‐positive subset. Tumours were classified as basal‐like if they met standard morphological and immunohistochemical criteria. Fifteen per cent (8/53) of the breast tumours were positive for calretinin. Eighty‐eight per cent (7/8) of the calretinin‐positive tumours were grade 3, as compared with 20% (9/45) of the calretinin‐negative tumours (P < 0.001). Only 13% (1/8) of the calretinin‐positive tumours were also oestrogen receptor (ER)‐positive, as compared with 87% (39/45) of the calretinin‐negative tumours (P < 0.001). Eleven per cent (6/53) of the tumours were classified as basal‐like. Of these, four were positive for calretinin and two were negative (P = 0.003). Conclusions: Fifteen per cent of breast carcinomas stain with calretinin. These tumours are more likely to be high‐grade, ER‐negative, and display a basal‐like phenotype. These tumours may be misdiagnosed as malignant mesothelioma when they metastasize to the pleura.     

Expression of autophagy‐related markers beclin‐1, light chain 3A,light chain 3B and p62 according to the molecular subtype of breast cancer

Aims: To investigate the relationship between the expression of autophagy‐related proteins, including beclin‐1, light chain (LC) 3A, LC3B, and p62, and prognosis in invasive breast cancer. Methods and results: We constructed tissue microarrays from the breast cancer cells of 489 patients, and classified molecular subtypes using surrogate immunohistochemical stains. The tumoral expression levels of LC3A and LC3B were highest in triple‐negative breast cancer (TNBC) (P < 0.001), whereas these types of tumour had the lowest expression levels of these markers in the stroma (P = 0.005 and P < 0.001, respectively). Cytoplasmic beclin‐1 expression was highest in TNBC, but nuclear expression was lowest (P < 0.001). p62 cytoplasmic and nuclear expression were highest in HER2‐type tumours (P = 0.001 and P < 0.001, respectively). Tumoral LC3A and LC3B expression were associated with high histological grade (P < 0.001, and P < 0.028, respectively), but nuclear p62 expression was associated with lower histological grade (P = 0.004). Conclusions: Autophagy‐related markers are differentially expressed according to the molecular subtype of breast cancer. In particular, expression of LC3A, LC3B and beclin‐1 was highest in TNBC tumour cells, whereas that of LC3A and LC3B in the tumour stroma was lowest in TNBC.     

Cytoplasmic expression of high mobility group B1 (HMGB1) is associated with tumor‐infiltrating lymphocytes (TILs) in breast cancer

High mobility group box 1 (HMGB1) is a prototypic alarmin or damage‐associated molecule inducing inflammatory mediator release and immune response. Several studies have revealed the prognostic and predictive importance of tumor‐infiltrating lymphocytes (TILs) in breast cancer. The present study analyzed the expression of HMGB1 in each breast cancer subtype and the relationship between the expression level of HMGB1 and pathologic parameters including TILs. Two cohorts were studied: 575 consecutive breast cancer patients who underwent surgery between 1995 and 1998; and 767 triple negative breast cancer (TNBC) patients who underwent surgery between 2004 and 2010. The immunohistochemical expression level of HMGB1 in cytoplasm and nucleus was evaluated using tissue microarrays. High HMGB1 expression in cytoplasm was associated with high histologic grade, pT stage, and abundant TILs in the consecutive breast cancer cohort. Cytoplasmic HMGB1 expression was higher in TNBCs and HER2‐positive tumors than in hormone receptor‐positive tumors. In the TNBC cohort, high cytoplasmic HMGB1 expression was significantly associated with high histologic grade, abundant TILs, and high numbers of CD8+ cells. However, nuclear HMGB1 expression was not associated with histologic grade or TIL levels. Neither cytoplasmic nor nuclear expression of HMGB1 showed prognostic significance in TNBC. Cytoplasmic HMGB1 expression is associated with TIL levels in breast cancer.     

718例浸润性乳腺癌分子分型中CK5/6和EGFR的表达及临床病理分析

目的 探讨CK5/6和EGFR在浸润性乳腺癌(invasive breast carcinoma,IBC)分子分型中的表达及相关性.方法 采用免疫组化法检测718例IBC中CK5/6、EGFR、ER、PR、HER-2及Ki-67蛋白的表达,分析CK5/6、EGFR与IBC组织学类型、分子分型及其他相关标志物之间的关系....     

Salivary duct carcinomas can be classified into luminal androgen receptor‐positive,HER2 and basal‐like phenotypes*

Di Palma S, Simpson R H W, Marchiò C, Skálová A, Ungari M, Sandison A, Whitaker S, Parry S & Reis‐Filho J S
(2012) Histopathology  61, 629–643 Salivary duct carcinomas can be classified into luminal androgen receptor‐positive, HER2 and basal‐like phenotypes Aims: The aim of this study was to devise a molecular classification for salivary duct carcinomas (SDCs) based on the similarities between SDCs and breast carcinomas and on characteristics of the microarray‐based gene expression profiling‐defined molecular subtypes of breast cancer. Methods and results: Forty‐two pure salivary duct carcinomas, 35 of which contained an in‐situ component as defined by histological review and/or immunohistochemical analysis, were stained with antibodies for oestrogen receptor (ER), progesterone receptor (PR), androgen receptor (AR), human epidermal growth factor receptor 2 (HER2), epidermal growth factor receptor (EGFR) and cytokeratin (CK) 5/6. Based on these markers, tumours were classified into HER2, luminal androgen receptor‐positive, basal‐like, luminal and indeterminate phenotype. Analysis revealed that 16.7%, 69%, 4.8%, 9.5% and 0% were of HER2, luminal androgen receptor‐positive, basal‐like, indeterminate and luminal phenotype, respectively. The in‐situ and invasive components displayed the same molecular subtype in all but one case. Conclusions: Salivary duct carcinomas can be classified into molecular subgroups approximately equivalent to those in the breast. We also report on the existence of a subgroup of bona fide pure salivary duct carcinomas that have a ‘basal‐like’ phenotype. Understanding the phenotypic complexity of SDCs may help to expedite the identification of novel therapeutic targets for these aggressive tumours.     

The repertoire of somatic genetic alterations of acinic cell carcinomas of the breast: an exploratory,hypothesis‐generating study

Acinic cell carcinoma (ACC) of the breast is a rare form of triple‐negative (that is, oestrogen receptor‐negative, progesterone receptor‐negative, HER2‐negative) salivary gland‐type tumour displaying serous acinar differentiation. Despite its triple‐negative phenotype, breast ACCs are reported to have an indolent clinical behaviour. Here, we sought to define whether ACCs have a mutational repertoire distinct from that of other triple‐negative breast cancers (TNBCs). DNA was extracted from microdissected formalin‐fixed, paraffin‐embedded sections of tumour and normal tissue from two pure and six mixed breast ACCs. Each tumour component of the mixed cases was microdissected separately. Tumour and normal samples were subjected to targeted capture massively parallel sequencing targeting all exons of 254 genes, including genes most frequently mutated in breast cancer and related to DNA repair. Selected somatic mutations were validated by targeted amplicon resequencing and Sanger sequencing. Akin to other forms of TNBC, the most frequently mutated gene found in breast ACCs was TP53 (one pure and six mixed cases). Additional somatic mutations affecting breast cancer‐related genes found in ACCs included PIK3CA, MTOR, CTNNB1, BRCA1, ERBB4, ERBB3, INPP4B, and FGFR2. Copy number alteration analysis revealed complex patterns of gains and losses similar to those of common forms of TNBCs. Of the mixed cases analysed, identical somatic mutations were found in the acinic and the high‐grade non‐acinic components in two out of four cases analysed, providing evidence of their clonal relatedness. In conclusion, breast ACCs display the hallmark somatic genetic alterations found in high‐grade forms of TNBC, including complex patterns of gene copy number alterations and recurrent TP53 mutations. Furthermore, we provide circumstantial genetic evidence to suggest that ACCs may constitute the substrate for the development of more aggressive forms of triple‐negative disease. Copyright © 2015 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.