De-escalation of axillary surgery in breast cancer (BC) reduces surgical morbidity but limits pathological assessment of nodal burden, a key determinant of prognosis and adjuvant therapy in estrogen receptor-positive (ER+)/HER2- BC. Tumor-intrinsic biomarkers that reflect the extent of lymph node disease may help bridge this gap. We performed genome-wide DNA methylation profiling of primary tumors from patients with ER+/HER2- BC stratified by pathological nodal stage (1-3 positive nodes, pN1; 4 or more positive nodes, >pN1). Findings were validated across multiple independent cohorts (TCGA-BRCA, SCAN-B, AURORA US), integrating molecular and clinical data. Forty-seven tumors passed EPIC quality control (pN1: n=29; >pN1: n=18). Tumors with >pN1 disease showed epigenetic reprogramming, including promoter hypermethylation and suppression of genes in pathways related to development and cell adhesion. Across datasets, five genes (TTC23, ARL10, RIC3, CXCL14, KCNH2) were consistently associated with nodal involvement and outcomes. Based on these genes, we developed the LION (Lymph-node Involvement Outcome Numerator) score, which distinguishes tumors with >pN1 disease and is associated with worse distant metastasis-free survival across cohorts. The LION score represents a biologically informed molecular metric associated with nodal involvement in ER+/HER2- BC. These findings provide insight into tumor-intrinsic epigenetic programs linked to dissemination.

De-escalation of axillary surgery has resulted in the loss of pathologic nodal information, yet the extent of lymph node involvement remains an important determinant of treatment decisions in estrogen receptor-positive (ER+)/HER2− disease. We examined whether primary tumors differed molecularly according to the extent of this regional dissemination. Genome-wide DNA methylation profiling of primary ER+/HER2− tumors from 47 patients with pN1 (n = 29) vs. >pN1 (n = 18) disease showed differences concentrated at promoters of developmental and cell-adhesion genes. By integrating methylomes with transcriptomes from the TCGA-BRCA cohort (n = 148) and clinical outcomes from KM Plotter (RFS, n = 1154; OS, n = 442; DMFS, n = 423), we identified four genes (ARL10, RIC3, CXCL14, KCNH2) showing concordant molecular and clinical associations, from which we derived the Lymph-node Involvement Outcome Numerator (LION) score. Lower LION scores were observed in metastatic lesions from the AURORA US cohort (n = 45). In SCAN-B (n = 3969), lower scores were associated with shorter distant recurrence-free intervals (HR = 0.38; 95% CI 0.23–0.62); this association persisted after adjustment for age, nodal and tumor category but was lost after adjustment for histological grade (HR = 0.83; 95% CI 0.48–1.44), indicating that the score and grade capture overlapping biology. These findings suggest that primary tumors already display coordinated epigenetic and transcriptional alterations associated with the extent of metastatic dissemination.

Breast ductal carcinoma in situ is a common non-invasive clinical finding that can progress to invasive breast cancer (IBC). Spatial proteomics can provide an additional dimension to our understanding of this disease and its capacity to progress. A subset (n = 103 patients) of a previously established cohort of primary DCIS specimens with known clinical outcomes was analyzed using a multiplexed proteomic platform (Nanostring GeoMx) for simultaneous quantitative measurement of 53 antigens. 1262 spatially distinct regions of interest (ROIs) (1226 ROIs after filtering) were collected, including inside DCIS epithelium, adjacent stroma, co-existing benign breast epithelium, and biopsy sites. We identified two predominant subgroups of DCIS, ER high/HER2 low and ER low/HER2 high. Levels of tumor associated proteins varied between benign and DCIS, between ER + and ER- patients, and between different regions within the DCIS epithelium. In addition, we identified several immune-related antigens (CD127, CD8, and PD-L2) within the DCIS epithelium that are associated with invasive progression. Comparison of antigen levels in matched ipsilateral breast events (both DCIS recurrences and IBC) demonstrates an effect of hormonal therapy on the phenotype of subsequent cancers. This study adds a spatially resolved proteomic dimension to our understanding of DCIS, its microenvironment, and its propensity to progress to IBC.

Background: Over 50,000 women in the United States will be diagnosed with ductal carcinoma in situ (DCIS) this year alone. Almost all of these diagnoses will be made in completely asymptomatic individuals with a highly variable risk of progression to invasive cancer. In some low-risk malignancies, “watchful waiting,” is offered as a treatment option. Such an approach is likely reasonable for some DCIS and could reduce the harms of treatment while helping to identify those most likely to benefit from more aggressive therapy. To date, this approach has not been tested in a clinical trial setting. Methods: The COMET study (Comparing an Operation to Monitoring, with or without Endocrine Therapy for low risk DCIS; AFT-25) is a large pragmatic randomized non-inferiority trial that compares oncologic outcomes between patients randomized to guideline concordant care (GCC; surgery +/- radiation therapy) or active monitoring (AM). The study population were women seeking treatment for DCIS at one of the Alliance Clinical Trial sites. Eligible participants were age>40 with low-intermediate grade estrogen and/or progesterone receptor positive, HER2 receptor negative (if HER2 tested) DCIS on core biopsy without microinvasive or invasive cancer. The choice for endocrine therapy was offered in both groups. Participants in the AM group had surgical intervention only upon diagnosis of invasive progression. All study endpoints were collected prospectively. Results: This is the first planned interim Intention-to-Treat (ITT) analysis of the COMET trial primary endpoints at a median follow up of XX months. We will present patient characteristics for the 997 participants who enrolled in the study and were randomized to either GCC or AM. The primary endpoint to be presented is whether the ipsilateral invasive cancer rate for AM is non-inferior to that for GCC. Characteristics of invasive cancer events in the two groups will be compared. Secondary endpoints (rates of mastectomy, radiation, chemotherapy) and survival endpoints between groups will also be presented. Conclusion: These data will provide the first randomized trial evidence of whether an active monitoring strategy is a safe alternative for women with low-risk DCIS. Longer-term data could support practice changing guidance as to how DCIS is managed and treated and will have future implications for treatment guidelines for these excellent prognosis patients. Citation Format: Eun-Sil Hwang, Terry Hyslop, Thomas Lynch, Marc D Ryser, Anna Weiss, Anna Wolf, Kelsey Norris, Meredith Witten, Lars Grimm, Stuart Schnitt, Sunil Badve, Rachel Factor, Elizabeth Frank, Deborah Collyar, Desiree Basila, Donna Pinto, Mark A Watson, Robert West, Louise Davies, Jenny Donovan, Ayako Shimada, Yutong Li, Yan Li, Antonia V Bennett, Shoshana Rosenberg, Jeff Marks, Eric Winer, Marc Boisvert, Armando Giuliano, Kelsey Larson, Kathleen Yost, Priscilla McAuliffe, Lisa Carey, Alastair Thompson, Ann H Partridge. Early Oncologic Outcomes Following Active Monitoring or Surgery (+/- Radiation) for Low Risk DCIS: the Comparing an Operation to Monitoring, with or without Endocrine Therapy (COMET) Study (AFT-25) [abstract]. In: Proceedings of the San Antonio Breast Cancer Symposium 2024; 2024 Dec 10-13; San Antonio, TX. Philadelphia (PA): AACR; Clin Cancer Res 2025;31(12 Suppl):Abstract nr GS2-05.

End stage breast cancer often presents with oligometastatic tumors and lacks effective treatment options. Previous studies leveraged post-mortem tissue procurement (also called rapid autopsy) programs to collect tumors shortly after death for profiling by bulk whole exome sequencing (WES). This has revealed substantial heterogeneity in the genomes of metastatic estrogen receptor-positive (ER+) and triple-negative breast cancers. In order to understand the heterogeneity of both the genotypes, transcriptional phenotypes, and evolution of these tumors, we collected multi-site metastatic tumors from two end-stage ER+ breast cancer patients enrolled in the LEGACY rapid post-mortem tissue procurement trial. Metastatic tumors were profiled using WES and single-nuclei RNA sequencing (snRNA-seq). We reconstructed high resolution phylogenies for each patient using the mutation called from the snRNA-seq reads to determine the subclonal architecture of cancer cells. Based on the mutation patterns, the gene expression profiles, and the subclonal architecture, we found that the tumors in each patient were divided into two distinct subtypes. A majority of the tumors were grouped into a subtype characterized by a high intra-tumor heterogeneity, with many cell lineages shared widely across metastasis, indicating extensive and undirected dissemination. The cancer cells of this subtype exhibited an EMT gene expression signature. In contrast, the second tumor subtype observed was rare and demonstrated little intra-tumor heterogeneity, a proliferative gene expression signature, and an interferon response signature present widely across cells in the microenvironment. Across all tumors, macrophages comprised the majority of the immune cells. Low diversity tumor macrophages exhibited strong activation of multiple interferon signaling pathways compared to high diversity tumor macrophages. Interestingly, these macrophages expressed a mixture of M1 and M2 polarization markers as STAT1, SOCS1, ISG15, ISG20, MX1, MX2, OAS1, OAS3 that did not correspond to classical M1 or M2 polarization states. This contrast demonstrates that multi-site metastatic tumors and their microenvironment adopt dichotomous states, which may contribute to the difficulties in treating progressive disease. It also underscores the need for a comprehensive and personalized late-stage therapeutic strategy to target the diversity of existing tumor phenotypes. Isaac Bishara, Xuan Liu, Jason l. Griffiths, Patrick A. Cosgrove, Jasmine R. McQuerry, Jiayi Liu, Kena K. Ihle, Eliza R. Bacon, Feng Chi, Pierre Wallet, Vince Grolmusz, Diana Simons, Benjamin Copeland, Lance Pflieger, JinFeng Chen, Sumana Majumdar, Terron T. Crowder, Rena Emond, Rachel Factor, David D. Bowtell, Adam L. Cohen, Daniel D. Schmolze, Peter P. Lee, Lusine Tumyan, James R. Waisman, Andrea Bild, Aritro Nath, Jeffrey T. Chang. End-stage breast cancer metastases manifest as two subtypes with distinct dissemination patterns, proliferation/EMT signatures, and immune microenvironments [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2025; Part 1 (Regular Abstracts); 2025 Apr 25-30; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2025;85(8_Suppl_1):Abstract nr 5133.

Ductal carcinoma in situ (DCIS) is a potential precursor to invasive breast cancer (IBC). The trajectory of an individual’s DCIS, if it will progress to IBC or remain as DCIS is difficult to predict. Currently >80% of DCIS is detected through mammographic screening of breast calcifications. Despite the close association of calcifications with DCIS, their role in the development of DCIS and/or its progression to IBC remains largely unexplored. In this study, we present a spectroscopy based analytical approach to probe chemical compositional changes of both DCIS associated breast calcifications and surrounding soft tissue aiming to identify a cohort at increased risk for invasive progression. Tissue samples from 316 DCIS patients without invasive cancer were obtained from multiple centres as part of the PRECISION consortium (The Netherlands, UK and USA). Three consecutive tissue sections were obtained each of the tissue biopsies. Mid-infrared (mid-IR) and Raman hyperspectral imaging was performed independently on two sections that were left unstained. The third H&E-stained section was used to annotate calcifications and histopathological features. All DCIS samples had known outcome (i) ‘pure DCIS as controls’ (DCIS without progression to invasion) (n=193), (ii) ‘DCIS with progression to invasion as cases’ (DCIS from patients who subsequently developed invasive disease after initial treatment) (n=123). Spectral features of DCIS calcifications and surrounding soft tissue were used as inputs for analysis. Data was divided into a discovery and a validation set. Cluster analysis followed by Principal component analysis fed linear discriminant analysis was carried out on the discovery set to develop DCIS prediction models. For the Raman data, a mean area under the receiver operating characteristic curve (AUROC) value of 0.85 was obtained using calcification spectral features, and 0.75 using soft tissue spectral features in distinguishing controls from cases (N=118 vs 52). Similar analysis on the IR data showed a mean AUROC value of 0.68 for calcification, 0.78 for epithelial and 0.80 for stromal components (N=97 vs 61). Preliminary analysis shows changes in phosphate to carbonate ratio and variations in magnesium whitlockite content in calcifications, and protein secondary structural changes in soft tissue, between the two groups. The models will be tested independently on the validation set and the outcomes will be presented at the AACR conference. Spectroscopic chemical analysis of breast calcifications and soft tissue show promise in predicting the likely progression of DCIS to IBC. Pending further independent validation, these techniques appear to be novel image-based risk assessment tools that can potentially be utilised to inform DCIS prognosis and treatment options. Jayakrupakar Nallala, Doriana Calabrese, Sarah Gosling, Esther Lips, Ihssane Bouybayoune, Rachel Factor, Sarah Pinder, Lorraine King, Jeffrey Marks, Thomas Lynch, Donna Pinto, Alastair Thompson, Elinor Sawyer, Jelle Wesseling, Shelley Hwang, Keith Rogers, Nick Stone, Grand Challenge PRECISION consortium. Predicting the prognosis of ductal carcinoma in situ through chemical analysis of breast microcalcifications and soft tissue using infrared and Raman spectroscopy [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2025; Part 1 (Regular Abstracts); 2025 Apr 25-30; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2025;85(8_Suppl_1):Abstract nr 3353.

[This corrects the article DOI: 10.1016/j.jpi.2022.100092.].

Ductal carcinoma in situ (DCIS) is a risk factor for subsequent invasive breast cancer (IBC). To identify events in DCIS that lead to invasive cancer, we performed single-cell RNA sequencing on DCIS lesions and matched normal breast tissue. Inferred copy-number variation was used to identify neoplastic epithelial cells from clinical specimens, which contained a mixture of DCIS and normal ducts. Phylogenetic analysis demonstrated intratumoral clonal heterogeneity that was associated with significant gene expression differences. Classification of epithelial cells into mammary cell states revealed that subclones contained a mixture of cell states, suggesting an ongoing pattern of differentiation after neoplastic transformation. Cell state proportions were significantly different based on estrogen receptor expression, with estrogen receptor-negative DCIS more closely resembling the distribution in the normal breast, particularly with respect to cells with basal characteristics. Specific alterations in cell state proportions were associated with progression to invasive cancer in a cohort of DCIS with longitudinal outcome. Ongoing transcription of key basement membrane (BM) genes occurred in specific subsets of epithelial cell states, including basal/myoepithelial, which are diminished in DCIS. In the transition to IBC, the BM protein laminin, but not COL4, was altered in DCIS adjacent to invasion. Loss of COL4, but not laminin, in an in vitro DCIS model led to an invasive phenotype. These findings suggest that the process of invasion is a loss-of-function event due to an imbalance in critical cell populations essential for BM integrity rather than a gain of an invasive phenotype by neoplastic cells.Significance: Single-cell analyses reveal ductal carcinoma in situ comprises multiple genetic clones with significant phenotypic diversity and link alterations in epithelial cell states and basement membrane integrity with invasive breast cancer progression.

Importance: Active monitoring for low-risk ductal carcinoma in situ (DCIS) of the breast has been proposed as an alternative to guideline-concordant care, but the safety of this approach is unknown. Objective: To compare rates of invasive cancer in patients with low-risk DCIS receiving active monitoring vs guideline-concordant care. Design, setting, and participants: Prospective, randomized noninferiority trial enrolling 995 women aged 40 years or older with a new diagnosis of hormone receptor-positive grade 1 or grade 2 DCIS without invasive cancer at 100 US Alliance Cancer Cooperative Group clinical trial sites from 2017 to 2023. Interventions: Participants were randomized to receive active monitoring (follow-up every 6 months with breast imaging and physical examination; n = 484) or guideline-concordant care (surgery with or without radiation therapy; n = 473). Main outcomes and measures: The primary outcome was 2-year cumulative risk of ipsilateral invasive cancer diagnosis, according to planned intention-to-treat and per-protocol analyses, with a noninferiority bound of 0.05%. Results: The median age of the 957 participants analyzed was 63.6 (95% CI, 55.5-70.5) years in the guideline-concordant care group and 63.7 (95% CI, 60.0-71.6) years in the active monitoring group. Overall, 15.7% of participants were Black and 75.0% were White. In this prespecified primary analysis, median follow-up was 36.9 months; 346 patients had surgery for DCIS, 264 in the guideline-concordant care group and 82 in the active monitoring group. Forty-six women were diagnosed with invasive cancer, 19 in the active monitoring group and 27 in the guideline-concordant care group. The 2-year Kaplan-Meier cumulative rate of ipsilateral invasive cancer was 4.2% in the active monitoring group vs 5.9% in the guideline-concordant care group, a difference of -1.7% (upper limit of the 95% CI, 0.95%), indicating that active monitoring is not inferior to guideline-concordant care. Invasive tumor characteristics did not differ significantly between groups. Conclusions and relevance: Women with low-risk DCIS randomized to active monitoring did not have a higher rate of invasive cancer in the same breast at 2 years compared with those randomized to guideline-concordant care.

Abstract Introduction: A phase III multicenter prospective randomized clinical trial called “Comparing an Operation to Monitoring, with or without Endocrine Therapy (COMET)” (NCT02926911) assesses the risks/benefits of active monitoring (AM) versus surgery for women with low-risk ductal carcinoma in situ (DCIS). It is funded by the Patient-Centered Outcomes Research Institute and enrolled 997 women between 06/30/17 and 01/13/23. Research Patient Advocates (PAs) have been embedded from the study design stage and continue to provide guidance as part of the COMET leadership team. The COMET biobank is funded by independent foundations and is managed through monthly Translational Working Group (TWG) meetings. The TWG includes PAs, clinicians, pathologists, radiologists, and researchers from multiple institutions who discuss topics like categorization of biospecimens into discovery/validation sets; development of a pathology workflow/sample tracking process; use of small samples; and potential areas of future research/technologies that may improve DCIS diagnostics, prognostics, and care management. Methods: The TWG leveraged the existing Alliance Foundation Trials, LLC biobank infrastructure and facilitates the collection, submission, storage and analysis/use of blood, tissue, and breast images collected at specified timepoints and stored in central tissue/image repositories. PAs are active and integral in the TWG, assisting with logistical issues (contracts, transfer agreements, resource requests); communicating with sites; identifying study topics and biomarkers relevant to diverse patients; providing guidance on commercial predictive/prognostic tests; promoting effective stewardship of samples; ensuring overall focus remains on advancing clinical utility; and reporting translational study results to trial participants who agreed to donate samples/images. Results: Over 90% of requested samples/images have been submitted by ˃85 sites. Each patient’s biospecimens and pathology images are linked and de-identified for research. Use of artificial intelligence (AI) is being considered to assist in sample review. TWG members have complementary areas of expertise/experience and promote active stewardship for effective management of these scarce resources. PAs have played key roles concerning equitable data-sharing and acceleration of data and material transfer agreements. They have also been active in development of standards for discovery/training sets, validation test sets; communication procedures for patient cases that progress to future breast events; ways to catalog technologies (e.g., multi-omics, AI); and in research proposal review. Consensus has been achieved regarding major issues such as authorship, biospecimen custodianship, intellectual property, and criteria relevant to patient needs. Logistical barriers, including data sharing and technicalities of biospecimen release, have been resolved. The TWG also played an integral role in resolving recruitment challenges to COMET by creating standard pathology eligibility criteria, resulting in evidence-based protocol amendments that increased accrual. A retrospective review of biospecimens has been performed to determine adequacy for ensuing correlative molecular and spatial profiling studies. Conclusion: PAs help the COMET TWG set policy, and oversee biospecimen/image collection, and biobank use and sharing. PA input also facilitates equitable, transparent research studies and technology development that can improve personalized decisions for surgery versus AM in women with low-risk DCIS. PAs in the TWG aim to integrate the diagnostic and prognostic tools developed as part of the COMET study into future patient care. Citation Format: Deborah Collyar, Desiree Basila, Thomas Lynch, Stuart Schnitt, Jeffrey Marks, Siri Strand, Terry Hyslop, Sunil Badve, Mark Watson, H. T. Carisa Le-Petross, Lars Grimm, Robert West, Anna Weiss, Anna Rapperport, Lorraine King, Rachel Factor, Marc Ryser, Ann Partridge, E Shelley Hwang, Alastair Thompson. Added Value from Patient Advocates in a Translational Working Group: the COMET Study [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO4-13-04.

To identify mechanisms underlying the growth of ductal carcinoma in situ (DCIS) and properties that lead to progression to invasive cancer, we performed single-cell RNA-sequencing (scRNA-seq) on DCIS lesions and matched synchronous normal breast tissue. Using inferred copy number variations (CNV), we identified neoplastic epithelial cells from the clinical specimens which contained a mixture of DCIS and normal ducts. Phylogenetic analysis based on the CNVs demonstrated intratumoral clonal heterogeneity was associated with significant gene expression differences. We also classified epithelial cells into mammary cell states and found that individual genetic clones contained a mixture of cell states suggesting an ongoing pattern of differentiation after neoplastic transformation. Cell state proportions were significantly different based on estrogen receptor (ER) expression with ER-DCIS more closely resembling the distribution in the normal breast, particularly with respect to cells with basal characteristics. Using deconvolution from bulk RNA-seq in archival DCIS specimens, we show that specific alterations in cell state proportions are associated with progression to invasive cancer. Loss of an intact basement membrane (BM) is the functional definition of invasive breast cancer (IBC) and scRNA-seq data demonstrated that ongoing transcription of key BM genes occurs in specific subsets of epithelial cell states. Examining BM in archival microinvasive breast cancers and an in vitro model of invasion, we found that passive loss of BM gene expression due to cell state proportion alterations is associated with loss of the structural integrity of the duct leading to an invasive phenotype. Our analyses provide detailed insight into DCIS biology. SIGNIFICANCE:Single cell analysis reveals that preinvasive breast cancer is comprised of multiple genetic clones and there is substantial phenotypic diversity both within and between these clones. Ductal carcinoma in situ (DCIS) of the breast is a non-invasive condition commonly identified through mammographic screening. A primary diagnosis of DCIS carries little mortality risk on its own, but its presence is a risk factor for subsequent clonally related invasive breast cancer (IBC) (1-5).

Abstract Metastatic breast cancers show variable clinical responses due to inherent heterogeneity, both within tumors and among patients. Studies mainly examine molecular diversity across different patients' tumors and genetic variance within a single tumor. Yet, the variability among multiple tumors or metastases in a single patient remains underexplored. Our study investigates this intrapatient heterogeneity, examining cell and tumor evolution from a single genetic source in metastatic breast cancer. In a warm procurement trial involving 6 patients with multi-site tumors, samples were collected for detailed molecular analysis. Whole exome sequencing (WES) and single-cell RNA sequencing (scRNA-seq) were used to analyze genetic similarities and disparities. WES data revealed mutational patterns and copy number alterations, showing homogeneity and heterogeneity in tumors within patients. Further, phylogenetic analysis with scRNA-seq variant calls paired with transcriptional phenotypes uncovered a MYC-enriched subclonal population in a metastatic site. Integrating WES and scRNA-seq data provided a clearer understanding of the genomic and phenotypic features in and between patients. Our WES study revealed significant interpatient variations in genetic drivers and CNA profiles. Among five patients, two showed APOBEC and HR mutations, linked to increased tumor mutations. Despite general genetic homogeneity, there were exceptions. Tumors in Patient 3's upper lymph nodes had distinct genetics compared to abdominal tumors. Unique genetic patterns were also noted in the pancreas and mesentery of Patients 3 and 7, respectively. Genetic findings were supported by transcriptional analysis, showing distinct expression patterns in specific sites. Phylogenetic analysis highlighted intratumor heterogeneity, as shown by variations in phylogenetic composition and gene expression across samples. Notably, in patients with the most samples (Patients 3 and 7), a conserved cell clade, evolved early and primarily located in a single site, displayed a high proliferation gene expression signature closely associated with Myc activity. This underscores the importance of early clonal expansions in tumor evolution and suggests potential therapeutic targets in these early, proliferative cells. Our study highlights the vital role of intrapatient heterogeneity in understanding cancer complexity and treatment resistance. By analyzing genetic and phenotypic variability in multi-site tumors within patients, and Myc's key role in tumor growth and evolution, our research offers new insights into tumor evolution. This underscores the need for personalized oncology treatments based on each patient's tumor genetics. Citation Format: Isaac Bishara, Xuan Liu, Jason Griffiths, Jiayi Liu, Patrick Cosgrove, Jasmine R. McQuerry, Feng Chi, Pierre Wallet, Vince K. Grolmusz, Benjamin Copeland, Lance Pflieger, Jinfeng Chen, Sumana Majumdar, Grace Ronquillo, Terron Crowder, Rena Emond, Rachel Factor, Eliza Barragan, David Bowtell, Adam Cohen, Daniel D. Schmolze, Peter Lee, Kena Ihle, Lusine Tumyan, Aritro Nath, James Waisman, Andrea Bild, Jeff Chang. Exploring intrapatient heterogeneity in metastatic breast cancer: Insights into tumor evolution from a warm procurement trial [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 7353.

We demonstrate an automated two-step tumor segmentation method leveraging color information from brightfield images of fresh core needle biopsies of breast tissue. Three different color spaces (HSV, CIELAB, YCbCr) were explored for the segmentation task. By leveraging white-light and green-light images, we identified two different types of color transformations that could separate adipose from benign and tumor or cancerous tissue. We leveraged these two distinct color transformation methods in a two-step process where adipose tissue segmentation was followed by benign tissue segmentation thereby isolating the malignant region of the biopsy. Our tumor segmentation algorithm and imaging probe could highlight suspicious regions on unprocessed biopsy tissue to guide selection of areas most similar to malignant tissues for tissue pathology whether it be formalin fixed or frozen sections, expedite tissue selection for molecular testing, detect positive tumor margins, or serve an alternative to tissue pathology, in countries where these services are lacking.

Myeloid sarcoma (MS) is a rare extramedullary solid tumor arising most often in patients with current or subsequent acute myeloid leukemia (AML). Patients of all ages may present with involvement of the skin, lymph nodes, intestinal tract, bone, and/or central nervous system. Isolated involvement of the breast is rare, and only a small number of cases have been described in the literature. Breast MS may present as a palpable mass on clinical evaluation. In this broad literature review from 2010 to 2022, the most common findings on mammography are either solitary or multiple masses, followed by architectural distortion and, less commonly, no discrete findings. Sonography may demonstrate hypoechoic or mixed echogenicity mass(es) with circumscribed or indistinct, not discrete margins. Myeloid sarcoma may present as an enhancing mass or nonmass enhancement on breast MRI and is typically moderately radiotracer avid on 18F-fluorodeoxyglucose-PET. At histopathology, MS is characterized by myeloid blasts in varying stages of granulocytic or neutrophilic maturation; diagnosis typically requires immunophenotyping. There is no consensus for treatment of MS, although systemic chemotherapy for AML is often used as MS is considered the tissue equivalent of AML. This article will discuss and illustrate imaging and pathology findings when the breast is involved by MS.

Equations to calculate sample size in a homozygous discordant design. Supplemental Table: Sample size requirements (n in each group)