Reliability of Her2/neu, estrogen receptor, and progesterone receptor testing by immunohistochemistry on cell block of FNA and serous effusions from patients with primary and metastatic breast carcinoma

The prognostic and predictive value of Her2/neu and the hormone receptors in patient with primary or metastatic breast cancer is essential for a favorable outcome of treatment. We have been experiencing increasing requests to test cytologic specimens for these markers in patients with metastatic breast carcinoma. A recent study threw some doubts on the validity of such testing using cell blocks. In this study we compared our immunohistochemical Her2/neu, ER and PR testing performed on 42 formalin-fixed, paraffin-embedded cell blocks from 27 fine needle aspirations (FNA) and 15 serous effusions of 42 patients with metastatic (n = 38) and primary (n = 4) breast carcinoma to the test results obtained on tissue sections. In seven cases the Her2/neu immunohistochemistry (IHC) results on cell blocks were also compared with Her2/neu fluorescence in situ hybridization (FISH) on tissue or cell block. The study revealed 100% correlation for positive and negative Her2/neu results. For ER testing the results showed 85.7% sensitivity, 100% specificity, 100% positive predictive value (PPV), and 85.7% negative predictive value (NPV). For PR testing the results showed 80% sensitivity, 100% specificity, 100% PPV, and 88.8% NPV respectively. In conclusion, IHC for Her2/neu, ER and PR performed on formalin-fixed, paraffin-embedded cell blocks prepared from fresh FNA and serous fluid is reliable in predicting the expression of these markers when correlated with IHC and FISH performed on the corresponding tumor tissue.     

Association between tumour characteristics and HER-2/neu by immunohistochemistry in 1362 women with primary operable breast cancer

AIMS: To investigate the association between tumour characteristics and HER-2/neu by immunohistochemistry in primary operable breast cancer. METHODS: The association between HER-2/neu and other clinicopathological factors was evaluated in 1362 consecutive patients with primary breast cancer treated between 2000 and July 2003 in one centre. Microscopic tumour size, tumour grade, lymph node status, patient's age, oestrogen receptor (ER), progesterone receptor (PR), and joint ER/PR status were evaluated, using the chi2 test for univariate analysis and logistic regression for multivariate analysis. The hormone receptors and HER-2/neu were studied immunohistochemically. Using the HER-2/neu DAKO scoring system, scores of 0, 1+, or 2+ were defined as negative and 3+ as positive. Data for DAKO scores 2+/3+ versus 0/1+ are also presented. RESULTS: Hormone receptor negative breast cancers were more often HER-2/neu positive than hormone receptor positive cancers, both for ER (28.7% v 6.8%) and PR (19.9% v 5.9%). In multivariate analysis, both ER, PR, and tumour grade were independently associated with HER-2/neu. In ER+ tumours, HER-2/neu overexpression was significantly lower in PR+ than in PR- cases (11.5% v 5.4%). HER-2/neu overexpression (2.7%) was lowest in the large subgroup of ER+PR+ tumours with low tumour grade (grade 1-2), comprising 46.1% of all patients. CONCLUSIONS: ER, PR, and tumour grade are independent predictors for HER-2/neu overexpression in women with primary operable breast cancer. ER and PR are negatively associated with HER-2/neu, whereas tumour grade is positively associated with HER-2/neu. In women with ER+ tumours, PR status also affects the likelihood of HER-2/neu expression.     

Breast cancer in the elderly: a histological assessment

Aims:  To understand the correlation between the expression status of different biological markers in breast cancers in the elderly.
Methods and results:  Three hundred and ninety-seven cases were evaluated for expression of hormone receptors [oestrogen receptors (ER) α and β, progesterone receptor (PR)], basal markers [p63, cytokeratin (CK) 5/6 and CK14] and others (HER2/neu, synaptophysin and chromogranin). The expression rates were 60, 29, 25, 6, 14, 8, 28, 17 and 5%, respectively, for these markers. The expression of ER α and β, PR, synaptophysin and chromogranin at any level correlated with low nuclear or tumour grades, whereas the expression of HER2/neu, CK5/6 and CK14 at any level correlated with high nuclear grade. By using hierarchical clustering, groups of HER2, luminal and basal types were identified. In addition, a neuroendocrine group was also identified, being characterized by expression of synaptophysin, chromogranin, ER and PR, but not HER2/neu, and other basal cytokeratins. This group was associated with lower nuclear grade, and hence better prognosis.
Conclusions:  Breast cancer in the elderly shows similar molecular groupings as other breast cancers, with an additional neuroendocrine group that is associated with a favourable biological marker profile.     

Flow cytometry: a new approach for the molecular profiling of breast cancer

The established method in prognosis of breast cancer includes detection of molecular markers, such as the estrogen receptor (ER), progesterone receptor (PR), and HER-2/neu. These markers are routinely checked via immunohistochemistry (IHC). HER-2/neu is also detected by fluorescent in situ hybridization (FISH). Flow cytometric analysis has not yet been used for detection of such markers. Flow cytometry was performed on four established breast cancer cell lines: MCF7, T47D, BT474, MDA-MB-231, and on one normal breast epithelial cell line: MCF10A. Flow cytometric analysis was used for the detection of ER, PR, HER-2/neu, epidermal growth factor receptor (EGFR), and E-cadherin. Currently, EGFR and E-cadherin are not standard predictive factors in determining survival of breast cancer patients, but both may be beneficial to prognosis. Cells undergoing flow cytometric analysis lost marker expression with increasing passage number. The highest expression was found at cells passaged 0-1 times. MCF7, T47D, and BT474 all had similar marker expression patterns. E-cadherin demonstrated a strongly positive pattern with marker expression of 85-92% among the three cell lines. ER, PR, and HER-2/neu demonstrated a weakly positive expression pattern when compared with E-cadherin. Marker expression ranged from 15 to 61%. These three cell lines were almost negative for expression of EGFR where expression ranged from 0 to 6%. MDA-MB-231 had almost no expression of all 5 markers, with positive values ranging from 0 to 5%. MCF10A had weak positive to almost negative expression values of ER, PR, HER-2/neu, and E-cadherin, which ranged from 3 to 13%. EGFR, both surface and cytoplasmic markers, again were not expressed in MCF10A cells with an expression value of <1%. We found that ER, PR, and HER-2/neu marker expressions in 5 out of 5 cell lines were consistent with established expression patterns. EGFR and E-cadherin expression in 4 out of 5 cell lines were also consistent with established expression patterns. We have shown that flow cytometry provides quantitative data on expression patterns of important prognostic markers in breast cancer.     

Expression of E-cadherin and c-erbB-2/HER-2/neu oncoprotein in high-grade breast cancer

E-cadherin (E-CD) is an epithelial-specific cell adhesion molecule, whose expression is lost in invasive lobular (ILC) but not in invasive ductal carcinoma (IDC) of the breast. This cell adhesion system can be disrupted by tyrosine kinase c-erbB-2/HER-2/neu. We examined 106 cases of high-grade invasive breast cancer, including 91 IDCs, 12 ILCs and 3 pleomorphic lobular carcinomas (PLCs). We determined Nottingham histological grade and performed immunohistochemistry for estrogen and progesterone receptors (ER/PR), Ki-67, E-CD and c-erbB-2/HER-2/neu with subsequent fluorescence in situ hybridization. Amplification of c-erbB-2/HER-2/neu gene was observed in 55/91 (60.4%) of IDCs, 3/12 (25%) of ILCs and 1/3 (33.3%) of PLCs, and associated with positive axillary lymph nodes. E-CD expression was lost in 14/91 (15.4%) of IDCs, 10/12 (83.3%) of ILCs and 2/3 (66.7%) of PLCs. The loss of E-CD immunoreactivity in IDCs appeared to be associated with c-erbB-2/HER-2/neu gene amplification, negative ER/PR status and positive lymph nodes, whereas E-CD-positive ILCs tended to be HER-2/neu-positive. The biological significance of E-CD expression seems to be different in high-grade IDC and ILC. Oncogenic pathway mediated by c-erbB-2/HER-2/neu may affect the E-CD expression in most invasive ductal breast carcinomas in vivo.     

Pathological, clinical and prognostic characteristics of breast cancer in Central Sudan versus Northern Italy: implications for breast cancer in Africa

Aims:  In patients of Black African ethnicity, breast cancer is reportedly characterized by aggressive, poorly differentiated phenotype(s). To highlight possible differences between breast cancer in indigenous sub-Saharan African and European patients, two breast cancer case series, from Central Sudan (Khartoum) and Northern Italy (Milan), were compared for clinicopathological characteristics, expression of oestrogen receptor (ER), progesterone receptor (PR), Her-2/neu, basal cytokeratin (CK) 5/6 and CK17, and breast cancer subtypes.
Methods and results:  After careful antigen retrieval, 114 and 138 consecutive formalin-fixed paraffin-embedded (FFPE) breast cancer cases from the Radiation and Isotope Centre (Khartoum) and from MultiMedica (Milan), respectively, were screened by immunohistochemistry for ER, PR, Her-2/neu, CK5/6 and CK17. Compared with the Italian patients, the Sudanese patients were younger ( P  < 0.0001) and their tumours were larger ( P  < 0.0001), more advanced in stage ( P  < 0.00001), higher grade ( P  < 0.00001) and more frequently positive for nodal metastases ( P  < 0.00001). ER expression varied between the two series ( P  < 0.0008), but no significant differences were found for PR ( P  < 0.32), combined hormone receptors ( P  < 0.12), Her-2/neu ( P  < 0.09), CK5/6 ( P  < 0.1), CK17 ( P  = 0.4), combined basal CK status ( P  = 1) or breast cancer subtypes ( P  = 0.12).
Conclusion:  The differences between the Sudanese and Italian breast cancer series reflect stage at diagnosis rather than intrinsic biological characteristics. This may have relevant implications for breast cancer prevention and treatment in Africa.     

Androgen receptors are frequently expressed in mammary and extramammary Paget's disease.

Mammary Paget's disease and extramammary Paget's disease are rare intraepithelial neoplasms. Mammary Paget's disease is almost exclusively associated with underlying invasive breast carcinoma or high-grade ductal carcinoma in situ (DCIS G3). Extramammary Paget's disease arises in areas rich in apocrine glands and is suspected to have apocrine gland origin. The aim of the study was to investigate the presence of estrogen receptor (ER), progesterone receptor (PR), androgen receptor (AR) and Her2/neu in a large number of cases. We investigated 58 cases of mammary and 23 cases of extramammary Paget's disease. Formalin-fixed and paraffin-embedded tissues were analyzed using antibodies against AR, PR, ER and Her2/neu according to standardized procedures. In mammary Paget's disease, positive immunoreactions for Her2/neu, AR and ER were observed in 56 of 58 (97%), 51 of 58 (88%), and respectively in six of 58 (10%) cases. All cases of mammary Paget's disease were negative for PR and showed a coexpression of Her2/neu and AR in 51 out of 58 cases (88%). In extramammary Paget's disease, positive immunoreactions for AR, Her2/neu and ER were observed in 18 of 23 (78%), 12 of 23 (52%), and respectively in 1 of 23 (4%) cases. All cases of extramammary Paget's disease were negative for PR and showed a coexpression of AR and Her2/neu in 12 out of 23 cases (52%). In contrast to ER and PR, AR and Her2/neu are commonly expressed in mammary and extramammary Paget's disease. The knowledge about frequent expression of AR in Paget's disease could lead to the development of a new adjuvant therapy, particularly in patients with recurrent disease.     

P-cadherin and cytokeratin 5: useful adjunct markers to distinguish basal-like ductal carcinomas in situ

Gene expression profiles of invasive breast carcinomas have identified a subgroup of tumours with worse prognosis, which have been called "basal-like". These are characterized by a specific pattern of expression, being estrogen receptor (ER) and HER2 negative, and frequently expressing at least one basal marker such as basal cytokeratins or epidermal growth factor receptor (EGFR). Previously, our group characterized basal-like tumours in a series of invasive breast carcinomas using P-cadherin (P-CD), p63 and cytokeratin 5 (CK5). Based on that study, we hypothesized that those high-grade basal-like invasive carcinomas might have a pre-invasive counterpart, which could be identified using the same approach. A series of 79 ductal carcinomas in situ (DCIS) were classified into distinct subgroups according to their ER, HER2 and basal markers expression. Luminal DCIS expressed ER and constituted 64.6% of the series; the HER2 overexpressing tumours did not express ER and represented 25.3% of the cases, whereas 10.1% lack the expression of ER and HER2 and expressed at least one basal marker (P-CD, CK5, CK14, p63, vimentin and/or EGFR). These basal-like DCIS were mostly high-grade, with comedo-type necrosis, and consistently showed expression of P-CD and CK5. In conclusion, DCIS with a basal-like phenotype represent a small percentage in our series, being P-CD and CK5, the most useful adjunct markers to distinguish this subset of carcinomas in situ of the breast.     

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.     

Expression of cytokeratin markers, ER-alpha, PR, HER-2/neu, and EGFR in pure ductal carcinoma in situ (DCIS) and DCIS with co-existing invasive ductal carcinoma (IDC) of the breast

Previously, we showed that pure ductal carcinoma in situ (DCIS) of the breast can be divided into 3 subtypes (luminal, basal/stem, and null) based on the expression of 5 cytokeratin (CK) markers: CK5/6, CK14, CK17 (stem/basal), and CK8, CK18 (luminal). The distributions of CK subtypes were associated with nuclear grade and differential expression of estrogen receptor-alpha (ER-alpha), progesterone receptor (PR), HER-2/neu, and epidermal growth factor receptor (EGFR). In this study, we further explore the expression patterns of CK markers, ER-alpha, PR, HER-2/neu, and EGFR by immunohistochemical (IHC) analysis of 99 cases of pure DCIS and 96 cases of DCIS with co-existing invasive ductal carcinoma (DCIS/IDC). We show that between high-grade DCIS and DCIS/IDC, there are differential expression patterns for ER-alpha, PR, and EGFR in corresponding CK subtypes, suggesting that at least some pure DCIS is molecularly distinct from DCIS/IDC. In most cases there is a high degree of co-expression of these markers between DCIS and the co-existing IDC, suggesting that DCIS is frequently a precursor lesion for co-existing IDC. The rate of discordant expression of these markers is low and is more frequently associated with high-grade carcinoma, suggesting that other molecular pathways also may also be present. There are significant differences in the expression of these molecular markers between high-grade and non-high-grade carcinomas, supporting the view that high-grade and non-high-grade carcinomas of the breast are molecularly distinct entities.     

肿瘤干细胞相关标记物CD44及CD24在乳腺癌中的表达及其意义

目的探讨肿瘤干细胞相关标记物CD44及CD24在乳腺癌组织中的表达特点、CD44+/CD24-细胞与HER-2、ER、PR、CK5/6表达的相互关系及其与临床病理因素的关系。方法采用免疫组化SP单染及双染法检测42例乳腺导管原位癌及126例乳腺浸润性导管癌组织中CD44及CD24的表达情况,检测126例乳腺浸润性导管癌组织中HER-2、ER、PR、CK5/6表达状况以进行免疫分型。结果 (1)CD44阳性定位于癌细胞膜。在浸润癌中阳性率为56.3%,在导管原位癌中阳性率为85.7%。两者差异有显著性意义(P<0.05)。在不同分化程度的乳腺浸润性癌中,CD44阳性率分别为69.2%、58.1%及44.7%,差异有显著性意义(P<0.05)。(2)CD24阳性表达于非癌性乳腺组织中小管的腔缘;在癌组织中除腔缘阳性外,可出现膜质阳性。在浸润癌中阳性率为32.5%,在导管原位癌中阳性率为64.3%。两者差异有显著性意义(P<0.05)。(3)126例浸润性导管癌中CD44+/CD24-者65例,占51.6%;CD44+/CD24-阳性细胞在Luminal A型为47.5%、Luminal B型为42.9%、HER-...     

Predominance of the basal type and HER-2/neu type in brain metastasis from breast cancer.

Although breast cancer is the second most common cause of central nervous system (CNS) metastases with a notable increase of incidence, only few studies on brain-metastasizing breast cancer are available. In this immunohistochemical and fluorescence in situ hybridization (FISH) study, metastases to the CNS (n=85) and primary breast cancers, with known involvement of the CNS (n=44) including paired primary and metastasized tumours (n=23), were investigated retrospectively for the expression of oestrogen- (ER) and progesterone- (PR) hormone receptors, Her-2/neu, epidermal growth factor receptor (EGFR), Ki-67, and cytokeratins (CKs) 5/14. The majority of brain metastases were steroid hormone receptor negative (ER 66%, PR 82%) corresponding to the findings in primary tumours with known involvement of the CNS (68% ER-negative, 75% PR-negative). The frequency of HER-2/neu-overexpressing or -amplified cancers was increased in both groups (34 and 32%, respectively). EGFR expression was more frequent in metastases (41%) than in primary tumours (16%). The proportions of cases with a basal phenotype were 26 and 30%, respectively. In paired primary tumours and metastases to the CNS, constancy of Her-2/neu status was observed in 87% of cases with only one sample turning Her-2/neu-negative and two samples acquiring overexpression/amplification in brain metastases. In contrast, steroid hormone receptors exhibited more frequently a loss of expression (17%) than a gain (9%) with 74% revealing a constant phenotype. We conclude that brain-metastasizing breast cancer belongs predominantly to the basal type or Her-2/neu type. Primary and metastatic tumours differ from each other only in a minority of cases, leading rather to a loss of steroid hormone receptors and to a gain of EGFR and Her-2/neu.     

Cytokeratin profiles of male breast cancers

AIMS: The prognostic factors and expression of molecular markers in male breast carcinomas are similar to those in female breast cancers. The identification of distinct cytokeratin (CK) profiles (basal as opposed to luminal cells) helps to identify subsets of tumours with different clinical behaviour. The aim of this study was to investigate CK expression in male breast cancer. METHODS AND RESULTS: Thirty-two cases of male breast cancer were studied. The panel of CKs studied by immunohistochemistry included: 5/6, 14, 17, 18 and 19. Pathological findings and CK expression were analysed in all cases. Histological patterns included ductal carcinoma in situ, invasive ductal carcinoma and mixed patterns. Four cases were positive for CK5/6 and CK14, identifying a basal-like phenotype. CK17 was negative in all but two cases. All cases expressing either CK5/6 or CK14 were invasive carcinomas of high nuclear and histological grade and were also larger compared with the tumours not expressing CK5/6 and CK14. All tumours except three (also negative for CK5/6) expressed CK18 and CK19. The four basal-like tumours were negative for Her-2 expression. CONCLUSIONS: Male breast carcinomas have a basal-like phenotype that is similar in frequency to that of female breast carcinomas. The expression of CK5/6 and CK14 identifies a subset of pathologically aggressive male breast cancers.     

Estrogen,progesterone, and HER‐2 receptor immunostaining in cytology: The effect of varied fixation on human breast cancer cells

The ASCO/CAP Expert Panel recommends that all invasive breast carcinomas and breast cancer recurrences be tested for ER, PR and HER‐2 expression. The guidelines for testing of surgical specimens by immunohistochemistry (IHC) are well defined, whereas they are lacking for cytological samples. We evaluated various fixation protocols for optimal receptor testing by immunohistochemistry and immunocytochemistry (ICC) of human breast cancer cell lines MCF‐7 (ER/PR positive) and SKBR‐3 (overexpressing HER‐2). The cells were fixed in 10% neutral buffered formalin or Saccomanno Fixative (SF) for various time points, and either embedded in paraffin as cell blocks or prepared as cytospins. ER and PR slides were assigned a proportion score (PS; 0–5), an intensity score (IS; 0–3) and a total score (TS = PS + IS). Standard DAKO scoring system ranging from 0 to 3+ was used for the evaluation of HER‐2 staining. Human breast cancer cells stained successfully for ER, PR and HER‐2 when fixed in formalin and prepared as cell blocks. The optimal fixation time for formalin‐fixed cells ranged from 2 to 96 hours. Cells fixed in SF from 2 to 96 hours also stained well for ER and PR. However, SF produced variable results for HER‐2 staining; particularly, SF fixation beyond 24 hours caused false negative results. The interpretation of HER‐2 staining on cytospins was not feasible irrespective of the fixative and fixation time. In summary, formalin fixation from 2 to 96 hours and preparation of cells as cell blocks produces optimal results for ER, PR, and HER‐2 testing in human breast cancer cells. Diagn. Cytopathol. 2013;41:864–870. © 2013 Wiley Periodicals, Inc.     

Clinicopathologic significance of the basal-like subtype of breast cancer: a comparison with hormone receptor and Her2/neu-overexpressing phenotypes

DNA microarray profiling studies have led to the classification of invasive breast carcinoma into luminal/estrogen receptor-positive, normal breast-like, Her2/neu-overexpressing, and basal-like types. Among these groups, the basal-like subtype is associated with the poorest clinical outcome in Western countries. To date, the clinicopathologic characteristics of the basal-like carcinomas, compared with other subtypes, have not been described in the Korean population. In this study, we used tissue microarray to examine the expression of basal cytokeratins (CK) (CK5 and CK14) and luminal CK (CK8/18), epidermal growth factor receptor, c-kit, hormone receptors (HRs), p53, and Her2/neu in 776 consecutive patients diagnosed with invasive breast carcinoma from January 1993 to December 1998 and categorized these cases into 5 subgroups (basal-like, HR-expressing, Her2/neu-overexpressing, HR and Her2/neu-expressing, and null subtypes negative for all markers), based on the immunohistochemical data. We identified cases of 114 (14.7%) basal-like, 345 (44.5%) HR-expressing, 133 (17.1%) Her2/neu-overexpressing, 61 (7.8%) HR and Her2/neu-expressing, and 123 (15.9%) null subtypes. Histologically, most basal-like breast cancers were invasive ductal carcinoma, not otherwise specified (98 cases, 86.0%), with high nuclear and/or histologic grades, and most metaplastic carcinomas (6 [75.0%] of 8 cases) were the basal-like subtype. Both basal-like and Her2/neu-overexpressing subtypes were associated with larger tumor sizes (mean, 3.6 and 3.3 cm, respectively) than the HR-expressing group (mean, 2.8 cm) (P = .001 and P = .036, respectively). Nodal stage of Her2/neu-overexpressing subtype was higher than that of basal-like subtype; however, overall stage was not different between the 2 groups (P = .010 and .123, respectively). Distant metastasis was most frequently observed in the Her2/neu-overexpressing subtype (33.8%), which was prognostically the worst subgroup of breast cancers. In contrast to previous findings from Western countries, our analyses reveal that the Her2/neu status is the most important prognostic factor of breast cancers.     

Refinement of immunohistologic parameters for Her2/neu scoring validation by FISH and CISH.

The conventional method of scoring Her2/neu immunostaining is recognized to result in a high false-positive rate among 2+ cases when compared with results obtained with fluorescence in situ hybridization (FISH); however, costs and convenience dictates that immunohistochemistry remains the screening test for Her2/neu status in patients with breast cancer. We describe refined criteria for scoring of Her2/neu on the basis of anatomic localization rather than the subjective assessment of intensity. The presence of a circumferential tram track pattern that results from the staining of apposing cell membranes in >25% of the tumor cells was necessary for a 3+ score (Her2/neu overexpressed) and the presence of the tram track pattern in <25% was scored 2+ (equivocal); granular and fragmented membrane staining was scored 1+ (negative). The tram track pattern of Her2/neu overexpression showed 100% concordance with gene amplification. FISH and CISH testing in selected cases from the other categories validated the revised scoring method. These criteria reduced the numbers of equivocal staining cases that required FISH testing.     

Coordinated expression of ER, PR and HER2 define different prognostic subtypes among poorly differentiated breast carcinomas

Aims:  Histological grade is one of the most important prognostic factors in breast carcinomas, but poorly differentiated neoplasms still have quite heterogeneous biological behaviour, since they can be genetically classified as basal-like, HER2+ or even luminal. The aim was to analyse the frequency of oestrogen receptor (ER), progesterone receptor (PR) and HER2 expression profiles among breast carcinomas with <10% tubular formation, and their correlation with classic prognostic factors.
Methods and results:  One hundred and thirty-four samples of paraffin-embedded tumours were studied retrospectively. The tumours were classified in to four groups by their ER/PR/HER2 profile: (i) ER+ and/or PR+ but HER2−; (ii) ER+ and/or PR+ and HER2+; (iii) ER− and/or PR− but HER2+; and (iv) ER−, PR− and HER2− (triple-negative). The histological features of triple-negative and HER2+ carcinomas overlap. The only difference was the expression of basal cytokeratins (basal CK), which was more frequent among triple-negative carcinomas. Basal-CK expression defined a more aggressive group of tumours, according to the pathological features, regardless of the immunohistochemical profile.
Conclusions:  Group 1 and 2 tumours (ER+ and/or PR+ tumours with or without HER2 expression) were not statistically different, suggesting that poorly differentiated carcinomas with hormone receptors correspond to the luminal B type of tumour. Among poorly differentiated breast carcinomas, the classic profile associated with basal-CK identifies distinct subtypes equivalent to those seen by genetic classification.     

Expression of luminal and basal cytokeratins in human breast carcinoma

We have examined basal and luminal cell cytokeratin expression in 1944 cases of invasive breast carcinoma, using tissue microarray (TMA) technology, to determine the frequency of expression of each cytokeratin subtype, their relationships and prognostic relevance, if any. Expression was determined by immunocytochemistry staining using antibodies to the luminal cytokeratins (CKs) 7/8, 18 and 19 and the basal markers CK 5/6 and CK 14. Additionally, assessment of alpha-smooth muscle actin (SMA) and oestrogen receptor status (ER) was performed. The vast majority of the cases showed positivity for CK 7/8, 18 and 19 indicating a differentiated glandular phenotype, a finding associated with good prognosis, ER positivity and older patient age. In contrast, basal marker expression was significantly related to poor prognosis, ER negativity and younger patient age. Multivariate analysis showed that CK 5/6 was an independent indicator for relapse free interval. We were able to subgroup the cases into four distinct phenotype categories (pure luminal, mixed luminal/basal, pure basal and null), which had significant differences in relation to the biological features and the clinical course of the disease. Tumours classified as expressing a basal phenotype (the combined luminal plus basal and the pure basal) were in a poor prognostic subgroup, typically ER negative in most cases. These findings provide further evidence that breast cancer has distinct differentiation subclasses that have both biological and clinical relevance.     

Pathobiologic findings in DCIS of the breast: morphologic features, angiogenesis, HER-2/neu and hormone receptors.

With the increasing incidence of ductal carcinoma in situ (DCIS) of the breast and its relationship to invasive breast carcinoma, it is important to understand the biology of this entity. We report on a hospital-based survey of 219 case subjects with DCIS of the breast without associated invasive carcinoma diagnosed between 1982 and 1994. The cases of DCIS were analyzed for architectural type, size, nuclear grade, necrosis, calcification, periductal fibrosis, neovascularization, estrogen receptor (ER), progesterone receptor (PR), and HER-2/neu expression. Periductal neovascularization was associated with tumor size, microcalcifications, periductal fibrosis, and HER-2/neu overexpression. Expression of ER and PR was observed in 60 and 62% of the cases, respectively, and HER-2/neu overexpression in 28% of the cases. ER and PR expression were both inversely associated with comedo histology and nuclear grade. HER-2/neu overexpression was positively associated with comedo histology, high nuclear grade, and periductal neovascularization and was inversely correlated with both ER and PR expression. High nuclear grade was positively associated with comedocarcinoma, necrosis, microcalcification, and periductal fibrosis. The role of these molecular/pathologic markers in the biology of DCIS and their potential clinical implications are discussed.