The molecular journey from ductal carcinoma in situ to invasive breast cancer

Mammographic features of calcifications in DCIS: correlation with oestrogen receptor and human epidermal growth factor receptor 2 status

OBJECTIVE

This study investigated the correlation of oestrogen receptor (ER) and human epidermal growth factor receptor 2 (HER2) status with the probability of malignancy (POM) of mammographic calcifications in ductal carcinoma in situ (DCIS).

METHODS

A total of 101 women (age range, 27-83 years) with pure DCIS that presented as mammographic calcifications were included. Three radiologists independently reviewed mammograms according to the BI-RADS lexicon and provided 100-point POM scores and a BI-RADS category. ER, HER2 and breast cancer subtypes were determined using immunohistochemistry (IHC) and fluorescence in situ hybridisation. Pairwise correlations between POM and IHC biomarker scores were calculated, and mammographic features were compared between breast cancer subtypes.

RESULTS

HER2 level positively correlated with the POM score (P < 0.0001) and BI-RADS category (P < 0.0001), and ER level inversely correlated with the POM score (P < 0.013) and BI-RADS category (P < 0.010). Fine linear branching (P = 0.004) and segmental (P = 0.014) calcifications were significantly associated with HER2-positive cancers, and clustered calcifications were more frequently observed in ER-positive cancers (P = 0.014).

CONCLUSION

HER2 status in DCIS correlated positively with the POM of mammographic calcifications, as determined by radiologists on the basis of the BI-RADS lexicon.

KEY POINTS

• Prediction of malignancy on mammographic ductal carcinoma in situ is difficult. • HER2 level correlated positively with the probability of malignancy assigned by radiologists. • ER level correlated inversely with the probability of malignancy assigned by radiologists. • HER2-positive DCIS more frequently exhibited fine linear branching or segmental calcifications. • ER-positive DCIS more frequently exhibited clustered calcifications.

Different distribution of breast ductal carcinoma in situ, ductal carcinoma in situ with microinvasion, and invasion breast cancer

Background

Breast ductal cancer in situ (DCIS) can recur or progress to invasive ductal cancer (IDC), and the interim stage include DCIS with microinvasion (DCIS-Mi). In this article, we attempt to study the study the differences of clinicopathological features, imaging data, and immunohistochemical-based subtypes among DCIS, DCIS-Mi, and IDC.

Methods

In this retrospective study, we attempt to compare the clinicopathological features, immunohistochemical results and imaging data of 866 patients (included 73 DCIS, 72 DCIS-Mi, and 721 IDC).

Results

Patients with DCIS and DCIS-Mi were younger than those with IDC (P = 0.007). DCIS and DCIS-Mi often happened in premenopausal women while IDC was opposite (P <0.001). The incidence of IDC with node-positive was significantly higher than it in DCIS and DCIS-Mi (P <0.001). We also observed that the Her2-positive was more often found in patients with pure DCIS compared to those with DCIS-Mi and DCIS-I (P <0.001). There was a significant difference between the four subgroups (Luminal-A, Luminal-B, ERBB2+, Basal-like) from DCIS, DCIS-Mi, and IDC (P <0.001). Basal-like patients were fewer than other subgroups in DCIS, DCIS-Mi, and IDC. The incidence of the first performance of ultrasound (catheter winded and nodular mass) and mammography (nodular mass) had significantly difference among patients with DCIS, DCIS-Mi, and IDC (P <0.001).

Conclusions

Different clinicopathological, immunohistochemical, and imaging features among DCIS, DCIS-Mi, and IDC indicate that they are distinct entities. A larger sample size is needed for further study.

Pro-metastatic tumor–stroma interactions in breast cancer

The vast majority of breast cancer-related deaths are due to metastatic disease. Reciprocal and complex interactions between epithelial tumor cells and the various components of the tumor microenvironment influence tumor progression and metastases although the molecular mechanisms underlying these metastasis-promoting effects are not fully characterized. Identifying and understanding pathways of tumor–stroma cross-talk are likely to lead to the development of novel prognostic biomarkers for metastasis and strategies to prevent metastasis at its earliest stages, resulting in improved patient outcomes.

Automated reconstruction algorithm for identification of 3D architectures of cribriform ductal carcinoma in situ

Ductal carcinoma in situ (DCIS) is a pre-invasive carcinoma of the breast that exhibits several distinct morphologies but the link between morphology and patient outcome is not clear. We hypothesize that different mechanisms of growth may still result in similar 2D morphologies, which may look different in 3D. To elucidate the connection between growth and 3D morphology, we reconstruct the 3D architecture of cribriform DCIS from resected patient material. We produce a fully automated algorithm that aligns, segments, and reconstructs 3D architectures from microscopy images of 2D serial sections from human specimens. The alignment algorithm is based on normalized cross correlation, the segmentation algorithm uses histogram equilization, Otsu's thresholding, and morphology techniques to segment the duct and cribra. The reconstruction method combines these images in 3D. We show that two distinct 3D architectures are indeed found in samples whose 2D histological sections are similarly identified as cribriform DCIS. These differences in architecture support the hypothesis that luminal spaces may form due to different mechanisms, either isolated cell death or merging fronds, leading to the different architectures. We find that out of 15 samples, 6 were found to have 'bubble-like' cribra, 6 were found to have 'tube-like' criba and 3 were 'unknown.' We propose that the 3D architectures found, 'bubbles' and 'tubes', account for some of the heterogeneity of the disease and may be prognostic indicators of different patient outcomes.

Ductal carcinoma in situ of the breast: a surgical perspective

Ductal carcinoma in situ (DCIS) of the breast is a heterogeneous neoplasm with invasive potential. Risk factors include age, family history, hormone replacement therapy, genetic mutation, and patient lifestyle. The incidence of DCIS has increased due to more widespread use of screening and diagnostic mammography; almost 80% of cases are diagnosed with imaging with final diagnosis established by biopsy and histological examination. There are various classification systems used for DCIS, the most recent of which is based on the presence of intraepithelial neoplasia of the ductal epithelium (DIN). A number of molecular assays are now available that can identify high-risk patients as well as help establish the prognosis of patients with diagnosed DCIS. Current surgical treatment options include total mastectomy, simple lumpectomy in very low-risk patients, and lumpectomy with radiation. Adjuvant therapy is tailored based on the molecular profile of the neoplasm and can include aromatase inhibitors, anti-estrogen, anti-progesterone (or a combination of antiestrogen and antiprogesterone), and HER2 neu suppression therapy. Chemopreventive therapies are under investigation for DCIS, as are various molecular-targeted drugs. It is anticipated that new biologic agents, when combined with hormonal agents such as SERMs and aromatase inhibitors, may one day prevent all forms of breast cancer.

Oestrogen-induced genes in ductal carcinoma in situ: their comparison with invasive ductal carcinoma

It is well known that oestrogens play important roles in both the pathogenesis and development of invasive ductal carcinoma (IDC) of human breast. However, molecular features of oestrogen actions have remained largely unclear in pure ductal carcinoma in situ (pDCIS), regarded as a precursor lesion of many IDCs. This is partly due to the fact that gene expression profiles of oestrogen-responsive genes have not been examined in pDCIS. Therefore, we first examined the profiles of oestrogen-induced genes in oestrogen receptor (ER)-positive pDCIS and DCIS (DCIS component (DCIS-c)) and IDC (IDC component (IDC-c)) components of IDC cases (n=4 respectively) by microarray analysis. Oestrogen-induced genes identified in this study were tentatively classified into three different groups in the hierarchical clustering analysis, and 33% of the genes were predominantly expressed in pDCIS rather than DCIS-c or IDC-c cases. Among these genes, the status of MYB (C-MYB), RBBP7 (RBAP46) and BIRC5 (survivin) expressions in carcinoma cells was significantly higher in ER-positive pDCIS (n=53) than that in ER-positive DCIS-c (n=27) or IDC-c (n=27) by subsequent immunohistochemical analysis of the corresponding genes (P<0.0001, P=0.03 and P=0.0003 respectively). In particular, the status of C-MYB immunoreactivity was inversely (P=0.006) correlated with Ki67 in the pDCIS cases. These results suggest that expression profiles of oestrogen-induced genes in pDCIS may be different from those in IDC; and C-MYB, RBAP46 and survivin may play important roles particularly among oestrogen-induced genes in ER-positive pDCIS.

The rebel angel: mutant p53 as the driving oncogene in breast cancer

Breast cancer is the most frequent invasive tumor diagnosed in women, causing over 400 000 deaths yearly worldwide. Like other tumors, it is a disease with a complex, heterogeneous genetic and biochemical background. No single genomic or metabolic condition can be regarded as decisive for its formation and progression. However, a few key players can be pointed out and among them is the TP53 tumor suppressor gene, commonly mutated in breast cancer. In particular, TP53 mutations are exceptionally frequent and apparently among the key driving factors in triple negative breast cancer -the most aggressive breast cancer subgroup-whose management still represents a clinical challenge. The majority of TP53 mutations result in the substitution of single aminoacids in the central region of the p53 protein, generating a spectrum of variants ('mutant p53s', for short). These mutants lose the normal p53 oncosuppressive functions to various extents but can also acquire oncogenic properties by gain-of-function mechanisms. This review discusses the molecular processes translating gene mutations to the pathologic consequences of mutant p53 tumorigenic activity, reconciling cell and animal models with clinical outcomes in breast cancer. Existing and speculative therapeutic methods targeting mutant p53 are also discussed, taking into account the overlap of mutant and wild-type p53 regulatory mechanisms and the crosstalk between mutant p53 and other oncogenic pathways in breast cancer. The studies described here concern breast cancer models and patients-unless it is indicated otherwise and justified by the importance of data obtained in other models.

Intraductal proliferative lesions of the breast-terminology and biology matter: premalignant lesions or preinvasive cancer?

Morphological criteria for the diagnosis of intraductal proliferative lesions of the breast have been an object of research and much controversy, and its terminology is rather confusing. Knowledge of the molecular aspects of this disease probably necessitates further research to clarify if these entities can be identified as breast cancer precursors or as a malignant preinvasive disease. These issues are of great interest not only for their biological implications, but also to the clinician who must understand the disease and direct therapies. Molecular studies have shown that epitheliosis (usual ductal hyperplasia) is not monoclonal, while malignant lesions (atypical ductal hyperplasia, flat epithelial atypia, low-grade and high-grade intraductal carcinoma) constantly show these characteristics. These malignant lesions, classified with a DIN grading system (ductal intraepithelial neoplasia), are not obligate precursors of invasive ductal carcinoma and do not represent different evolving grades in a linear model of cancerogenesis. Breast cancerogenesis probably has different pathways with different morphologic precursors.

Silencing of HSulf-2 expression in MCF10DCIS.com cells attenuate ductal carcinoma in situ progression to invasive ductal carcinoma in vivo

INTRODUCTION

Ductal carcinoma in situ (DCIS) of the breast is a heterogeneous group of proliferative cellular lesions that have the potential to become invasive. Very little is known about the molecular alterations involved in the progression from DCIS to invasive ductal carcinoma (IDC). Heparan endosulfatase (HSulf-2) edits sulfate moieties on heparan sulfate proteoglycans (HSPGs) and has been implicated in modulating heparin binding growth factor signaling, angiogenesis and tumorigenesis. However, the role of HSulf-2 in breast cancer progression is poorly understood. MCF10DCIS.com cells (referred as MCF10DCIS) express HSulf-2 and form comedo type DCIS and progress to IDC when transplanted in immune-deficient mice and, therefore, is an ideal model to study breast cancer progression. We evaluated the role of HSulf-2 in progression from DCIS to IDC using mouse fat pad mammary xenografts.

METHODS

Non-target control (NTC) and HSulf-2 knockdown in MCF10DCIS breast cancer cells were achieved by NTC shRNA and two different lentiviral shRNA against HSulf-2 respectively. Xenografts were established by injecting NTC and HSulf-2 deficient MCF10DCIS cells in mouse mammary fat pads. Xenografts were subjected to H&E staining for morphological analysis, TUNEL and Propidium iodide staining (to determine the extent of apoptosis), Western blot analysis and zymography.

RESULTS

Using a mouse mammary fat pad derived xenograft model, we observed that compared to control treated xenografts, down-regulation of HSulf-2 was associated with significant delays in growth at Week 7 (P-value < 0.05). Histological examination of the tumors demonstrated substantial differences in comedo necrosis, with marked luminal apoptosis and up-regulation of apoptotic markers Bim, cleaved PARP and cleaved caspase 3 in HSulf-2 depleted xenografts. Furthermore, HSulf-2 depleted xenografts retained the basement membrane integrity with decreased activity and expression of matrix metalloproteinase 9 (MMP-9), an enzyme critical for degradation of extracellular matrix compared to nontargeted control.

CONCLUSION

Our data suggest that HSulf-2 expression may be critical for human breast cancer progression. Down-regulation of HSulf-2 leads to retention of comedo type DCIS and delays the progression of DCIS to IDC. Further studies are necessary to determine if therapeutic targeting of HSulf-2 expression might delay the progression of DCIS to IDC.

Expression of class 3 semaphorins and their receptors in human breast neoplasia

AIMS

This study aimed to identify the involvement of class 3 semaphorins (Sema3) and receptors, neuropilins (Np1 and Np2) and plexins (A1-A4) in breast cancer development and angiogenesis.

METHODS AND RESULTS

We quantified and correlated Sema3A, Sema3B, Sema3F and their known receptors and coreceptors Plexin-A1, Plexin-A3, Np1 and Np2 in sections of normal human breast, benign and pre-malignant hyperplastic tissue, pre-invasive and invasive cancer, and compared these findings with our previously published data on vascular endothelial growth factor (VEGF) and microvessel density (MVD) in the same samples. Histological analysis revealed that Sema3B was expressed more strongly and widely than Sema3A and 3F in normal breast tissue and all three semaphorins decreased with the transition from in situ to invasive cancer (P < 0.014). Plexin-A3 decreased significantly with progression towards invasive cancer (P < 0.045), whereas Plexin-A1 expression was only significantly reduced once invasion had occurred (P = 0.012). Np1 and Np2 were expressed in both endothelial and epithelial/tumour cells. Np2 expression did not change, but Np1 expression significantly increased in the spectrum from hyperplasia to ductal carcinoma in situ (P < 0.035), but decreased with invasive cancer.

CONCLUSION

 These data suggest that a decrease in class 3 semaphorin and their plexin receptors have some relationship with disease progression in ductal breast carcinoma.

Mechanobiology of tumor invasion: engineering meets oncology

The physical sciences and engineering have introduced novel perspectives into the study of cancer through model systems, tools, and metrics that enable integration of basic science observations with clinical data. These methods have contributed to the identification of several overarching mechanisms that drive processes during cancer progression including tumor growth, angiogenesis, and metastasis. During tumor cell invasion - the first clinically observable step of metastasis - cells demonstrate diverse and evolving physical phenotypes that cannot typically be defined by any single molecular mechanism, and mechanobiology has been used to study the physical cell behaviors that comprise the "invasive phenotype". In this review, we discuss the continually evolving pathological characterization and in vitro mechanobiological characterization of tumor invasion, with emphasis on emerging physical biology and mechanobiology strategies that have contributed to a more robust mechanistic understanding of tumor cell invasion. These physical approaches may ultimately help to better predict and identify tumor metastasis.

The multisubstrate deoxyribonucleoside kinase of Drosophila melanogaster as a therapeutic suicide gene of breast cancer cells

BACKGROUND

The multisubstrate deoxyribonucleoside kinase of Drosophila melanogaster (Dm-dNK) was investigated for its broader substrate specificity and higher catalytic rate as a suicide gene in a combined gene/chemotherapy of cancer.

METHODS

To evaluate the effects of nucleoside analog phosphorylation by Dm-dNK in vitro and in vivo, we generated a replication-deficient retroviral vector expressing Dm-dNK to transduce human breast cancer cells MCF7 (ER+) and MDA-MB-231 (ER-). We further determined the enzymatic activity and the sensitivity of the nontransduced and Dm-dNK-transduced 231/dNK and MCF7/dNK cells to the pyrimidine nucleoside analogs araC and araT.

RESULTS

The data obtained show that Dm-dNK is enzymatically active and its overexpression in the nuclei of breast cancer cells results in an increased sensitivity to the nucleoside analogs araC and araT in vitro. Furthermore, subcutaneously transplanted 231/dNK cells were significantly inhibited after araC treatment, whereas nontransduced cancer cells continued to grow and develop in vivo.

CONCLUSIONS

These results suggest that the Dm-dNK/nucleoside analog system could be a novel therapeutic strategy for treating breast cancer and improving anti-tumor efficacy, as well as for optimizing approaches for suicide gene therapy.

Independent predictors of breast malignancy in screen-detected microcalcifications: biopsy results in 2545 cases

Background:

Mammographic microcalcifications are associated with many benign lesions, ductal carcinoma in situ (DCIS) and invasive cancer. Careful assessment criteria are required to minimise benign biopsies while optimising cancer diagnosis. We wished to evaluate the assessment outcomes of microcalcifications biopsied in the setting of population-based breast cancer screening.

Methods:

Between January 1992 and December 2007, cases biopsied in which microcalcifications were the only imaging abnormality were included. Patient demographics, imaging features and final histology were subjected to statistical analysis to determine independent predictors of malignancy.

Results:

In all, 2545 lesions, with a mean diameter of 21.8 mm (s.d. 23.8 mm) and observed in patients with a mean age of 57.7 years (s.d. 8.4 years), were included. Using the grading system adopted by the RANZCR, the grade was 3 in 47.7% 4 in 28.3% and 5 in 24.0%. After assessment, 1220 lesions (47.9%) were malignant (809 DCIS only, 411 DCIS with invasive cancer) and 1325 (52.1%) were non-malignant, including 122 (4.8%) premalignant lesions (lobular carcinoma in situ, atypical lobular hyperplasia and atypical ductal hyperplasia). Only 30.9% of the DCIS was of low grade.

Mammographic extent of microcalcifications >15 mm, imaging grade, their pattern of distribution, presence of a palpable mass and detection after the first screening episode showed significant univariate associations with malignancy. On multivariate modeling imaging grade, mammographic extent of microcalcifications >15 mm, palpable mass and screening episode were retained as independent predictors of malignancy. Radiological grade had the largest effect with lesions of grade 4 and 5 being 2.2 and 3.3 times more likely to be malignant, respectively, than grade 3 lesions.

Conclusion:

The radiological grading scheme used throughout Australia and parts of Europe is validated as a useful system of stratifying microcalcifications into groups with significantly different risks of malignancy. Biopsy assessment of appropriately selected microcalcifications is an effective method of detecting invasive breast cancer and DCIS, particularly of non-low-grade subtypes.

A Comparative Analysis of Biomarker Expression and Molecular Subtypes of Pure Ductal Carcinoma In Situ and Invasive Breast Carcinoma by Image Analysis: Relationship of the Subtypes with Histologic Grade, Ki67, p53 Overexpression, and DNA Ploidy

There is a paucity of data regarding molecular subtypes of pure ductal carcinoma in situ (pDCIS). We evaluated the expression of ER, PR, HER2, Ki67, and p53 and DNA ploidy in 118 pDCIS and 100 invasive breast carcinomas (IBCAs) by routine IHC and classified them according to molecular subtypes. Quantification of biomarkers and DNA ploidy was performed by image analysis. Expression of ER, PR, and high ki67 was more frequent in pDCIS compared to IBCA. High-grade tumors had lower ER and PR expression, high Ki67, overexpression of HER2 and p53, and DNA aneuploidy. Luminal A and HER2 subtypes were more common in pDCIS, and triple negative was more prevalent in IBCA. In both groups, HER2 and triple negative subtypes were characterized by high ki67, overexpression of p53, and DNA aneuploidy compared to luminal subtypes. Molecular subtypes of IBCA are distinct from those of pDCIS. Invasion is characterized by change in phenotype in some tumors.

Mammographic morphology and distribution of calcifications in ductal carcinoma in situ diagnosed in organized screening

BACKGROUND

Ductal carcinoma in situ of the breast (DCIS) represents a challenge in mammographic screening due to its unknown progression into invasive cancer. The majority of the DCIS is detected due to signs of calcifications on the mammograms.

PURPOSE

To analyze the combinations of mammographic morphology and distribution of calcifications by Van Nuys nuclear grade (grade).

MATERIAL AND METHODS

A total of 217 DCIS diagnosed in women aged 50-69 years old who participated in the Norwegian Breast Cancer Screening Program in the period November 1995 to December 2007 were reviewed by four breast imaging specialists. The mammograms were classified according to the morphology and distribution of the calcifications, using BI-RADS nomenclature. Chi square test was used to compare the groups of morphology and distribution by grade.

RESULTS

Calcifications were identified in 93% (202/217) of the cases, 15% (30/202) as grade 1 and 74% (149/202) as grade 3. Fine pleomorphic calcifications were seen in 38% (77/202) of the lesions and fine linear and fine linear branching in 31% (62/202). Sixty-nine percent (53/77) of the fine pleomorphic and 84% (52/62) of the fine linear and fine linear branching calcifications were high grade lesions. Grouped distribution was seen in about half of all the cases (104/202). Among the high grade lesions with fine pleomorphic or fine linear and fine linear branching calcifications, 75% (40/53) and 69% (36/52), respectively, had grouped or segmental distribution.

CONCLUSION

DCIS presented overlapping groups of morphology and distribution of calcification by grade, but fine pleomorphic and fine linear and fine linear branching calcifications with grouped and segmental distributions were associated with high grade DCIS. Seeking for further knowledge that allows separation of non-high grade from high grade DCIS has to continue to improve the quality of mammographic screening.

Molecular differences between ductal carcinoma in situ and adjacent invasive breast carcinoma: a multiplex ligation-dependent probe amplification study

Background

Ductal carcinoma in situ (DCIS) accounts for approximately 20% of mammographically detected breast cancers. Although DCIS is generally highly curable, some women with DCIS will develop life-threatening invasive breast cancer, but the determinants of progression to infiltrating ductal cancer (IDC) are largely unknown.

Methods

In the current study, we used multiplex ligation-dependent probe amplification (MLPA), a multiplex PCR-based test, to compare copy numbers of 21 breast cancer related genes between laser-microdissected DCIS and adjacent IDC lesions in 39 patients. Genes included in this study were ESR1, EGFR, FGFR1, ADAM9, IKBKB, PRDM14, MTDH, MYC, CCND1, EMSY, CDH1, TRAF4, CPD, MED1, HER2, CDC6, TOP2A, MAPT, BIRC5, CCNE1 and AURKA.

Results

There were no significant differences in copy number for the 21 genes between DCIS and adjacent IDC. Low/intermediate-grade DCIS showed on average 6 gains/amplifications versus 8 in high-grade DCIS (p = 0.158). Furthermore, alterations of AURKA and CCNE1 were exclusively found in high-grade DCIS, and HER2, PRDM14 and EMSY amplification was more frequent in high-grade DCIS than in low/intermediate-grade DCIS. In contrast, the average number of alterations in low/intermediate and high grade IDC was similar, and although EGFR alterations were exclusively found in high grade IDC compared to low/intermediate-grade IDC, there were generally fewer differences between low/intermediate-grade and high-grade IDC than between low/intermediate-grade and high-grade DCIS.

Conclusion

In conclusion, there were no significant differences in copy number for 21 breast cancer related genes between DCIS and adjacent IDC, indicating that DCIS is genetically as advanced as its invasive counterpart. However, high grade DCIS showed more copy number changes than low/intermediate grade DCIS with specifically involved genes, supporting a model in which different histological grades of DCIS are associated with distinct genomic changes that progress to IDC in different routes. These high grade DCIS specific genes may be potential targets for treatment and/or predict progression.

Electronic supplementary material

The online version of this article (doi:10.1007/s13402-011-0043-7) contains supplementary material, which is available to authorized users.

Radiographic features for triple negative ductal carcinoma in situ of the breast

BACKGROUND

Triple negative (TN) breast cancer is characterized as having a high malignancy potential and a poor prognosis. An understanding of the radiological features of TN DCIS will enable the early detection of intractable TN invasive breast cancer.

METHODS

Our cohort of 494 DCIS patients, including 18 TN DCIS cases (3.6%), was diagnosed and treated between January 2006 and November 2009. We reviewed the TN DCIS cases in order to assess mammogram (MMG), ultrasound (US), magnetic resonance imaging (MRI), and pathology findings. Routine diagnostic MMG, US, and MRI were performed before surgery in our institution.

RESULTS

The average age of TN DCIS patients was 54.2 years (40-73). MMG findings were as follows: no abnormal findings (n = 4), masses (n = 3), focal asymmetric density (n = 2), architectural distortion (n = 5), and calcifications (n = 4). US findings included low echoic masses (n = 17) and architectural distortion (n = 4). MRI findings (two patients did not undergo this examination) included mass (n = 6) and non-mass-like enhancements (n = 10). The average lesion measured 3.3 cm in diameter (0.5-8.5 cm). The histological findings were non-comedo type (n = 9) and mixed type including some comedo components (n = 9). Notably, our study revealed that only 22% of TN DCIS cases were detected via mammographic abnormal calcifications. This percentage was less than in non-TN DCIS cases. TN DCIS cases were detected mainly because of masses or asymmetry. US and MRI findings of TN DCIS revealed the same features considered to be common DCIS findings.

CONCLUSION

We diagnosed TN DCIS in 3.6% of our cohort including 494 DCIS patients. Incidences of TN DCIS with mammographic abnormal calcifications were fewer than those of non-TN DCIS cases.

Molecular phenotypes of matched in situ and invasive components of breast carcinomas

The current system of pathologic classification of human breast cancers does not take into account the biologic determinants of prognosis, nor is there a consensus regarding the progression from in situ to invasive carcinoma. The present study compared the molecular phenotypes of in situ and invasive components of breast cancer in the same sample. We built a series of 189 in situ and invasive carcinomas using tissue microarrays and classified them according to their immunoprofiles regarding estrogen receptor, progesterone receptor, human epidermal growth factor receptor 2, epidermal growth factor receptor, cytokeratin 5, P-cadherin, and the antigen Ki-67 into luminal A and B, human epidermal growth factor receptor 2 overexpressing, and basal-like carcinomas. We also correlated the subgroups of carcinomas with some of the classical prognostic factors such as histologic grade, tumor size, and lymph node metastasis, as well as with the age of the patient at diagnosis. The overall concordance on the molecular phenotypes between in situ and invasive components was 94%. For the in situ component, 63% of the cases were luminal A; 15%, luminal B; 12%, human epidermal growth factor receptor 2 overexpressing; and 7%, basal-like. Regarding the invasive component, 61% of the cases were luminal A; 16%, luminal B; 12%, human epidermal growth factor receptor 2 overexpressing; and 8%, basal-like. The present study allowed the identification of different immunoprofiles of in situ and invasive breast carcinomas using a specific panel of biomarkers and showed that in most cases, there is a concordance between in situ and invasive component profiles, supporting the theory of parallel disease in breast tumorigenesis.

Identification of early molecular markers for breast cancer

Background

The ductal carcinoma in situ (DCIS) of the mammary gland represents an early, pre-invasive stage in the development of invasive breast carcinoma. Since DCIS is a curable disease, it would be highly desirable to identify molecular markers that allow early detection. Mice transgenic for the WAP-SV40 early genome region were used as a model for DCIS development. Gene expression profiling was carried out on DCIS-bearing mice and control animals. Additionally, a set of human DCIS and invasive mammary tumors were analyzed in a similar fashion. Enhanced expression of these marker genes in human and murine samples was validated by quantitative RT-PCR. Besides, marker gene expression was also validated by immunohistochemistry of human samples. Furthermore in silico analyses using an online microarray database were performed.

Results

In DCIS-mice seven genes were identified that were significantly up-regulated in DCIS: DEPDC1, NUSAP1, EXO1, RRM2, FOXM1, MUC1 and SPP1. A similar up-regulation of homologues of the murine genes was observed in human DCIS samples. Enhanced expression of these genes in DCIS and IDC (invasive ductal carcinoma) was validated by quantitative RT-PCR and immunohistochemistry.

Conclusions

By comparing murine markers for the ductal carcinoma in situ (DCIS) of the mammary gland with genes up-regulated in human DCIS-samples we were able to identify a set of genes which might allow early detection of DCIS and invasive carcinomas in the future. The similarities between gene expression in DCIS and invasive carcinomas in our data suggest that the early detection and treatment of DCIS is of utmost relevance for the survival of patients who are at high risk of developing breast carcinomas.

Bidirectional signaling of mammary epithelium and stroma: implications for breast cancer--preventive actions of dietary factors

The mammary gland is composed of two major cellular compartments: a highly dynamic epithelium that undergoes cycles of proliferation, differentiation and apoptosis in response to local and endocrine signals and the underlying stroma comprised of fibroblasts, endothelial cells and adipocytes, which collectively form the mammary fat pad. Breast cancer originates from subversions of normal growth regulatory pathways in mammary epithelial cells due to genetic mutations and epigenetic modifications in tumor suppressors, oncogenes and DNA repair genes. Diet is considered a highly modifiable determinant of breast cancer risk; thus, considerable efforts are focused on understanding how certain dietary factors may promote resistance of mammary epithelial cells to growth dysregulation. The recent indications that stromal cells contribute to the maintenance of the mammary epithelial 'niche' and the increasing appreciation for adipose tissue as an endocrine organ with a complex secretome have led to the novel paradigm that the mammary stromal compartment is itself a relevant target of bioactive dietary factors. In this review, we address the potential influence of dietary factors on mammary epithelial-stromal bidirectional signaling to provide mechanistic insights into how dietary factors may promote early mammary epithelial differentiation to decrease adult breast cancer risk.

Breast fine-needle aspiration malondialdehyde deoxyguanosine adduct in breast cancer

This study has analysed the generation of 3-(2-deoxy-β-D-erythro-pentafuranosyl)pyrimido[1,2-α]purin-10(3H)-one deoxyguanosine adduct [M₁dG], a biomarker of oxidative stress and lipid peroxidation, in breast fine-needle aspirate samples of 22 patients with breast cancer, at different clinical stages, in respect to 13 controls. The multivariate analysis show that M(1)dG adduct was higher in cases than in controls (Mean Ratio (MR) = 5.26, 95% CI = 3.16-8.77). Increased M₁dG was observed in women with a tumour grade 3 and a pathological diameter 2 (MR = 7.61, 95% CI = 3.91-14.80 and MR = 5.75, 95% CI = 3.13-10.59, respectively). A trend with increasing tumour grade and pathological diameter was present (MR = 1.98, 95% CI = 1.57-2.50 and MR = 2.44, 95% CI = 1.71-3.48, respectively). Not significant effects of age and smoking habit were found (MR = 1.58, 95% CI = 0.92-2.72 and MR = 1.68, 95% CI 0.88-3.20, respectively). An increment over the background frequency of M₁dG can contribute to breast cancer development. Increasing severity of breast tumour can influence DNA damage level.

Classification of breast cancer precursors through exhaled breath

Certain benign breast diseases are considered to be precursors of invasive breast cancer. Currently available techniques for diagnosing benign breast conditions lack accuracy. The purpose of this study was to deliver a proof-of-concept for a novel method that is based on breath testing to identify breast cancer precursors. Within this context, the authors explored the possibility of using exhaled alveolar breath to identify and distinguish between benign breast conditions, malignant lesions, and healthy states, using a small-scale, case-controlled, cross-sectional clinical trial. Breath samples were collected from 36 volunteers and were analyzed using a tailor-made nanoscale artificial NOSE (NA-NOSE). The NA-NOSE signals were analyzed using two independent methods: (i) principal component analysis, ANOVA and Student's t-test and (ii) support vector machine analysis to detect statistically significant differences between the sub-populations. The NA-NOSE could distinguish between all studied test populations. Breath testing with a NA-NOSE holds future potential as a cost-effective, fast, and reliable diagnostic test for breast cancer risk factors and precursors, with possible future potential as screening method.

Microenvironmental influences that drive progression from benign breast disease to invasive breast cancer

Invasive breast cancer represents the endpoint of a developmental process that originates in the terminal duct lobular units and is believed to progress through stages of increasing proliferation, atypical hyperplasia, and carcinoma in situ before the cancer acquires invasive and metastatic capabilities. By comparison with invasive breast cancer, which has been studied extensively, the preceding stages of benign breast disease are more poorly understood. Much less is known about the molecular changes underlying benign breast disease development and progression, as well as the transition from in situ into invasive disease. Even less focus has been given to the specific role of stroma in this progression. The reasons for lack of knowledge about these lesions often come from their small size and limited sample availability. More challenges are posed by limitations of the models used to investigate the lesions preceding invasive breast cancer. However, recent studies have identified alterations in stromal cell function that may be critical for disease progression from benign disease to invasive cancer: key functions of myoepithelial cells that maintain tissue structure are lost, while tissue fibroblasts become activated to produce proteases that degrade the extracellular matrix and trigger the invasive cellular phenotype. Gene expression profiling of stromal alterations associated with disease progression has also identified key transcriptional changes that occur early in disease development. In this review, we will summarize recent studies showing how stromal factors can facilitate progression of ductal carcinoma in situ to invasive disease. We also suggest approaches to identify processes that control earlier stages of disease progression.

Ras-related protein 1 and the insulin-like growth factor type I receptor are associated with risk of progression in patients diagnosed with carcinoma in situ

Currently, there are no applied molecular markers to aid in predicting risk of carcinoma in situ (CIS) progression to invasive cancer, and therefore, all women diagnosed with CIS undergo surgery. Standard assessment of protein expression in fixed tissue by immunohistochemistry (IHC) is not quantitative and hence is not well suited for measuring biomarkers. In this study, we developed an original analytical method for IHC quantification. Using our novel image-based uniplex (IBU) method, quantitative protein profiling was performed on 90 samples of the breast (17 histologically normal tissues, 16 benign lesions, 15 CIS, and 42 invasive carcinomas). Differences between groups were assessed using analysis of variance (ANOVA) and mixed effects models. Measuring protein expression on a continuous scale revealed a significant increase in Ras-related protein 1 (Rap1) and the insulin-like growth factor type I receptor (IGF-IR) in conjunction with the presence of cancer invasion. Women with invasive cancers were four times more likely to have increased levels of Rap1 [odds ratio (OR) = 3.91; P = 0.0002] and IGF-IR (OR=4.33; P<0.0001) than women with non-invasive lesions. Furthermore, expression of both proteins was also increased significantly in CIS adjacent to invasive tumors compared with non-cancerous tissue. These novel findings of a significant up-regulation of Rap1 and IGF-IR in CIS progressing to invasive cancers warrant further investigation of Rap1 and IGF-IR together as a dual biomarker to aid in predicting risk of progression and ultimately providing non-surgical treatment options to those at lower risk.

Performance of mammography in women aged under 40 years

Evaluation of: Yankaskas BC, Haneuse S, Kapp JM, Kerlikowske K, Geller B, Buist DSM; For the Breast Cancer Surveillance Consortium: Performance of first mammography examination in women younger than 40 years. J. Natl Cancer Inst. 102(10), 692–700 (2010). By using pooled data from six mammography registries across the USA, 117,737 women aged 18–39 years were identified who had received their first mammography in the period 1995–2005. A distinction was made between diagnostic mammography for women who presented with a breast problem (n = 30,956), and screening mammography (n = 86,781). The age-adjusted positive predictive value of screening mammography was 1.3% (95% CI: 1.1–1.5%), as compared with 14.6% (95% CI: 13.3–15.8%) for diagnostic mammography. Considering the high recall rates, the high number of false-positive test results and the low cancer detection rate, the appropriateness of mammography for women younger than 40 without symptoms is questionable.

Targeting DNA replication before it starts: Cdc7 as a therapeutic target in p53-mutant breast cancers

Treatment options for triple-receptor negative (ER-/PR-/Her2-) and Her2-overexpressing (ER-/PR-/Her2+) breast cancers with acquired or de novo resistance are limited, and metastatic disease remains incurable. Targeting of growth signaling networks is often constrained by pathway redundancy or growth-independent cancer cell cycles. The cell-cycle protein Cdc7 regulates S phase by promoting DNA replication. This essential kinase acts as a convergence point for upstream growth signaling pathways and is therefore an attractive therapeutic target. We show that increased Cdc7 expression during mammary tumorigenesis is linked to Her2-overexpressing and triple-negative subtypes, accelerated cell cycle progression (P < 0.001), arrested tumor differentiation (P < 0.001), genomic instability (P = 0.019), increasing NPI score (P < 0.001), and reduced disease-free survival (HR = 1.98 [95% CI: 1.27-3.10]; P = 0.003), thus implicating its deregulation in the development of aggressive disease. Targeting Cdc7 with RNAi, we demonstrate that p53-mutant Her2-overexpressing and triple-negative breast cancer cell lines undergo an abortive S phase and apoptotic cell death due to loss of a p53-dependent Cdc7-inhibition checkpoint. In contrast, untransformed breast epithelial cells arrest in G1, remain viable, and are able to resume cell proliferation on recovery of Cdc7 kinase activity. Thus, Cdc7 appears to represent a potent and highly specific anticancer target in Her2-overexpressing and triple-negative breast cancers. Emerging Cdc7 kinase inhibitors may therefore significantly broaden the therapeutic armamentarium for treatment of the aggressive p53-mutant breast cancer subtypes identified in this study.

A 2D mechanistic model of breast ductal carcinoma in situ (DCIS) morphology and progression

Ductal carcinoma in situ (DCIS) of the breast is a non-invasive tumor in which cells proliferate abnormally, but remain confined within a duct. Although four distinguishable DCIS morphologies are recognized, the mechanisms that generate these different morphological classes remain unclear, and consequently the prognostic strength of DCIS classification is not strong. To improve the understanding of the relation between morphology and time course, we have developed a 2D in silico particle model of the growth of DCIS within a single breast duct. This model considers mechanical effects such as cellular adhesion and intra-ductal pressure, and biological features including proliferation, apoptosis, necrosis, and cell polarity. Using this model, we find that different regions of parameter space generate distinct morphological subtypes of DCIS, so elucidating the relation between morphology and time course. Furthermore, we find that tumors with similar architectures may in fact be produced through different mechanisms, and we propose future work to further disentangle the mechanisms involved in DCIS progression.

Nuclear expression of KLF6 tumor suppressor factor is highly associated with overexpression of ERBB2 oncoprotein in ductal breast carcinomas

Background

Krüppel-like factor 6 (KLF6) is an evolutionarily conserved and ubiquitously expressed protein that belongs to the mammalian Sp1/KLF family of transcriptional regulators. Though KLF6 is a transcription factor and harbors a nuclear localization signal it is not systematically located in the nucleus but it was detected in the cytoplasm of several tissues and cell lines. Hence, it is still not fully settled whether the tumor suppressor function of KLF6 is directly associated with its ability to regulate target genes.

Methodology/Principal Findings

In this study we analyzed KLF6 expression and sub-cellular distribution by immunohistochemistry in several normal and tumor tissues in a microarray format representing fifteen human organs. Results indicate that while both nuclear and cytoplasmic distribution of KLF6 is detected in normal breast tissues, breast carcinomas express KLF6 mainly detected in the cytoplasm. Expression of KLF6 was further analyzed in breast cancer tissues overexpressing ERBB2 oncoprotein, which is associated with poor disease prognosis and patient's survival. The analysis of 48 ductal carcinomas revealed a significant population expressing KLF6 predominantly in the nuclear compartment (X²p = 0.005; Fisher p = 0.003). Moreover, this expression pattern correlates directly with early stage and small ductal breast tumors and linked to metastatic events in lymph nodes.

Conclusions/Significance

Data are consistent with a preferential localization of KLF6 in the nuclear compartment of early stage and small HER2-ERBB2 overexpressing ductal breast tumor cells, also presenting lymph node metastatic events. Thus, KLF6 tumor suppressor could represent a new molecular marker candidate for tumor prognosis and/or a potential target for therapy strategies.

Immunohistochemical analysis of oxidative stress and DNA repair proteins in normal mammary and breast cancer tissues

BACKGROUND

During the course of normal cellular metabolism, oxygen is consumed and reactive oxygen species (ROS) are produced. If not effectively dissipated, ROS can accumulate and damage resident proteins, lipids, and DNA. Enzymes involved in redox regulation and DNA repair dissipate ROS and repair the resulting damage in order to preserve a functional cellular environment. Because increased ROS accumulation and/or unrepaired DNA damage can lead to initiation and progression of cancer and we had identified a number of oxidative stress and DNA repair proteins that influence estrogen responsiveness of MCF-7 breast cancer cells, it seemed possible that these proteins might be differentially expressed in normal mammary tissue, benign hyperplasia (BH), ductal carcinoma in situ (DCIS) and invasive breast cancer (IBC).

METHODS

Immunohistochemistry was used to examine the expression of a number of oxidative stress proteins, DNA repair proteins, and damage markers in 60 human mammary tissues which were classified as BH, DCIS or IBC. The relative mean intensity was determined for each tissue section and ANOVA was used to detect statistical differences in the relative expression of BH, DCIS and IBC compared to normal mammary tissue.

RESULTS

We found that a number of these proteins were overexpressed and that the cellular localization was altered in human breast cancer tissue.

CONCLUSIONS

Our studies suggest that oxidative stress and DNA repair proteins not only protect normal cells from the damaging effects of ROS, but may also promote survival of mammary tumor cells.

Frequent aberrant DNA methylation of ABCB1, FOXC1, PPP2R2B and PTEN in ductal carcinoma in situ and early invasive breast cancer

Introduction

Ductal carcinoma in situ (DCIS) is a non-invasive lesion of the breast that is frequently detected by mammography and subsequently removed by surgery. However, it is estimated that about half of the detected lesions would never have progressed into invasive cancer. Identifying DCIS and invasive cancer specific epigenetic lesions and understanding how these epigenetic changes are involved in triggering tumour progression is important for a better understanding of which lesions are at risk of becoming invasive.

Methods

Quantitative DNA methylation analysis of ABCB1, CDKN2A/p16^INK4a, ESR1, FOXC1, GSTP1, IGF2, MGMT, MLH1, PPP2R2B, PTEN and RASSF1A was performed by pyrosequencing in a series of 27 pure DCIS, 28 small invasive ductal carcinomas (IDCs), 34 IDCs with a DCIS component and 5 normal breast tissue samples. FOXC1, ABCB1, PPP2R2B and PTEN were analyzed in 23 additional normal breast tissue samples. Real-Time PCR expression analysis was performed for FOXC1.

Results

Aberrant DNA methylation was observed in all three diagnosis groups for the following genes: ABCB1, FOXC1, GSTP1, MGMT, MLH1, PPP2R2B, PTEN and RASSF1A. For most of these genes, methylation was already present at the DCIS level with the same frequency as within IDCs. For FOXC1 significant differences in methylation levels were observed between normal breast tissue and invasive tumours (P < 0.001). The average DNA methylation levels were significantly higher in the pure IDCs and IDCs with DCIS compared to pure DCIS (P = 0.007 and P = 0.001, respectively). Real-time PCR analysis of FOXC1 expression from 25 DCIS, 23 IDCs and 28 normal tissue samples showed lower gene expression levels of FOXC1 in both methylated and unmethylated tumours compared to normal tissue (P < 0.001). DNA methylation levels of FOXC1, GSTP1, ABCB1 and RASSF1A were higher in oestrogen receptor (ER) positive vs. ER negative tumours; whereas methylation levels of FOXC1, ABCB1, PPP2R2B and PTEN were lower in tumours with a TP53 mutation.

Conclusions

Quantitative methylation analysis identified ABCB1, FOXC1, PPP2R2B and PTEN as novel genes to be methylated in DCIS. In particular, FOXC1 showed a significant increase in the methylation frequency in invasive tumours. Low FOXC1 gene expression in both methylated and unmethylated DCIS and IDCs indicates that the loss of its expression is an early event during breast cancer progression.

Comparative evaluation of the erbB2 and hormone receptor status of neighboring invasive and in situ components of ductal carcinomas of the breast

Background

It remains unknown whether erbB2 expression and hormone receptor status predict the invasive potential of ductal carcinoma in situ (DCIS) of the breast.

Objectives

To examine erbB2 and estrogen/progesterone receptor (ER/PR) status in the precise areas where DCIS turns into invasive ductal carcinoma (IDC).

Subjects and methods

Eighty-seven cases of breast malignancies harboring contiguous regions of DCIS and IDC were selected. Separate histological samples from the DCIS and the neighboring IDC were obtained using tissue microarrays. The erbB2 and ER/PR statuses were assessed using immunohistochemistry (erbB2 and ER/PR) and fluorescence in situ hybridization (FISH – only erbB2).

Results

The expression of erbB2 did not differ in the DCIS and IDC components of the breast tumors (p=0.35). There was good agreement in sample-by-sample comparisons of erbB2 (intraclass correlation coefficient [ICC]=0.78), PR (ICC=0.61) and ER (ICC=0.70) expression in the DCIS and IDC components.

Conclusion

Our findings suggest that the expressions of erbB2 and ER/PR do not differ in the contiguous regions from DCIS to IDC.

Angiogenesis is associated with the onset of hyperplasia in human ductal breast disease

BACKGROUND

The precise timing of the angiogenic switch and the role of angiogenesis in the development of breast malignancy is currently unknown.

METHODS

Therefore, the expression of CD31 (pan endothelial cells (ECs)), endoglin (actively proliferating ECs), hypoxia-inducible factor-1 (HIF-1alpha), vascular endothelial growth factor-A (VEGF) and tissue factor (TF) were quantified in 140 surgical specimens comprising normal human breast, benign and pre-malignant hyperplastic tissue, in situ and invasive breast cancer specimens.

RESULTS

Significant increases in angiogenesis (microvessel density) were observed between normal and benign hyperplastic breast tissue (P<0.005), and between in situ and invasive carcinomas (P<0.0005). In addition, significant increases in proliferating ECs were observed in benign hyperplastic breast compared with normal breast (P<0.05) cancers and in invasive compared with in situ cancers (P<0.005). Hypoxia-inducible factor-1alpha, VEGF and TF expression were significantly associated with increases in both angiogenesis and proliferating ECs (P<0.05). Moreover, HIF-1alpha was expressed by 60-75% of the hyperplastic lesions, and a significant association was observed between VEGF and TF in ECs (P<0.005) and invasive tumour cells (P<0.01).

CONCLUSIONS

These findings are the first to suggest that the angiogenic switch, associated with increases in HIF-1alpha, VEGF and TF expression, occurs at the onset of hyperplasia in the mammary duct, although the greatest increase in angiogenesis occurs with the development of invasion.

Amplification of the urokinase-type plasminogen activator receptor (uPAR) gene in ductal pancreatic carcinomas identifies a clinically high-risk group

The serine protease urokinase-type plasminogen activator (uPA) and its receptor (uPAR) are known to be involved in the invasion and metastasis of many solid tumors. In this study, we analyzed the role of the uPAR/uPA system in both the development and progression of pancreatic cancer in invasive ductal adenocarcinomas of the pancreas (PDA) and their premalignant precursors (PanIN lesions) in 50 patients with long-term clinical follow-up. We found overexpression of the uPAR in 48 of 50 invasive carcinomas as well as in a large proportion of high-grade PanIN lesions by immunohistochemistry and in situ hybridization. Fluorescence in situ hybridization analysis showed both high- and low-level amplification of the uPAR gene in approximately 50% of cases with strictly identical patterns between invasive cancers and their accompanying precursor lesions. These results suggest that PDA may develop from PanIN lesions along an alternative rather than a sequential molecular pathway. The detection of the gene amplification of uPAR was a highly significant, adverse prognostic parameter (P < 0.001) because it likely renders the tumors more sensitive to uPA and its proproliferative and anti-apoptotic signals. We conclude that the activation of the uPAR/uPA system is an early event in the development of PDA and that uPAR gene amplifications identify a subgroup of particularly aggressive tumors, making the uPAR/uPA system a critical and highly promising target for therapeutic interventions.

Accuracy of self-reported breast cancer among women undergoing mammography

This study estimated the sensitivity and specificity of self-reported breast cancer and their associations with patient factors and pathologic findings using data from the Breast Cancer Surveillance Consortium. We included 24,631 women with and 463,804 women without a prior diagnosis of breast cancer who completed a questionnaire (including breast cancer history) at participating US mammography facilities between 1996 and 2006. We determined "true" cancer status using cancer registries and pathology databases. Multivariable logistic regression models were used to examine associations with patient factors and pathologic findings. Sensitivity of self-reported breast cancer was higher for women with invasive cancer (96.9%) than for those with ductal carcinoma in situ (DCIS) (90.2%). Specificity was high overall (99.7%) but much lower for women with a history of lobular carcinoma in situ (LCIS) (65.0%). In multivariable models, women reporting older ages, a nonwhite race/ethnicity, or less education had lower sensitivities and specificities. Sensitivity was reduced when there was evidence of prior DCIS, especially when this diagnosis had been made more than 2 years before questionnaire completion. Women reporting a family history of breast cancer had higher sensitivity. Evidence of prior LCIS was associated with lower specificity. The accuracy of self-reported breast cancer depends on the respondent's characteristics and prior diagnoses. Accuracy is lower among nonwhite women and women reporting less education. There appears to be uncertainty surrounding breast findings such as DCIS and LCIS. These results have important implications for research relying on self-report and for patient communication and care.

Intracrinology of sex steroids in ductal carcinoma in situ (DCIS) of human breast: comparison to invasive ductal carcinoma (IDC) and non-neoplastic breast

Sex steroids, including those through intratumoral production in an intracrine manner, play important roles in the development of invasive ductal carcinoma (IDC) of human breast, but biological and/or clinical significance of intratumoral production and metabolism of sex steroids, have remained largely unknown in the ductal carcinoma in situ (DCIS), an important precursor lesion of IDC. We recently examined tissue concentration of estradiol and 5-dihydrotestosterone using liquid chromatography/electrospray tandem mass spectrometry in non-neoplastic breast, DCIS, and IDC tissues. Results of our study suggest that intratumoral concentrations of both estradiol and 5-dihydrotestosterone are increased in DCIS, which is considered due to intratumoral production of these sex steroids. Therefore, both estradiol and 5-dehydrotestosterone are considered to play important roles in the development of DCIS as well as IDC through an intracrine manner. Intratumoral metabolism and synthesis of estrogens and androgens as a result of the interactions of various enzymes are therefore also considered to play important roles in hormone dependent DCIS. Aromatase, which is one of the estrogen synthesis enzymes, plays an important role in intratumoral production of estrogen but other enzymes also play pivotal roles in intratumoral estrogen and androgen productions in human breast carcinoma. Therefore, in this review, we also focused on the importance of key intracrine enzymes such as 17beta-hydroxysteroid dehydrogenases, steroid sulfatase,estrogen sulfotransferase, 5alpha-reductases in both IDC and DCIS.

Nm23-H1/nucleoside diphosphate kinase as a key molecule in breast tumor angiogenesis

BACKGROUND

Neo-angiogenesis seems to be a critical feature of breast tumor growth, migration and metastasis. Inhibition of angiogenesis may provide information regarding treatment. Since angiogenesis is the result of complex processes, controlled by several angiogenic (pro- and/or -anti) factors and their receptors, multiple ways to prevent or retrogress tumor-induced angiogenesis have been proposed. The clinically significant activity of bevacizumab and other antiangiogenic treatments have attracted a great deal of interest.

OBJECTIVE/METHODS

We discuss biological aspects of breast cancer angiogenesis and nucleoside diphosphate kinase (NDPK) as a key molecule in this process.

RESULTS/CONCLUSIONS

In clinical and experimental trials, it was reported that NDPK is inversely related to breast cancer metastasis and angiogenesis. To inhibit the metastatic potential of cancer cells, Nm23-H1/NDP kinase appears to interact with many proteins involved in cellular signal transduction in angiogenesis and tumorigenesis, and therefore reduces the activation of the extracellular signal-regulated kinase (ERK)/MAPK in response to those signals.

Comparing screening mammography for early breast cancer detection in Vermont and Norway

BACKGROUND

Most screening mammography in the United States differs from that in countries with formal screening programs by having a shorter screening interval and interpretation by a single reader vs independent double reading. We examined how these differences affect early detection of breast cancer by comparing performance measures and histopathologic outcomes in women undergoing opportunistic screening in Vermont and organized screening in Norway.

METHODS

We evaluated recall, screen detection, and interval cancer rates and prognostic tumor characteristics for women aged 50-69 years who underwent screening mammography in Vermont (n = 45 050) and in Norway (n = 194 430) from 1997 through 2003. Rates were directly adjusted for age by weighting the rates within 5-year age intervals to reflect the age distribution in the combined data and were compared using two-sided Z tests.

RESULTS

The age-adjusted recall rate was 9.8% in Vermont and 2.7% in Norway (P < .001). The age-adjusted screen detection rate per 1000 woman-years after 2 years of follow-up was 2.77 in Vermont and 2.57 in Norway (P = .12), whereas the interval cancer rate per 1000 woman-years was 1.24 and 0.86, respectively (P < .001). Larger proportions of invasive interval cancers in Vermont than in Norway were 15 mm or smaller (55.9% vs 38.2%, P < .001) and had no lymph node involvement (67.5% vs 57%, P = .01). The prognostic characteristics of all invasive cancers (screen-detected and interval cancer) were similar in Vermont and Norway.

CONCLUSION

Screening mammography detected cancer at about the same rate and at the same prognostic stage in Norway and Vermont, with a statistically significantly lower recall rate in Norway. The interval cancer rate was higher in Vermont than in Norway, but tumors that were diagnosed in the Vermont women tended to be at an earlier stage than those diagnosed in the Norwegian women.

Changes in subcellular localisation of MI-ER1 alpha, a novel oestrogen receptor-alpha interacting protein, is associated with breast cancer progression

The oestrogen receptor-α (ERα) plays a key role in breast development and tumorigenesis and inhibiting its activity remains a prime strategy in the treatment of ERα-positive breast cancers. Thus, elucidation of the molecular mechanisms responsible for regulating ERα activity may facilitate the design of new, more effective breast cancer therapies. The MI-ER1α is a novel transcriptional repressor that contains an LXXLL motif for interaction with nuclear hormone receptors. We investigated the ability of MI-ER1α to bind to ERα in HEK293 and MCF-7 breast carcinoma cells, using co-immunoprecipitation assays. In both cell lines, MI-ER1α interacted with ERα in the presence and absence of oestrogen, but the interaction was stronger in the absence of ligand. Functional analysis revealed that overexpression of MI-ER1α in T47D breast carcinoma cells results in inhibition of oestrogen-stimulated anchorage-independent growth, suggesting that MI-ER1α may play a role in regulating breast carcinoma cell proliferation in vivo. To explore this further, we performed an immunohistochemical analysis of normal breast tissue and breast carcinoma; a total of 110 cases were examined in whole tissue sections and 771 cases were analysed in tissue microarrays. No consistent difference in the MI-ER1α expression level between normal breast tissue and breast carcinoma was discernible. However, there was a dramatic shift in the subcellular localisation: nuclear MI-ER1α was detectable in 75% of normal breast samples and in 77% of hyperplasia, but in breast carcinoma, only 51% of DCIS, 25% of ILC and 4% of IDC contained nuclear staining. This shift from nuclear to cytoplasmic localisation of MI-ER1α during breast cancer progression suggests that loss of nuclear MI-ER1α might contribute to the development of invasive breast carcinoma.

[Effect of miskleron (clofibrate) on dimethylhydrazine induction of intestinal tumors in rats]

In this review, we report on the complexity of breast cancer stem cells as key cells in the emergence of a chemoresistant tumor phenotype, and as a result, the appearance of distant metastasis in breast cancer patients. The search for mechanisms that increase sensitivity to chemotherapy and also allow activation of the tumor-specific immune response is of high priority. As we observed throughout this review, natural products isolated or in standardized extracts, such as P2Et or others, could act synergistically, increasing tumor sensitivity to chemotherapy, recovering the tumor microenvironment, and participating in the induction of a specific immune response. This, in turn, would lead to the destruction of cancer stem cells and the decrease in metastasis.

Source of Data: Relevant studies were found using the following keywords or medical subject headings (MeSH) in PubMed, and Google Scholar: “immune response” and “polyphenols” and “natural products” and “BCSC” and “therapy” and “metabolism” and “immunogenic cell death.” The focus was primarily on the most recent scientific publication.