Emma C. Paish

Expression of mucins (MUC1, MUC2, MUC3, MUC4, MUC5AC and MUC6) and their prognostic significance in human breast cancer

Mucins are a large family of glycoproteins expressed by many epithelial cells and their malignant counterparts. Much interest has been focused on expression of its members in breast cancer because of their potential role as prognostic indicators and their involvement in cancer therapy. We have examined 1447 cases of invasive breast carcinoma with a long-term follow-up, using tissue microarray (TMA) technology and immunohistochemistry to evaluate the expression profiles of several mucins (MUC1, MUC2, MUC3, MUC4, MUC5AC and MUC6) and to assess their prognostic value. We detected MUC1 expression in 91% of tumours. MUC1 overexpression was associated with a lower grade, smaller tumour size, a higher oestrogen receptor (ER)-positive phenotype and absence of both regional recurrence and distance metastasis. The subcellular localization but not the level of expression had a prognostic value in predicting outcome. The aberrant cytoplasmic and membranous localization of MUC1 was associated with poor outcome compared with apical localization, which is the normal physiological site of expression. MUC2 expression was noticed in only 8.3% of all cases and was restricted to the cytoplasm of the tumour cells. An inverse trend was identified between MUC2 expression and lymph node stage and vascular invasion status. On excluding cases of mucinous carcinoma from the analysis, the inverse association with vascular invasion was still defined and in addition an inverse association with ER status emerged. MUC3 expression was detected in 91% of cases and its expression was associated with increased local recurrence, and lymph node stage. The membranous expression of MUC3 was found to be a potentially poor prognostic feature, with higher grade and poorer Nottingham Prognostic Index (NPI), and negative ER expression. MUC4, MUC5AC and MUC6 were expressed in 95, 37 and 20% of cases, respectively. Apart from an association between MUC4 expression and tumour grade and between MUC6 and ER-negative tumours, no other associations with any clinicopathological variables were found. Apart from the higher expression of MUC2 and MUC6 in mucinous carcinomas, no association was found between the expression of different mucins and tumour type. No association between the level of expression of any of the studied mucins and patient outcomes has been identified. In conclusion, most breast carcinomas express MUC1, MUC3 and MUC4. Among the various mucins expressed in breast cancer, MUC1 and MUC3 are potential prognostic indicators, MUC1 having the strongest relationship with patient outcome.

Nuclear and Cytoplasmic Expression of ERβ1, ERβ2, and ERβ5 Identifies Distinct Prognostic Outcome for Breast Cancer Patients

Purpose: Previous conflicting results about the prognostic significance of estrogen receptor (ER)-β in breast cancer may be explained by contribution of isoforms, of which five exist. Our aim was to elucidate the prognostic significance of ERβ1, ERβ2, and ERβ5 by immunohistochemistry in a large cohort of breast carcinomas with long-term follow-up. Experimental Design: Tissue microarrays were stained with ERβ1, ERβ2, and ERβ5 antibodies and scored as percentage of positive tumor cells and using the Allred system. Nuclear and cytoplasmic staining was evaluated and correlated with histopathologic characteristics, overall survival (OS), and disease-free survival (DFS). Results: Nuclear ERβ2 and ERβ5, but not ERβ1, significantly correlated with OS (P = 0.006, P = 0.039, and P = 0.099, respectively), and ERβ2 additionally with DFS (P = 0.013). ERβ2 also predicted response to endocrine therapy (P = 0.036); correlated positively with ERα, progesterone receptor, androgen receptor, and BRCA1; and correlated inversely with metastasis and vascular invasion. Tumors coexpressing ERβ2 and ERα had better OS and DFS. Cytoplasmic ERβ2 expression, alone or combined with nuclear staining, predicted significantly worse OS. Notably, patients with only cytoplasmic ERβ2 expression had significantly worse outcome (P = 0.0014). Conclusions: This is the first study elucidating the prognostic role of ERβ1, ERβ2, and ERβ5 in a large breast cancer series. ERβ2 is a powerful prognostic indicator in breast cancer, but nuclear and cytoplasmic expression differentially affect outcome. Measuring these in clinical breast cancer could provide a more comprehensive picture of patient outcome, complementing ERα.

Breast carcinoma with basal differentiation: a proposal for pathology definition based on basal cytokeratin expression.

Aim:  To assess the expression and coexpression of a range of different biomarkers that have been used to define breast carcinomas with a basal phenotype (BP) and their relationship with prognosis in an attempt to refine the definition of BP and to evaluate the reliability of using a single biomarker to identify these tumours.

Prognostic significance of vascular endothelial cell growth factors -A, -C and -D in breast cancer and their relationship with angio-and lymphangiogenesis

Vascular endothelial cell growth factors (VEGF)-A, -C and -D have potent angio and lymphangiogenic functions in experimental models, although their role in the progression of human breast cancer is unclear. The aims of the current study were to examine the relationship between the expression of the aforementioned growth factors with the angio and lymphangiogenic characteristics of breast cancer, and to assess their suitability as potential prognostic factors. Paraffin-embedded sections of 177 primary invasive breast cancer, with complete clinical follow-up information for 10 years, were stained for VEGF-A, -C, -D, podoplanin and CD34 using standard immunohistochemical approaches. The expression of the growth factors was correlated with clinicopathological criteria and patients’ survival. Lymph vessel density (LVD) and microvessel density (MVD) were assessed and correlated with expression of the growth factors. Vascular endothelial cell growth factor-A, -C and -D were highly expressed in 40, 37 and 42% of specimens, respectively. High expression of VEGF-A and - C, but not of -D, was associated with a higher LVD (P=0.013 and P=0.014, respectively), a higher MVD (P<0.001 and P=0.002, respectively), the presence of lymph node metastasis (P<0.001 and P<0.001, respectively), distant metastasis (P=0.010 and P=0.008, respectively) and a shorter Overall Survival (P=0.029 and 0.028, respectively). In conclusion, breast cancers that express high levels of VEGF-A and -C are characterised by a poor prognosis, likely through the induction of angio and lymphangiogenesis. Examination of expression of VEGF-A and -C in breast cancer may be beneficial in the identification of a subset of tumours that have a higher probability of recurrence and metastatic spread.

The role of PTEN and its signalling pathways, including AKT, in breast cancer; an assessment of relationships with other prognostic factors and with outcome

PTEN is a novel tumour suppressor gene located on chromosome 10. PTEN mutations are believed to exert their effects through the putative PI3K–AKT–mTOR signalling pathway. Specifically, loss of PTEN leads to activation of AKT, which in turn promotes anti‐apoptotic and pro‐cell cycle entry pathways believed to be essential in tumourigenesis. Whilst PTEN mutations are frequent in a variety of sporadic cancers and inherited cancer syndromes, it is not clear how frequently PTEN mutations and immunohistochemical loss of PTEN expression occur in sporadic breast cancer. This study used tissue microarrays (TMAs) to assess wild‐type PTEN and pAKT immunohistochemical staining in 670 and 691 cases, respectively, of primary operable breast cancer. Scores of 0, 1, and 2 were given for negative, weakly positive, and strongly positive degrees of immunoreactivity, respectively. In addition, immunohistochemical assessment of epidermal growth factor receptor (EGFR), Her2, and proliferation by MIB1 expression was performed on the same TMAs and the scores were compared with those of PTEN and pAKT. Eight per cent of cases did not express wild‐type PTEN. No correlation was observed between patient, tumour and outcome variables and PTEN. pAKT expression correlated inversely with adverse tumour variables such as tumour grade (p < 0.001) and correlated positively with ER status (p < 0.001). No correlation was seen between either PTEN or AKT and EGFR, Her2 or MIB1. No association of PTEN or pAKT was seen in Kaplan–Meier or multivariate analysis for overall survival. The results indicate that loss of PTEN expression is infrequent in breast cancer. PTEN and AKT do not appear to be prognostic markers. The study argues against the current model of a simple linear tumourigenic PTEN–PI3K–AKT–mTOR pathway in breast cancer. It also suggests that, in this group of breast cancers, the most common upstream regulator of AKT may be ER rather than PTEN, EGFR or Her2. Copyright

Improved Methods of Detection of Lymphovascular Invasion Demonstrate That It is the Predominant Method of Vascular Invasion in Breast Cancer and has Important Clinical Consequences

The presence of vascular invasion (VI), encompassing both lymphovascular invasion (LVI) and blood vascular invasion (BVI), in breast cancer has been found to be a poor prognostic factor. It is not clear, however, which type of VI plays the major role in metastasis. The aims of this study were to use an endothelial subtype specific immunohistochemical approach to distinguish between LVI and BVI by comparing the differential expression of blood vascular (CD34 and CD31) and lymphatic markers (podoplanin/D2-40) to determine their prognostic role in a well-characterized group of breast cancer patients with known long-term follow-up. Sections from177 consecutive paraffin-embedded archival specimens of primary invasive breast cancer were stained for expression of podoplanin, D2-40, CD31, and CD34. BVI and LVI were identified and results were correlated with clinicopathologic criteria and patient survival. VI was detected in 56/177 specimens (31.6%); 54 (96.4%) were LVI and 2 (3.5%) were BVI. The presence of LVI was significantly associated with the presence of lymph node metastasis, larger tumor size, development of distant metastasis, regional recurrence and worse disease-free interval and overall survival. In multivariate analysis, LVI retained significance association with decreased disease-free interval and overall survival. In conclusion, VI in breast cancer is predominantly of lymph vessels and is a powerful independent prognostic factor, which is associated with risk of recurrence and death from the disease. The use of immunohistochemical staining with a lymphendothelial specific marker such as podoplanin/D2-40 increases the accuracy of identification of patients with tumor associated LVI.

Tumour-infiltrating macrophages and clinical outcome in breast cancer

Background Macrophages constitute a major component of the leucocytic infiltrate of tumours. Human studies show an association between tumour-associated macrophages and tumours with poor prognostic features. In breast cancer, the presence of macrophages has been correlated with increased angiogenesis and poor prognosis but little information is available about the independent prognostic role of macrophages infiltrating breast carcinomas. Aims and methods This study used immunohistochemistry and tissue microarrays to assess the density and localisation of CD68 macrophages infiltrating 1322 breast tumours and to identify any relationship with clinicopathological factors and patient outcome. Results Tumour-infiltrating macrophages were present in the majority of tumours with a predominantly diffuse pattern. The density of distant stromal macrophages (infiltrating stroma away from the carcinoma, median count 14 cells) was higher than intratumoural (median zero cells) and adjacent stromal macrophages (median three cells). Higher total macrophage number was associated with higher tumour grade (rs=0.39, p<0.001), ER and PgR negativity, HER-2 positivity and basal phenotype (p<0.001). In univariate survival analysis, higher numbers of CD68 macrophages were significantly associated with worse breast cancer-specific survival (p<0.001) and shorter disease-free interval (p=0.004). However in multivariate model analysis, the CD68 macrophage count was not an independent prognostic marker. Conclusions Macrophages are heterogeneous with different subsets having different functions. The present study suggests that overall macrophage numbers are not related to prognosis in breast cancer. However, further studies are needed to investigate the potential role of different subsets of macrophages.

Neuroendocrine differentiation and prognosis in breast adenocarcinoma

Neuroendocrine differentiation and prognosis in breast adenocarcinoma

A validated gene expression profile for detecting clinical outcome in breast cancer using artificial neural networks

Gene expression microarrays allow for the high throughput analysis of huge numbers of gene transcripts and this technology has been widely applied to the molecular and biological classification of cancer patients and in predicting clinical outcome. A potential handicap of such data intensive molecular technologies is the translation to clinical application in routine practice. In using an artificial neural network bioinformatic approach, we have reduced a 70 gene signature to just 9 genes capable of accurately predicting distant metastases in the original dataset. Upon validation in a follow-up cohort, this signature was an independent predictor of metastases free and overall survival in the presence of the 70 gene signature and other factors. Interestingly, the ANN signature and CA9 expression also split the groups defined by the 70 gene signature into prognostically distinct groups. Subsequently, the presence of protein for the principal prognosticator gene was categorically assessed in breast cancer tissue of an experimental and independent validation patient cohort, using immunohistochemistry. Importantly our principal prognosticator, CA9, showed that it is capable of selecting an aggressive subgroup of patients who are known to have poor prognosis.

Prognostic significance of BRCA1 expression in sporadic breast carcinomas

BRCA1 is a tumour suppresser gene frequently mutated in familial breast cancer and thought to influence the progression of sporadic breast cancer. Decreased BRCA1 mRNA and protein expression has been identified in breast cancer cell lines and sporadic breast tumours. Here the prognostic significance of reduced BRCA1 protein expression is investigated in primary operable breast cancer. Immunohistochemical analysis was used to determine the level of BRCA1 protein expression in 100 breast cancers. BRCA1 expression was compared with known prognostic factors and survival to investigate its prognostic significance. BRCA1 nuclear expression was reduced by varying amounts in breast carcinomas. A progressive loss of BRCA1 expression correlated well with higher histological grade (p = 0.002) and an excess of medullary/atypical medullary/grade 3 ductal carcinomas (p = 0.0001). When adjusted for grade, patients with loss of BRCA1 expression had a significantly longer disease‐free survival time. Loss of BRCA1 expression associated with high‐grade breast tumours suggests that BRCA1 may play an important role in the pathogenesis of sporadic breast cancer. Copyright