A comprehensive single-cell breast tumor atlas defines epithelial and immune heterogeneity and interactions predicting anti-PD-1 therapy response

We present an integrated single-cell RNA sequencing atlas of the primary breast tumor microenvironment (TME) containing 236,363 cells from 119 biopsy samples across eight datasets. In this study, we leverage this resource for multiple analyses of immune and cancer epithelial cell heterogeneity. We define natural killer (NK) cell heterogeneity through six subsets in the breast TME. Because NK cell heterogeneity correlates with epithelial cell heterogeneity, we characterize epithelial cells at the level of single-gene expression, molecular subtype, and 10 categories reflecting intratumoral transcriptional heterogeneity. We develop InteractPrint, which considers how cancer epithelial cell heterogeneity influences cancer-immune interactions. We use T cell InteractPrint to predict response to immune checkpoint inhibition (ICI) in two breast cancer clinical trials testing neoadjuvant anti-PD-1 therapy. T cell InteractPrint was predictive of response in both trials versus PD-L1 (AUC = 0.82, 0.83 vs. 0.50, 0.72). This resource enables additional high-resolution investigations of the breast TME.

The Right Dose: Results of a Patient Advocate-Led Survey of Individuals With Metastatic Breast Cancer Regarding Treatment-Related Side Effects and Views About Dosage Assessment to Optimize Quality of Life

PURPOSE

Although patients with metastatic breast cancer (MBC) have been living longer with the advent of more effective treatments such as targeted therapy and immunotherapy, the disease remains incurable, and most patients will undergo therapy indefinitely. When beginning therapy, patients are typically prescribed dose often based upon the maximum tolerated dose identified in phase I clinical trials. However, patients' perspectives about tolerability and willingness to discuss individualized dosing of drugs upon initiation of a new regimen and throughout the course of treatment have not been comprehensively evaluated.

METHODS

Patient advocates and medical oncologists from the Patient-Centered Dosing Initiative (PCDI) developed a survey to ascertain the prevalence and severity of MBC patients' treatment-related side effects, the level of patient-physician communication, mitigation strategies, perception about the relative efficacy of higher versus lower doses, and willingness to discuss alternative dosing. The PCDI distributed the anonymous confidential online survey in August 2020 to individuals with self-reported MBC.

RESULTS

One thousand and two hundred twenty-one patients with MBC completed the survey. 86.1% (n = 1,051) reported experiencing at least one significant treatment-related side effect, and of these, 20.3% (n = 213) visited the emergency room/hospital and 43.2% (n = 454) missed at least one treatment. Nearly all patients with side effects (97.6%, n = 1,026) informed their doctor and 81.7% (n = 838) received assistance. Of the 556 patients given a dose reduction for side-effect mitigation, 82.6% (n = 459) reported relief. Notably, majority of patients (53.3%, n = 651) do not believe that higher dose is always more effective than lower dose, and 92.3% (n = 1,127) would be willing to discuss flexible dosing options with their physicians based upon personal characteristics to optimize quality of life.

CONCLUSION

Given that the majority of patients with MBC experienced at least one substantial treatment-related side effect and most patients given a dose reduction reported improvement, innovative dosage-related strategies are warranted to sustain and improve patients' well-being. Patient-physician discussions in which the patient's unique attributes and circumstances are assessed upon initiation of new treatment and throughout the course of therapy may facilitate the identification of the most favorable dose for each patient, and the majority of patients would be receptive to this approach.

Systematic symptom management in the IMPACT Consortium: rationale and design for 3 effectiveness-implementation trials

Cancer and its treatment produce deleterious symptoms across the phases of care. Poorly controlled symptoms negatively affect quality of life and result in increased health-care needs and hospitalization. The Improving the Management of symPtoms during And following Cancer Treatment (IMPACT) Consortium was created to develop 3 large-scale, systematic symptom management systems, deployed through electronic health record platforms, and to test them in pragmatic, randomized, hybrid effectiveness and implementation trials. Here, we describe the IMPACT Consortium's conceptual framework, its organizational components, and plans for evaluation. The study designs and lessons learned are highlighted in the context of disruptions related to the COVID-19 pandemic.

National Cancer Institute Collaborative Workshop on Shaping the Landscape of Brain Metastases Research: challenges and recommended priorities

Brain metastases are an increasing global public health concern, even as survival rates improve for patients with metastatic disease. Both metastases and the sequelae of their treatment are key determinants of the inter-related priorities of patient survival, function, and quality of life, mandating a multidimensional approach to clinical care and research. At a virtual National Cancer Institute Workshop in September, 2022, key stakeholders convened to define research priorities to address the crucial areas of unmet need for patients with brain metastases to achieve meaningful advances in patient outcomes. This Policy Review outlines existing knowledge gaps, collaborative opportunities, and specific recommendations regarding consensus priorities and future directions in brain metastases research. Achieving major advances in research will require enhanced coordination between the ongoing efforts of individual organisations and consortia. Importantly, the continual and active engagement of patients and patient advocates will be necessary to ensure that the directionality of all efforts reflects what is most meaningful in the context of patient care.

Abstract P4-03-43: Disease characteristics and outcomes of people with metastatic breast cancer in a single center cohort study: The Dallas Metastatic Breast Cancer Study

Background: Breast cancer is the most common cancer in women, and metastatic disease accounts for most breast cancer related deaths. Identifying risk factors for the onset and progression of metastatic breast cancer (MBC) can help us understand how to address and improve morbidity and mortality due to MBC. Large national databases, such the Surveillance, Epidemiology, and End Results (SEER) Program are limited in their ability to capture granular details from patients’ cancer histories. The Dallas Metastatic Breast Cancer Study (DMBCS) is a clinical database established at a single academic medical system to track patient demographics, associated pathology, treatments, and other variables to improve outcomes for patients with MBC. Methods: The DMBCS database was generated from a registry of breast cancer patients submitted to the National Cancer Institute from 2010 to 2021. Patients were initially excluded if they were identified as non-metastatic from this list. Chart review was then done to identify MBC patients from this subsequent group. Demographics, clinical history, pathologic features, lines of treatment, and subsequent recurrences were collected for all patients. Clinical data was stored in REDCap, a secure data collection platform for entering and managing data. Results: 230 cases were included in this preliminary data set. Of the 230 cases, 185 cases were metastatic at time of diagnosis while 45 cases were metastatic recurrences of breast cancer. At diagnosis, 14.8% were less than 40 years of age, 17.3% were 40-49, 35.7% were 50-59, 18.7% were 60-69, and 13.5% were greater than 70 years of age. In terms of ethnicity, 63.5% were White, 27.4% were Black, and 21.7% identified as Hispanic. At time of diagnosis, 30.9% of patients had a BMI classified as overweight and 40.4% were considered obese. Medical comorbidities included hypertension in 43% of cases, diabetes (18.3%), hyperlipidemia (27.4%), and autoimmune disease (13.0%). Clinical subtype analysis revealed 57.8% of patients were hormone receptor positive, 24.8% HER2 positive, and 17.4% triple negative, at diagnosis. 14.8% of cases were diagnosed as inflammatory breast cancer. The most common site of metastasis at presentation was bone with 69.1% of cases, followed by lung (33.9%), liver (30.0%), and brain (15.2%). Over 90% of patients were treated with at least one antineoplastic regimen and 39.6% underwent at least 4 therapies. Calculated 1-year survival after diagnosis was 85.7%. Conclusions: The introduction of the DMBCS will allow continued investigation into clinical drivers of MBC. In this first cohort of patients, we characterized key, yet often underreported, variables and outcomes. Potential applications of this database include investigating the association between obesity and overall survival in patients with MBC, understanding how socioeconomic disparities affects outcomes of patients with MBC, and exploring correlations between autoimmune disease and the progression of MBC.

Citation Format: Meng Cao, Mir Lim, Anna Moscowitz, Jonathan Ladner, Christine Hodgdon, Julia Maues, Sangeetha Reddy, Isaac Chan. Disease characteristics and outcomes of people with metastatic breast cancer in a single center cohort study: The Dallas Metastatic Breast Cancer Study. [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr P4-03-43.

Abstract GS5-06: InteractPrint predicts clinically meaningful interactions between cancer epithelial cells and immune cells: Lessons from a single-cell breast cancer atlas

BACKGROUND: While immunotherapy has revolutionized the treatment of many solid tumors, the efficacy of immunotherapy regimens is comparatively lower in breast cancer. Immunotherapy efficacy is often negatively correlated with intratumor heterogeneity. Novel immunotherapy approaches in breast cancer should leverage how cancer epithelial cell heterogeneity affects immune cells in the tumor microenvironment. However, current definitions of cancer epithelial cell heterogeneity in breast cancer have limited resolution. Single cell RNA-seq (scRNA-seq) provides an unprecedented opportunity to further define cancer epithelial cell heterogeneity and identify how heterogeneity influences interactions with immune cells. METHODS: We generated a novel scRNA-seq dataset of 236,363 cells from 119 primary breast tumors biopsied from 88 patients taken from 8 publicly available datasets, currently the largest published scRNA-seq dataset in breast cancer. To define cancer epithelial cell heterogeneity, we performed unsupervised clustering and supervised clustering based on molecular subtype and expression of clinical target genes on all cancer epithelial cells. This identified 11 gene elements (GEs), which reflect key molecular features that vary between cancer epithelial cells. Receptor-ligand pairing analysis allowed us to determine how cells that highly express each GE interact with various immune cells. We developed InteractPrint, a score to predict the predominant tumor-interacting immune cells, based on the GE composition of an individual patient tumor. RESULTS: In our dataset, 17% of samples were HER2+, 41% were HR+, and 42% were TNBC. This dataset was statistically powered to characterize cancer epithelial cell heterogeneity. For each of the 11 GEs, we predicted interactions with immune cells. Experimentally, GEs with predicted NK cell interactions showed sensitivity to NK cell cytotoxicity. In a spatially resolved transcriptomics dataset, GEs with predicted T cell interactions demonstrated colocalization with CD8+ T cells, while those with limited predicted T cell interactions did not. To infer GE-immune interactions at the patient level (GEs define cell-level interactions), we developed InteractPrint. To validate InteractPrint, we assessed the accuracy of the T cell InteractPrint in predicting response to anti-PD-1 therapy. Across two trials and all breast cancer subtypes, T cell InteractPrint demonstrated significant improvement over PD-L1 in predicting response to anti-PD-1 therapy. In an scRNA-seq dataset of samples from patients treated with pembrolizumab, we observed AUC of 85% (p < 0.005) for T cell InteractPrint vs. 61% (p > 0.05) for PD-L1 in predicting response to anti-PD-1 therapy. In patients treated with paclitaxel + pembrolizumab in the I-SPY 2 trial, we observed AUC of 81% (p < 0.00001) for T cell InteractPrint versus 72% (p = 0.001) for PD-L1. CONCLUSIONS: Our results demonstrate considerable cancer epithelial cell heterogeneity across primary breast tumor samples and clinical subtypes. We defined this heterogeneity and leveraged it to predict immune cell interactions within a patient’s tumor. We developed T cell InteractPrint to capture heterogeneous interactions between cancer epithelial cells and CD8+ T cells. T cell InteractPrint is predictive of response to anti-PD-1 immune checkpoint inhibition at higher AUC than PD-L1. This provides a path forward for the interpretation of cancer epithelial cell heterogeneity in a clinically meaningful way.

Citation Format: Lily Xu, Kaitlyn Saunders, Hildur Knutsdottir, Kenian Chen, Julia Maues, Christine Hodgdon, Evanthia T. Roussos Torres, Sangeetha Reddy, Lin Xu, Isaac Chan. InteractPrint predicts clinically meaningful interactions between cancer epithelial cells and immune cells: Lessons from a single-cell breast cancer atlas [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr GS5-06.

Abstract P6-14-02: Hope for OTHERS – An organ donation program for metastatic breast cancer research

Background: Previous studies have shown that rapid autopsies (RA) provide a unique opportunity for tissue collection from patients who succumb to the disease. Because cancer patients are unable to donate their organs to other people, this program provides the patient an opportunity to leave a legacy by donating their body to research. These donations are vital for advancing breast cancer research. The UPMC/Pitt RA group revamped an existing program in 2018 through the formation of a larger multidisciplinary team that includes breast cancer laboratory and clinical researchers, pathologists, nurses, bioinformaticians, and tissue bankers. Because recruitment to the RA program was a challenge, we recently added patient advocates to the team to provide their essential perspective, and a dedicated research coordinator who serves as an ambassador for the program. Methods: Autopsy is performed by the Autopsy and Forensic Pathology Center of Excellence/Decedent Affairs Service of UPMC. Samples are banked in the Pitt Biospecimen Core (PBC), in addition to immediate processing including preparing of samples for sequencing and growing of organoids in the laboratory. Immunohistochemical (IHC) analysis is performed by UPMC/Magee Pathology. Results: The research coordinator quickly became an integral part of the program and closely interacts with care providers, patients and their families, pathologists on call, and manages interactions with transport services. Five breast cancer advocates have been instrumental in advising on additional changes to the program. The advocates attend regular team meetings and have formulated patient considerations for the the RA program, including appropriate and sensitive recruitment of patients, the role of physicians in decision making by the patient, registration for more than one RA program, potential issues with transporting a body across state lines and more. The advocates also developed the name for the program - “Hope for OTHERS” with Others standing for “Our Tissue Helping Enhance Research & Science”. As of June 2022, the team has completed 26 autopsies, and an additional 20 patients have consented to the program. The completed autopsies include patients with breast tumors representing different molecular and histological classes, ethnicities, and genders. The average disease-free survival and overall survival of patients that underwent autopsy was 81.6 and 127.8 months, respectively. Most patients passed outside the hospital (86%), with 62% in home hospice and 24% in inpatient hospice. Average time between death and start and end of autopsy was 4.56 hrs and 7.09 hours, respectively. The most common metastatic sites from which specimens are collected are liver, lung and lymph nodes. Per patient we collect on average specimens from 4 different organs. In addition to the metastatic lesions, we have access to primary tumor tissue and liquid biopsies obtained during the breast cancer disease progression for 44% and 73% of the patients, respectively. For a subset of the patients, tissue has been grown as patient-derived organoids or xenograft models. Preliminary IHC and sequencing analysis has provided insight into inter- and intra-patient and intra-tumor heterogeneity. Further molecular studies are ongoing. Conclusion In summary, over the last 5+ years, we have established a successful post-mortem tissue collection program, by addressing a series of barriers through the formation and work of a multi-disciplinary well-coordinated team. We are currently expanding our omics studies using state-of-the-art technologies to improve understanding how intra- and inter-tumor heterogeneity play a role in the clinical course of advanced breast cancer, to increase diversity of the patients enrolled in the RA program, and to support the successful implementation of other RA programs nationwide and worldwide.

Citation Format: Steffi Oesterreich, Lori Miller, Margaret Q. Rosenzweig, Tanner L. Bartholow, Megan Yates, Ashuvinee Elangovan, Laura Savariau, Allison N. Casey, Nolan Priedigkeit, Kai Ding, Abdalla Wedn, Jie Bin Liu, Daniel D. Brown, Tara Hyder, Geoffrey Pecar, Neil Carleton, Humberto Trejo Bittar, Daniel Geisler, Oscar Lopez-Nunez, Amanda M. Clark, Alan Wells, Partha Roy, Shannon Puhalla, Naomi Howard, Christine Needles, Susan Trent, Stephanie Walker, Christine Hodgdon, Rohit Bhargava, Jennifer M. Atkinson, Adrian V. Lee. Hope for OTHERS – An organ donation program for metastatic breast cancer research [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr P6-14-02.

Updated FDA pooled analysis of pain medication use in trial participants with HR+, HER2-negative metastatic breast cancer treated with endocrine therapy and a CDK 4/6 inhibitor

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Background: Pain medications (PMs) are commonly used to treat pain in patients with advanced or metastatic breast cancer (MBC). We previously reported an initial analysis of PM prescribing patterns in clinical trial participants with breast cancer receiving CDK 4/6 inhibitor (CDKI)-based treatment. We present an updated analysis here. Methods: We pooled data from 7 randomized controlled trials of CDKI + endocrine therapy (ET) in patients with HR+, HER2-negative MBC. All analyzed patients received at least 1 dose of CDKI/placebo+ET and a concomitant PM with a documented start date. Medications administered during hospitalizations were not included. We looked at PM use in all patients, patients who took PM only before or after the trial started, and those who took PM both before and during the trial. PMs were categorized as opioid (includes codeine-containing), NSAIDS, or other (i.e. bone-directed, antiepileptic, topical PMs). Results: 4200 patients enrolled across the 7 trials who received at least one dose of CDKI/placebo+ET (n = 2616 CDKI, n = 1548 placebo). Of these, 2881 took a PM at any time (n = 1774 CDKI, n = 1107 placebo). Of the 1774 patients who received CDKI+ET, 487 (27%) took at least one opioid and one NSAID at any time, 782 (44%) took at least one NSAID at any time but no opioids, 244 (14%) took at least one opioid at any time but no NSAIDs, and 261 (15%) took only PM that were not opioids or NSAIDs. Of the 1107 patients who received placebo+ET, 297 (27%) took at least one opioid and one NSAID at any time, 490 (44%) took at least one NSAID at any time but no opioids, 153 (14%) took at least one opioid at any time but no NSAIDS, and 167 (15%) took only PM that were not opioids or NSAIDs. Of the 2881 patients who took a PM at any time, 2038 patients (n = 1222 CDKI, n = 816 placebo) had documented start for their PM. Of these, 544 took PM only before the trial started (n = 334 CDKI, n = 210 placebo), 915 took a PM only during the trial (n = 551 CDKI, n = 364 placebo), and 579 took a PM both before and during the trial (n = 337 CDKI, n = 242 placebo). Overall, more patients took NSAIDs only compared to opioids only. Patient characteristics at baseline were balanced between the two arms. Conclusions: Overall, PM prescribing patterns were similar between the arms. NSAID use was higher than opiates in all groups. These findings are hypothesis generating and additional research is needed to determine the impact of PM on participants’ pain and physical function. Further research should include an understanding of the duration of PM needed in patients with MBC.

INNV-02. ACCELERATING RESEARCH FOR BREAST CANCER BRAIN METASTASIS AND LEPTOMENINGEAL DISEASE THROUGH PATIENT-LED COLLABORATIONS

PATIENT-DRIVEN INITIATIVE OF THE METASTATIC BREAST CANCER (MBC) ALLIANCE

The Breast Cancer Brain Metastasis (BCBM) Initiative: Marina Kaplan Project launched in June 2020 as an official project of the MBC Alliance which includes 32 nonprofits, 12 industry partners, and 30 individual patient advocates. The project has grown to include 35 members with representation from industry, research institutions, and individual patients. Nearly one-third of the group is comprised of patients living with brain metastases or LMD.

DISPARITIES FOR PATIENTS LIVING WITH BCBM & LMD

In the US, approximately 200,000 new cases of brain metastases are diagnosed each year.1 Approximately 10-15% of patients with MBC will develop brain metastases, and may be as high as 30-50% for certain subtypes.2 A diagnosis of central nervous system (CNS) metastasis often accelerates an already incurable diagnosis. CNS metastasis are difficult to image and detect, tend to have poorer prognoses with lower overall survival, and are treated with invasive therapies which can have lasting side effects. Furthermore, most clinical trials exclude patients with CNS metastasis which further hinders research.

VALUES & OBJECTIVES

The overarching goal of this initiative is to accelerate the scope and breadth of evidence-based CNS metastasis research by targeting entities conducting clinical trials and collaborating with them to do the following: (1) Increase the quality and quantity of basic research; (2) increase the number of clinical trials in areas where research is lacking; (3) diversify the type of clinical trial interventions; (4) eliminate restrictive eligibility criteria in clinical trials; (5) Incorporate clinically meaningful trial endpoints.

References

Eichler, April F et al. The biology of brain metastases-translation to new therapies. Nat Rev. Clinical oncology vol. 8,6 (2011): 344-56. doi: 10.1038/nrclinonc.2011.58

Brosnan EM, Anders CK. Understanding patterns of brain metastasis in breast cancer and designing rational therapeutic strategies. Ann Transl Med. 2018;6(9):163. doi: 10.21037/atm.2018.04.35

A common goal to CARE: Cancer Advocates, Researchers, and Clinicians Explore current treatments and clinical trials for breast cancer brain metastases

Breast cancer is the most commonly diagnosed cancer in women worldwide. Approximately one-tenth of all patients with advanced breast cancer develop brain metastases resulting in an overall survival rate of fewer than 2 years. The challenges lie in developing new approaches to treat, monitor, and prevent breast cancer brain metastasis (BCBM). This review will provide an overview of BCBM from the integrated perspective of clinicians, researchers, and patient advocates. We will summarize the current management of BCBM, including diagnosis, treatment, and monitoring. We will highlight ongoing translational research for BCBM, including clinical trials and improved detection methods that can become the mainstay for BCBM treatment if they demonstrate efficacy. We will discuss preclinical BCBM research that focuses on the intrinsic properties of breast cancer cells and the influence of the brain microenvironment. Finally, we will spotlight emerging studies and future research needs to improve survival outcomes and preserve the quality of life for patients with BCBM.

OTHR-09. Accelerating Research for Breast Cancer Brain Metastasis and Leptomeningeal Disease through Patient-led Collaborations

Patient-driven Initiative of the Metastatic Breast Cancer (MBC) Alliance

The Breast Cancer Brain Metastasis (BCBM) Initiative: Marina Kaplan Project launched in June 2020 as an official project of the MBC Alliance which includes 32 nonprofits, 12 industry partners, and 30 individual patient advocates. The Marina Project has grown to include 35members with representation from industry, research institutions, and individual patients. Nearly one-third of the group is comprised of patients living with brain metastases or leptomeningeal disease (LMD).

Disparities for Patients Living with BCBM & LMD

In the US, approximately 200,000 new cases of brain metastases are diagnosed each year[1]. Approximately 10–15% of patients with MBC will develop brain metastases, and may be as high as 30–50% for certain subtypes[2].

A diagnosis of central nervous system (CNS) metastasis often accelerates an already incurable diagnosis. CNS metastasis are difficult to image and detect, tend to have poorer prognoses with lower overall survival, and are treated with invasive therapies which can have lasting side effects. Furthermore, most clinical trials exclude patients with CNS metastasis which further hinders research.

Values and Objectives

The overarching goal of this initiative is to accelerate the scope and breadth of evidence-based CNS metastasis research by targeting entities conducting clinical trials and collaborating with them to do the following:

(i) Increase the quality and quantity of basic research;

(ii) Increase the number of clinical trials in areas where research is lacking;

(iii) Diversify the type of clinical trial interventions;

(iv) Eliminate restrictive eligibility criteria in clinical trials;

(v) Incorporate clinically meaningful trial endpoints

[1] Eichler, April F et al. The biology of brain metastases-translation to new therapies. Nature reviews. Clinical oncology vol. 8,6 (2011): 344–56. doi: 10.1038/nrclinonc.2011.58

[2] Brosnan EM, Anders CK. Understanding patterns of brain metastasis in breast cancer and designing rational therapeutic strategies. Ann Transl Med. 2018;6(9):163. doi: 10.21037/atm.2018.04.35

Abstract OT-13-08: A remote-directed “virtual” clinical trial in metastatic breast cancer to determine feasibility of evaluating patient response to immunotherapy using spliceosome mutational markers (SF3B1): The PRISMM trial (NCT04447651)

Background:

Next-generation sequencing (NGS) is becoming increasingly routine in patients with advanced cancers, and rare mutations may occasionally be identified. Evaluating the efficacy of targeting rare mutations is challenging given the low observed frequencies, which can result in slow accrual to clinical trials. The internet and social media have revolutionized the way we receive information and connect with each other, and may potentially be leveraged to identify patients with rare mutations. Spliceosome mutations, such as SF3B1, occur in approximately 4% of breast cancers. The Park Lab has demonstrated that somatic cell knock-in of an SF3B1 hotspot mutation results in new mRNA transcripts can be translated into aberrant proteins. These preliminary data suggest that spliceosome mutations could produce a high number of neoantigens, which may increase sensitivity to immune checkpoint inhibitors (ICI). Indeed, since response rates to immunotherapy in patients with metastatic breast cancer is low, identifying biomarkers predictive of response is critical. We therefore designed a remotely directed “virtual” clinical trial to determine the feasibility of evaluating Patient Response to Immunotherapy using Spliceosome Mutational Markers (PRISMM, NCT04447651). Methods: The is a prospective feasibility trial in which patients will be identified via a social media campaign that directs potential participants to a landing page where they can fill out an online form. Patients will need to self-identify as having metastatic breast cancer (any receptor status) with an SF3B1 mutation (main eligibility criteria); once this information is confirmed by the study team, outside records will be obtained and their case will be reviewed at an institutional Molecular Tumor Board; ICI may be recommended or not. Recommendations from the Board will be provided to the patient and local oncologist, who will then decide whether to proceed with the Board’s recommendation or not. Efficacy of next line therapy will be followed by physician and patient questionnaires every one to three months. During routine blood collection, we will evaluate plasma tumor DNA (ptDNA) and peripheral blood mononuclear cells (PBMCs) at baseline and three months. The primary objective of this study is to evaluate the feasibility of conducting a prospective study using online recruitment tools, and the feasibility of real-time case review by a centralized Molecular Tumor Board to assist in therapeutic decision making. Secondary objectives include evaluating the clinical effect of ICI including progression-free and overall survival, correlate SF3B1 mutations in ptDNA with tissue-based NGS, and describe immunopharmacodynamic changes by PBMC evaluation. We anticipate screening approximately 5000 patients via our social media campaign to identify 60 eligible patients. We will conduct efficacy interim analysis after 23, 35, 47, and 56 patients are enrolled. The response rate of 1% 5%, 10%, and 20% correspond to 99.8%, 74.7%, 24.9%, and 1.1% chance that the study will stop early with an average sample size of 26.2, 41.3, 53.6, and 58.7 patients enrolled and treated respectively. If the true response rate exceeds 15% the Board will continue to make recommendation for ICI in patients with SF3B1 mutations. For more information please contact us at PRISMM@jhmi.edu.

Citation Format: Natasha Hunter, Jeffrey Wang, Leslie Cope, Christine Hodgdon, Vered Stearns, Elizabeth Jaffee, Ben Park, Cesar A Santa-Maria. A remote-directed “virtual” clinical trial in metastatic breast cancer to determine feasibility of evaluating patient response to immunotherapy using spliceosome mutational markers (SF3B1): The PRISMM trial (NCT04447651) [abstract]. In: Proceedings of the 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr OT-13-08.

Abstract PO-033: 'Pull Up A Seat': A program shining a light on the experiences of Black women with breast cancer for healthcare providers and the scientific community

Breast cancer incidence rates for Black women are lower than that of their white counterparts, yet the mortality of Black women is 40 percent higher. Among women under 50, the mortality disparity is even greater: double that of white women. The gap between breast cancer incidence and mortality among Black women is complex and multifactorial. Social, economic, behavioral factors may partially account for the disparity, along with historical and systemic racism causing trauma and mistrust within this community. Black women are also more likely than white women to have inadequate health insurance or access to health care facilities, which may affect access to screening, follow-up care, and completion of treatment. This study measures social, economic and behavioral factors that affect access to adequate healthcare through listening sessions entitled 'Pull Up A Seat: Shining a Light on the Experiences of Black Women with Breast Cancer’. 'Pull Ups' are events in partnership with The Tigerlily Foundation and GRASP, bringing together health equity experts, healthcare providers, scientists, researchers, clinicians and Black women with a history of breast cancer. Each meeting consists of a lecture on broad topics such as racism in medical research, clinical trial exclusion/inclusion criteria and history of mistrust from Black community. After the lecture, breakout rooms led by Black patient advocates are held for healthcare providers with the concept that patients are experts in living with the disease and have much to share – and teach – healthcare providers and researchers. Our methodology will be based on surveys post-event to attendants and an impact report with metrics and teachings to health providers and researchers to determine learning and changes to be made in practices. We believe this program created for and by black patients affected by breast cancer from across diverse and underserved populations will help increase the participation of black women with breast cancer in clinical trials through patient empowerment and health provider awareness of unconscious biases. In addition, we believe this program will result in co-creating solutions to limit barriers for Black women.

Citation Format: Julia Maues, Maimah Karmo, Shanda Cooper, Sheila McGlown, Jamil Rivers, Chawnte Randall, Tania Koulakian, Christine Hodgdon, Isaac Chan. 'Pull Up A Seat': A program shining a light on the experiences of Black women with breast cancer for healthcare providers and the scientific community [abstract]. In: Proceedings of the AACR Virtual Conference: Thirteenth AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2020 Oct 2-4. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2020;29(12 Suppl):Abstract nr PO-033.

Management of Breast Cancer During the COVID-19 Pandemic: A Stage- and Subtype-Specific Approach

The COVID-19 pandemic has rapidly changed delivery of cancer care. Many nonurgent surgeries are delayed to preserve hospital resources, and patient visits to health care settings are limited to reduce exposure to SARS-CoV-2. Providers must carefully weigh risks and benefits of delivering immunosuppressive therapy during the pandemic. For breast cancer, a key difference is increased use of neoadjuvant systemic therapy due to deferral of many breast surgeries during the pandemic. In some cases, this necessitates increased use of genomic tumor profiling on core biopsy specimens to guide neoadjuvant therapy decisions. Breast cancer treatment during the pandemic requires multidisciplinary input and varies according to stage, tumor biology, comorbidities, age, patient preferences, and available hospital resources. We present here the Johns Hopkins Women's Malignancies Program approach to breast cancer management during the COVID-19 pandemic. We include algorithms based on tumor biology and extent of disease that guide management decisions during the pandemic. These algorithms emphasize medical oncology treatment decisions and demonstrate how we have operationalized the general treatment recommendations during the pandemic proposed by national groups, such as the COVID-19 Pandemic Breast Cancer Consortium. Our recommendations can be adapted by other institutions and medical oncology practices in accordance with local conditions and resources. Guidelines such as these will be important as we continue to balance treatment of breast cancer against risk of SARS-CoV-2 exposure and infection until approval of a vaccine.

Pain medication use in patients with HR+, HER2-neg advanced breast cancer treated with endocrine therapy and a CDK 4/6 inhibitor: A U.S. FDA pooled analysis

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Background: Pain medications (PMs) are commonly used to treat pain in patients (pts) with advanced/metastatic breast cancer (MBC). We examined PM usage patterns in pts receiving CDK 4/6 inhibitor (CDKI) based treatment. Methods: We pooled data from seven phase 3 randomized, controlled trials of CDKI + endocrine therapy in pts with hormone receptor positive, human epidermal growth factor receptor-2 negative MBC. PM were categorized as opioid (includes codeine-containing), NSAID, or other (i.e. bone-directed, antiepileptic, topical PMs). All analyzed pts received at least 1 dose of CDKI/placebo and had concomitant PM with a documented start date. Medications prescribed during hospitalizations were not included. We evaluated percent PM by demographic factors and pts with bone mets, and liver/lung mets. Results: 2416 pts met the inclusion criteria, of which 928 pts started a PM before the study and 1488 pts did not start PM before the study. Of the 1488 pts not on a PM before the study, 739 started a PM after study started, and 749 did not receive any PM at any time. Of the 739 pts who started a PM only after study start, overall, 59% were prescribed only an NSAID, 10% were prescribed only opioid, 17% were prescribed both an NSAID and opioid, and 14% were prescribed other PMs. The PM use by percent in demographic subgroups in the 1488 pts who took none or more PMs only after study start are presented in the table. Conclusions: To our knowledge, this is the first analysis of PM usage patterns in pts with MBC receiving CDKI or placebo with hormonal therapy on clinical trials. NSAID use was higher than opiates in all prespecified subgroups. Future analyses will examine the benefit of different classes of pain medications in treating symptoms of pain and whether there are differences between study treatment arms Percent PM Use by Class (Patients Who Took None or More PM Only After Study Start). [Table: see text]

Patient-reported pain and pain medication impact in patients with HR+ Her2-neg advanced breast cancer: A U.S. FDA pooled analysis

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Background: Despite the ubiquitous prescribing of pain medications (PMs) in cancer clinical trials, the impact of such prescribing patterns and reporting on the experience of pain is not often investigated. We examined patient-reported pain before initiation of PM reporting and at the next available pain assessment. Our aim was to understand change in patient-reported pain. Methods: We pooled data from 7 phase 3 randomized, controlled, registration trials of CDKI with endocrine therapy in patients with hormone receptor positive, human epidermal growth factor receptor-2 negative MBC. We restricted our analyses to patients who started therapy with no PM reported and looked at patients who had NSAID or opioid medication documented. We calculated change between 2 assessments in patient-reported pain before and after PM using the pain occurrence item (Q9) on the EORTC Quality of Life questionnaire (QLQ-C30). Results: Of the 4200 patients who received at least 1 dose of CDKI/placebo, 1488 started with no documented PM, with 48% reporting none at all when asked about pain at baseline. Subsequently, 185 patients had documented NSAID and 43 an opioid and had a pain PRO assessment before and after. NSAIDs documentation occurred on average 11 weeks into trial and opioids 5. Before documentation of NSAIDs, 45% of patients reported no pain compared to 23% of patients with an opioid. Patients who had documented NSAIDs, 29% experienced an improvement in their self-reported pain, whereas 32% of patients with documented opioids improved. On average the time between the 2 pain assessments was around 58 days for both PMs. Conclusions: In this analysis in patients who had a pain assessment before and after documentation of a PM, there is a small group whose pain improved. It is important to note that patients’ response to the pain item was not provided to the clinical care team, which may explain why there may have been suboptimal pain control. Further study is needed to examine how pain management can be achieved in patients with advanced breast cancer. Future analysis should be performed with patients whose PRO pain results are communicated with the clinical care team in real-time. [Table: see text]