Defining lymphocyte‐predominant breast cancer by the proportion of lymphocyte‐rich stroma and its significance in routine histopathological diagnosis

Lymphocyte‐predominant breast cancer (LPBC) defined by the density of stromal lymphocytes shows favorable behavior. However, considerable distribution heterogeneity of lymphocytes is a major problem. The present study defined LPBC by the proportion of lymphocyte‐rich stroma with the cut‐off values of 30, 50, and 75%, and clinicopathologically analyzed mainly LPBC (area > 30%) defined by the cut‐off value of 30%. LPBCs (area > 30%), 39 cases in total, were composed mainly of triple‐negative and HER2⁺/ER^‐ subtypes, without any luminal A‐like subtype. LPBCs were composed predominantly of histological grade 3 tumors, without any grade 1 lesions. Multivariate analyses on 477 consecutive tumors revealed that ER‐negativity and grade 3 status associated significantly with LPBC. LPBC (area > 30%) showed better disease‐free survival than grade‐matched controls, and it was a good indicator of complete pathological remission after pre‐operative chemotherapy. Patients with LPBC with the cut‐off value of 50% and that of 75% showed 100% disease‐free survival. These results demonstrated the validity of our definition of LPBC. Our data also suggest that de‐differentiated cancers without TILs could be regarded as high‐grade cancer without lymphocyte‐mediated responses. In conclusion, the definition of LPBC by the proportion of lymphoid stroma is useful for prognostication of high grade breast cancer in routine diagnosis.     

Podoplanin expression by cancer-associated fibroblasts predicts poor outcome in invasive ductal breast carcinoma

Pula B, Jethon A, Piotrowska A, Gomulkiewicz A, Owczarek T, Calik J, Wojnar A, Witkiewicz W, Rys J, Ugorski M, Dziegiel P & Podhorska‐Okolow M
(2011) Histopathology  59, 1249–1260
Podoplanin expression by cancer‐associated fibroblasts predicts poor outcome in invasive ductal breast carcinoma Aims: It has recently been shown that podoplanin, a mucin‐type glycoprotein, is expressed by cancer cells and cancer‐associated fibroblasts (CAFs), and promotes cancer cell migration and invasiveness. The biological role of podoplanin expression in tumour stroma of invasive ductal carcinoma of the breast (IDC) has not been determined. Methods and results: Podoplanin expression was analysed in 117 cases of IDC and 27 cases of fibrocystic change, as well as in breast cancer cell lines, with the use of immunohistochemistry and real‐time polymerase chain reaction. In 82.1% of analysed tumours, podoplanin was found only in CAFs. Only two of 117 IDC cases (1.7%) were characterized by expression of this glycoprotein in cancer cells. None of the fibrocystic changes or stroma surrounding normal ducts showed podoplanin expression. Podoplanin‐positive CAFs correlated with tumour size (P = 0.0125), grade of malignancy (P = 0.0058), lymph node metastasis (P = 0.0149), lymphovascular invasion (LVI) (P = 0.0486) and Ki67 expression in cancer cells (P = 0.0128). High‐level podoplanin expression (>50% of positive stroma) in the tumour stroma was significantly associated with a negative oestrogen status (P = 0.0201). Univariate, but not multivariate, analysis showed that podoplanin expression by CAFs was associated with poor patient outcome (P = 0.0202). Conclusions: Our results suggest that podoplanin expression by CAFs could be an unfavourable prognostic marker for IDC.     

The use of fine‐needle aspiration biopsy samples for the assessment of basal phenotype in triple negative breast cancer patients: A correlative study

Molecular profiling of breast cancer has gained popularity due to the possibility of studying the biological spectrum of the disease and to evaluate prognostic and predictive characteristics that can lead to more accurate therapeutic decisions. Although studies have been carried out on tissue using tissue microarray technology (TMA), to our knowledge, this technology has not been applied to samples obtained by fine‐needle aspiration biopsy (FNAB). This study was designed to correlate FNAB samples with corresponding surgical specimens for the assessment of basal phenotype in patients with triple negative breast cancer (TNBC). A total of 198 cases of TNBC with matching FNAB and surgical specimens were identified. Forty‐six cases with sufficient tissue in both FNAB cell blocks and surgical specimens were selected. Tissue microarray blocks were prepared and stained with six biomarkers (CK5/6, p63, SMA, EGFR, C‐Kit, and p53). For statistical analysis, we used the observed (Gross) percentage of agreement and also calculated the Cohen's Kappa for each biomarker. We found a high agreement between the two groups as shown by the values of Observed (Gross) percentage of agreement (mostly 90% or higher except for the C‐Kit which was 78%). In addition, Cohen's Kappa point estimate showed substantial agreement (0.61–0.80) for CK 5/6, p63, EGFR, p53, moderate agreement (0.41–0.60) for C‐Kit, and, fair agreement (0.21–0.40) for SMA. Our study shows that the advantages of FNAB are not restricted to cost‐effectiveness, but also attested that cytology samples are suitable for the evaluation of biomarkers that have important implications on patient's therapy and prognosis. Diagn. Cytopathol. 2011;39:1–7. © 2010 Wiley‐Liss, Inc.     

Seminar in breast self-examination for female medical students integrated into a human gross anatomy course

A breast self-examination (BSE) seminar for first-year female medical students is presented and a single-gender approach for other subjects in the medical curriculum is discussed. In 1999 a small group seminar on BSE was offered at the Hannover Medical School to female medical students as part of their curriculum in human gross anatomy. An evaluation questionnaire was answered by 94 students (87% of participants). Frequencies of answers to two open questions were used as indicators of: 1) the acceptance of a single-gender course and 2) an increased awareness of breast cancer prevention. A linear regression analysis was carried out to identify the most important predictors for the global course evaluation and a heightened interest in breast cancer prevention. The mean global rating of the seminar was 13.8 (minimum: 1 point; maximum: 15 points). Factors that significantly influenced the global rating were the course atmosphere, the teacher's enthusiasm, and the professional interest of the students. An increased concern for breast cancer prevention was significantly dependent on the professional interest and the self-awareness of the women. The results suggest that there is a need for single-gender seminars in academic medicine and that instruction of female students in BSE is an ideal subject for this approach. Because of the prevalence of breast cancer, it is recommended that such a seminar become an integral part of the preclinical curriculum for all female medical students.     

Metaplastic breast carcinoma on fine-needle cytology samples: a report of three cases

Metaplastic breast carcinoma (MBC) may have a varied presentation on fine-needle cytology samples. We herewith describe three cases of MBC found in our series. One of these cases showed a peculiar mixture of malignant ductal, apocrine type, and squamous epithelial cells with fascicles of spindle cells with variable degree of atypia and was diagnosed as metaplastic carcinoma of the carcino-sarcomatous type. The other two lesions were characterized by an abundant chondroid extracellular matrix to which were variably admixed carcinomatous and chondroid-type cells, with variable degree of atypia. Both these latter cases were defined as matrix-producing metaplastic carcinomas. Because of the various presentation of MBC on fine-needle cytology samples and the possible influence of needle "sampling" on the cytological specimen, the spectrum of differential diagnoses to be considered may encompass a number of benign and malignant entities, like keratinous subareolar cysts, malignant fibroepithelial lesions with myxo-chondroid stroma, and true sarcomas of the breast, with cartilaginous metaplasia. It is the Authors' feeling that, with optimal samples, the cytomorphological findings of this rare variant of breast carcinoma permit its accurate pre-operative diagnosis.     

MICA‐129 Met/Val polymorphism could be a genetic biomarker for Familial Breast Cancer in the Tunisian population

Identification of candidate genes associated with susceptibility of breast cancer can have a significant impact at a cancer management national healthcare systems level, making genetic testing more affordable and cost‐effective. We have previously shown that the major histocompatibility complex class I‐related chain A (MICA) was related to breast cancer and plays an important role in modulating immune response mechanisms through NKG2D receptor activation. Compared to our previous study, in this work, we recruited a new cohort composed of 354 unrelated Tunisian women affected by breast cancer and 380 age‐matched women as controls, all genotyped for MICA‐129 Met/Val (rs 1051792). Subsequently, we exanimated the distribution of this polymorphism in ten families. As a result, an association was found between the Val allele and Val/Val genotype and the risk of breast cancer (p = 2.5 × 10^–15; OR = 2.40; p = 6.5 × 10^–13; OR = 3.03, respectively). Stratified analysis with age and family history of cancer revealed an association between the Val/Val genotype and younger patients <40 years (p = .003; OR = 2.03). Among those patients having a family history of cancer, 68% had a Val/Val genotype (p = .02; OR = 1.82). In the family study, an analyse of pedigrees revealed that the majority of families showed the development of breast cancer at a young age. Moreover, all patients diagnosed with early‐onset breast cancer had a Val/Val genotype. Our results lead us to propose that this polymorphism may be an inherited genetic biomarker contributing to an increased breast cancer risk in Tunisian women.     

Microglandular adenosis: a prime suspect in triple‐negative breast cancer development

Microglandular adenosis (MGA) and atypical MGA (AMGA) are unusual lesions of the breast. They were once regarded as benign proliferative lesions and innocent bystanders. Several lines of evidence suggested that they could be neoplastic, clonal lesions and a non‐obligate precursor for triple‐negative breast cancers (TNBC). Recent work published in The Journal of Pathology by Guerini‐Rocco and colleagues provided further evidence regarding the precursor–product relationship between MGA/AMGA and TNBC. Using a massively parallel sequencing approach, they demonstrated that MGA/AMGA, particularly those associated with TNBC, could be clonal neoplastic lesions showing clonal non‐synonymous mutations, but none in pure MGA. Importantly, those alterations were observed in the associated TNBC. They were also able to identify recurrent alterations in TP53 in those MGA/AMGA cases as well as their associated TNBC. The findings, in conjunction with others, underscore the significance for MGA in clinical diagnosis. The potential of a benign lesion to progress into an aggressive malignant tumour implies that modification of the current management approach may be necessary. Copyright © 2016 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.     

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.     

Cytomorphology of male breast lesions: diagnostic pitfalls and clinical implications

Because lesions of the male breast have been exceeded in number by those of the female breast, marginal attention was given to these lesions in the past. Fortunately, this has changed over the years leading to an increased awareness about male breast cancer. Although male breast cancer constitutes only about 1% of all diagnosed breast cancer cases, an increased mortality is seen in this patient population. This is probably caused by late diagnosis as a consequence of low level of concern about breast cancer among male patients. However, the vast majority of lesions of the male breast are benign, gynecomastia being the number one cause of unilateral or bilateral breast mass. Since it is important to avoid unnecessary surgical treatment without missing malignancy, accurate diagnostic tools are necessary in order to triage these patients. Fine-needle aspiration biopsy has demonstrated excellent accuracy in the diagnosis and management of breast lesions in female patients. In addition, several authors have proven the value of this technique in the evaluation of lesions of the male breast. Fine-needle aspiration biopsy permits accurate diagnosis in many lesions arising in the male breast. It also allows gathering cytological material that can be used for ancillary studies which enhances the diagnostic value of this technique.     

Lactate detection in inducible and orthotopic Her2/neu mammary gland tumours in mouse models

This study compared the steady state concentration of lactate in an inducible Her2/nue transgenic breast cancer mouse model and in tumours from the same Her2/neu model grown orthotopically. In vivo lactate was detected by MRS using the Hadamard encoded selective multiple quantum coherence pulse sequence (HadSelMQC) recently developed by our laboratory. A lower lactate signal was observed in the inducible tumours compared to orthotopic tumours in vivo, while ex vivo analysis of perchloric acid extracts revealed similar amounts of this metabolite in both models. Histological staining of mammary tumour specimens showed a much higher level of fat tissue in inducible tumours compared to the orthotopic model. Phantom studies with [3‐¹³C] lactate indicated that a lipid environment could significantly reduce the T2 of lactate and impede its detection. The transgenic inducible model for breast cancer not only better recapitulated the biological aspects of the human disease but also provided additional characteristics related to in vivo detection of lactate that are not available in orthotopic or xenograft models. This study suggests that the level of lactate measured by the HadSelMQC pulse sequence may be underestimated in human patients in the presence of high lipid levels that are typically encountered in the breast. Copyright © 2012 John Wiley & Sons, Ltd.     

Are bilateral breast cancers and breast cancers coexisting with ovarian cancer different from solitary tumors? A pair‐matched immunohistochemical analysis aimed at intrinsic tumor phenotype

Patients with bilateral breast cancer (BBC) and breast‐ovarian cancer syndrome (BOCS) constitute populations potentially enriched for molecular defects involved in the pathomechanisms of these malignancies. The aim of our study was to compare tumor morphology and expression of estrogen and progesterone receptor, HER2, Ki67, cytokeratin 5/6, E‐cadherin, vimentin and epidermal growth factor receptor in tissue microarrays from 199 tumors from BBC or BOCS patients and 199 age‐matched solitary tumors. Compared to controls, BBC and BOCS considered jointly had lower incidence of DCIS, lower expression of PgR and HER2, and higher expression of Ki67 and vimentin. BOCS tumors were of higher grade, had lower expression of ER and PgR and higher expression of Ki67, CK5/6, vimentin and EGFR. BBC had less DCIS component, lower HER2 expression and higher Ki67 expression. Metachronous BBC (mBBC) had lower expression of ER, PgR and HER2, and higher expression of Ki67 and vimentin. Synchronous BBC (sBBC) had less DCIS component, higher expression of ER, and lower expression of CK5/6, EGFR and E‐cadherin. BBC and breast cancers in BOCS differ in many aspects from solitary tumors. BBC are a heterogeneous group of tumors, differing between sBBC and mBBC. mBBC phenotype shares many features with BOCS tumors.     

Cytological study of 20 cases of solid-papillary carcinoma of the breast

Solid-papillary carcinoma (SPC) of the breast is a rare variant of low-grade intraductal carcinoma but there are few cytological studies. We examined 20 cases of SPC of the breast, aged 31-80 (mean age 66.0 yr), to define the cytological features. In each of the cytological specimens, we could find both malignant and benign cytological features; the former were characterized by hypercellularity, highly discohesive clusters, numerous isolated cells, and severe overcrowding cells, while the latter were marked by small and bland nuclei, a low nuclear-cytoplasmic ratio, and inconspicuous nucleoli. Neither abnormal naked nuclei of tumor cell origin nor oval naked nuclei of myoepithelial cell origin were seen.We also reviewed the cytological findings of SPC as well as neuroendocrine carcinomas with intraductal components that had been reported and we concluded that the coexistence of malignant and benign features was the most characteristic cytological feature of SPC.     

Epidermal growth factor receptor gene amplification and protein overexpression in basal-like carcinoma of the breast

Shao M‐M, Zhang F, Meng G, Wang X‐X, Xu H, Yu X‐W, Chen L‐Y & Tse G M
(2011) Histopathology 59 , 264–273 Epidermal growth factor receptor gene amplification and protein overexpression in basal‐like carcinoma of the breast Aims: Epidermal growth factor receptor (EGFR) is frequently expressed in basal‐like breast cancer (BLBC). The aim of this study was to evaluate their correlation as detected by immunohistochemistry (IHC) or fluorescence in‐situ hybridization (FISH). Methods and results: IHC for oestrogen receptor (ER), progesterone receptor (PR), human epidermal growth factor receptor (HER) 2, cytokeratin (CK) 5/6 and EGFR, and FISH for EGFR amplification, were performed in 59 cases of BLBC. EGFR IHC results were scored semiquantitatively, and compared with its gene amplification status. ER, PR and HER2 were negative in all cases, whereas 35 and 55 cases were positive for CK5/6 and EGFR. For EGFR IHC, 20, 11, 11 and 17 cases showed a negative, a low, an intermediate or a high staining level, respectively, and seven cases showed gene amplification by FISH, with two, 19, 11 and 20 cases showing balanced monosony, disomy, trisomy, and polysomy respectively. Immunohistochemical expression in gene‐amplified tumours was significantly higher than in those without amplification, including balanced polysomy tumours. EGFR immunohistochemical expression also correlated with the EGFR/chromosome 7 ratio. High sensitivity (86%) and negative predictive value (98%) were achieved with high‐level immunohistochemical expression as a cut‐off to predict gene amplification. Conclusions: High‐level EGFR immunohistochemical expression correlated with and predicted EGFR amplification, and may be used as a screening method to exclude gene amplification.     

Increased tumor cell expression of Axl is a marker of aggressive features in breast cancer among African women

Axl, a receptor tyrosine kinase belonging to the Tyro/Axl/Mer (TAM) family, has been shown to be overexpressed in breast cancer with poor outcome. Moreover, Axl was associated with a basal‐like phenotype (BLP) in these tumors. Our aim was to investigate Axl expression in breast cancers from an African population since these tumors are known to be aggressive and have a high frequency of the basal‐like phenotype. We studied 170 paraffin‐embedded breast carcinoma cases by tissue microarrays and immunohistochemical methods. In total, 128 tumor cases (75%) had strong Axl expression and 42 cases (25%) had weak or negative staining. Strong expression of Axl was associated with high tumor grade (p < 0.0005), estrogen receptor (ER) negativity (p = 0.024), p53 expression (p = 0.004), P‐cadherin positivity (p = 0.017), and basal‐like phenotypic profiles BLP2 (p = 0.033) and BLP3 (p = 0.022). In addition, Axl overexpression also showed an association with markers of tumor cell proliferation and tumor angiogenesis. In conclusion, our findings indicate strong expression of Axl in a high proportion of breast cancer cases among African women and associations with markers of aggressive features, indicating poor prognosis. These findings suggest Axl as a potential therapeutic target in this population.     

Triple negative breast cancer: adjuvant chemotherapy effect on survival

PurposeThe purpose of this study was to evaluate the overall survival of patients with triple negative breast cancer and the impact of different adjuvant chemotherapy regimens on survival.Material/MethodsThe study group consisted of 99 breast cancer patients with immunohistochemically confirmed triple negative breast cancer. The impact of various factors as well as the impact of different chemotherapy regimens on survival was evaluated.ResultsThe overall survival of breast cancer patients was 97.0% (95% CI 90.9–99.0), 84.9% (95% CI 76.1–90.6) and 66.5% (95% CI 55.5–75.3) 10, 30 and 60 months after diagnosis, respectively. Univariate analysis demonstrated that the following were significant risk factors for breast cancer patients survival: patient's age, stage of disease, tumour size, lymph node status, type of surgery and chemotherapy. Better survival was related to younger patients’ age, smaller tumour size, lower stage of disease, no lymph nodes involvement. Survival rates were higher among patients who received adjuvant chemotherapy and underwent quadrantectomy. In the multivariate statistical analysis the significant independent prognostic variables influencing survival were lymph node status and adjuvant chemotherapy. Survival rates of the patients, who received adjuvant anthracycline containing chemotherapy were higher, than those in non-anthracycline containing treatment group, but the difference was not statistically significant.ConclusionPatients who had lymph node status N2–3 and those who did not receive adjuvant chemotherapy showed worse prognosis and survival than other patients. The impact of chemotherapy type (anthracycline containing or non-anthracycline containing) on patients survival was not statistically significant.     

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.     

The mammary ducts create a favourable microenvironment for xenografting of luminal and molecular apocrine breast tumours

There is a paucity of models for hormone receptor‐positive (HR+) breast cancer because of the difficulty of establishing xenografts from these tumours. We show that this obstacle can be overcome by injecting human tumour cells directly into the mammary ducts of immunodeficient mice. Tumours from 31 patients were infected overnight with a lentiviral vector expressing tdTomato and injected through the nipple into the mammary ducts of NOD‐SCID‐IL2RG?/? mice. Tumours formed in the mice in 77% of cases after the first injection (6/8 luminal A, 15/20 luminal B, and 3/3 molecular apocrine). Four luminal A and one molecular apocrine graft were tested in secondary and tertiary grafts: all were successfully passaged in secondary and 4/5 in tertiary grafts. None of the samples engrafted when injected subcutaneously. The morphology, oestrogen receptor (ER), progesterone receptor (PR), androgen receptor (AR), and Ki‐67 profiles of the clinical samples were maintained in the tertiary grafts. We also show that the intraductal approach can be used to test the response to targeted therapy with fulvestrant and palbociclib, using a genetically defined ER+ model. We conclude that the mammary ducts create a microenvironment that is uniquely favourable to the survival and growth of tumours derived from mammary hormone‐sensing cells. This approach opens the door to testing genomically targeted treatment of HR+ tumours in precision medicine programmes. Copyright © 2016 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.     

The multifunctional role of the immunohistochemical expression of MMP-7 in invasive breast cancer

The secretion of matrix metalloproteinases (MMPs) is crucial in the metastasis of cancer cells, since MMPs are responsible for the degradation of extracellular matrix (ECM). Among them, matrix metalloproteinase-7 (MMP-7) or matrilysin 1 is a stromelysin which degrades type-IV collagen, fibronectin and laminin. Immunohistochemistry was performed to detect MMP-7 protein in infiltrative breast carcinomas. MMP-7 was studied along with clinicopathological parameters, disease-free and overall survival, and p53, c-erbB-2, topoIIa, MMP-2, uPAR and beta-catenin. MMP-7 immunoreactivity was detected in the cytoplasm of cancer cells in 54.2% (96/177) and tumor stromal cells in 47.5% (84/177), as well as in normal epithelium adjacent to malignant epithelium. MMP-7 reactivity in cancer cells displayed an inverse association with nuclear grade (p=0.049) and topoIIa (p=0.03). A parallel association was observed between the expression of MMP-7 in both malignant and stromal cells with uPAR in cancer cells (p=0.033 and p=0.027, respectively). MMP-7 of tumor stromal cells depicted a parallel correlation with MMP-2 of the same cell type (p=0.044), while abnormal beta-catenin expression was inversely associated with MMP-7 of cancer cells (p=0.047). Our results show the multifunctional role of MMP-7 in the mammary gland, since it seems to be associated with a less aggressive phenotype, while, at the same time, being involved in invasion, through its collaboration with indicators of invasion.