Aggressive Ductal Carcinoma In Situ Research Articles

Abstract PR003: Pioneering genetic rat models of Ductal Carcinoma in situ (DCIS)

Abstract DCIS has been virtually unknown before the introduction of breast cancer screening programs in the 1980s. Since then, its incidence has been rising steeply and it now accounts for about 25% of all newly diagnosed ‘breast cancer’ cases. Despite the increase in occurrence, the molecular underpinnings regulating DCIS initiation and progression remain elusive. In addition, almost all DCIS cases are hormone dependent, a characteristic which remains one of the biggest challenges to recapitulate in breast cancer research. We could successfully establish models for DCIS as well as estrogen receptor positive disease subtypes by somatically engineering the rat mammary gland via intraductal injection of lentiviral vectors encoding for the most commonly mutated genes (Ccnd1, Myc, Pik3ca and p53) in (pre-) breast cancer. Models with one perturbed gene remained mostly mammary tumor-free after an observation period of 18 months. However, when perturbed in two loci, animals showed mammary lesion formation within 5 and after up to 40 weeks. Histopathological analysis of these lesions characterized a broad spectrum of tumor types including ductal and lobular carcinomas, with both in situ and invasive phenotypes. Among these tumor types, DCIS lesions as well as invasive ductal carcinoma showed estrogen receptor positivity after immunohistochemical staining. Two distinct growth patterns were observed: a flat growing tumor, shaped by, and replacing the host rat mammary duct, and a round growing lesion, disregarding ductal structures. Interestingly, the flat growing tumor pattern evolved mostly in models expressing luminal drivers (Ccnd1 and Pik3ca) and strongly correlated with in situ growth. To increase luminal subtypes and to narrow down the broad tumor spectrum observed in these models, we generated a luminal cell type-specific promoter expressing our genes of interest. Pathological analysis of the arisen tumors indeed revealed a more homogeneous tumor subtype for all models, with an average tumor latency of 28 to 40 weeks. These genetically engineered models for DCIS and estrogen receptor positive breast cancer may aid in an improved treatment stratification by distinguishment between indolent and aggressive DCIS, a persisting challenge as of today. Additionally, these models broaden the scope of available hormone dependent breast cancer models, benefitting the search for novel treatment regiments for patients suffering from this breast cancer subtype. Citation Format: Catrin Lutz, Madelon Badoux, Timo Eijkman, Bim de Klein, Ji-Ying Song, Linda Henneman, Colinda Scheele, Jelle Wesseling, Jos Jonkers. Pioneering genetic rat models of Ductal Carcinoma in situ (DCIS) [abstract]. In: Proceedings of the AACR Special Conference on Rethinking DCIS: An Opportunity for Prevention?; 2022 Sep 8-11; Philadelphia, PA. Philadelphia (PA): AACR; Can Prev Res 2022;15(12 Suppl_1): Abstract nr PR003.

271 (PB-095) Poster - Morphometric analysis of ductal carcinoma in situ identifies features associated with low risk of progression to invasive breast cancer

Background: Ductal carcinoma in situ (DCIS) is a potential precursor of invasive breast cancer (IBC). However, the majority of DCIS will never progress to IBC if left untreated. As almost all DCIS are treated by surgery often supplemented by radiotherapy, overtreatment of indolent DCIS occurs. Consequently, there is an urgent need to identify biomarkers to distinguish harmless from aggressive DCIS. We hypothesised that morphometric features observed in Hematoxylin-Eosin (HE) sections of DCIS, such as number, geometry and density of DCIS ducts and cells could identify harmless DCIS lesions.

Abstract LB165: Preclinical evaluation of carnosic acid (CA) and rosemary extract standardized to 40% carnosic acid (RE40CA) for the prevention of invasive breast cancer

Abstract Background: There is an unmet need for the development of safer and more effective therapies for the prevention of human invasive breast cancer, for which ductal carcinoma in situ (DCIS) is a precursor. Currently, anti-hormonal therapies are the only option in individuals previously diagnosed with hormone receptor positive breast cancer. However, these agents are associated with many side effects. Furthermore, there are currently no preventive options for hormone receptor negative breast cancers. To study DCIS progression, we developed a model referred to as MIND (Mouse-INtraDuctal) in which patient-derived DCIS cells and cell lines are injected intraductally and studied as they progress to invasive ductal carcinoma (IDC). Previously we provided strong evidence for the role of B Cell Lymphoma-9 (BCL9) as a potential driver of DCIS malignancy. We chose to target BCL9 using RE40CA and its active ingredient CA previously identified in a screen for inhibitors of β-catenin binding to BCL9. Experimental Strategy: CA and RE40CA were administered to DCIS.COM MIND animal models for four weeks by oral gavage or mixed in a powder diet formulation. Drug plasma levels were evaluated by LC-MS. Four weeks following drug administration, mammary glands were excised and evaluated for efficacy and expression of biomarkers of aggressive DCIS, nuclear β-catenin and BCL9. For efficacy studies, mammary glands containing DCIS like lesions were processed and subjected to immunofluorescence staining using anti-human CK-5, anti-SMA, Dapi, β-catenin and BCL9. Extent of DCIS in vivo growth, number of invasive lesions, tumor number and tumor volume were evaluated for each mammary gland. Results: Efficacy studies showed a significant reduction in the number of invasive lesions by administration of CA by oral gavage (CA OG:10mg/kg), CA at 200mg/kg diet (CA200), CA400 and RE40CA 500. A significant reduction in extent of DCIS in vivo growth was achieved by CA OG and RE40CA 500. A significant reduction in the number of tumors was achieved by CA OG, RE40CA OG (25mg/kg equivalent to CA 10mg/kg), RE40CA 100, RE40CA 500 and RE40CA 1000. A significant reduction in tumor volume was achieved by CA OG, RE40CA OG, RE40CA 100, RE40CA 500 and RE40CA 1000. Linear regression modelling was used to compare statistical differences among the groups and differences that reached p-value <0.05 were considered significant. Administration of CA or RE40CA by oral gavage was also associated with a significant loss of nuclear BCL9/β-catenin expression in DCIS epithelial cells. Dietary administration of CA and RE40CA as OG or mixed in powder diet showed an increasing trend in plasma concentrations as the dose was increased. Evaluation of HE stained sections of animal organs by histopathology showed no evidence in any tissue of necrosis, degeneration, inflammation or neoplasia. Additionally, no consistent lesions attributable to treatment were observed in any of the animals or groups. Conclusion: Administration of CA and RE40CA are safe and effective in prevention of DCIS malignancy. Future studies are aimed at testing the efficacy of CA/RE40CA using DCIS cell lines representing other DCIS subtypes (ER+/PR+ and HER2 overexpressing) as well as patient derived DCIS MIND animal models. Supported by NCI PREVENT Cancer Preclinical Drug Development Program, 75N91019D00016/75N91020F00001. Citation Format: Yan Hong, Aditi Rastogi, Aryamitra Banerjee, Brandon L. Plattner, Matthew Lindeblad, Alexander V. Lyubimov, Timothy Fields, Seema A. Khan, Altaf Mohammed, Jeremy J. Johnson, Fariba Behbod. Preclinical evaluation of carnosic acid (CA) and rosemary extract standardized to 40% carnosic acid (RE40CA) for the prevention of invasive breast cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr LB165.

Functional Antagonism of Junctional Adhesion Molecule-A (JAM-A), Overexpressed in Breast Ductal Carcinoma In Situ (DCIS), Reduces HER2-Positive Tumor Progression.

Simple SummarySpecific drug targets for breast ductal carcinoma in situ (DCIS) remain elusive, despite increasing disease prevalence and burden to healthcare services. Estrogen receptor (ER)-negative HER2-positive DCIS, associated with the poorest patient prognosis, is in particular need of novel therapeutic avenues. This report provides the first evidence that a cell surface protein called JAM-A is upregulated on human DCIS patient tissues and can be readily targeted by a novel JAM-A-binding peptide inhibitor in separate in vivo models of DCIS. The anti-tumor efficacy and lack of systemic toxicity of this lead inhibitor, coupled with early indications of potential signaling pathways implicated, support the value of future studies investigating JAM-A as a novel drug target in DCIS patients.Breast ductal carcinoma in situ (DCIS) is clinically challenging, featuring high diagnosis rates and few targeted therapies. Expression/signaling from junctional adhesion molecule-A (JAM-A) has been linked to poor prognosis in invasive breast cancers, but its role in DCIS is unknown. Since progression from DCIS to invasive cancer has been linked with overexpression of the human epidermal growth factor receptor-2 (HER2), and JAM-A regulates HER2 expression, we evaluated JAM-A as a therapeutic target in DCIS. JAM-A expression was immunohistochemically assessed in patient DCIS tissues. A novel JAM-A antagonist (JBS2) was designed and tested alone/in combination with the HER2 kinase inhibitor lapatinib, using SUM-225 cells in vitro and in vivo as validated DCIS models. Murine tumors were proteomically analyzed. JAM-A expression was moderate/high in 96% of DCIS patient tissues, versus 23% of normal adjacent tissues. JBS2 bound to recombinant JAM-A, inhibiting cell viability in SUM-225 cells and a primary DCIS culture in vitro and in a chick embryo xenograft model. JBS2 reduced tumor progression in in vivo models of SUM-225 cells engrafted into mammary fat pads or directly injected into the mammary ducts of NOD-SCID mice. Preliminary proteomic analysis revealed alterations in angiogenic and apoptotic pathways. High JAM-A expression in aggressive DCIS lesions and their sensitivity to treatment by a novel JAM-A antagonist support the viability of testing JAM-A as a novel therapeutic target in DCIS.

Abstract P5-01-01: Intraductal patient-derived xenograft models of ductal carcinoma in situ (DCIS) to distinguish indolent DCIS from aggressive DCIS

Abstract Ductal Carcinoma in Situ (DCIS) is a starting lesion in the milk duct of the breast, which accounts for 25% of all ‘breast cancers’ detected. DCIS is usually treated by surgery combined with radiotherapy, which can have a large impact on the life of patients. However, there is little to no evidence that treatment of low and intermediate grade DCIS reduces mortality, while women diagnosed with DCIS do perceive their risk of dying the same as patients with invasive disease. To reduce the negative perception and the overtreatment of DCIS, but assure proper treatment for high risk DCIS, it is crucial to understand the biology underlying DCIS. In order to study the biology of DCIS we established patient-derived xenograft (PDX) models by intraductally injecting fresh patient DCIS material into the mammary ducts of female immunocompromised mice (Mouse Mammary Intraductal(MIND)). To date, 150 primary DCIS patient samples were engrafted and >100 have been incubated in vivo for a period of 12 months. Using this method we obtain a take rate of 89% with 36% of our models showing progression. Histology and molecular subtyping by PAM50 classification are well preserved in the outgrown PDX lesions compared to the original human counterpart, ensuring that our models are a good representation of the patient disease. For >80 primary samples we obtained RNAseq as well as >50 matched PDX profiles. In addition WES or WGS data is generated from the same primary DCIS samples together with 10 matched PDX WES profiles as well as >40 matched CNV PDX profiles. On top of this we used whole mount imaging, in order to create 3D sections of the injected mammary glands extracted from our PDX models, showing two distinct growth patterns correlated with invasion. And as this is all done in the context of the PRECISION consortium this allows us to confirm and validate our findings in larger sequencing and imaging efforts of human samples. Besides collecting large amounts of data which we can now link to DCIS progression we have successfully sequentially transplanted >25 of our PDX models in order to create models that can be shared with the scientific community and can be manipulated to validate the role of genes in DCIS progression. As an example we took HER2 overexpression, which in our models was found to be associated to progressive disease. On the one hand we treated three progressive HER2 overexpressing DCIS PDX models with a HER2-antibody Herceptin showing a massive decline in growth, while on the other hand we infected two indolent HER2 negative DCIS PDX models with a HER2-GFP lentivirus showing a transformation to HER2 positive progressive growth. In conclusion all this data together enables us to create a well-characterized biobank of DCIS models of which we can follow the progression, sequentially transplant >25 models, find mutational and expression profiles related to high risk DCIS and manipulate gene expression to validate the role of genes in DCIS progression. Citation Format: Jelle Wesseling, Stefan Hutten, Catrin Lutz, Colinda Scheele, Madelon Badoux, Timo Eijkman, Roebi de Bruijn, Mathilde Almekinders, Joyce Sanders, Esther Lips, Jacco van Rheenen, Jos Jonkers, Grand challenge PRECISION consortium. Intraductal patient-derived xenograft models of ductal carcinoma in situ (DCIS) to distinguish indolent DCIS from aggressive DCIS [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr P5-01-01.

Abstract P1-05-01: The tumor immune microenvironment and HER2 landscape of high-risk ductal carcinoma in situ: The DEFENSE study

Abstract Introduction: Ductal carcinoma in situ (DCIS) of the breast is a premalignant lesion representing a spectrum of biology from indolent to aggressive. A minority of women present with clinically high-risk features associated with poor outcome. Yet even in patients with biologically aggressive DCIS, the risk of breast cancer mortality is only 3.3% compared to 30-40% in patients with biologically aggressive invasive cancer of the same size.1 We hypothesize that the tumor immune microenvironment could play a proactive role in preventing invasion in high grade clinically high-risk DCIS and that HER2 status, including specific HER2 isoform expression and post-translational modification of HER2, could impact progression. Methods: DCIS: Elaboration of Factors from Enlarged lesions that Nevertheless remain Stage 0 Entities (DEFENSE) is a study of high-risk DCIS, defined as having at least two of the following characteristics: large (>5cm), high grade, hormone receptor-negative status and/or HER2+ status. Slides obtained from FFPE tissue blocks were stained with fluorescence-based multiplex immunohistochemistry (mIHC) panels and imaged to characterize immune infiltrate within the ducts and the stromal compartments. mIHC was also used to detect extracellular and intracellular domains of HER2 with imaging analysis performed to identify HER2 isoforms of HER2+ specimens. Isoforms were characterized as 1) full-length/extracellular domain (ECD) intact, 2) pure/complete loss of ECD (p95 isoform), 3) subclonal populations of both full-length ECD and p95 and 4) gradient/representing partial loss of ECD per cell (reflecting post-translational cleavage). Clinical characteristics were correlated with molecular profile, tumor immune infiltrates, and HER2 isoform. Finally, expression profiling with a 44k array was conducted by Agendia, and MammaPrint and BluePrint results were generated. Results: Of 92 total patients, median age is 46 years. The average DCIS lesion size is 8.2cm, and 33% are hormone receptor negative (HR-). Based upon initial analysis, mIHC demonstrates significant heterogeneity in immune infiltrate populations of pathologically identical DCIS specimens and within regions of the same specimen. High-grade HR- disease has highly reactive stroma, characterized by dense CD3+, CD34+, and CD68+ infiltrate within the stromal compartment. HER2 testing of the first 51 cases demonstrates a high rate of positivity of 67% (34/51). Of those tested for HER2 isoform expression (n=21), none had homogeneous intact full-length HER2. Six (29%) demonstrate the pure p95 isoform, 3 (14%) demonstrate the subclonal isoform, and 12 (57%) demonstrate a gradient HER2 isoform phenotype. Preliminary data from expression profiling shows that the HER2+ cases are also HER2 intrinsic sub-type by BluePrint. Across all of the high-risk DCIS cases, all were scored as MammaPrint high risk, either Luminal B or HER2-type, with only 1 basal and no Luminal A. Additional analyses are ongoing, including completion of testing for the whole data set as well whole exome DNA sequencing and SMART-3SEQ RNA sequencing. Conclusions: Clinically high-risk and pathologically homogenous DCIS lesions demonstrate significant immune infiltrate heterogeneity. Nearly 70% of these large clinically high-risk DCIS lesions are HER2+ with HER2 isoforms most commonly representing either partial or complete loss of the HER2 ECD. This is significantly higher than what is reported for invasive HER2+ breast cancer. A comparison to size and molecularly matched invasive cancers, including from the I-SPY 2 trial, is underway in an effort to elucidate how molecularly aggressive lesions remain in situ despite their large size.

The frequency and clinical significance of DNA polymerase beta (POL\u03b2) expression in breast ductal carcinoma in situ (DCIS)

BackgroundThe prediction of clinical behaviour of breast ductal carcinoma in situ (DCIS) and its progression to invasive disease remains a challenge. Alterations of DNA damage repair mechanisms are associated with invasive breast cancer (BC). This study aims to assess the role of base excision repair (BER) DNA Polymerase Beta (POLβ) in DCIS.MethodsA cohort of DCIS comprising pure DCIS (n = 776) and DCIS coexisting with invasive BC (n = 239) were prepared as tissue microarrays. POLβ protein expression was assessed using immunohistochemistry and correlated with clinicopathological parameters and patient outcome. Preclinically, we investigated the impact of POLβ depletion on stem cell markers in representative DCIS cell line models.ResultsReduced POLβ expression was associated with aggressive DCIS features including high nuclear grade, comedo necrosis, larger tumour size, hormonal receptor negativity, HER2 overexpression and high Ki67 index. Combined low nuclear/low cytoplasmic POLβ expression showed the strongest association with the features’ characteristics of aggressive behaviour. There was a gradual reduction in the POLβ expression from normal breast tissue, to DCIS, with the lowest expression observed in the invasive BC. Low POLβ expression was an independent predictor of recurrence in DCIS patients treated with breast conserving surgery (BCS). POLβ knockdown was associated with a significant increase in cell stemness markers including SOX2, NANOG and OCT4 levels in MCF10-DCIS cell lines.ConclusionLoss of POLβ in DCIS is associated with aggressive behaviour and it can predict recurrence. POLβ expression in DCIS provides an additional feature for patients’ risk stratification for personalised therapy.

Abstract PS18-14: Elucidating the biology of high-risk ductal carcinoma in situ (DCIS) through genomics and immunohistochemical profiling of the tumor microenvironment: The DEFENSE study

Abstract Introduction: Ductal carcinoma in situ (DCIS) of the breast is a premalignant lesion representing a spectrum of biology and risk. While many patients with DCIS undergo surgical resection with no survival benefit given the indolent nature of their disease, others do possess biologically aggressive DCIS that has the potential to evolve into invasive cancer if left untreated. Yet even among those patients with biologically aggressive DCIS, their risk of dying from metastatic breast cancer is only 3.3% compared to 30-40% among patients with biologically aggressive invasive cancer.1 The DEFENSE study, supported with funding from the NCI Molecular Characterization of Screen-Detected Lesions (MCL) consortium, was designed to identify molecular, immunological, and stromal-related factors that allow DCIS to develop high-risk features without ever becoming invasive breast cancer. Methods: The overall objective of the DEFENSE study is to compare 100 patients with invasive high-risk breast cancer enrolled on the I-SPY2 trial matched based upon age and tumor molecular profile (Mammaprint) to 100 patients with high-risk DCIS, defined as having at least two of the following characteristics: large (>5cm), high-grade, hormone receptor-negative status and/or HER2-positive status. Tumors obtained from each of these patients are divided into 22 sequential sections with regions of pathologic interest identified prior to undergoing whole exome DNA sequencing, SMART-3SEQ RNA sequencing, multiplex immunofluoresence (mIF) for immune cell infiltrates, and stromal profiling by IHC. Each profiling modality is performed by a different institution included in the MCL consortium (UCSF, UCD, UCSD, Stanford, and UVM). In order to evaluate the logistic and financial feasibility of our multi-institution protocol prior to expanding to our proposed full-scale study, we are conducting a pilot study of 11 high-risk DCIS specimens. Results: The 11 pilot specimens have been successfully sent and received by each institution. H&E images from the sectioned specimens have been uploaded to the NASA Jet Propulsion Lab (JPL) cloud-based platform and shared for pathologic annotation among institutions. mIF of the pilot cohort has been completed, but interpretation of associations between tumor subtype and immune cell infiltrate is limited by the small sample size. Whole exome DNA sequencing, SMART-3SEQ RNA sequencing, and stromal profiling of the pilot cohort are each ongoing. We anticipate being able to provide full results from each profiling modality performed from the pilot cohort, as well as results from an expanded cohort of 40 additional specimens, by December 2020. Conclusions: We have successfully shown that a multi-institution collaboration can effectively share pathologic data and conduct data analyses using a variety of tumor profiling modalities. We anticipate that data from our expanded cohort will allow us to differentiate the underlying biology of high-risk DCIS from invasive breast cancer, identifying mechanistic opportunities for future intervention.

Abstract PR02: Inferring the evolutionary dynamics of ductal carcinoma in situ through multi-regional sequencing and mathematical modeling

Abstract Introduction. The natural history of preinvasive breast cancer, or ductal carcinoma in situ (DCIS) remains poorly understood. Overcoming this gap would allow risk-appropriate treatment for patients diagnosed with DCIS. We used a multiregional sequencing approach in combination with mathematical modeling to characterize the evolutionary dynamics of DCIS initiation and progression. Methods. We analyzed a cohort of 18 patients diagnosed with DCIS, either with (n=9) or without (n=9) synchronous invasive cancer. Based on whole exome sequencing, tumor-specific mutation panels were constructed, each targeting 29-75 mutations (median: 60). From each tumor, and using selective ultraviolet radiation fractionation (SURF), we microdissected small spots (encompassing 1-3 duct cross-sections) from 3-4 spatially separated microscope sections (mean slide separation: 1.25cm, range: 0.34-6.0cm). Spots were spatially registered and genotyped based on targeted sequencing of the tumor-specific mutation panels. For each tumor, we performed unsupervised clonal deconvolution of the spot genotypes (CloneFinder) and constructed phylogenetic subclone trees. To quantify the spatial patterns of subclonal mutations, we introduced a dispersion index (DI), ranging from low (DI=0%) to high (DI=100%). To provide a spatio-temporal context for the heterogeneity patterns we developed a family of stochastic mathematical models of DCIS initiation and progression. Thereby, we embedded the evolutionary dynamics of tumor cell expansion in the branching topology of mammary ductal trees. Results. A total of 485 microdissected spots (median per tumor: 23, range: 10-50) were spatially registered and sequenced (median depth: 9,000x). All tumors were multiclonal, containing a median of 5 subclones (range: 2-14). Surprisingly, the correlation between spatial and genomic distances of spots was low. Individual subclones were diffusely dispersed across tumors. DCIS with synchronous DCIS and invasive cancer (mixed DCIS) had a higher mutation dispersion (DI=84.7%) than those without (pure DCIS, DI=70.5%; p=0.03, Wilcoxon rank-sum test). Mixed DCIS also had a higher fraction of spots containing more than one subclone than pure DCIS (median: 30.4% vs 0%, p=0.03). Among 7 mixed DCIS with invasive spots, 5 showed evidence of multiclonal invasion, that is more than one invading subclones were found in both in situ and invasive regions of the tumor. Mathematical modeling analyses show that the observed spatial patterns of genetic heterogeneity are consistent with a single expansion of mixing subclones across the ductal tree architecture. Conclusions. Our findings provide novel insights into the early growth and invasion dynamics of DCIS lesions. Further, we identified potential evolutionary markers for the delineation between indolent (pure) and aggressive (mixed) DCIS. This constitutes an important step towards identification of patients with low-risk DCIS who could be appropriately managed with less aggressive treatment. Citation Format: Marc D. Ryser, Inmaculada C. Sorribes, Matthew Greenwald, Ethan Wu, Allison Hall, Diego Mallo, Lorraine M. King, Timothy Hardman, Lunden Simpson, Carlo C. Maley, Jeffrey R. Marks, Darryl Shibata, E. Shelley Hwang. Inferring the evolutionary dynamics of ductal carcinoma in situ through multi-regional sequencing and mathematical modeling [abstract]. In: Proceedings of the AACR Virtual Special Conference on Tumor Heterogeneity: From Single Cells to Clinical Impact; 2020 Sep 17-18. Philadelphia (PA): AACR; Cancer Res 2020;80(21 Suppl):Abstract nr PR02.

Abstract 5440: Understanding the biology of high-risk ductal carcinoma in situ (DCIS) through genomics and the tumor immune microenvironment: The DEFENSE study

Abstract Introduction: Ductal carcinoma in situ (DCIS) of the breast is a premalignant lesion representing a spectrum of biology and risk. While many patients with DCIS undergo surgical resection with no survival benefit given the indolent nature of their disease, others do possess biologically aggressive DCIS that has the potential to evolve into invasive cancer if left untreated. Yet even among those patients with biologically aggressive DCIS, their risk of dying from metastatic breast cancer is only 3.3% compared to 30-40% among patients with biologically aggressive invasive cancer.1 We are interested in identifying molecular and tumor immune microenvironment factors that allow DCIS to develop high-risk features without ever becoming invasive breast cancer. Methods: We are conducting a retrospective pilot study (DEFENSE) of 10 patients with invasive high-risk breast cancer enrolled on the I-SPY2 trial matched based upon age and tumor molecular profile to 10 patients with high-risk DCIS, defined as having at least two of the following characteristics: large (>5cm), high-grade, hormone receptor-negative status and/or HER2-positive status. Tumors obtained from each of these patients will be divided into 22 sequential sections with regions of pathologic interest identified prior to undergoing whole exome DNA sequencing, SMART-3SEQ RNA sequencing, multiplex immunohistochemistry (mIHC) using three immune panels, and stromal profiling. Each profiling modality will be performed by a different institution included in the NIH Molecular Characterization of Screen-Detected Lesions (MCL) consortium. This pilot study will inform our decision to expand our study to a full-scale review of 200 patients (100 DCIS, 100 invasive cancer) among our institutions. Results: We have thus far demonstrated the feasibility of our pilot study with 10 blocks in total sent to and received by each institution. Whole exome DNA sequencing, SMART-3SEQ, mIHC, and stromal profiling work has begun and will be available for presentation, and we plan to make pathology, clinical and genomic data available through the MCL's collaborative partnership with the NASA Jet Propulsion Lab (JPL) cloud-based platform. Conclusions: We have successfully shown that a multi-institution collaborative can effectively share pathologic data and conduct data analyses using a variety of tumor profiling modalities. We anticipate that our data will allow us to differentiate the underlying biology of high-risk DCIS from invasive breast cancer, identifying mechanistic opportunities for future intervention.

Downregulation of miR-223 Expression Is an Early Event during Mammary Transformation and Confers Resistance to CDK4/6 Inhibitors in Luminal Breast Cancer.

miR-223 is an anti-inflammatory miRNA that in cancer acts either as an oncosuppressor or oncopromoter, in a context-dependent manner. In breast cancer, we demonstrated that it dampens the activation of the EGF pathway. However, little is known on the role of miR-223 during breast cancer onset and progression. miR-223 expression was decreased in breast cancer of luminal and HER2 subtypes and inversely correlated with patients' prognosis. In normal luminal mammary epithelial cells, miR-223 acted cell autonomously in the control of their growth and morphology in three-dimensional context. In the MMTV-Δ16HER2 transgenic mouse model, oncogene transformation resulted in a timely abrogation of miR-223 expression, likely due to activation of E2F1, a known repressor of miR-223 transcription. Accordingly, treatment with CDK4/6 inhibitors, which eventually results in restraining E2F1 activity, restored miR-223 expression and miR-223 ablation induced luminal breast cancer resistance to CDK4/6 inhibition, both in vitro and in vivo. Notably, miR-223 expression was lost in microdissected ductal carcinoma in situ (DCIS) from patients with luminal and HER2-positive breast cancer. Altogether, these results identify downmodulation of miR-223 as an early step in luminal breast cancer onset and suggest that it could be used to identify aggressive DCIS and predict the response to targeted therapy. SIGNIFICANCE: miR-223 may represent a predictive biomarker of response to CDK4/6 inhibitors and its loss could identify DCIS lesions that are likely to progress into invasive breast cancer.

Ductal Carcinoma in Situ: Current Concepts in Biology, Imaging, and Treatment.

Ductal carcinoma in situ (DCIS) of the breast is a group of heterogeneous epithelial proliferations confined to the milk ducts that nearly always present in asymptomatic women on breast cancer screening. A stage 0, preinvasive breast cancer, increased detection of DCIS was initially hailed as a means to prevent invasive breast cancer through surgical treatment with adjuvant radiation and/or endocrine therapies. However, controversy in the medical community has emerged in the past two decades that a fraction of DCIS represents overdiagnosis, leading to unnecessary treatments and resulting morbidity. The imaging hallmarks of DCIS include linearly or segmentally distributed calcifications on mammography or nonmass enhancement on breast MRI. Imaging features have been shown to reflect the biological heterogeneity of DCIS lesions, with recent studies indicating MRI may identify a greater fraction of higher-grade lesions than mammography does. There is strong interest in the surgical, imaging, and oncology communities to better align DCIS management with biology, which has resulted in trials of active surveillance and therapy that is less aggressive. However, risk stratification of DCIS remains imperfect, which has limited the development of precision therapy approaches matched to DCIS aggressiveness. Accordingly, there are opportunities for breast imaging radiologists to assist the oncology community by leveraging advanced imaging techniques to identify appropriate patients for the less aggressive DCIS treatments.

Can dedicated breast PET help to reduce overdiagnosis and overtreatment by differentiating between indolent and potentially aggressive ductal carcinoma in situ?

To analyze the utility of metabolic imaging, and specifically of dedicated breast positron emission tomography (dbPET) to differentiate between indolent and potentially aggressive ductal carcinoma in situ (DCIS). After institutional review board approval, we retrospectively reviewed the cases of pure DCIS who underwent dbPET before biopsy and surgery in Lucus Augusti Universitary Hospital (Lugo, Spain) and in Fudan Cancer Institute (Shanghai, China) between January 2016 and May 2018. Grade 1 and "non-comedo" grade 2 DCIS were considered low-risk disease, while intermediate-grade with necrosis or grade 3 cases were included in the high-risk group. DbPET sensitivity and specificity to differentiate between indolent and potentially aggressive DCIS were determined along with their respective 95% confidence intervals. We enrolled 139 surgery-confirmed pure DCIS cases. Fifty were high-risk neoplasms and 89 low-risk DCIS. Only seven low-risk lesions were positive at dbPET and five of potentially aggressive neoplasms did not show FDG uptake, all included into the field of view (FOV). Sensitivity and specificity of dbPET to differentiate between indolent and potentially aggressive DCIS were 90% (95% CI, 77-96%) and 92% (95% CI, 84-97%), respectively. Metabolic imaging could help to identify the subgroup of indolent lesions from those potentially aggressive ones that may be managed by active surveillance. • Low- and high-grade DCIS likely arise from two distinct evolutionary paths and when low-grade lesions progress to invasive cancer, the tumor is frequently low grade and well differentiated. • Ongoing clinical trials evaluate whether patients with low-risk DCIS could be safely managed by an active surveillance approach, with avoidance of unnecessary treatments and without impact on ipsilateral invasive breast cancer free survival time. • Dedicated breast PET may differentiate harmless from potentially hazardous DCIS, supporting active surveillance for the management of those women with low-grade DCIS, decreasing the rate of the upgrade to invasive carcinoma at surgical excision.

Abstract P3-14-01: Molecular definition of the transition of ductal carcinoma in situ (DCIS) to invasive ductal carcinoma (IDC).

Abstract Background: Ductal carcinoma in situ (DCIS) is thought to be a precursor lesion to invasive ductal carcinoma and sometimes occurs in combination with invasive disease. However, the majority of DCIS lesions do not progress to invasive disease. To date no molecular markers have been identified that associate with the potential for development to invasive disease. Our work has sought to identify molecular markers that can be used to determine the likelihood of DCIS being associated with invasive disease. Identification of such markers could be of direct therapeutic benefit, since patients with a high likelihood of associated or subsequent invasive disease could be managed more aggressively. Methods: We have compiled matched pairs, consisting of patients that have recurred with DCIS, compared to those who have DCIS plus invasive disease. Laser-capture microdissection was used to isolate in situ and invasive components of the latter, and in situ components of the former. We analyzed these samples by parallel cDNA-mediated Annealing, Selection, Extension, and Ligation (DASL) analysis of transcription, and DNA copy number analysis by resequencing. In addition, exome capture deep re-sequencing has been conducted on multiple cored in situ versus invasive components of DCIS from the same tumor sample. Results: Gene expression analysis revealed candidate genes that were specific to DCIS and others that were expressed only in the adjacent invasive component of the tissue. These genes are currently being evaluated to identify interesting candidates. Additionally, we characterized the gene expression signatures from tumors that recurred as DCIS only, to the DCIS component of those tumors that recurred with adjacent invasive disease. We identified genes that were differentially expressed between these data sets. The DNA copy number analysis of laser-captured samples indicated a single dominant clone in each DCIS. In contrast to previously reported observations, the profiles of invasive versus non-invasive lesions differ significantly from one another. Observations of non-invasive versus invasive components of adjacent disease in two of the pairs indicate that the profile of the invasive lesions differ from that of the non-invasive component, however the profiles share many individual features. Discussion: Our data identify differences between in situ and neighboring invasive tumor that may mark features associated with progression. Integration of the copy number and transcription profiling datasets will reveal the extent to which genomic alterations drive changes in gene expression. Identification of markers that distinguish indolent and aggressive subsets of DCIS that can be used to predict an association with invasive disease has the potential for near term clinical utility and may identify therapeutic targets for aggressive DCIS. Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P3-14-01.

Ductal Carcinoma In Situ: Challenges, Opportunities, and Uncharted Waters

Ductal carcinoma in situ (DCIS) is a heterogeneous group of diseases that differ in biology and clinical behavior. Until 1980, DCIS represented less than 1% of all breast cancer cases. With the increased utilization of mammography, DCIS now accounts for 15% to 25% of newly diagnosed breast cancer cases in the United States. Although our ability to detect DCIS has radically improved, our understanding of the pathophysiology and factors involved in its progression to invasive carcinoma is still poorly defined. In many patients, DCIS will never progress to invasive breast cancer and these women are overtreated. In contrast, some DCIS cases are clinically aggressive and the women may be undertreated. We are able to define some of the predictors of aggressive DCIS compared with DCIS of low malignant potential. However, our ability to risk-stratify DCIS is still in its infancy. Clinical risk factors that predict aggressive disease and increased risk of local recurrence include young age at diagnosis, large lesion size, high nuclear grade, comedo necrosis, and involved margins. Treatment factors such as wider surgical margins and radiation therapy reduce the risk of local recurrence. DCIS represents a key intermediate in the stepwise progression to malignancy, but not all aggressive breast cancers appear to have a DCIS intermediate, notably within triple-negative breast cancer. Ongoing studies of the genetic and epigenetic alterations in precancerous breast lesions (atypia and DCIS) as well as the breast microenvironment are important for developing effective early detection and individualized targeted prevention.

Biological Markers in DCIS and Risk of Breast Recurrence: A Systematic Review

Understanding of the biology and clinical behavior of ductal carcinoma in situ (DCIS) is currently inadequate. The aim of this comprehensive review was to identify important molecular biological markers associated with DCIS and candidate markers associated with increased risk of ipsilateral recurrence after diagnosis of DCIS. A comprehensive systematic review was performed to identify studies published in the past 10 years that investigated biological markers in DCIS. To be included in this review, studies that investigated the rate of biological expression of markers had to report on at least 30 patients; studies that analyzed the recurrence risk associated with biomarker expression had to report on at least 50 patients. There were 6,252 patients altogether in our review. Biological markers evaluated included steroid receptors, proliferation markers, cell cycle regulation and apoptotic markers, angiogenesis-related proteins, epidermal growth factor receptor family receptors, extracellular matrix-related proteins, and COX-2. Although the studies in this review provide valuable preliminary information regarding the expression and prognostic significance of biomarkers in DCIS, common limitations of published studies (case-series, cohort, and case-control studies) were that they were limited to small patient cohorts in which the extent of surgery and use of radiotherapy or endocrine therapy varied from patient to patient, and variable methods of determining biomarker expression. These constraints made it difficult to interpret the absolute effect of expression of various biomarkers on risk of local recurrence. No prospective validation studies were identified. As the study of biomarkers are in their relative infancy in DCIS compared with invasive breast cancer, key significant prognostic and predictive markers associated with invasive breast cancer have not been adequately studied in DCIS. There is a critical need for prospective analyses of novel and other known breast cancer molecular markers in large cohorts of patient with DCIS to differentiate indolent from aggressive DCIS and better tailor the need and extent of current therapies.

Expression patterns of lymphangiogenic and angiogenic factors in a model of breast ductal carcinoma in situ

Background Foci of invasion are found in greater than 20% of excised specimens of breast ductal carcinoma in situ (DCIS). Since lymphangiogenesis markers are associated with the potential for increased lymph node metastasis, the purpose of the current study was to determine expression of lymphangiogenesis molecular markers in a model of aggressive DCIS. Methods From the MCF10A xenograft model, comedo type MCF10DCIS.com cells, premalignant MCF10AT, and invasive MCF10CA1a.cl1 cells were tested. Invasion was tested by Matrigel invasion assays (Becton-Dickinson, Bedford, MA). Gene expression was determined by reverse transcriptase–polymerase chain reaction and protein expression by immunoblot, normalized to β-actin. Results MCF10DCIS.com cells were 4-fold more invasive than MCF10AT cells ( P < .01), and expressed several-fold more mRNA and protein than MCF10AT and MCF10CA1a.cl1 cells for vascular endothelial growth factor C, vascular endothelial growth factor D, and lymphatic vessel endothelial hyaluronan receptor 1 ( P < .01). Conclusions A subset of comedo-type DCIS cells are invasive, and expression of lymphangiogenesis markers is greater at the mRNA and protein levels than by invasive cancer cells ( P < .01). These additional molecular markers may characterize aggressive DCIS more precisely.

Differential expression of c‐Met, its ligand HGF/SF and HER2/neu in DCIS and adjacent normal breast tissue

Tyrosine kinase receptors Her2/neu and c-Met play an important role in breast cancer development and progression. Our aim was to determine the expression of c-Met, its ligand hepatocyte growth factor/scatter factor (HGF/SF) and Her2/neu in ductal carcinoma in situ (DCIS) lesions of the breast (n = 39) by two different immunocytochemical techniques, classical immunohistochemistry and immunofluorescence, and to correlate their expression levels with histopathological and clinical characteristics. Both methods revealed similar c-Met staining patterns in both the in situ component and the adjacent normal tissue (P < 0.001). However, an imbalance in c-Met expression between tumour and surrounding normal tissue was correlated with high-grade DCIS (Van Nuys Grade 3). No correlation existed between Her2/neu and c-Met expression. High HGF/SF immunoreactivity was observed in 43.6% of the cases, yet the adjacent cellular stroma revealed only low levels of HGF/SF. No correlation existed between c-Met, Her2/neu or HGF/SF expression and clinicopathological factors. An imbalance in c-Met expression between tumour and surrounding normal tissue is associated with an aggressive DCIS phenotype. Moreover, c-Met and HGF/SF may contribute to tumour development by different means than those controlled by Her2/neu.

In situ carcinomas of the female breast. Incidence, clinical findings and DBCG proposals for management.

In situ carcinomas of the female breast (CIS) include lobular carcinoma in situ (LCIS) and ductal carcinoma in situ (DCIS). Also associated are controversial forms of epithelial hyperplasia, lobular cell atypia (ALH) and ductal cell atypia (ADH). Based upon recent Danish autopsy studies, it has been estimated that about 25% of all women will develop in situ carcinoma, predominantly in the form of DCIS. Only a fraction of these lesions will evolve into a clinical manifest form, however. Thus, in a clinical setting, the frequency of CIS is 0.09 cases per 1,000 woman-years for a Danish female population aged twenty years or more. The lifetime risk of having CIS demonstrated is estimated at 0.53% for women in this age group. CIS makes up a few per cent of all newly diagnosed breast cancers in Denmark. Enforced employment of mammography in the early detection of breast cancer will increase CIS incidence from about 4-6% to about 9-10% of all newly diagnosed breast cancers, and aggressive DCIS growths will mainly constitute the increment. In concurrence with the new DBCG protocols in 1988, new strategies for the management of in situ carcinomas, based upon histogenetic types and growth patterns, are being introduced. The aim will be breast-conserving treatment whenever it can be achieved.