Pleomorphic lobular carcinoma of the breast: is it a prognostically significant pathological subtype independent of histological grade?

Pleomorphic lobular carcinoma is regarded as a biologically aggressive variant of invasive lobular carcinoma of the breast. However, there is no consensus on the definition and whether this subtype adds useful information to histological grade. Two-hundred and two grade 2 or grade 3 invasive lobular carcinomas were studied. Tumours were categorised according to the components of histological grade: tubules, pleomorphism and mitoses. Pleomorphic lobular carcinoma was defined as a carcinoma with a lobular growth pattern and marked nuclear pleomorphism (pleomorphism 3). Breast cancer-specific survival was used in analysis of prognosis. Grade 3 pleomorphic lobular carcinomas (tubules 3, pleomorphism 3, mitoses 2 and tubules 3, pleomorphism 3, mitoses 3) had a worse prognosis than grade 2 (tubules 3, pleomorphism 2, mitoses 1) carcinomas. Grade 2 lobular carcinomas with marked nuclear pleomorphism (tubules 3, pleomorphism 3, mitoses 1) had a similar prognosis to grade 2 carcinomas with moderate pleomorphism (tubules 3, pleomorphism 2, mitoses 1). Survival was associated with mitotic score, but not with nuclear pleomorphism on both univariate and multivariate analysis. A non-classical growth pattern was seen more frequently in all subgroups with marked nuclear pleomorphism and was associated with worse survival. Histological grade and nodal status were independent of prognostic factors. This study shows that histological grade (in particular the mitotic component) in invasive lobular carcinomas is of prognostic importance, but pleomorphic type does not provide useful additional prognostic information.

EpCAM expression is an indicator of recurrence in basal-like breast cancer.

Advances in the understanding of the molecular basis of breast cancer have necessitated a definition of more sensitive and specific indicators of prognosis that are central to the underlying cancer biology and that reflect the complicated and heterogeneous nature of the disease. This study investigates the expression of epithelial cell adhesion molecule (EpCAM) in breast cancer particularly basal-like phenotype group which remains unclear. EpCAM expression was assessed using immunohistochemistry in a large well-characterised series of breast carcinomas prepared as tissue microarrays. Relationships between EpCAM expression with molecular subtypes, clinicopathological variables and patients' outcome were examined. EpCAM expression was associated with higher tumour grade (P < 0.001), larger tumour size (P < 0.001) and basal phenotype (P = 0.03). Importantly, within the basal-like tumours those positive for EpCAM showed a significantly shorter DFI (LR = 7.97, P = 0.005) and MFS (LR 4.01, P = 0.045). EpCAM may play a role in breast cancer progression and its expression is associated with poor patient outcome in basal-like breast cancer, independent of other prognostic factors.

Transferrin receptor (CD71) is a marker of poor prognosis in breast cancer and can predict response to tamoxifen.

Transferrin receptor (CD71) is involved in the cellular uptake of iron and is expressed on cells with high proliferation. It may be implicated in promoting the growth of endocrine resistant phenotypes within ER+/luminal-like breast cancer. We used a panel of in vitro cell models of acquired resistance to tamoxifen (TAMR), Faslodex (FASR) or severe oestrogen deprivation (MCF-7X) and the ER+ luminal MCF-7 parental line to determine CD71 mRNA expression and to study transferrin (Tf) effects on in vitro tumour growth and its inhibition. Furthermore, CD71 protein expression was assessed in a well-characterized series of patients with invasive breast carcinoma using tissue microarrays. Our results demonstrated a striking elevation of CD71 in all cell models of acquired resistance. Exogenous Tf significantly promoted growth in MCF-7-X and MCF-7 cells but more so in MCF-7-X; this growth was significantly reduced by Faslodex (FAS) or a phosphoinositide-3 kinase inhibitor (LY294002). Increased CD71 expression was associated with poor NPI score, tumour proliferation, basal CKs, p53, EGFR, HER2, steroid receptor negativity and shortened breast cancer specific survival (P < 0.001). On multivariate analysis, CD71 was found to be an independent prognostic factor in the ER+ cohort of patients. In conclusion, therapies of current interest in breast cancer (e.g. FAS, PI3K-inhibitors) appear able to partially impact on transferrin/CD71-promoted growth, but further investigation of this important mitogenic mechanism may assist in designing new therapeutic strategies to target highly proliferative, endocrine resistant breast cancers. CD71 appears to be a candidate marker of a subgroup of ER+/luminal-like breast cancer characterised by poor outcome and resistance to tamoxifen.

Loss of expression of chromosome 16q genes DPEP1 and CTCF in lobular carcinoma in situ of the breast.

BACKGROUND: Loss of the chromosomal material at 16q is the most frequent genetic event in invasive and in situ (LCIS) lobular carcinoma of the breast. However, the smallest region of overlap at 16q is not restricted to just the CDH1 locus harbouring E-cadherin, suggesting that neighbouring genes might be involved in the development and progression of these tumours. Potential novel tumour suppressor genes (TSG) at 16q include CCCTC-binding factor (CTCF), Decreased Expression in Renal and Prostate Cancer (DERPC) and Dipeptidase 1 (DPEP1). The aim of this study is to assess the expression of these genes in LCIS and compare them with normal breast, using CDH1 as a control, in order to evaluate their role as TSGs. METHODS: Cells from LCIS cases and normal breast lobules were microdissected and expression of target genes were quantified using real-time PCR. In addition, immunohistochemistry (IHC) for E-cadherin and CTCF was performed on paraffin processed LCIS (n=49) and normal breast cases. RESULTS: All LCIS showed negative expression of E-cadherin. Similar to CDH1, CTCF and DPEP1 gene expression was significantly lower in LCIS cases compared with normal cases (P<0.05). CTCF IHC expression showed significant reduction in LCIS compared to normal parenchymal cells. However, there was no difference in expression of DERPC between LCIS and normal breast tissue. CONCLUSIONS: In addition to CDH1, loss of CTCF and DPEP1 gene expression suggest they are possible TSG in breast cancer and may, similar to CDH1, be potentially utilised as markers of predisposition of women diagnosed with LCIS.

IL-17 expression by breast-cancer-associated macrophages: IL-17 promotes invasiveness of breast cancer cell lines.

INTRODUCTION: IL-17 plays an important role in autoimmunity, promoting autoimmunity, inflammation and invasion in multiple sclerosis, rheumatoid arthritis and type I diabetes. The role of IL-17 in cancer is unclear, however, as there are few studies examining IL-17 protein expression in cancer. We therefore examined IL-17 protein expression in human breast cancer and modelled its potential biological significance in vitro. METHODS: Immunohistochemistry was used to determine IL-17 expression in breast cancers. Matrigel invasion assays were employed to examine the effect of IL-17 on cancer cell invasion by a panel of breast cancer cell lines. The role of matrix metalloproteinases (MMPs) was investigated with selective antagonists and immunoassays for MMP-2, MMP-3, MMP-9 and tissue inhibitor of MMP. RESULTS: IL-17-expressing cells with macrophage morphology were identified in the peritumoural area of a proportion of patients (8/19 patients). Macrophages were confirmed by CD68 staining on serial sections. With the exception of occasional lymphocytes, one patient with rare multinucleate giant cells and one patient with occasional expression of IL-17 in tumour cells, no other IL-17-positive cells were detected. Addition of IL-17 to cell lines in vitro stimulated marked invasion of Matrigel. In contrast, IL-17 did not promote the invasion of MCF7 or T47D cell lines. Invasion was initially thought to be dependent on MMPs, as evidenced by the broad-spectrum MMP inhibitor GM6001 and selective antagonists of MMP-2/MMP-9 and MMP-3. Measurement of MMP-2, MMP-3 and MMP-9, and tissue inhibitor of MMP 1 secretion, failed to reveal any changes in expression following IL-17 exposure. In contrast, TNF promoted secretion of MMPs but IL-17 did not augment TNF, indicating that IL-17 acts via an independent mechanism. CONCLUSIONS: The present study is the first to describe in situ expression of IL-17 protein in human breast tumours and to propose a direct association between IL-17 and breast cancer invasion. The precise effectors of IL-17-dependent invasion remain to be characterised but could include a range of proteases such as a disintegrin and metalloproteinase protein or astacins. Nevertheless, this work identifies a novel potential mechanism for breast cancer invasion and tumour progression, the prognostic implication of which is currently under investigation.

Breast carcinoma with basal phenotype: mammographic findings.

OBJECTIVE: Basal phenotype has been found to be an independent poor prognostic factor for breast cancer. The aim of this study was to assess the mammographic appearance of screening-detected breast carcinoma with the basal phenotype. MATERIALS AND METHODS: A series of 1,944 consecutively enrolled patients with operable invasive breast cancer underwent immunohistochemical analysis with cytokeratin 5/6 and cytokeratin 14 markers to identify tumors exhibiting basal phenotype characteristics. Among those patients, 356 women with breast cancer were common to a prospectively collected database of screening-detected cases of breast cancer. The predominant mammographic appearance and any associated features were reported by experienced image readers blinded to phenotype status. A chi-square test was used to assess difference between the mammographic appearances of a group of tumors with the basal phenotype and those of a group with the nonbasal phenotype. RESULTS: Forty-one (12%) of the screening-detected tumors had basal phenotypic expression, and these were compared with 309 (88%) nonbasal tumors. Basal-phenotype tumors were significantly more likely to manifest as an ill-defined mass (basal phenotype, 25 [61%] of 41 tumors; nonbasal phenotype, 75 [24%] of 309 tumors; p < 0.001) or with comedo calcification (basal phenotype, nine [22%] of 41 tumors; nonbasal phenotype, 30 [10%] of 309 tumors; p = 0.019). Nonbasal-phenotype tumors were more likely to manifest as a spiculated mass (nonbasal phenotype, 150 [49%] of 309 tumors; basal phenotype, eight [20%] of 41 tumors; p < 0.001). The low rate of spiculation in basal tumors was independent of histologic grade. CONCLUSION: Screening-detected breast tumors with a basal phenotype have a mammographic appearance different from that of nonbasal tumors. This finding may explain the good prognostic value of mammographic spiculation reported in previous studies.

Comparison of the PharmDx immunohistochemical system with standard methods for assessing estrogen and progesterone receptors in invasive carcinoma of the breast.

AIM: Accurate assessment of estrogen receptor (ER) and progesterone receptor (PR) status of breast cancers is essential for selecting patients for endocrine treatment. This study aimed to compare immunohistochemistry for these markers using the pharmDx system and standard methods. METHODS: Sections of 203 core biopsies of invasive carcinoma of the breast were stained for ER and PR using the pharmDx system and standard methods. RESULTS: Using a cutoff of H score of 10, there was agreement between the 2 methods in 201 tumors (99%) for both ER and PR. Using a cutoff of 1% staining there was agreement of 99.5% for ER and 96% for PR. CONCLUSIONS: The pharmDx system shows good agreement with standard methods for assessing ER and PR in breast cancer.

Lymph-node metastases in invasive lobular carcinoma are different from those in ductal carcinoma of the breast.

AIM: Invasive lobular carcinoma (ILC) and invasive ductal carcinoma (IDC) of the breast are distinct morphological entities with different biological features and clinical behaviour. In the present study, the authors compare the axillary-lymph-node (ALN) status of patients with grade-matched ILC (no=426) and IDC (no=820). The pattern of nodal metastatic deposits (nodular, sinusoidal and diffuse) and the proportion of involved nodes were also analysed in a selected group of 246 tumours, which were associated with a single positive ALN. RESULTS: Compared with grade-matched IDC, ILC was associated with a higher nodal stage (13.1% vs 4.5% of ILC and IDC were stage 3), higher absolute number of positive nodes and higher ratio of positive nodes (0.46±0.30 and 0.33±0.23 in ILC and IDC respectively). These differences were maintained in the different size subgroups. The most common metastatic morphological pattern was nodular in both types of carcinomas. A sinusoidal pattern was more frequent in IDC, and the diffuse pattern was more frequent in ILC. Despite these differences, ILC and grade-matched IDC exhibited similar rates of regional recurrences (RR) and breast-cancer survival. CONCLUSION: This study provides clinical evidence which further demonstrates that ILC and IDC are biologically distinct entities with different lymph-node involvement patterns and ILC having a tendency to metastasise to more nodes than IDC. However, this difference was not associated with a significant impact on patient outcome.

The prognostic significance of steroid receptor co-regulators in breast cancer: co-repressor NCOR2/SMRT is an independent indicator of poor outcome.

BACKGROUND: Advances in understanding the molecular basis of breast cancer has necessitated a definition of improved indicators of prognosis that are central to the underlying cancer biology and that reflect the heterogeneous nature of the disease. This study investigates the pattern of expression of the steroid receptor co-regulators NCOA1/SRC1, NCOA3/RAC3, NCOR2/SMRT, and CBP/p300 in breast cancer. The aims were to identify whether their expression was related to patient outcome, their relationships to known prognostic factors and to provide a basis for further research into the mechanistic significance of such associations. METHODS: The protein levels of steroid receptor co-regulators were assessed by immunohistochemistry in a large well-characterised series of breast carcinomas prepared as tissue microarrays. Relationships between these targets, other clinicopathological variables and patients' outcome were examined. RESULTS: NCOR2/SMRT was an independent prognostic indicator of overall patient survival (OS) and disease free interval (DFI) and was significantly correlated with distant metastases and local recurrence whereas tumours expressing NCOA1/SRC1 had a significantly longer OS and DFI. There were also significant correlations between co-regulator expression of NCOA1/SRC1, CBP/p300 and NCOA3/RAC3, which were associated with lower tumour grade. NCOA1/SRC1 was also correlated with smaller tumour size. Furthermore, the co-activators had a significant association with steroid receptors, particularly ERalpha. CONCLUSIONS: NCOR2/SMRT is associated with poor patient outcome, independent of other prognostic factors. In contrast, steroid receptor co-activator expression is generally associated with a good prognosis. Further investigations are needed to establish the mechanisms of these links between the steroid receptor co-regulator system and patient outcome.

Biologic and clinical characteristics of breast cancer with single hormone receptor positive phenotype.

PURPOSE: Response to endocrine therapy in breast cancer correlates with estrogen receptor (ER) and progesterone receptor (PgR) status. It is usually easier to decide treatment strategies in cases of double-positive/-negative phenotypes than in single-positive tumors. PATIENTS AND METHODS: We have examined a large and well-characterized series of primary invasive breast carcinoma (1,944 cases) with long-term clinical follow-up and hormone therapy data. Patients were stratified according to ER and PgR expression and the study was focused on the single-positive groups (ER-/PgR+ and ER+/PgR-), to assess their main features and evaluate any prognostic and predictive difference between them and compare them with the double-positive/-negative tumors. RESULTS: ER+/PgR-tumors were found more frequently in elderly, postmenopausal women. The majority were grade 2 ductal/no specific type carcinomas. There was no difference between the two groups with regard to lymph node stage. Survival analyses showed no difference between the two groups in terms of disease-free interval and overall survival. However, when compared with the double-negative phenotype, ER+/PgR-showed an association with better outcome but no such survival advantage was detected in case of ER-/PgR+ tumors. In the group of patients with ER+ tumors who received adjuvant hormonal therapy, absence of PgR (ER+/PgR-) was an independent predictor of development of recurrence and shorter survival and, hence, poorer response to hormonal therapy. CONCLUSION: ER+/PgR-and ER-/PgR+ tumors are biologically and clinically distinct groups of breast cancer that may require different treatment strategies with ER-/PgR+ exhibiting more aggressive behavioral characteristics.

Expression of E2F-4 in invasive breast carcinomas is associated with poor prognosis.

The E2F family of transcription factors plays a key role in the control of cellular proliferation and apoptosis. Some family members act as oncogenes and others act as tumour suppressor genes (TSGs), behaviour which appears to be tissue-specific. E2F-4 is a member of the E2F family, located at chromosome band 16q22.1, that shows frequent deletion in breast cancer, suggesting that it may function as a TSG in breast carcinogenesis. In the present study, the expression of E2F-4 was assessed immunohistochemically on paraffin wax sections from 265 breast carcinomas and expression was compared with both clinicopathological variables and disease outcome in an attempt to identify its possible role as a TSG and to assess its prognostic value, if any, in breast cancer. E2F-4 protein expression was detected in the nuclei and in the cytoplasm of normal and malignant breast epithelial cells. In the malignant tissues, no significant loss or decrease of expression was seen in association with any specific tumour type. There was a correlation between increased nuclear expression of E2F-4 and indicators of poor prognosis including larger tumour size (p = 0.000), grade 3 lesions (p = 0.033), lymph node stage (p = 0.037), and poorer Nottingham prognostic index group (p = 0.003). Increased immunoreactivity was also seen in association with the development of recurrent disease (p = 0.004), distant metastasis (p = 0.001), and poorer outcome including poorer overall survival time (p = 0.002) and shorter disease-free interval (p = 0.001). In multivariate analysis, E2F-4 was of independent prognostic significance along with grade and lymph node stage. These results suggest that E2F-4 may play a role in breast cancer progression and that increased nuclear expression is associated with more advanced tumours with poor outcomes. E2F-4 appears to have an oncogenic role rather than a tumour suppressor role in breast carcinogenesis and, hence, it is not the gene targeted by 16q22.1 loss in breast carcinoma.