Fluorescentin situ hybridization assessment of chromosome 8 copy number in breast cancer

Summary Conventional cytogenetics of breast and other solid tumors has been hampered by a number of factors. An analysis of breast tumor tissues was therefore undertaken using fluorescentin situ hybridization (FISH). A total of 34 specimens were analyzed using a chromosome 8-specific -satellite probe. Various approaches were tested and compared. Among 30 informative samples, 11 infiltrating ductal carcinomas, not otherwise specified (NOS), 5 ductal carcinomasin situ, 5 lobular carcinomas, 3 papillary carcinomas, and 6 benign lesions were studied. Of the 11 cases of infiltrating ductal carcinomas (NOS) analyzed, four cases showed 3 signals, one case showed 4 signals, and the rest showed 2 signals. Of the 5 cases of ductal carcinomain situ samples, 1 showed 3 signals and the other 4 cases showed 2 signals. All cases of lobular carcinomas, papillary carcinomas, and benign lesions showed 2 signals. We inferred from these data that 36% of the infiltrating ductal carcinomas (NOS) were trisomic and 9% were tetrasomic, whereas 20% of the ductal carcinomasin situ were trisomic. All samples from lobular carcinomas, papillary carcinomas, and the benign lesions were disomic. From our preliminary data, it can further be concluded that a subset of breast cancer is characterized by chromosome 8 trisomy. These data are consistent with an ever-increasing database on the association of chromosomal 8 trisomy with other cancers such as leukemia, lymphoma, prostate cancer, ovarian carcinoma, salivary gland tumor, malignant melanoma, desmoid tumors, and recently gestational trophoblastic disease. It is also noted that the ability to analyze formalin-fixed, paraffin-embedded archival material will enable a more comprehensive cytogenetic study of breast cancer than is currently available.     

p63 expression in normal,hyperplastic and malignant breast tissues

BACKGROUND: p63 is a homologue of the p53 tumor suppressor gene and its protein is selectively expressed in the basal cells of a variety of epithelial tissues. It has recently been confirmed that p63 is expressed in the basal cells of normal prostate glands but not in prostatic carcinomas. Whether expression of p63 in breast correlates with tumor progression is the focus of this study. METHODS: Forty cases, which all contained normal breast tissue, ductal hyperplasia, ductal carcinoma in situ and invasive ductal carcinoma in the same patient were included in this investigation using an indirect immunohistochemical method and double staining. RESULTS: p63 was exclusively expressed in the myoepithelial cells of normal breast, partially expressed in ductal hyperplasia, rarely expressed in carcinoma in situ and not expressed in invasive carcinomas. CONCLUSION: The results suggest an association between loss of p63 expression and progression of breast ductal carcinoma. p63 immunostaining might be of assistance for distinguishing invasive ductal carcinoma from ductal carcinoma in situ or rare questionable ductal hyperplastic lesions, leading to correct therapy clinically.     

Altered expression and localization of PKC eta in human breast tumors

Protein kinase C (PKC) eta is a PKC isoform whose upregulation is associated with differentiation in many epithelial tissues, including the rat mammary gland. The purpose of this study was to examine whether PKC eta is altered, in expression or localization, in human breast cancer. Paraffin sections of 49 in situ breast lesions, 29 invasive breast tumors, and nine normal breast biopsies were examined for PKC eta expression by immunohisto chemistry. Adjacent regions of normal epithelium, and in situ lesions that were present adjacent to invasive lesions were also analyzed. In normal epithelium, regardlessof the presence of adjacent in situ or invasive lesions, PKC eta was present in the cytoplasm of the luminal epithelium, and increased inareas of normal lobular development, similar to normal rat mammary gland. PKC eta staining intensity was homogeneous in normal lobules, but heterogeneous in in situ and invasive lesions, being focally increased in cells with aberrant nuclear morphology. In situ lesions were similar to adjacent normal epithelium in average staining intensity, regardless of whether invasion was also present. However, the invasive lesions themselves were significantly decreased in staining intensity compared to adjacent in situ lesions. In addition, 75% of invasive breast cancer lesions showed decreased staining relative to adjacent normal epithelium, compared to 37% of in situ lesions. The invasive tumors which possessed high PKC eta staining were associated with positive lymph node status. These results demonstrate that quantitative and qualitative alterations in PKC eta occur in human breast cancers.     

Cell kinetics of histologic variants ofin situ breast carcinoma

Summary A thymidine labeling study of cell kinetics of 61in situ breast carcinomas showed relationships between histological characteristics and kinetics. The thymidine labeling index (TLI) was significantly lower in cribriform-papillary intraductal carcinoma (median 1.30%, geometric mean 1.18%, mean 1.83 ± 0.45%) and lobular carcinomain situ (median 1.43%, geometric mean 1.12%, mean 1.63 ± 0.46%) than in comedo intraductal carcinoma (median 4.40%, geometric mean 3.74%, mean 5.15 ± 0.86%). The results for solid intraductal carcinoma, which is a less well defined and more heterogeneous entity, were intermediate (median 2.45%, geometric mean 2.40%, mean 3.32 ± 0.80%). When invasive carcinoma was also available for kinetic study, the TLI ofin situ and invasive components were usually similar (r = 0.66). The data indicate that the TLI usually does not change during the transition fromin situ to invasive carcinoma. Cribriform-papillary intraductal carcinoma is a slowly proliferating entity that gives rise to slowly proliferating invasive carcinomas with relatively high levels of estrogen and progesterone receptors. Lobular carcinomain situ similarly has low proliferative rates and gives rise to slowly proliferating invasive carcinomas. Intraductal comedocarcinoma has relatively high proliferative rates and gives rise to invasive carcinomas with high proliferative rates that often are receptor-negative. Nine of the 11in situ carcinomas that were associated with invasive tumor and subsequent local recurrence or metastasis had TLIs above the median, and seven were comedo type with high TLIs. Our observations from thymidine labeling are consistent with a viewpoint regarding cribriform-papillary intraductal carcinoma as relatively bland, and comedo intraductal carcinoma as a distinctly more dangerous entity. Solid intraductal carcinoma seems to resemble cribriform-papillary more closely than comedo intraductal carcinoma.     

Regulation of in situ to invasive breast carcinoma transition

The transition of ductal carcinoma in situ (DCIS) to invasive carcinoma is a poorly understood key event in breast tumor progression. Here, we analyzed the role of myoepithelial cells and fibroblasts in the progression of in situ carcinomas using a model of human DCIS and primary breast tumors. Progression to invasion was promoted by fibroblasts and inhibited by normal myoepithelial cells. Molecular profiles of isolated luminal epithelial and myoepithelial cells identified an intricate interaction network involving TGFbeta, Hedgehog, cell adhesion, and p63 required for myoepithelial cell differentiation, the elimination of which resulted in loss of myoepithelial cells and progression to invasion.     

Immunohistochemical distribution of c-erbB-2 in infiltrating and in situ breast cancer

An immunohistochemical study of c-erbB-2 expression was performed on invasive and in situ breast cancer. Strong membrane staining was seen in 16% of the infiltrating ductal carcinomas and 44% of the in situ lesions. c-erbB-2 was overexpressed in ductal rather than lobular tumours. Our results indicate that a small sub-group of breast carcinomas are associated with over-expression of this oncogene which may define an important subgroup of in situ and infiltrating ductal carcinomas.     

p53 Protein Accumulation in Non-Invasive Lesions Surrounding p53 Mutation Positive Invasive Breast Cancers

p53 mutation is a common event in sporadic breast cancer being found in 15–50% of invasive carcinomas. The purpose of this study was to determine the earliest histologic stage at which p53 mutation could be detected with a widely used anti-p53 antibody (DO7, Novocastra) which recognizes both wild type and mutant forms. p53 expression was assessed immunohistochemically in 12 primary breast carcinomas with known p53 mutations and in all pre-malignant epithelial lesions surrounding these invasive cancers. Strong p53 nuclear staining was found in all of the tumors known to have missense mutations and none of the tumors with truncation mutations. In cases with intense staining in the invasive carcinoma, a similar quality of staining was also seen in all areas of DCIS (ductal carcinoma in situ) and was representative of missense p53 mutations. Lighter nuclear staining intensity was observed in up to 40% of cells in areas of hyperplasia and in up to 30% of normal breast lobules irrespective of the type of mutation found in the invasive carcinoma. This weak staining was not specific to mutated p53 and may indicate increased amounts of normal p53 protein.We conclude that p53 inactivation occurs prior to invasion in breast carcinogenesis, with mutations being uniformly identified in DCIS associated with p53-mutated invasive carcinomas. In contrast, there is no evidence that epithelial hyperplasia or epithelial cells of the terminal duct lobular unit harbor the same mutations as their associated invasive carcinoma.     

Mucin expression in mucinous carcinoma and other invasive carcinomas of the breast.

To investigate mucin expression in breast cancer, immunohistochemical staining was performed on 30 mucinous carcinomas and 95 non-mucinous invasive carcinomas. MUC2 expression was detected in all mucinous carcinomas, but only in 11.1% of invasive ductal carcinomas, and in none of the invasive lobular carcinomas and medullary carcinomas. MUC1 is often expressed in invasive breast carcinoma, but not in medullary carcinoma. Strong cytoplasmic staining was seen in invasive ductal carcinoma, in contrast to surface membrane staining in mucinous carcinoma and intracytoplasmic vacuole staining in invasive lobular carcinoma. CA19-9 and CA50 expression in more than 25% of tumor cells was seen in 17.2 and 16.0% of invasive ductal carcinomas, respectively, but not in mucinous carcinomas. CA125 and human gastric mucin were rarely expressed in breast cancer, irrespective of histologic type.     

Subtype‐specific micro‐RNA expression signatures in breast cancer progression

Robust markers of invasiveness may help reduce the overtreatment of in situ carcinomas. Breast cancer is a heterogeneous disease and biological mechanisms for carcinogenesis vary between subtypes. Stratification by subtype is therefore necessary to identify relevant and robust signatures of invasive disease. We have identified microRNA (miRNA) alterations during breast cancer progression in two separate datasets and used stratification and external validation to strengthen the findings. We analyzed two separate datasets (METABRIC and AHUS) consisting of a total of 186 normal breast tissue samples, 18 ductal carcinoma in situ (DCIS) and 1,338 invasive breast carcinomas. Validation in a separate dataset and stratification by molecular subtypes based on immunohistochemistry, PAM50 and integrated cluster classifications were performed. We propose subtype‐specific miRNA signatures of invasive carcinoma and a validated signature of DCIS. miRNAs included in the invasive signatures include downregulation of miR‐139‐5p in aggressive subtypes and upregulation of miR‐29c‐5p expression in the luminal subtypes. No miRNAs were differentially expressed in the transition from DCIS to invasive carcinomas on the whole, indicating the need for subtype stratification. A total of 27 miRNAs were included in our proposed DCIS signature. Significant alterations of expression included upregulation of miR‐21‐5p and the miR‐200 family and downregulation of let‐7 family members in DCIS samples. The signatures proposed here can form the basis for studies exploring DCIS samples with increased invasive potential and serum biomarkers for in situ and invasive breast cancer.     

EGFR与HER-2在不同分子类型乳腺癌中的表达及其相关性分析

目的：探讨EGFR和HER-2在不同分子类型乳腺癌组织中的表达及其相关性。方法：回顾性分析2015年1月—2020年3月在邯郸市中心医院行手术治疗的乳腺癌患者资料650例(其中浸润性导管癌600例，浸润性小叶癌50例)及乳腺纤维腺瘤30例，应用免疫组织化学(IHC)方法对手术切除标本进行EGFR和HER-2蛋白表达检测，采用χ²检验及Spearman相关分析对数据进行统计学分析。结果：EGFR在乳腺浸润性导管癌中表达阳性率为48.7%，显著高于浸润性小叶癌(24.0%)及纤维腺瘤(16.7%)(P<0.01)。HER-2在乳腺浸润性导管癌中表达阳性率为27.8%，显著高于浸润性小叶癌(8.0%)及纤维腺瘤(6.7%)(P=0.002)。乳腺浸润性导管癌与浸润性小叶癌中，EGFR阳性率与HER-2评分等级呈正相关(r=1.000，P<0.05)，且EGFR阳性率与HER-2阳性表达呈正相关(r=1.000，P<0.05)。EGFR阳性率在HER-2过表达型与三阴型乳腺癌组织中显著高于Luminal A型和Luminal B型，且Luminal B中HER-2阳性显著高于HER-2阴性亚型(P<0.001)。结论：EGFR、HER-2阳性率在乳腺浸润性导管癌显著升高，且EGFR阳性率与HER-2的评分等级及阳性表达率均呈正相关，EGFR在HER-2过表达型与三阴型乳腺癌组织中显著升高，为进一步研究HER-2阳性乳腺癌及三阴型乳腺癌的靶向药物治疗提供线索及理论依据。     

Tamoxifen Suppresses Histologic Progression to Atypia and DCIS in MCFIOAT Xenografts, a Model of Early Human Breast Cancer

We evaluated the effects of tamoxifen on the growth and progression of MCFIOAT xenografts, an estrogen responsive model of human breast tumor progression, in which cells are injected orthotopically into the mammary fat pad of female nude mice. At 10 weeks following implantation, histologic sections of each graft were evaluated microscopically for histologic lesions analogous to human breast tumor progression, graded as simple hyperplasia, complex hyperplasia, atypical hyperplasia, ductal carcinoma in situ and invasive carcinoma. Three out of five xenografts in (endocrine intact) control animals progressed to atypical hyperplasia, one progressed to ductal carcinoma in situ and one to invasive carcinoma. The latter two control grafts also contained foci of putative precursor lesions (i.e. atypical hyperplasia and in situ carcinoma, respectively). Tamoxifen supplemented xenografts (N=17) were uniformly smaller than controls, but contained invasive carcinoma in a similar proportion (4/17, 24%). However, none of these grafts exhibited ductal carcinoma in situ and only one contained atypical hyperplasia. Most grafts in tamoxifen supplemented animals (10/17, including all four with carcinomas) showed complex hyperplasia, which typically dominated the graft. We conclude that tamoxifen selectively inhibits the appearance or growth of preinvasive index lesions. Development of malignancy in the absence of such precursors, though, implies selection for alternative histogenetic pathways as a result of endocrine manipulation.     

Identification of insulin-like growth factor binding proteins in breast cancer cells

Summary The overexpression of the c-erbB-2 oncoprotein is now thought by most authors to be associated with adverse prognosis in breast carcinoma. In this study, we investigate the relationship between overexpression of the c-erbB-2 oncoprotein and nuclear size by morphometry in a series of 150 human breast carcinomas, comprising 65 cases of ductal carcinomain situ (DCIS) and 85 cases of invasive adenocarcinoma. The mean nuclear size for c-erbB-2 positive cases of DCIS was 54.8 µm² and invasive carcinoma was 52.1 µm² respectively, in contrast with 41.6 µm² and 42.5 µm² for c-erbB-2 negative cases of DCIS and invasive carcinoma respectively. Flow cytometric examination of DNA in a subset of 91 of these tumours showed no association between tumour cell aneuploidy and c-erbB-2 overexpression.S-phase fraction could be calculated on 20 cases of DCIS and 48 invasive carcinomas. There was a strong association between c-erbB-2 overexpression, S-phase fraction (p<0.001) and proliferative index (p<0.001) in 20 cases of DCIS.A weak association of S-phase fraction and c-erbB-2 overexpression was seen in 48 invasive carcinomas (p=0.047). This study confirms the subjective impression that there is a relationship between large tumour cell nuclear size and an overexpression of the c-erbB-2 oncoprotein, and also shows an association with increased tumour cell proliferation.     

Epithelial proliferative lesions and carcinomas in fibroadenomas of the breast

Sixteen cases of fibroadenomas with epithelial proliferative lesions (EP lesions) with histologic features resembling those of epithelial hyperplasia, sclerosing adenosis, and microglandular adenosis, and four cases of carcinomas in fibroadenomas (CA lesions) were studied histopathologically and immunohistochemically. The CA lesions included one intraductal carcinoma, two invasive ductal carcinomas, and one lobular carcinoma in situ. The histologic features of the EP lesions and CA lesions were fundamentally the same as those of carcinomas commonly observed in the mammary gland. Immunohistochemically, smooth muscle actin was useful in the detection of myoepithelial cells, particularly in EP lesions of the adenosis type (sclerosing adenosis or microglandular adenosis), and in distinguishing carcinoma. The differences between EP lesions and CA lesions of sites of immunoreactivity to CA15-3, CEA, and EMA were also helpful for differential diagnosis.     

Carcinoma in situ of the breast: correlation of histopathology to immunohistochemical markers and DNA ploidy

In a consecutive and unselected series of 178 cases of carcinoma in situ of the breast (CIS), comprising both ductal (DCIS) and lobular type (LCIS), and a series of 48 cases of invasive carcinoma (IC) with predominance of DCIS, the association between histopathology, immunohistochemical markers (ER, PgR, MIB-1, c-erbB-2, and p53), and DNA ploidy was investigated, in order to discriminate biologically different groups. In DCIS, significant correlation was shown between large nuclear size and comedonecrosis, both of which showed also strong association to DNA aneuploidy, high proliferation activity, low steroid receptor content, and overexpression of c-erbB-2 and p53 – factors that may indicate an aggressive behavior. Small nuclear CIS, whether LCIS or DCIS, on the contrary, were DNA diploid with low proliferation, and no cases showed overexpression of c-erbB-2 and p53. Heterogeneity with respect to the investigated parameters was also a frequent finding that may reflect a development complexity. In IC, comparison of the DCIS and the invasive component showed similar patterns. No significant differences were shown between DCIS without and with invasion. This may indicate that none of the investigated parameters on its own are essential for the event of invasion.     

Role of microRNA221 in regulating normal mammary epithelial hierarchy and breast cancer stem-like cells

Increasing evidence suggests that lineage specific subpopulations and stem-like cells exist in normal and malignant breast tissues. Epigenetic mechanisms maintaining this hierarchical homeostasis remain to be investigated. In this study, we found the level of microRNA221 (miR-221) was higher in stem-like and myoepithelial cells than in luminal cells isolated from normal and malignant breast tissue. In normal breast cells, over-expression of miR-221 generated more myoepithelial cells whereas knock-down of miR-221 increased luminal cells. Over-expression of miR-221 stimulated stem-like cells in luminal type of cancer and the miR-221 level was correlated with clinical outcome in breast cancer patients. Epithelial-mesenchymal transition (EMT) was induced by overexpression of miR-221 in normal and breast cancer cells. The EMT related gene ATXN1 was found to be a miR-221 target gene regulating breast cell hierarchy. In conclusion, we propose that miR-221 contributes to lineage homeostasis of normal and malignant breast epithelium.     

Evaluation of breast cancer with a computer-aided detection system by mammographic appearance and histopathology

BACKGROUND: The objective of this study was to evaluate the performance of a computer-aided detection (CAD) system for the detection of breast cancer, based on mammographic appearance and histopathology. METHODS: From 1000 consecutive screening mammograms from women with biopsy-proven breast carcinoma, 273 mammograms were selected randomly for retrospective evaluation by CAD. The sensitivity of the CAD system for breast cancer was assessed from the proportion of masses and microcalcifications detected. The corresponding tumor histopathologies also were evaluated. Normal mammograms (n = 155 patients) were used to determine the false-positive rate of the system. RESULTS: Of the 273 breast carcinomas, 149 appeared mammographically as masses, and 88 appeared as microcalcifications, including 36 carcinomas that presented as mixed lesions. The CAD system marked 125 of 149 masses correctly (84%), marked 86 of 88 microcalcifications correctly (98%), and marked 32 of 36 of mixed lesions correctly (89%.). The system showed a high sensitivity for the detection of ductal carcinoma in situ (95%; 73 of 77 lesions), invasive lobular carcinoma (95%; 18 of 19 lesions), invasive ductal carcinoma (85%; 125 of 147 lesions), and invasive mammary carcinoma (90%; 27 of 30 lesions). The highest CAD system sensitivity was for all invasive carcinomas that presented as microcalcifications (100%). On normal mammograms, there was an average of 1.3 false-positive CAD marks per image. CONCLUSIONS: The CAD system correctly marked a large majority of biopsy-proven breast cancers, with a greater sensitivity for lesions with microcalcifications and without significant impact of performance based on tumor histopathology. CAD was highly effective in detecting invasive lobular carcinoma (sensitivity, 95%) and ductal carcinoma in situ (sensitivity, 95%). CAD represents a useful tool for the detection of breast cancer.     

Nuclear morphometry of benign and malignant breast lesions

The mean nuclear area (MNA) of mammary gland epithelium was measured in 403 breast specimens, comprising 239 invasive carcinomas, 49 carcinomas in situ, 45 cases of fibrocystic disease (f.c.d.) with intraductal epithelial hyperplasia, and 60 cases of f.c.d. without intraductal hyperplasia. Normal breast tissue adjacent to other benign or malignant lesions was measured in 170 specimens. Statistical analysis revealed no difference between the MNA of invasive ductal carcinoma and ductal carcinoma in situ. The MNA of lobular and ductal carcinomas were significantly different. Significant differences were also found between ductal carcinoma and the two classes of f.c.d. The MNA of f.c.d. with and without intraductal hyperplasia were also significantly different, the former having the highest MNA. All breast lesions showed MNA significantly higher than that of normal breast epithelium. These findings show that there is a gradual increase in MNA from the baseline value of normal breast epithelium, via fibrocystic disease without and with intraductal proliferation to invasive carcinomas. Measurement of MNA may aid in pinpointing cases of intraductal epithelial hyperplasia with malignant potential.     

Neuropilin-1 is differentially expressed in myoepithelial cells and vascular smooth muscle cells in preneoplastic and neoplastic human breast: a possible marker for the progression of breast cancer

The expression and distribution of neuropilin-1 (NRP-1) was examined in the samples of normal human breast tissues and in non-neoplastic and neoplastic areas of breast tissue removed for carcinoma using RT-PCR as well as conventional and tissue microarrays immunohistochemical analyses. The NRP-1 mRNA expression was significantly higher in neoplastic tissues as compared to normal breast samples. Immunohistochemically, the myoepithelial cells of the mammary ducts and lobules display positive reactions for NRP-1, whereas the inner ductal and lobular epithelial cell layers failed to react. The myoepithelial cells of ducts and lobules in both neoplastic and non-neoplastic tissue specimens displayed a stronger positive reaction for NRP-1 than those in the normal breast. A positive reaction for NRP-1, but with a gradual reduction in intensity, was observed in the myoepithelial cells of ducts with atypical epithelial hyperplasia and ductal carcinoma in situ (DCIS). The reaction was undetected or minimally detected in the areas of invasive carcinoma. NRP-1 positive immunolabeling was also localized in the vascular smooth muscle cells and in some endothelial cells of the blood vessels in normal, non-neoplastic and neoplastic breast tissue samples. In areas of breast carcinoma, NRP-1 immunolabeling was more prominent in both vascular smooth muscle cells and in some endothelial cells than in similar cells in normal breast. The specificity of the newly developed antibody for NRP-1 was confirmed by in situ hybridization with DIG-labeled PCR generated probe. These results suggest that NRP-1 may be a multiple function protein in human breast and may be involved in the induction of local invasiveness of neoplasia and angiogenesis and have direct relevance to the progression of breast cancer.     

Screening for breast cancer with MRI: recent experience from the Australian Capital Territory

The American Cancer Society now recommends annual MRI screening for women at 20–25% or greater lifetime risk of breast cancer. The role of MRI screening in other risk subgroups is unproved because of insufficient data. Our study comprised 209 breast MRI scans carried out in 171 asymptomatic patients (age range 22–67 years, mean 46 years), referred between January 2005 and June 2008. Targeted ultrasound was carried out in 32 episodes (15%) and biopsies were taken in 23 patients (13%). In four patients, MR‐guided procedures were required to establish a diagnosis, two using hook‐wire localization and two by means of vacuum‐assisted biopsy. Seven cancers were detected by MRI in the 171 patients, with a yield of 4.1%. Only one of the seven cancers was also shown by x‐ray mammography. Four patients had invasive ductal cancer (all axillary node negative) and three had high‐grade ductal carcinoma in situ or pleomorphic lobular carcinoma in situ. The three women with in situ disease were all potentially high risk, based on the National Breast and Ovarian Cancer Centre (NBOCC) criteria. Three women with invasive breast cancer were at only average risk based on NBOCC criteria, but two of these had extremely dense breasts. A fourth patient, found to have multifocal invasive cancer, had a personal history of contralateral breast cancer, but no relevant family history. Our findings suggest that breast MRI could be used to screen a larger Australian population at increased risk of developing breast cancer.