Prognostic and predictive molecular markers in DCIS: a review

Progression from ductal carcinoma in situ to invasive breast cancer: molecular features and clinical significance

Ductal carcinoma in situ (DCIS) represents pre-invasive breast carcinoma. In untreated cases, 25-60% DCIS progress to invasive ductal carcinoma (IDC). The challenge lies in distinguishing between non-progressive and progressive DCIS, often resulting in over- or under-treatment in many cases. With increasing screen-detected DCIS in these years, the nature of DCIS has aroused worldwide attention. A deeper understanding of the biological nature of DCIS and the molecular journey of the DCIS-IDC transition is crucial for more effective clinical management. Here, we reviewed the key signaling pathways in breast cancer that may contribute to DCIS initiation and progression. We also explored the molecular features of DCIS and IDC, shedding light on the progression of DCIS through both inherent changes within tumor cells and alterations in the tumor microenvironment. In addition, valuable research tools utilized in studying DCIS including preclinical models and newer advanced technologies such as single-cell sequencing, spatial transcriptomics and artificial intelligence, have been systematically summarized. Further, we thoroughly discussed the clinical advancements in DCIS and IDC, including prognostic biomarkers and clinical managements, with the aim of facilitating more personalized treatment strategies in the future. Research on DCIS has already yielded significant insights into breast carcinogenesis and will continue to pave the way for practical clinical applications.

Can Molecular Biomarkers Help Reduce the Overtreatment of DCIS?

Ductal carcinoma in situ (DCIS), especially in the era of mammographic screening, is a commonly diagnosed breast tumor. Despite the low breast cancer mortality risk, management with breast conserving surgery (BCS) and radiotherapy (RT) is the prevailing treatment approach in order to reduce the risk of local recurrence (LR), including invasive LR, which carries a subsequent risk of breast cancer mortality. However, reliable and accurate individual risk prediction remains elusive and RT continues to be standardly recommended for most women with DCIS. Three molecular biomarkers have been studied to better estimate LR risk after BCS-Oncotype DX DCIS score, DCISionRT Decision Score and its associated Residual Risk subtypes, and Oncotype 21-gene Recurrence Score. All these molecular biomarkers represent important efforts towards improving predicted risk of LR after BCS. To prove clinical utility, these biomarkers require careful predictive modeling with calibration and external validation, and evidence of benefit to patients; on this front, further research is needed. Most trials do not incorporate molecular biomarkers in evaluating de-escalation of therapy for DCIS; however, one-the Prospective Evaluation of Breast-Conserving Surgery Alone in Low-Risk DCIS (ELISA) trial-incorporates the Oncotype DX DCIS score in defining a low-risk population and is an important next step in this line of research.

Risk factors for breast cancer mortality after ductal carcinoma in situ diagnosis differ from those for invasive recurrence

BACKGROUND

Breast cancer mortality after ductal carcinoma in situ is rare, making it difficult to predict which patients are at risk and to identify whether risk factors for this outcome are the same as those for invasive recurrence. We aimed to identify whether risk factors for invasive recurrences are similar to those for breast cancer death after a diagnosis of pure ductal carcinoma in situ.

METHODS

The Surveillance, Epidemiology, and End Results Program was queried for female patients diagnosed with pure ductal carcinoma in situ. Cumulative incidence was estimated by treatment group using competing risks. Competing risks regression was then performed for the development of in-breast invasive recurrence with competing risks of breast and non-breast cancer death. Competing risks regression was then again performed for development of breast cancer mortality with the competing risk of non-breast cancer death.

RESULTS

A total of 29,515 patients were identified. Of them, 164 patients suffered breast cancer mortality without an intervening invasive recurrence, and 44 suffered breast cancer mortality after an invasive in-breast recurrence. On competing risks analysis for invasive in-breast recurrence, significant factors included lesion size >5 cm (hazard ratio = 1.59, 95% confidence interval 1.24-2.04, P < .001), diffuse disease (hazard ratio = 0.0005, 95% confidence interval 0.0003-0.0007, P < .001), other race (hazard ratio = 1.29, 95% confidence interval 1.10-1.52, P = .002), Black race (hazard ratio = 1.21, 95% confidence interval 1.01-1.46, P = .04), age at diagnosis (hazard ratio = 0.99, confidence interval 0.98-1.00, P = .02), low-grade disease (hazard ratio = 0.79, 95% confidence interval 0.64-0.96, P = .02), lumpectomy with radiation (hazard ratio = 0.67, 95% confidence interval 0.58-0.77, P < .001), and mastectomy (hazard ratio = 0.36, 95% confidence interval 0.30-0.44, P < .001). Significant factors for breast cancer mortality included age at diagnosis (hazard ratio = 1.04, 95% confidence interval 1.03-1.05, P < .001), Black race (hazard ratio = 2.88, 95% confidence interval 2.08-3.99, P < .001), diffuse disease (hazard ratio = 6.02, 95% confidence interval 1.39-26.07, P = .02), lumpectomy with radiation (hazard ratio = 0.51, 95% confidence interval 0.36-0.72, P < .001), and mastectomy (hazard ratio = 0.60, 95% confidence interval 0.50-0.92, P = .02).

CONCLUSION

Our results suggested that risk factors for in-breast invasive recurrence after a diagnosis of pure ductal carcinoma in situ differ from risk factors for breast cancer mortality and development of metastatic recurrence. In-breast invasive recurrence is not the only consideration for breast cancer specific mortality in ductal carcinoma in situ patients.

Higher densities of tumour-infiltrating lymphocytes and CD4+ T cells predict recurrence and progression of ductal carcinoma in situ of the breast

AIMS

Host immunity influences cancer progression and therapeutic response. We investigated the potential of tumour-infiltrating lymphocytes (TILs) around ductal carcinoma in situ (DCIS) in predicting recurrence and progression.

METHODS AND RESULTS

CD4, CD8, programmed cell death 1 (PD-1) and programmed cell death ligand 1 (PD-L1) expression in DCIS from 198 patients was determined by immunohistochemistry. We correlated disease-free survival (DFS), clinicopathological parameters and biomarker expression with TIL density and CD4/CD8 ratio. High TIL density was associated with high nuclear grade (P < 0.001), DCIS PD-L1 expression (P = 0.008), TIL PD-L1 expression (P < 0.001), oestrogen (ER) negativity (P < 0.001), progesterone (PR) negativity (P < 0.001), human epidermal growth factor receptor 2 (HER2) positivity (P = 0.002) and triple negativity (P = 0.001). TIL PD-L1 expression was associated with triple-negative DCIS (P = 0.028). TIL density was associated with molecular subtypes (P < 0.001). High CD4⁺ T cell density was associated with high nuclear grade (P = 0.001), microinvasion (P = 0.037), ER negativity (P < 0.001), PR negativity (P = 0.001), HER2 positivity (P = 0.004), triple negativity (P = 0.023) and PD-L1 expression in TILs (P < 0.011). High CD4/CD8 ratio was associated with PD-L1 expression in DCIS (P = 0.035) and TILs (P < 0.001). DCIS with higher TIL density disclosed worse DFS (P = 0.012) and was affirmed with multivariate analysis [95% confidence interval (CI) = 1.109-2.554, hazard ratio (HR) = 1.683, P = 0.014]. Poorer DFS for ipsilateral invasive recurrence was found for DCIS with higher CD4⁺ T cell density (P = 0.006) or CD4/CD8 ratio (P = 0.02), confirmed by multivariate analysis for the former (95% CI = 1.369-10.196, HR = 3.736, P = 0.01) and latter (95% CI = 1.311-7.935, HR = 3.225, P = 0.011).

CONCLUSION

DCIS with higher TIL density was associated with poorer prognostic parameters and predicted recurrence, while both CD4⁺ T cell density and CD4/CD8 ratio were associated with both recurrence and ipsilateral invasive recurrence.

Multi-modal imaging of high-risk ductal carcinoma in situ of the breast using C2Am: a targeted cell death imaging agent

BACKGROUND

Ductal carcinoma in situ (DCIS) is a non-invasive form of early breast cancer, with a poorly understood natural history of invasive transformation. Necrosis is a well-recognized adverse prognostic feature of DCIS, and non-invasive detection of its presence and spatial extent could provide information not obtainable by biopsy. We describe here imaging of the distribution and extent of comedo-type necrosis in a model of human DCIS using C2Am, an imaging agent that binds to the phosphatidylserine exposed by necrotic cells.

METHODS

We used an established xenograft model of human DCIS that mimics the histopathological features of the disease. Planar near-infrared and optoacoustic imaging, using fluorescently labeled C2Am, were used to image non-invasively the presence and extent of lesion necrosis.

RESULTS

C2Am showed specific and sensitive binding to necrotic areas in DCIS tissue, detectable both in vivo and ex vivo. The imaging signal generated in vivo using near-infrared (NIR) fluorescence imaging was up to 6-fold higher in DCIS lesions than in surrounding fat pad or skin tissue. There was a correlation between the C2Am NIR fluorescence (Pearson R = 0.783, P = 0.0125) and optoacoustic signals (R > 0.875, P < 0.022) in the DCIS lesions in vivo and the corresponding levels of cell death detected histologically.

CONCLUSIONS

C2Am is a targeted multi-modal imaging agent that could complement current anatomical imaging methods for detecting DCIS. Imaging the presence and spatial extent of necrosis may give better prognostic information than that obtained by biopsy alone.

Breast ductal Carcinoma in situ associated with microinvasion induces immunological response and predicts ipsilateral invasive recurrence

Although microinvasion (Mi) is often thought to be an interim stage between ductal carcinoma in situ (DCIS) and established invasive ductal carcinoma, survival outcomes and biological behaviour of DCIS-Mi are still poorly understood. This study investigated the potential influence of Mi on disease-free survival (DFS) and assessed its correlations with clinicopathological parameters, prognosis, molecular, and immune markers. CD4, CD8, forkhead box P3 (FOXP3), CD68, CD163, programmed cell death protein 1 (PD-1), and its ligand (PD-L1) expression in pure DCIS and DCIS-Mi, from a cohort of 198 patients, were determined by immunohistochemistry. DFS, clinicopathological parameters, immune markers, and biomarker expression were correlated with presence of Mi. Twelve out of 198 DCIS cases were associated with Mi. DCIS-Mi was significantly linked with ipsilateral invasive recurrence (p = 0.032). Kaplan-Meier analysis revealed that DCIS-Mi had worse DFS for ipsilateral invasive recurrence (p = 0.011) and this was affirmed by multivariate Cox regression analysis (95% CI 1.181-9.010, HR = 3.262, p = 0.023). DCIS-Mi was associated with higher densities of immune infiltrates positive for CD4 (p = 0.037), FOXP3 (p = 0.037), CD163 (p = 0.01), and PD-L1 (p = 0.015). This study demonstrated that DCIS-Mi was correlated with high densities of immune infiltrates and predicted ipsilateral invasive recurrence.

Novel role for the Golgi membrane protein TMEM165 in control of migration and invasion for breast carcinoma

The TMEM165 gene encodes for a multiple pass membrane protein localized in the Golgi that has been linked to congenital disorders of glycosylation. The TMEM165 protein is a putative ion transporter that regulates H⁺/Ca⁺⁺/Mn⁺⁺ homeostasis and pH in the Golgi. Previously, we identified TMEM165 as a potential biomarker for breast carcinoma in a glycoproteomic study using late stage invasive ductal carcinoma tissues with patient- matched adjacent normal tissues. The TMEM165 protein was not detected in non-malignant matched breast tissues and was detected in invasive ductal breast carcinoma tissues by mass spectrometry. Our hypothesis is that the TMEM165 protein confers a growth advantage to breast cancer. In this preliminary study we have investigated the expression of TMEM165 in earlier stage invasive ductal carcinoma and ductal carcinoma in situ cases. We created a CRISPR/Cas9 knockout of TMEM165 in the human invasive breast cancer cell line MDAMB231. Our results indicate that removal of TMEM165 in these cells results in a significant reduction of cell migration, tumor growth, and tumor vascularization in vivo. Furthermore, we find that TMEM165 expression alters the glycosylation of breast cancer cells and these changes promote the invasion and growth of breast cancer by altering the expression levels of key glycoproteins involved in regulation of the epithelial to mesenchymal transition such as E-cadherin. These studies illustrate new potential functions for this Golgi membrane protein in the control of breast cancer growth and invasion.

Higher density of stromal M2 macrophages in breast ductal carcinoma in situ predicts recurrence

Immune response can affect tumour progression and treatment outcome. This study investigated the potential of stromal macrophages around ductal carcinoma in situ (DCIS) in predicting recurrence and progression. CD68 and CD163 expression of macrophages in DCIS from 198 patients was determined by immunohistochemistry. Disease free survival (DFS), clinicopathological parameters and biomarker expression were correlated with the densities of both CD68⁺ and CD163⁺ macrophages. High CD68⁺ macrophage density was associated with high nuclear grade (p < 0.001), oestrogen receptor (ER) negativity (p = 0.029), progesterone receptor (PR) negativity (p = 0.008) and human epidermal growth factor receptor 2 (HER2) positivity (p < 0.001). High CD163⁺ macrophage density was associated with high nuclear grade (p = 0.003), microinvasion (p = 0.01), ER negativity (p < 0.001), PR negativity (p = 0.001), HER2 positivity (p = 0.001) and triple negativity (p = 0.022). DCIS with higher CD68⁺ macrophage density disclosed significantly worse DFS for ipsilateral invasive recurrence (p = 0.004) and is affirmed by multivariate Cox regression analysis (95% CI 1.126-5.102, HR = 2.397, p = 0.023). DCIS with higher CD163⁺ macrophage density showed significantly worse DFS for both recurrence (p = 0.001) and ipsilateral invasive recurrence (p = 0.001). These findings, for CD163⁺ macrophage density, were affirmed by multivariate Cox regression analysis respectively for both recurrence (95% CI 1.210-2.293, HR = 1.880, p = 0.005) and ipsilateral invasive recurrence (95% CI 1.122-5.176, HR = 2.410, p = 0.024). This study demonstrated that DCIS with higher macrophage density was associated with poorer prognostic parameters, while DCIS with higher CD163⁺ macrophage density predicted both  recurrence and ipsilateral invasive recurrence.

A whole slide image-based machine learning approach to predict ductal carcinoma in situ (DCIS) recurrence risk

Background

Breast ductal carcinoma in situ (DCIS) represent approximately 20% of screen-detected breast cancers. The overall risk for DCIS patients treated with breast-conserving surgery stems almost exclusively from local recurrence. Although a mastectomy or adjuvant radiation can reduce recurrence risk, there are significant concerns regarding patient over-/under-treatment. Current clinicopathological markers are insufficient to accurately assess the recurrence risk. To address this issue, we developed a novel machine learning (ML) pipeline to predict risk of ipsilateral recurrence using digitized whole slide images (WSI) and clinicopathologic long-term outcome data from a retrospectively collected cohort of DCIS patients (n = 344) treated with lumpectomy at Nottingham University Hospital, UK.

Methods

The cohort was split case-wise into training (n = 159, 31 with 10-year recurrence) and validation (n = 185, 26 with 10-year recurrence) sets. The sections from primary tumors were stained with H&E, then digitized and analyzed by the pipeline. In the first step, a classifier trained manually by pathologists was applied to digital slides to annotate the areas of stroma, normal/benign ducts, cancer ducts, dense lymphocyte region, and blood vessels. In the second step, a recurrence risk classifier was trained on eight select architectural and spatial organization tissue features from the annotated areas to predict recurrence risk.

Results

The recurrence classifier significantly predicted the 10-year recurrence risk in the training [hazard ratio (HR) = 11.6; 95% confidence interval (CI) 5.3–25.3, accuracy (Acc) = 0.87, sensitivity (Sn) = 0.71, and specificity (Sp) = 0.91] and independent validation [HR = 6.39 (95% CI 3.0–13.8), p < 0.0001;Acc = 0.85, Sn = 0.5, Sp = 0.91] cohorts. Despite the limitations of our cohorts, and in some cases inferior sensitivity performance, our tool showed superior accuracy, specificity, positive predictive value, concordance, and hazard ratios relative to tested clinicopathological variables in predicting recurrences (p < 0.0001). Furthermore, it significantly identified patients that might benefit from additional therapy (validation cohort p = 0.0006).

Conclusions

Our machine learning-based model fills an unmet clinical need for accurately predicting the recurrence risk for lumpectomy-treated DCIS patients.

Electronic supplementary material

The online version of this article (10.1186/s13058-019-1165-5) contains supplementary material, which is available to authorized users.

Systematic identification of mutations and copy number alterations associated with cancer patient prognosis

Successful treatment decisions in cancer depend on the accurate assessment of patient risk. To improve our understanding of the molecular alterations that underlie deadly malignancies, we analyzed the genomic profiles of 17,879 tumors from patients with known outcomes. We find that mutations in almost all cancer driver genes contain remarkably little information on patient prognosis. However, CNAs in these same driver genes harbor significant prognostic power. Focal CNAs are associated with worse outcomes than broad alterations, and CNAs in many driver genes remain prognostic when controlling for stage, grade, TP53 status, and total aneuploidy. By performing a meta-analysis across independent patient cohorts, we identify robust prognostic biomarkers in specific cancer types, and we demonstrate that a subset of these alterations also confer specific therapeutic vulnerabilities. In total, our analysis establishes a comprehensive resource for cancer biomarker identification and underscores the importance of gene copy number profiling in assessing clinical risk.

Organotypic microfluidic breast cancer model reveals starvation-induced spatial-temporal metabolic adaptations

BACKGROUND

Ductal carcinoma in situ (DCIS) is the earliest stage of breast cancer. During DCIS, tumor cells remain inside the mammary duct, growing under a microenvironment characterized by hypoxia, nutrient starvation, and waste product accumulation; this harsh microenvironment promotes genomic instability and eventually cell invasion. However, there is a lack of biomarkers to predict what patients will transition to a more invasive tumor or how DCIS cells manage to survive in this harsh microenvironment.

METHODS

In this work, we have developed a microfluidic model that recapitulates the DCIS microenvironment. In the microdevice, a DCIS model cell line was grown inside a luminal mammary duct model, embedded in a 3D hydrogel with mammary fibroblasts. Cell behavior was monitored by confocal microscopy and optical metabolic imaging. Additionally, metabolite profile was studied by NMR whereas gene expression was analyzed by RT-qPCR.

FINDINGS

DCIS cell metabolism led to hypoxia and nutrient starvation; revealing an altered metabolism focused on glycolysis and other hypoxia-associated pathways. In response to this starvation and hypoxia, DCIS cells modified the expression of multiple genes, and a gradient of different metabolic phenotypes was observed across the mammary duct model. These genetic changes observed in the model were in good agreement with patient genomic profiles; identifying multiple compounds targeting the affected pathways. In this context, the hypoxia-activated prodrug tirapazamine selectively destroyed hypoxic DCIS cells.

INTERPRETATION

The results showed the capacity of the microfluidic model to mimic the DCIS structure, identifying multiple cellular adaptations to endure the hypoxia and nutrient starvation generated within the mammary duct. These findings may suggest new potential therapeutic directions to treat DCIS. In summary, given the lack of in vitro models to study DCIS, this microfluidic device holds great potential to find new DCIS predictors and therapies and translate them to the clinic.

Ultrasonographic features of pure ductal carcinoma in situ of the breast: correlations with pathologic features and biological markers

Purpose

The purpose of this study was to evaluate the ultrasonographic features of pure ductal carcinoma in situ (DCIS) of the breast and to evaluate the correlations of ultrasonographic features with pathologic and biological features.

Methods

A total of 141 lesions in 138 women with pure DCIS who underwent preoperative breast ultrasonography were retrospectively reviewed. Ultrasonographic features were analyzed using the American College of Radiology Breast Imaging Reporting and Data System (BI-RADS) ultrasonography lexicon and the diagnostic criteria of the Japan Society of Ultrasonics in Medicine. Pathologic features including the nuclear grade and presence of comedonecrosis were evaluated. Biological markers including estrogen receptor, progesterone receptor, and human epidermal growth factor receptor 2 (HER2) status, as well as the Ki-67 index, were recorded. Ultrasonographic features were compared with pathologic findings and biological markers using the chi-square test. P-values of <0.05 were considered to indicate statistical significance.

Results

Of the 141 lesions, 75 (53.2%) were mass lesions, 56 (39.7%) were non-mass lesions, and 10 (7.1%) were not visible. The most common feature of the mass pattern was a mass with irregular shape (32.6%), an indistinct margin (27.7%), and hypoechogenicity (37.6%). Microcalcifications were observed in 48 cases (36.6%) as an associated feature. Calcifications outside of a mass were more common than calcifications within a mass. Ultrasonographic microcalcifications and ductal changes were frequently observed in non-mass lesions. Ultrasonographic non-mass lesions were associated with high-grade DCIS (P=0.004) and the presence of comedonecrosis (P=0.006). Microcalcifications were significantly associated with high-grade DCIS (P<0.001), the presence of comedonecrosis (P<0.001), an elevated Ki-67 (P<0.001), and HER2 positivity (P=0.003).

Conclusion

The most common ultrasonographic feature of pure DCIS was an irregular, hypoechoic mass with an indistinct margin. Ultrasonographic microcalcifications and ductal changes were more frequent in non-mass lesions, which were correlated with poor prognostic factors, such as a high nuclear grade, comedonecrosis, HER2 positivity, and an elevated Ki-67 index.

Comparison of HER2 amplification status among breast cancer subgroups offers new insights in pathways of breast cancer progression

Although the prognostic and predictive significance of human epidermal growth factor receptor 2 (HER2) in invasive breast cancer is well established, its role in ductal carcinoma in situ (DCIS) remains unclear. Reports on combined evaluation of both HER2 protein expression and HER2 amplification status in pure DCIS and DCIS adjacent to invasive ductal carcinoma (i.e., admixed DCIS) are scarce. In this study, immunohistochemistry and fluorescence in situ hybridization (FISH) were used to assess HER2 status in 72 cases of pure DCIS, 73 cases of DCIS admixed with invasive ductal carcinoma (IDC), and 60 cases of pure IDC. HER2 copy number-based amplification was present in 49% of pure DCIS, 16% of admixed DCIS, 18% of admixed IDC, and 8% of pure IDC. Amplified pure DCIS with clusters of HER2 signals showed a significantly lower HER2 copy number than amplified admixed DCIS with clusters. Whereas pure DCIS and admixed DCIS presented significant differences, the in situ and invasive component of admixed tumors showed striking similarities regarding mean HER2 and chromosome 17 centromere (CEP17) copy number, grade, and estrogen and progesterone receptor expression. The discrepant prevalence of HER2 amplification among breast cancer subgroups indirectly suggests that HER2 may not play a crucial role in the transition of in situ to invasive breast cancer. The similarities in HER2 amplification status between the in situ and invasive component of admixed tumors hint at a common biological pathway for both components. Our data support the theory that pure DCIS, pure IDC, and admixed lesions have a common progenitor, but can progress as separate lineages.

Her2 and Ki67 Biomarkers Predict Recurrence of Ductal Carcinoma in Situ

BACKGROUND

A subset of patients with ductal carcinoma in situ (DCIS) experience recurrence or progression to invasive cancer. Current clinical practice is not reliably guided by DCIS recurrence prediction, although recurrence risk for invasive breast cancer can now be assessed. We analyzed a panel of biomarkers (estrogen receptor, Her2, Ki67, p53, cyclin D1, COX-2, caveolin-1, survivin, and PPAR-γ) and DCIS histologic and clinical features to determine associations with DCIS recurrence.

MATERIALS AND METHODS

Seventy DCIS cases diagnosed between 1995 and 2010 were divided into 2 groups: 52 had DCIS without known recurrence after excision and 18 had DCIS with subsequent recurrence after excision as DCIS or invasive carcinoma in the ipsilateral or contralateral breast. Tissue microarrays were prepared, immunohistochemistry performed, and expression of the biomarkers scored semiquantitatively. Variables analyzed included age, tumor size, margin status, DCIS grade, necrosis, histologic type, and immunohistochemistry scores. Differences between groups were evaluated using t tests for continuous variables and Fisher exact tests for categorical variables.

RESULTS

Intraductal necrosis was associated with increased recurrence risk: 46% of nonrecurrent cases showed necrosis compared with 83% of those who recurred (P=0.007). Her2 (human epidermal growth factor receptor 2) and Ki67 expression distributions were significantly different between nonrecurrent and recurrent cases. Her2 was overexpressed in 14% of nonrecurrent cases compared with 50% in the recurrent cases (P=0.03). A total of 87% of nonrecurrent cases had low Ki67 staining (0% to 10%) compared with 50% among the recurrent cases (P=0.002).

CONCLUSION

Our results suggest that Her2 and Ki67 immunohistochemistry and the presence of intraductal necrosis aid in DCIS risk stratification.

miR-155 downregulates ErbB2 and suppresses ErbB2-induced malignant transformation of breast epithelial cells

ErbB2 is a vital breast cancer gene and its overexpression has a decisive role in breast tumor initiation and malignant progression. However, the molecular mechanisms that underlie ErbB2 dysregulation in breast cancer cells remain incompletely understood. In this study, we found that ErbB2 expression is inversely correlated with the level of miR-155, a well-documented oncogenic miRNA, in ErbB2-positive breast tumors. We further determined that miR-155 potently suppresses ErbB2 in breast cancer cells. Mechanistically, miR-155 acts to downregulate ErbB2 via two distinct mechanisms. First, miR-155 represses ErbB2 transcription by targeting HDAC2, a transcriptional activator of ErbB2. Second, miR-155 directly targets ErbB2 via a regulatory element in its coding region. Intriguingly, miR-155 is upregulated by trastuzumab and in turn leads to a reduction of ErbB2 expression in trastuzumab-treated ErbB2-positive breast cancer cells. Functional studies showed that miR-155 inhibits ErbB2-induced malignant transformation of human breast epithelial cells. Thus, our findings reveal an intriguing miR-155-ErbB2 context in regulating the malignant transformation of breast epithelial cells, and thereby indicate a novel mode of action for miR-155 in ErbB2-positive breast cancer.

Correlation between sonographic findings and clinicopathologic and biologic features of pure ductal carcinoma in situ in 691 patients

OBJECTIVE

The objective of our study was to compare the sonographic features of pure ductal carcinoma in situ (DCIS) lesions with the initial clinical presentation and histopathologic findings.

MATERIALS AND METHODS

The images and records of 691 patients with pure DCIS who underwent preoperative mammography and whole-breast sonography as part of staging workup in a single institution from January 1, 1996, through July 31, 2009, were reviewed. The BI-RADS sonography lexicon was used when reviewing the sonographic studies. Histopathologic features recorded included estrogen receptor (ER) status, nuclear grade, and presence or absence of comedonecrosis. Statistical comparisons were made using the Student t test, chi-square test, Fisher exact test, Kruskal-Wallis or Wilcoxon rank sum test, multiple logistic regression analysis, and Pearson correlation coefficient.

RESULTS

A total of 304 (44%) tumors were visible on mammography and sonography; 315 (46%), on mammography only; 58 (8%), on sonography only; and 14 (2%), on neither mammography nor sonography. The most common sonographic appearance of DCIS was an irregular hypoechoic mass with indistinct margins and normal posterior features that was indistinguishable from invasive carcinoma. Patients with symptomatic high-nuclear-grade DCIS, dense breasts, and comedonecrosis were younger and had larger tumors on sonography than asymptomatic women with nondense breasts and low-nuclear-grade and noncomedo DCIS. Women with ER-negative DCIS were older and had larger tumors on sonography than women with ER-positive DCIS. ER-negative tumors were more frequently visible on sonography than ER-positive tumors (p=0.007). High-grade DCIS (p<0.0001) and comedo DCIS (p<0.0001) presented more frequently as microcalcifications, architectural distortion, and ductal changes on sonography than low-grade DCIS or noncomedo DCIS.

CONCLUSION

Of the 691 pure DCIS lesions, 362 (52%) were visible on sonography and presented most commonly as a mass. Lesion visibility of DCIS on sonography was not related to nuclear grade or the presence of comedonecrosis.

Co-Expression of p16, Ki67 and COX-2 Is Associated with Basal Phenotype in High-Grade Ductal Carcinoma In Situ of the Breast

We assessed the co-expression of cell cycle-related biomarkers in a series of 121 consecutive cases of high-grade ductal carcinoma in situ (DCIS), pure or associated with invasive carcinoma, and their associations with the different immunoprofiles of DCIS. Cases were identified from the histopathology files of the Breast Pathology Laboratory, Federal University of Minas Gerais, Brazil, from 2003 to 2008. The expression of estrogen receptor, progesterone receptor, HER2 overexpression, cytokeratin 5, epidermal growth factor receptor 1, cyclooxygenase-2, p16 and Ki67 were assessed. Tumors were placed into five subgroups according to their immunohistochemical profile: luminal A, luminal B, HER2, basal-like and "not classified". We found that the basal phenotype was associated with a higher frequency of p16-positive cases (83%) and the luminal A phenotype showed a higher frequency of p16-negative cases (93%; p=0.000). The association of biomarkers p16(+)/Ki67(+)/COX2(+) was expressed in 02/06 cases (33.3%) of the basal phenotype but in only 01/70 cases (1.4%) of the luminal A phenotype (p=0.01). The co-expression of p16(+)/Ki67(+)/COX2(-) was associated with a basal phenotype (p=0.004). P16 expression, p16(+)/Ki67(+)/COX2(+) and p16(+)/Ki67(+)/COX2(-) co-expression showed significant associations with the basal phenotype and these profiles could be used to guide more aggressive treatment strategies in patients with high-grade DCIS.

Ductal carcinoma in situ of the breast: correlation between histopathological features and age of patients

Background

The histopathological subtype, nuclear grade and presence or absence of comedonecrosis are established as critical elements in the reporting of ductal carcinoma in situ (DCIS) of the breast. The aims of this study were to determine the frequencies of morphological subtypes of DCIS, nuclear grade and comedonecrosis; to compare the age of patients with the histopathological characteristics of DCIS, and to assess the agreement of grade between in situ and invasive components in DCIS cases that were associated with invasive carcinoma.

Methods

We evaluated a series of 403 cases of DCIS, pure or associated with invasive mammary carcinoma, consecutively identified from the histopathology files of the Breast Pathology Laboratory, Federal University of Minas Gerais, Brazil, from 2003 to 2008.

Results

DCIS displayed a single growth pattern in most cases (55.1%) and the solid subtype was the most common morphology (42.2% of the total). High-grade DCIS was identified in 293/403 cases (72.7%) and comedonecrosis was present in 222/403 cases (55%). Among DCIS with a single architectural pattern, high grade was more common in the solid subtype (151/168 cases, 89.9%; p < 0.001). Only 32% of tumours with a cribriform pattern had high nuclear grade. Comedonecrosis was more common in the solid morphology than in the cribriform, papillary and micropapillary subtypes (p < 0.001). Patients with high-grade DCIS were younger in relation to patients with low-grade DCIS (p = 0.027) and patients with tumours with comedonecrosis were also younger in comparison to patients with tumours without comedonecrosis (p = 0.003). Fair agreement was observed between in situ and invasive components with regard to grade (weighted kappa = 0.23).

Conclusions

The high nuclear grade and the presence of comedonecrosis were identified more frequently in younger patients and more often correlated with the solid pattern of DCIS.

Virtual Slides

The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/13000_2014_227

GATA4 immunolocalization in breast carcinoma as a potent prognostic predictor

Transcriptional GATA factors are known lineage selector genes and regulate a variety of biological processes including specification and differentiation of tissues. In the present study, we examined expression profiles of six GATA factor genes in invasive ductal carcinomas (IDC) of the breast using microarray analysis (n = 20) and found that GATA4 expression was closely correlated with recurrence in patients. Because the significance of GATA4 has remained largely unknown in breast carcinoma, we further immunolocalized GATA4 in ductal carcinoma in situ (DCIS) of the breast (n = 48) and IDC (n = 163). GATA4 immunoreactivity was detected in the nuclei of carcinoma cells and was positive in 27% of DCIS and 31% of IDC cases. GATA4 status was significantly associated with nuclear grade and van Nuys classification in DCIS and was positively associated with distant metastasis, histological grade and HER2 status, but negatively correlated with progesterone receptor labeling index in IDC. Subsequent multivariate analysis demonstrated that GATA4 status was an independent prognostic factor for both disease-free and breast cancer-specific survival of IDC patients. All of these results indicate that GATA4 plays important roles in the progression of breast carcinoma from an early stage and that immunohistochemical GATA4 status is considered a potent prognostic factor in human breast cancer patients.

Transforming potential and matrix stiffness co-regulate confinement sensitivity of tumor cell migration

It is now well established that tumor cell invasion through tissue is strongly regulated by the microstructural and mechanical properties of the extracellular matrix (ECM). However, it remains unclear how these physical microenvironmental inputs are jointly processed with oncogenic lesions to drive invasion. In this study, we address this open question by combining a microfabricated polyacrylamide channel (μPAC) platform that enables independent control of ECM stiffness and confinement with an isogenically-matched breast tumor progression series in which the oncogenes ErbB2 and 14-3-3ζ are overexpressed independently or in tandem. We find that increasing channel confinement and overexpressing ErbB2 both promote cell migration to a similar degree when other parameters are kept constant. In contrast, 14-3-3ζ overexpression slows migration speed, and does so in a fashion that dwarfs effects of ECM confinement and stiffness. We also find that ECM stiffness dramatically enhances cell motility when combined with ErbB2 overexpression, demonstrating that biophysical cues and cell-intrinsic parameters promote cell invasion in an integrative manner. Morphometric analysis of cells inside the μPAC platform reveals that the rapid cell migration induced by narrow channels and ErbB2 overexpression are both accompanied by increased cell polarization. Disruption of this polarization occurs by pharmacological inhibition of Rac GTPase phenocopies 14-3-3ζ overexpression by reducing cell polarization and slowing migration. By systematically measuring migration speed as a function of matrix stiffness and confinement, we also quantify for the first time the sensitivity of migration speed to microchannel properties and transforming potential. These results demonstrate that oncogenic lesions and ECM biophysical properties can synergistically interact to drive invasive migration, and that both inputs may act through common molecular mechanisms to enhance migration speed.

The nuclear coactivator amplified in breast cancer 1 maintains tumor-initiating cells during development of ductal carcinoma in situ

The key molecular events required for the formation of Ductal Carcinoma in Situ (DCIS) and its progression to invasive breast carcinoma have not been defined. Here we show that the nuclear receptor coactivator Amplified In Breast cancer 1 (AIB1) is expressed at low levels in normal breast but is highly expressed in DCIS lesions. This is of significance since reduction of AIB1 in human MCFDCIS cells restored a more normal 3D mammary acinar structure. Reduction of AIB1 in MCFDCIS cells, both prior to DCIS development or in existing MCFDCIS lesions in vivo, inhibited tumor growth and led to smaller, necrotic lesions. AIB1 reduction in MCFDCIS cells was correlated with significant reduction in the CD24−/CD44+ Breast Cancer Initiating Cells (BCIC) population, and a decrease in myoepithelial progenitor cells in the DCIS lesions in vitro and in vivo. Loss of AIB1 in MCFDCIS cells was also accompanied by a loss of expression of NOTCH 2, 3 and 4, JAG2, HES1, GATA3, HER2 and HER3 in vivo. These signaling molecules have been associated with differentiation of breast epithelial progenitor cells. These data indicate that AIB1 plays a central role in the initiation and maintenance of DCIS and that reduction of AIB1 causes loss of BCIC, loss of components of the NOTCH, HER2 and HER3 signaling pathways and fewer DCIS myoepithelial progenitor cells in vivo. We propose that increased expression of AIB1, through maintenance of BCIC, facilitates formation of DCIS, a necessary step prior to development of invasive disease.

DCIS and LCIS are confusing and outdated terms. They should be abandoned in favor of ductal intraepithelial neoplasia (DIN) and lobular intraepithelial neoplasia (LIN)

The terms ductal and lobular intraepithelial neoplasia (DIN and LIN) were introduced by Tavossoli 15 years ago, who proposed they should replace, respectively, ductal and lobular carcinoma in situ (DCIS and LCIS). This proposal has been slowly gaining ground. We argue that DCIS and LCIS should now be definitively abandoned. Bringing together 'in situ' and other entities into the simpler and more logical DIN/LIN framework--as has been done with intraepithelial neoplasias of cervix, vagina, vulva, prostate, and pancreas--would eliminate the artificial and illogical distinctions between 'not cancers' (e.g. flat epithelial atypia, atypical ductal hyperplasia--now classified as low grade DIN) and 'cancers' (e.g. DCIS--now considered medium-high grade DIN). Elimination of the term 'carcinoma' from entities that cannot metastasize will reduce confusion among health professionals and patients, and contribute to reducing the risk of overtreatment, as well as reducing adverse psychological reactions in patients.

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.

Dysregulation of cell polarity proteins synergize with oncogenes or the microenvironment to induce invasive behavior in epithelial cells

Changes in expression and localization of proteins that regulate cell and tissue polarity are frequently observed in carcinoma. However, the mechanisms by which changes in cell polarity proteins regulate carcinoma progression are not well understood. Here, we report that loss of polarity protein expression in epithelial cells primes them for cooperation with oncogenes or changes in tissue microenvironment to promote invasive behavior. Activation of ErbB2 in cells lacking the polarity regulators Scribble, Dlg1 or AF-6, induced invasive properties. This cooperation required the ability of ErbB2 to regulate the Par6/aPKC polarity complex. Inhibition of the ErbB2-Par6 pathway was sufficient to block ErbB2-induced invasion suggesting that two polarity hits may be needed for ErbB2 to promote invasion. Interestingly, in the absence of ErbB2 activation, either a combined loss of two polarity proteins, or exposure of cells lacking one polarity protein to cytokines IL-6 or TNFα induced invasive behavior in epithelial cells. We observed the invasive behavior only when cells were plated on a stiff matrix (Matrigel/Collagen-1) and not when plated on a soft matrix (Matrigel alone). Cells lacking two polarity proteins upregulated expression of EGFR and activated Akt. Inhibition of Akt activity blocked the invasive behavior identifying a mechanism by which loss of polarity promotes invasion of epithelial cells. Thus, we demonstrate that loss of polarity proteins confers phenotypic plasticity to epithelial cells such that they display normal behavior under normal culture conditions but display aggressive behavior in response to activation of oncogenes or exposure to cytokines.

14-3-3 Proteins: diverse functions in cell proliferation and cancer progression

The 14-3-3 proteins were the first phosphoserine/phosphothreonine-binding proteins to be discovered, a finding that provided the foundation for their prominent role in cell signaling. 14-3-3 family members interact with a wide spectrum of proteins including transcription factors, biosynthetic enzymes, cytoskeletal proteins, signaling molecules, apoptosis factors, and tumor suppressors. The interaction with 14-3-3 can have a profound effect on a target protein, altering its localization, stability, conformation, phosphorylation state, activity, and/or molecular interactions. Thus, by modulating the function of a diverse array of binding partners, 14-3-3 proteins have become key regulatory components in many vital cellular processes - processes that are crucial for normal growth and development and that often become dysregulated in human cancer. This review will examine the recent advances that further elucidate the role of 14-3-3 proteins in normal growth and cancer signaling with a particular emphasis on the signaling pathways that impact cell proliferation, cell migration, and epithelial-to-mesenchymal transition.

Cancer cell migration: integrated roles of matrix mechanics and transforming potential

Significant progress has been achieved toward elucidating the molecular mechanisms that underlie breast cancer progression; yet, much less is known about the associated cellular biophysical traits. To this end, we use time-lapsed confocal microscopy to investigate the interplay among cell motility, three-dimensional (3D) matrix stiffness, matrix architecture, and transforming potential in a mammary epithelial cell (MEC) cancer progression series. We use a well characterized breast cancer progression model where human-derived MCF10A MECs overexpress either ErbB2, 14-3-3ζ, or both ErbB2 and 14-3-3ζ, with empty vector as a control. Cell motility assays showed that MECs overexpressing ErbB2 alone exhibited notably high migration speeds when cultured atop two-dimensional (2D) matrices, while overexpression of 14-3-3ζ alone most suppressed migration atop 2D matrices (as compared to non-transformed MECs). Our results also suggest that co-overexpression of the 14-3-3ζ and ErbB2 proteins facilitates cell migratory capacity in 3D matrices, as reflected in cell migration speed. Additionally, 3D matrices of sufficient stiffness can significantly hinder the migratory ability of partially transformed cells, but increased 3D matrix stiffness has a lesser effect on the aggressive migratory behavior exhibited by fully transformed cells that co-overexpress both ErbB2 and 14-3-3ζ. Finally, this study shows that for MECs possessing partial or full transforming potential, those overexpressing ErbB2 alone show the greatest sensitivity of cell migration speed to matrix architecture, while those overexpressing 14-3-3ζ alone exhibit the least sensitivity to matrix architecture. Given the current knowledge of breast cancer mechanobiology, these findings overall suggest that cell motility is governed by a complex interplay between matrix mechanics and transforming potential.

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.

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.

Local outcomes in ductal carcinoma in situ based on patient and tumor characteristics

The term ductal carcinoma in situ (DCIS) encompasses a heterogeneous group of lesions that differ in their clinical behavior. Clinical factors such as symptomatic presentation and young age are associated with an increased risk of local recurrence in patients with DCIS managed with breast-conserving therapy. Treatment factors such as wider surgical margins, the use of radiation therapy, and the use of tamoxifen reduce the local recurrence risk. Pathological characteristics such as larger lesion size, high nuclear grade, comedo necrosis, and involved margins are associated with an increased risk of local recurrence in many studies. However, there are complex interactions between these pathological risk factors and other parameters such as treatment and length of follow-up. In fact, the magnitude of the effect of these pathological features on local recurrence risk is modified by these other factors. Analysis of genetic and molecular alterations as well as study of the microenvironment associated with DCIS are important avenues of research that may provide new insights into DCIS recurrence and progression risk, and this in turn may lead to new strategies for treatment and prevention.

HER2-positive status is an independent predictor for coexisting invasion of ductal carcinoma in situ of the breast presenting extensive DCIS component

DCIS of the breast with coexisting invasion is commonly seen, and no consensus on any biomarker capable of discriminating this subgroup has been reached yet. We retrospectively examined the receptor status and the histological grade in Chinese DCIS patients to identify any independent predictor in order to discriminate a subgroup with coexisting invasion from pure DCIS patients. A consecutive Chinese DCIS patient cohort registered at a single institution was included for ER, PR, and HER2 status, as well as for evaluation of the histological grade. Patients with invasion foci >1cm in diameter were excluded. The HER2 gene amplification status was further examined by FISH when the IHC result was HER2 (2+). Molecular subtypes were also profiled. Age, histological grade, ER, PR, and HER2 status were included in association analyses. In total, 183 patients were included. A hundred and forty patients had pure DCIS, and 43 patients had DCIS with invasion. The luminal A subtype accounted for 49.7% of all cases, the HER2-positive subtype for 27.9%, and only 10.4% and 12.0% represented the luminal B and basal-like subtypes, respectively. Univariate analyses showed that histological Grade 2, Grade 3, and HER2-positive status were associated with DCIS with invasion, odds ratios 5.1 (P = 0.017), 5.2 (P = 0.01) and 3.34 (P = 0.001), respectively. However, only the HER2-positive status was of statistical significance in the multivariate logistic regression analyses after adjustment for other markers, odds ratio 3.8 (95%CI 1.4-10, P = 0.008). The 43 cases with invasion were further stratified into extensive or small DCIS components according to the percentage of DCIS to total tumor area using 25% as the cutoff point. Multinomial logistic regression with pure DCIS cases as reference showed that the HER2-positive status was associated only with the group showing an extensive DCIS component, odds ratio 6.2 (95%CI 1.8-21, P = 0.003), but not with the group having a small DCIS component. Our study demonstrates that HER2-positive status is an independent predictor for DCIS, with invasion presenting an extensive DCIS component, and favors the hypothesis that HER2 overexpression or gene amplification is involved in the transition from DCIS to invasive disease.

Tissue proteomics of the human mammary gland: towards an abridged definition of the molecular phenotypes underlying epithelial normalcy

Our limited understanding of the biological impact of the whole spectrum of early breast lesions together with a lack of accurate molecular-based risk criteria for the diagnosis and assignment of prognostic significance to biopsy findings presents an important problem in the clinical management of patients harboring precancerous breast lesions. As a result, there is a need to identify biomarkers that can better determine the outcome of early breast lesions by identifying subpopulations of cells in breast premalignant disease that are at high-risk of progression to invasive disease. A first step towards achieving this goal will be to define the molecular phenotypes of the various cell types and precursors - generated by the stem cell hierarchy - that are present in normal and benign conditions of the breast. To date there have been very few systematic proteomic studies aimed at characterizing the phenotypes of the different cell subpopulations present in normal human mammary tissue, partly due to the formidable heterogeneity of mammary tissue, but also due to limitations of the current proteomic technologies. Work in our laboratories has attempted to address in a systematic fashion some of these limitations and here we present our efforts to search for biomarkers using normal fresh tissue from non-neoplastic breast samples. From the data generated by the 2D gel-based proteomic profiling we were able to compile a protein database of normal human breast epithelial tissue that was used to support the biomarker discovery program. We review and present new data on the putative cell-progenitor marker cytokeratin 15 (CK15), and describe a novel marker, dihydropyriminidase-related protein 3 (DRP3) that in combination with CK15 and other well known proteins were used to define molecular phenotypes of normal human breast epithelial cells and their progenitors in resting acini, lactating alveoli, and large collecting ducts of the nipple. Preliminary results are also presented concerning DRP3 positive usual ductal hyperplasias (UDHs) and on single cell layer columnar cells (CCCs). At least two bona fide biomarkers of undifferentiated ERα/PgR negative luminal cells emerged from these studies, CK15 and c-KIT, which in combination with transformation markers may lead to the establishment of a protein signature able to identify breast precancerous at risk of progressing to invasive disease.

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.

Ductal carcinoma in situ (DCIS): pathological features, differential diagnosis, prognostic factors and specimen evaluation

Ductal carcinoma in situ (DCIS) is a heterogeneous, unicentric precursor of invasive breast cancer, which is frequently identified through mammographic breast screening programs. The lesion can cause particular difficulties for specimen handling in the laboratory and typically requires even more diligent macroscopic assessment and sampling than invasive disease. Pitfalls and tips for macroscopic handling, microscopic diagnosis and assessment, including determination of prognostic factors, such as cytonuclear grade, presence or absence of necrosis, size of the lesion and distance to margins are described. All should be routinely included in histopathology reports of this disease; in order not to omit these clinically relevant details, synoptic reports, such as that produced by the College of American Pathologists are recommended. No biomarkers have been convincingly shown, and validated, to predict the behavior of DCIS till date.

Immunohistochemical study of matrix metalloproteinases and their inhibitors in pure and mixed invasive and in situ ductal carcinomas of the breast

We assessed differences in the patterns of expression of matrix metalloproteases and their inhibitors (tissue inhibitors of metalloproteases) in ductal carcinoma in situ alone and admixed with invasive ductal carcinomas (n = 40), as well as in pure invasive ductal carcinomas (n = 40), immunohistochemically and using tissue arrays. The invasive ductal carcinoma components showed higher expression of matrix metalloprotease-9 and -13 than did the admixed ductal carcinoma in situ, whereas stromal fibroblasts of the invasive components showed higher expression of matrix metalloprotease-2, -7, -9, -13, and -14 and tissue inhibitor of metalloprotease-1 and -3 than did fibroblasts around the neoplastic ducts of the admixed ductal carcinoma in situ. Expression of matrix metalloprotease-14 and tissue inhibitor of metalloprotease-3 was significantly higher in the mononuclear inflammatory cells of the invasive components. By contrast, matrix metalloprotease-1 expression was significantly higher in stromal cells of the ductal carcinoma in situ admixed with invasive ductal carcinoma. The pure invasive ductal carcinomas had significantly higher expression of matrix metalloprotease-1, -9, -11, and -14 and tissue inhibitor of metalloprotease-1 and -3 than the invasive ductal carcinomas admixed with ductal carcinoma in situ. Our findings indicate a significant association of matrix metalloprotease expression by the periductal stromal cells of the ductal carcinoma in situ component of mixed tumors and the occurrence of distant metastasis. Our data suggest that the molecular matrix metalloprotease/tissue inhibitor of metalloprotease profile can contribute to better characterization of early breast carcinomas.

14-3-3zeta Cooperates with ErbB2 to promote ductal carcinoma in situ progression to invasive breast cancer by inducing epithelial-mesenchymal transition

ErbB2, a metastasis-promoting oncoprotein, is overexpressed in approximately 25% of invasive/metastatic breast cancers, but in 50%-60% of noninvasive ductal carcinomas in situ (DCIS). It has been puzzling how a subset of ErbB2-overexpressing DCIS develops into invasive breast cancer (IBC). We found that co-overexpression of 14-3-3zeta in ErbB2-overexpressing DCIS conferred a higher risk of progression to IBC. ErbB2 and 14-3-3zeta overexpression, respectively, increased cell migration and decreased cell adhesion, two prerequisites of tumor cell invasion. 14-3-3zeta overexpression reduced cell adhesion by activating the TGF-beta/Smads pathway that led to ZFHX1B/SIP-1 upregulation, E-cadherin loss, and epithelial-mesenchymal transition. Importantly, patients whose breast tumors overexpressed both ErbB2 and 14-3-3zeta had higher rates of metastatic recurrence and death than those whose tumors overexpressed only one.

Study of matrix metalloproteinases and their tissue inhibitors in ductal in situ carcinomas of the breast

AIMS

To analyse the expression of metalloproteinases (MMPs) and their inhibitors (TIMPs) in ductal carcinoma in situ of the breast (DCIS).

METHODS AND RESULTS

An immunohistochemical study was performed in 56 patients with pure DCIS, in 39 with DCIS adjacent to invasive carcinoma (IDC) and 63 patients with T1 IDC, using tissue microarrays and specific antibodies against MMPs and TIMPs. Immunohistochemical results were categorized using a specific software program. The data were analysed by unsupervised hierarchical cluster analysis by each cellular type. IDC showed a higher expression rate of MMP-7 and TIMP-1 than pure DCIS, as well as a higher expression rate of MMP-9 and TIMP-3 than the DCIS component of mixed cases, whereas pure DCIS showed a higher rate of expression of MMP-9 and -11 and TIMP-3 than in the DCIS component of mixed cases. Pure DCIS with a periductal inflammatory infiltrate showed significantly higher MMP-2, -14 and TIMP-1. Dendograms identified two cluster groups with distinct MMP/TIMP expression profiles in neoplastic cells and fibroblastic or mononuclear inflammatory cells surrounding the neoplastic ducts of pure DCIS.

CONCLUSIONS

The results indicate the distinct variability in MMP/TIMP expression by DCIS, which may be of potential biological and clinical interest in breast cancer.

Does iron have a role in breast cancer?

Oestrogen and family history are two of the most important risk factors for breast cancer. However, these risk factors cannot explain the differences in the incidence and recurrence of breast cancer between premenopausal and postmenopausal women. In this paper I propose that, in premenopausal women, an iron deficiency caused by menstruation stabilises hypoxia inducible factor-1alpha, which increases the formation of vascular endothelial growth factor. This mechanism results in premenopausal women being more susceptible to angiogenesis and, consequently, leads to a high recurrence of breast cancer. Conversely, increased concentrations of iron in postmenopausal women, as a result of menstrual cessation, contribute to a high incidence of breast cancer via oxidative-stress pathways. Although the focus of this Personal View is on iron, this by no means negates the roles of other known risk factors in breast-cancer development. Characterisation of the role of iron in breast cancer could potentially benefit patients by decreasing recurrence and incidence and increasing overall survival.

[18FDG-PET in patients with in situ breast carcinomas. A cause of false negative results]

BACKGROUND AND OBJECTIVE

To study the behaviour of 18F-FDG-PET in patients with in situ breast carcinomas.

PATIENTS AND METHOD

The study group included 19 women with a tumor size between 0.8 and 2.2 cm. An uptake in breast with a SUV > 1.9 was considered as positive.

RESULTS

18F-FDG-PET was positive in 8 patients (SUV; range 0.6-2.8; 1.64 [0.59]) and only when the tumor size was higher than 1 cm. Likewise, only in the PET-positive tumors, an inverse (r = -0.637) and positive (p < 0.05) correlation between SUV and weight of patients was observed. When we compared the results with those obtained in 28 patients having infiltrating ductal carcinomas of the breast, we observed that the 18F-FDG-PET was positive only in tumors > 1 cm also, but the percentages of positives (89%) were higher than those obtained in in-situ carcinoma, regardless of tumor size.

CONCLUSIONS

The percentage of positive results of 18F-FDG-PET in in-situ breast carcinomas and the SUV are lower than those observed in infiltrating ductal carcinomas, regardless of tumor size. Those carcinomas can be a source of false negative results with such imaging technique.

Biological Markers Predictive of Invasive Recurrence in DCIS

DCIS is a heterogeneous group of non-invasive cancers of the breast characterized by various degrees of differentiation and unpredictable propensity for transformation into invasive carcinoma. We examined the expression and prognostic value of 9 biological markers with a potential role in tumor progression in 133 patients with pure DCIS treated with breast conserving surgery alone, between 1982–2000. Histology was reviewed and immunohistochemical staining was performed. Pearson correlation coefficient was used to determine the associations between markers and histopathological features. Univariate and multivariate analysis examined associations between time to recurrence and clinico-pathologic features and biological markers.

Median age at diagnosis was 55 years (25–85). With a median follow up of 8.91 years, 41/133 patients recurred (21 as invasive recurrence). In this cohort 13.5% had low, 43% intermediate and 42% high nuclear grade. Comedo necrosis was found in 65% of cases. Expression of ER (62.4%), PR (55.6%), HER2/neu (31.6%), MIB1 (39.8%), p53 (22.6%), p21 (39.8%), Cyclin D1 (95.5%) calgranulin (20.5%), psoriasin (12%), was found in DCIS. HER2/neu was overexpressed in 45% that recurred as DCIS and 42.9% that recurred as invasive cancer, and only in 26.1% in cases that never recurred. On univariate analysis, HER2/neu overexpression was the only marker associated with an increased risk for any recurrence (p = 0.044). The hazard ratio for recurrence for HER2/neu positive DCIS was 1.927 (confidence interval 1.016–3.653) compared to HER2 negative DCIS. On multivariate analysis, HER2/neu overexpression remained the only independent variable significantly associated with any recurrence (p = 0.014) and with invasive recurrence (p = 0.044).

This data suggest that HER2/neu testing may become an important parameter in the management of DCIS and the treatment of cases with positive HER2/neu status could be modified accordingly, similar to the current approach for HER2/neu positive invasive disease.

Metallographic in situ hybridization

Metallographic methods, in which a target is visualized using a probe or antibody that deposits metal selectively at its binding site, offers many advantages for bright-field in situ hybridization (ISH) detection as well as for other labeling and detection methods. Autometallographically enhanced gold labeling procedures have demonstrated higher sensitivity than conventional enzyme chromogens. Enzyme metallography, a novel procedure in which an enzymatic probe is used to deposit metal directly from solution, has been used to develop bright-field ISH methods for HER2 gene determination in breast cancer and other biopsy specimens. It provides the highest level of sensitivity and resolution, both for visualizing endogenous gene copies in nonamplified tissues and for resolving multiple gene copies to allow copy enumeration in amplified tissues without the need for oil immersion or fluorescence optics. An automated enzyme metallography procedure, silver ISH, has been developed for use in slide-staining instruments. Metallographic staining also provides excellent results for immunohistochemistry and may be combined with other staining procedures for the simultaneous detection of more than one gene or combinations of genes and proteins.