HER2-positive Disease Research Articles

Abstract 1917: Accurate modeling of HER2 positive breast cancer disease progression with a biophysical modeling software

Abstract Breast cancer (BC) progression during NAT is associated with development of distant metastases, positive LN status, and decreased OS/RFS. These can occur in the context of clinical trials and therapy de-escalation, where the focus is on delivering effective NAT to patients while reducing drug toxicity. The risks added by disease progression underscore the need for early identification of NAT progressors. To this end, we replicated the NeoSphere study in silico using TumorScope (TS), a biophysical modeling software, focusing on predicting disease progression during NAT. The NeoSphere trial studied the efficacy of docetaxel (T), pertuzumab (P), and trastuzumab (H) in combination with one another over 254 operable BC patients distributed across four study arms. We selected past BC patients with accompanying standard of care clinical data that matched NeoSphere sample composition based on patient and tumor characteristics. A total, 144 patients were included across four study arms (TH, THP, HP, and TP). Parameters from the NeoSphere study were mirrored where possible. Simulation generated volume trajectories of individual tumor’s response to therapy. Disease progressors were identified based on tumor volume at the final simulation timepoint compared to the first simulation timepoint. We then compared group means and proportions between progressors and responders using Welch’s two-sample t-test, and Fisher’s exact test, respectively. We replicated the NeoSphere trial using TS. pCR rates across study arms closely mirrored those of the actual trial. In the HP arm of our trial, we identified 12 (12/144) progressors. No difference was found when comparing it to that observed in the NeoSphere trial (p=1.00, OR=1.12). As expected, percent change in tumor volume from initial to final timepoints for the progressor group was significantly higher than the responder group (n=121, t=19.2, p=1.5x10-10, mean progressor=38.7, mean responder=-75.9). The progressor group was enriched with higher grade tumors (t=2.85, p=0.01), as well as HR-negative tumors (p=0.002, OR=7.54) compared to the responder group, and had lower HER2 receptor FISH ratios (t=-3.4, p=0.002). There were no differences observed between groups age, cancer subtype, or AJCC tumor stage (p>0.05). After trial replication, we identified clinical features that separated progressors from responders, which are being assessed for development of individualized predictive biomarkers of disease progression. While work is ongoing in the field to identify biomarkers of BC progression, it is evident that single markers are not sufficient. Comprehensive, multi-modal biomarkers of disease progression must be developed and applied to patient sub-populations to garner effective predictions. Using biophysical simulations, we are able to investigate the impact of drug delivery/sensitivity, metabolism, and spatial heterogeneity on BC progression. Citation Format: John Pfeiffer, Tim Foley, Eduardo Braun, Anu Antony, Lance Munn, Joseph R. Peterson, John A. Cole, The SimBioSys Team. Accurate modeling of HER2 positive breast cancer disease progression with a biophysical modeling software [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 1917.

Abstract 3686: Differences in disease presentation, and treatment outcomes of neoadjuvant chemotherapy for breast cancer among Hispanics in a minority-serving institution

Abstract Background: Response to neoadjuvant chemotherapy (NAC) for breast cancer varies by tumor characteristics and therapy regimen. Studies suggest that patient ethnicity is associated with differences in disease presentation, response to treatment, and outcomes. There exists a paucity of literature on the presentation and outcomes of NAC for breast cancer in Hispanic women. Methods: This is an IRB-approved retrospective study of breast cancer patients who underwent NAC at an NCI-designated Comprehensive Cancer Center from 2005-2020. We reviewed demographics, disease presentation, response to treatment, and outcomes. ER and PR status were categorized as low positive (1-9%), positive (≥ 10%) and negative. Treatment factors reviewed included completion of chemotherapy and type of surgery performed. Treatment response was noted as percent residual cellularity (0%, <10%, 10-30%, >30-80% and >80%) in the surgical specimen and pathologic stage. Outcomes were assessed as overall survival (OS) and recurrence. Results: 365 patients received neoadjuvant chemotherapy from 2005-2020, and 196 (53.7%) self-identified as Hispanic. Median follow-up was 13.65 years. Highest clinical stage at diagnosis was most frequently IIA (31.2%), followed by IIB (32.3%), with non-significant Hispanic ethnicity differences, although Hispanic patients presented with higher clinical prognostic stages: IIIA or higher (40.5% vs. 24.0%). Hispanics more frequently had grade 3 tumors (60% vs. 48%), ER low positive (10% vs. 7%) and ER negative (48% vs. 36%) (p=0.02). No significant differences were noted in triple negative disease or HER2 positive disease. Hispanics were diagnosed at younger average ages (48.9 vs. 53.0 years, p=0.001). No statistically significant differences were noted in time from diagnosis to NAC initiation, completion of chemotherapy, or surgical treatment received (lumpectomy vs. mastectomy, and sentinel node biopsy vs. dissection). Mastectomy was more likely for late-stage disease (OR=2.73, 95% CI: 1.66-4.49, p<0.001); Hispanic women with late-stage disease had 1.09-fold higher odds of receiving mastectomy, but this was non-significant (95% CI: 0.66-1.79). No significant ethnic differences were noted in pCR (p=0.69) or residual tumor cellularity (p=0.63). There was no significant association between residual cellularity and OS. OS rates were similar for Hispanic vs. Non-Hispanic women (HR: 1.15, 95% CI: 0.64-2.08, p=0.63). No difference was noted in ethnicity-based recurrence rates (21.4 vs. 20.1%). Conclusion: Self-identified Hispanic patients were diagnosed at a younger age, presented with higher ER negative and low-positive disease and worse prognostic clinical stage. However, given standard of care chemotherapy, there were no significant differences in their treatment response or outcomes compared to non-Hispanic patients. Citation Format: Sangeetha Prabhakaran, Christopher McNicoll, Vernon S. Pankratz, Nadja Falk, Jacklyn Nemunaitis, Jain Zhou, Payton A. Sandoval-Belt. Differences in disease presentation, and treatment outcomes of neoadjuvant chemotherapy for breast cancer among Hispanics in a minority-serving institution [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 3686.

Multidisciplinary Team Meeting Proposal and Final Therapeutic Choice in Early Breast Cancer: Is There an Agreement?

BackgroundA multidisciplinary team meeting (MDM) approach in breast cancer (BC) management is a standard of care. One of the roles of MDMs is to identify the best diagnostic and therapeutic strategies for patients (pts) with new diagnosis of early BC. The purpose of this study was to define whether there was an agreement between the planned program (i.e., MDMs-based decision) and that actually applied. In addition, the study explored factors associated with discordance.MethodsWe conducted a retrospective study of a consecutive series of 291 patients with new diagnosis of early BC, discussed at MDMs at the University Hospital of Udine (Italy), from January 2017 to June 2018. The association between clinico-biological factors and discordance between what was decided during the MDMs and what was consequently applied by the oncologist was explored through uni- and multivariate logistic regression analyses.ResultsThe median age was 62 years (range 27–88 years). Among invasive early BC patients, the most frequent phenotype was luminal A (38%), followed by luminal B (33%), HER2-positive (12%), and triple-negative (5%). In situ carcinoma (DCIS) represented 12% of cases. The median time from MDM discussion to first oncologic examination was 2 weeks. The rate of discordance between MDM-based decision and final choice, during a face-to-face consultation with the oncologist, was 15.8% (46/291). The most frequent reason for changing the MDM-based program was clinical decision (87%). Follow-up was preferred to the chemotherapy (CT) proposed within the MDMs in 15% of cases, and to the endocrine therapy (ET) in 39% of cases (among these, 44.5% had a diagnosis of DCIS). Therapeutic change from sequential CT-ET to ET alone was chosen in 16/46 pts (35%): among these patients, seven had a luminal B disease and six had an HER2-positive disease. On univariate analysis, factors associated with discordance were values of Ki-67 14%–30% (OR 3.91; 95% CI 1.19–12.9), age >70 years (OR 2.44, 95% CI 1.28–4.63), housewife/retired status (OR 2.35, 95% CI 1.14–4.85), polypharmacy (OR 1.95; 95% CI 1.02–3.72), postmenopausal status (OR 4.15; 95% CI 1.58–10.9), and high Charlson Comorbidity Index (OR 1.31; 95% CI 1.09–1.57). The association with marital status, educational level, alcohol and smoke habits, presence of a caregiver, parity, grading, histotype and phenotype, and stage was not statistically significant. On multivariate analysis, only Ki-67 value maintained its statistical significance.ConclusionThe results of our study could be useful for enhancing the role of MDMs in the clinical decision-making process in early BC.

Survival and prognostic factors in oligometastatic breast cancer.

1089 Background: Clinical guidelines for the treatment of oligometastatic breast cancer (OMBC) propagate multimodality treatment including polychemotherapy and ablative local therapy for all detected disease. The aim of this aggressive approach is prolonged disease remission, or even cure, but randomized data to support this strategy lack and long-term outcomes are not well known. We report prognostic factors, and event-free survival (EFS) and overall survival (OS) in a real world, single center cohort of patients with OMBC with long-term follow-up. Methods: Patients with breast cancer and 1-3 distant metastatic lesions who underwent treatment in the Netherlands Cancer Institute were identified via text mining of medical files. We collected patient, tumor and treatment characteristics as well as recurrence and survival data from the medical records. The Kaplan-Meier method was used to calculate EFS and OS estimates, and Cox regression analyses to assess potential prognostic factors. Results: The cohort included 239 patients (of whom two males), diagnosed between 1997 and 2020. Median follow-up was 75.0 months. Fifty-one percent had hormone receptor (HR)-positive/ human epidermal growth factor receptor 2 (HER2)-negative disease, 20.1% had HER2-positive disease, and 19.2% had triple negative (TN) disease. Median age at OMBC diagnosis was 49.0 years and 47.3% of patients had synchronous disease (metastases ≤6 months of primary diagnosis). Most patients (81.2%) received chemotherapy and local therapy (surgery, radiotherapy and/or radiofrequency ablation) of all metastatic lesions (83.7%). Of 239 patients, 134 experienced disease recurrence with a median EFS of 40.0 months (95% confidence interval (CI): 28.6-51.4); 97/239 died and median OS was 93.0 months (95% CI 74.5-111.5). The table shows factors associated with favorable OS in multivariable analysis. Cox regression analysis for EFS showed similar results. Conclusions: In this large real world cohort of OMBC patients, EFS and OS compare favorably to survival in the general MBC population. HR-positive and/or HER2-positive subtypes, synchronous disease or long DFI, favorable response to first-line systemic therapy and local therapy of all distant lesions are independently associated with better survival. Future studies should be directed at optimizing patient selection and therapy choices in this population with the potential for cure. [Table: see text]

Survival of stage 4 primary breast cancer cases after surgery by intrinsic subtype: HER2-positive subtype potentially curable.

e13026 Background: With the incorporation of anti-HER2 agents in the treatment of HER2 positive primary breast cancer, stage 4 disease of this subtype has become potentially curable. However, the duration of clinical CR that is needed be certain that the patient is cured, and therefore the necessary duration of anti-HER2 treatment is uncertain. We address this issue in this presentation. Methods: We present cases of stage 4 primary breast cancer who underwent breast surgery after their distant metastases were controlled, with continued post-operative systemic therapy. There were 52 cases of which the intrinsic subtype as of immunohistochemical analysis was as follows; Luminal A - 7 cases, Luminal B, - 14 cases, Luminal-HER2 - 9 cases, HER2-enriched - 7 cases, and Triple negative -15 cases. The patients were followed up for duration of treatment and overall survival. Results: The average post-operative observation period for all 52 cases was 32.6 months. The five year overall survival rate for HER2-enriched cases was 100%, for Luminal-HER2 cases 80%, for Luminal A cases 80%, for Luminal B cases 55%, and for Triple-negative cases 0%. Of the 16 HER2 positive cases (Luminal-HER2 and HER2 enriched), there was only one death at 48.4 months post-operation. The survival of 5 of 15 surviving HER2 positive cases exceed 60 months (5 years). Of the five, only one at 72.0 months has clinically observable disease (cSD). The remaining 4 cases all are clinically disease free (cCR). Of the 4 cCR cases, only 1 case which originally had multiple lung metastases is continuing anti-HER2 therapy at 90.3 months post-operation. The remaining three discontinued anti-HER2 therapy at 18.1 months (lung metastases CR, observation period 71.7 months), 72.3 months (liver and lymph node metastases CR, observation period 90.3 months), and 101.9 months (liver and bone metastases CR, observation period 102.3 months), respectively. The last case terminated anti-HER2 therapy after testing negative for ERBB2 related genes on liquid biopsy. Conclusions: With the proper incorporation of anti-HER2 therapy, Stage 4 HER2 positive primary breast cancer disease seems to be a potentially curable disease, and anti-HER2 therapy probably can be discontinued in cCR patients after 5 years. Liquid biopsy for tumor related genes (e.g. ctDNA, miRNA) might facilitate decision making.

Adjuvant study of amcenestrant (SAR439859) versus tamoxifen for patients with hormone receptor-positive (HR+) early breast cancer (EBC), who have discontinued adjuvant aromatase inhibitor therapy due to treatment-related toxicity (AMEERA-6).

TPS607 Background: There are currently limited treatment options for patients with HR+ EBC who have discontinued adjuvant treatment with aromatase inhibitors (AIs) due to treatment-related toxicity. Amcenestrant is an optimized oral selective estrogen receptor degrader (SERD) with potent dual activity which antagonizes and degrades the ER resulting in inhibition of the ER signalling pathway. Preliminary clinical evidence from the phase 1/2 AMEERA-1 trial has demonstrated meaningful antitumour activity and a favourable safety profile of amcenestrant in the treatment of HR+ advanced breast cancer (Linden HM, Campone M, Bardia A, et al: Abstract PD8-08: A phase 1/2 study of SAR439859, an oral selective estrogen receptor (ER) degrader (SERD), as monotherapy and in combination with other anti-cancer therapies in postmenopausal women with ER-positive (ER+)/human epidermal growth factor receptor 2-negative (HER2-) metastatic breast cancer (mBC): AMEERA-1. SABCS 2020 PD8-08). Methods: AMEERA-6 is a prospective, randomized, international, double-blind, double-dummy, phase 3 study. 3738 patients will be randomized 1:1 to receive either amcenestrant 200 mg daily or tamoxifen 20 mg daily. Eligible patients are pre-or postmenopausal women or men with HR+ EBC (stage IIB-III) who have received at least 6 months of adjuvant AIs (at least 3 months in the adjuvant setting if they have received prior neoadjuvant AI therapy) and discontinued them within 30 months of initiation due to treatment-related toxicity. Participants will be centrally assessed to have ER+ and/or PgR+ (≥10% positive stained cells) status by immunohistochemistry assay. Prior use of adjuvant CDK4/6 inhibitors are allowed. Patients are eligible irrespective of HER2 status; for patients with HER2-positive disease adjuvant anti-HER2 treatment and chemotherapy must be completed prior to randomization. Stratification factors include: duration of AI therapy, HER2 status, prior chemotherapy, prior CDK4/6 inhibitors, geographic region, and menopausal status. Planned treatment duration is 5 years. Patients will be followed-up for 10 years from randomization. The primary endpoint is invasive breast cancer-free survival (IBCFS). Invasive disease-free survival is a key secondary endpoint, while other secondary endpoints include distant relapse-free survival (RFS), locoregional RFS, overall survival, breast-cancer specific survival, safety, patient reported outcomes and pharmacokinetics. Adherence to treatment is an exploratory endpoint. AMEERA-6 opened for recruitment in January 2022. Clinical trial information: NCT05128773.

Dose-dense sequential adjuvant chemotherapy in the trastuzumab era: final long-term results of the Hellenic Cooperative Oncology Group Phase III HE10/05 Trial.

Dose-dense sequential chemotherapy with anthracyclines and taxanes achieved an 18% reduction of recurrence risk in early breast cancer (BC). The optimal chemotherapy schedule and interval between cycles remain under investigation. Overall, 990 patients were randomised to receive either three cycles of epirubicin (E, 110 mg/m2) every 2 weeks followed by 3 cycles of paclitaxel (T, 200 mg/m2) every 2 weeks followed by three cycles of intensified CMF (Control Arm A, E-T-CMF) that was previously used in BC or three cycles of epirubicin followed by three cycles of CMF followed by nine consecutive weekly cycles of docetaxel (wD) 35 mg/m2 (Arm B, E-CMF-wD) or nine consecutive weekly cycles of paclitaxel (wT) 80 mg/m2 (Arm C, E-CMF-wT). Trastuzumab was administered for HER2-positive disease. At a median follow-up of 13.3 years, 330 disease-free survival (DFS) events (33.3%) were reported. DFS and overall survival (OS) did not differ between patients in the combined B and C arms versus arm A either in the entire cohort (HR = 0.90, P = 0.38 and HR = 0.85, P = 0.20) or among trastuzumab-treated patients (HR = 0.69, P = 0.13 and HR = 0.67, P = 0.13). Thirty-four patients (3.4%) developed secondary neoplasms. Overall, no significant differences in survival were found amongst the studied regimens after a long-term observational period. Australian New Zealand Clinical Trials Registry ACTRN12610000151033.

Breast Cancer-Epidemiology, Classification, Pathogenesis and Treatment (Review of Literature).

Simple SummaryBreast cancer is the most-commonly diagnosed malignant tumor in women in the world, as well as the first cause of death from malignant tumors. The incidence of breast cancer is constantly increasing in all regions of the world. For this reason, despite the progress in its detection and treatment, which translates into improved mortality rates, it seems necessary to look for new therapeutic methods, predictive and prognostic factors. The article presents a review of the literature on breast carcinoma - a disease affecting women in the world.Breast cancer is the most-commonly diagnosed malignant tumor in women in the world, as well as the first cause of death from malignant tumors. The incidence of breast cancer is constantly increasing in all regions of the world. For this reason, despite the progress in its detection and treatment, which translates into improved mortality rates, it seems necessary to look for new therapeutic methods, and predictive and prognostic factors. Treatment strategies vary depending on the molecular subtype. Breast cancer treatment is multidisciplinary; it includes approaches to locoregional therapy (surgery and radiation therapy) and systemic therapy. Systemic therapies include hormone therapy for hormone-positive disease, chemotherapy, anti-HER2 therapy for HER2-positive disease, and quite recently, immunotherapy. Triple negative breast cancer is responsible for more than 15–20% of all breast cancers. It is of particular research interest as it presents a therapeutic challenge, mainly due to its low response to treatment and its highly invasive nature. Future therapeutic concepts for breast cancer aim to individualize therapy and de-escalate and escalate treatment based on cancer biology and early response to therapy. The article presents a review of the literature on breast carcinoma—a disease affecting women in the world.

220P Distant disease-free survival according to different subtypes in young breast cancer patients (YBCP)

Breast cancer (BC) is the most common cause of cancer-related death in young women, but stages I to III are highly curable regardless of age. Classically HER2-positive disease has been considered a poor prognosis but few studies have evaluated the impact of anti-HER2 treatments. Knowing the risk of recurrence and time to recurrence can determine follow-up and time to follow, key issues for a population with a potentially long survival.

HER2-Low Breast Cancer: Prognosis and Future Treatment Prospective

The human epidermal growth factor 2 (HER2) is a tyrosine kinase belonging to the Human Epidermal Receptor family [1]. HER2 is amplified leading to HER2 overexpression in 15% of breast cancers (BC) [2]. HER2 overexpression leads to poor prognosis, but offers the unique possibility to use a targeted therapy with monoclonal antibodies. This therapeutic option has radically changed the history of HER2 BC [3]. HER2 overexpression represents at present the most powerful predictive factor for likeliness of response to anti-HER2 agents [5]. The HER2 status is routinely assessed either using immunohistochemistry (HER2 protein expression level) or in situ hybridization (HER2 gene status) [2,5,6]. For the purpose of HER2 assessment, international guidelines have been developed by experts in the field, and have changed over the years according to new data. HER2 heterogeneity is linked to the complexity of equivocal results, HER2 mutations and the upcoming category of HER2-low BC [7]. Intratumor genetic heterogeneity interests various types of human cancers, including BC and HER2 overexpression and amplification, and it is demonstrated to be significantly more common in cases with HER2 equivocal status [8]. Equivocal cases frequently feature low levels of HER2 amplification. Several studies showed that HER2 heterogeneity is related to poor outcome, shorter disease-free survival and overall survival. Patients with HER2 heterogeneity are less responsive to target therapies as confirmed by a lower achievement of pathologic complete response following neoadjuvant treatment [9]. In spite of the scarcity of data still available on HER2-low BC, different intrinsic subtypes seem to influence different clinical behavior and response to treatment, as this has already been proved for other BC subtypes. HER2-low/HR- BC showed a higher frequency of HER2-enriched instrinsic subtype than HER2-/HR- BC. This might mean that, despite in clinical practice HER2-low/HR- BC is considered as HER2-/HR, these subtypes of BCs might reflect a different clinical behavior and a different response to targeted therapy [10]. Recent studies underlined that HER2-enriched instrinsic subtype are the most beneficial in reduction of risk of progression and death after CDK6/6-inhibitors treatment, compared to the other subtypes [11]. Traditionally HER2-positive BCs were separated from HER2-negative BCs, based on solid clinical data stating that only tumors driven by HER2 oncogene addition benefit from targeted therapies [12]. However in recent years new therapies have been developed, in particular the antibody drug conjugates which deliver chemotherapy inside the BC. Some of these agents - such as trastuzumab duocarmazine and trastuzumab deruxtecan showed encouraging response rates also in the so called HER2-low BC. For example, the phase 1 study of DS-8201 showed an overall response rate of 37% in pretreated HER2-low metastatic cancer patients, with a median duration of response of 10.4 months [13]. These data suggests a paradigm shift in the definition of HER2 status, which may be based on 3 groups: 1.HER2-positive, 2.HER2- negative, 3.HER2-low BCs, that may potentially benefit from a targeted therapy, even in absence of the addition of the tumor cells to the HER2 oncogene [7]. At present there are no formal definitions of HER2-low BC, but it seems reasonable to define as HER2-low all BCs displaying a score of 1+ or 2+ HER2 expression and no HER2 amplification. This assumption would categorize up to 55% of BCs as HER2-low. For this subtype there are no targeted therapies approved [7]. The majority of HER2 somatic mutations found in BCs have not been associated with HER2 gene amplification. However preclinical data suggest that functionally active HER2 mutations may lead to HER2 targeted therapies sensitivity [14]. Other preclinical models suggest that pertuzumab inhibits tumor proliferation even in absence of HER2 overexpression [15].So, HER2 mutation-positive but HER2-negative BC may benefit from targeted drugs, but further studies are needed. For example, trastuzumab, deruxtecan, a novel enzyme-cleavable linker, showed significant objective response and disease control in a group of patients including 25% HER2-low BCs, and therefore is worthy of further studies in this subgroup of patients [16]. The new agents being tested for HER2-low BC patients are antibody drug conjugates deploying anti-HER2 epitopes in their antibody component, but with different cytotoxic warheads and a bi-specific antibody targeting both HER2 and HER3 [17]. In conclusion, the concept of HER2-positive versus HER2-negative disease is changing, including the definition of “HER2-low” BC, against which new therapies such as antibody drug conjugates may be extremely effective.

Abstract OT1-18-08: Randomized phase II trial of pembrolizumab/carboplatin vs. carboplatin alone for breast cancer with chest wall recurrence: TBCRC044

Abstract Background: A significant number of patients with breast cancer may develop chest wall recurrence, which can be difficult to treat, and is associated with a poor prognosis. Given the inflammatory nature of chest wall disease, and the association of chest wall disease with lymphovascular invasion, we hypothesized that immunotherapy may be beneficial in this setting. Furthermore, combining immunotherapy and chemotherapy may have a synergistic effect; indeed, the combination of the anti-programmed cell death 1 (PD-1) antibody, pembrolizumab, with chemotherapy has been approved for metastatic triple negative breast cancer (TNBC). Consequently, in this study, we are evaluating the combination of pembrolizumab/carboplatin vs. carboplatin alone for chest wall recurrence. Trial design: This is a phase II study of patients with chest wall disease from breast cancer. Patients are randomized in a 2:1 manner to pembrolizumab/carboplatin x 6 cycles (Arm A) with the option to continue pembrolizumab +/- carboplatin after 6 cycles (Arm Ax) vs. carboplatin alone (Arm B) with the option to cross-over to pembrolizumab +/- carboplatin on progression (Arm Bx). Carboplatin is dosed at AUC 5 IV every 3 weeks, and pembrolizumab at 200 mg IV every 3 weeks. Trastuzumab may be continued with study treatment in patients with HER2 positive disease. Imaging scans (CT chest, abdomen, and pelvis, and bone scan) occur at baseline and every 3 cycles. Chest wall biopsies and peripheral blood is collected at baseline and after completing 2 cycles of treatment for correlative studies. Eligibility criteria: Patients must have chest wall disease from breast cancer. Distant metastases are allowed. TNBC, hormone receptor positive/HER2 negative disease (after 2 prior hormone therapies), and HER2 positive disease (progressed on standard HER2 directed treatment) are eligible. Any number of prior lines of chemotherapy are acceptable, including a prior platinum chemotherapy in the absence of disease progression on the platinum. Specific Aims: Primary aim is to determine disease control rate in the chest wall and other distant sites at 18 weeks of treatment with RECIST 1.1. Secondary aims including determining toxicity, progression-free survival, response based on irRECIST, and response based on tumor PD-L1 expression. Exploratory aims include studying changes in: 1) immune composition of tumor and peripheral blood, 2) peripheral blood cell-free DNA and circulating tumor cells, 3) soluble PD-L1 expression, and 4) association of MYC with PD-1 and immune markers, based on preclinical data demonstrating that MYC upregulates these markers. Statistical Methods: 84 patients (Arm A: 56, Arm B: 28) are being enrolled at 7 sites in the Translational Breast Cancer Research Consortium. The study is powered to identify a 20% difference in disease control rates between Arms A and B (HR 0.52, α= 0.10, ß=0.20). A futility analysis will occur for Arm B after 18 patients are enrolled to allow for early closure if lack of efficacy. Accrual: Present accrual is 57 patients (Arm A: 39, Arm B: 18). (NCT03095352). This trial is partly funded by grants from Merck and University of California San Francisco. Contact information: Neelima Vidula, MD, Massachusetts General Hospital, nvidula@mgh.harvard.edu Citation Format: Neelima Vidula, Rita Nanda, Kathy Miller, Leisha Emens, Vandana Abramson, Ben Park, Minetta C. Liu, Andrei Goga, Hope Rugo. Randomized phase II trial of pembrolizumab/carboplatin vs. carboplatin alone for breast cancer with chest wall recurrence: TBCRC044 [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 OT1-18-08.

Abstract P1-17-06: Impact of body mass index on the efficacy of aromatase inhibitors in patients with metastatic breast cancer

Abstract Background: Aromatase inhibitors (AIs) are part of standard endocrine therapy for hormone receptor (HR)-positive breast cancer (BC) and are used in both adjuvant and metastatic settings. Since AIs work by inhibiting the conversion of androgens to estrogen in peripheral adipose tissue, the higher levels of estrogen in obese patients may lead to incomplete inhibition by AIs and influence their efficacy. A retrospective analysis of the ABCSG-12 trial found that overweight premenopausal patients with early-stage BC treated with anastrozole had a 60% increased risk of disease recurrence and more than doubling in risk of death compared with normal weight patients on anastrozole. Similarly, an exploratory analysis from the ATAC trial found that in post-menopausal women with early-stage BC, overall recurrence rates were lower in patients randomized to anastrozole versus tamoxifen but in women with body mass index (BMI) > 30, there was no significant difference in disease recurrence between anastrozole and tamoxifen. While these findings raise concern for the efficacy of adjuvant AI therapy in obese patients with early-stage BC, this has not yet been demonstrated in the metastatic setting. The aim of this study was to determine the impact of BMI on efficacy of AIs in patients with metastatic HR-positive BC. Methods: We performed a retrospective chart review of all female patients with metastatic HR-positive BC on an AI in first- or second-line settings and seen at our academic institution between 2001-2020. The primary endpoint was progression-free survival (PFS), defined as the time from start of AI to disease progression or death from any cause. PFS was compared across BMI groups using Kaplan-Meier curves and log-rank tests. Cox proportional hazards regression model was used for univariate and multivariate analyses. Results: We identified 219 patients who had received an AI in the first- or second-line settings for metastatic HR-positive BC and with documented information on BMI. The median age was 59 with 45% of patients White, 29% African American, 16% Hispanic/Latino, 5.5% Asian and remainder other/unknown. 32% (71) had HER-2 positive disease. 82% (179) were on an AI in the first-line setting. Overall, 53% were on letrozole, 42% on anastrozole and 5.5% on exemestane. Of the 219 patients, 56% (123) had a low BMI (defined as < 27 kg/m2) and 44% (96) had a high BMI (≥ 27 kg/m2; based on the Breast Cancer Weight Loss [BWEL] trial). The median PFS was 21.9 months (95% CI, 14.5 to 28.4) in the low BMI group versus 20.2 months (95% CI, 14.3 to 27.5) in the high BMI group with no statistically significant difference (p =0.73). There were 8 (6.5%) deaths in the low BMI group and 7 (7.3%) deaths in the high BMI group. Multivariate cox regression model did not demonstrate any significant impact of BMI on PFS when adjusting for age, race/ethnicity, HER2 status, type of AI, line of therapy, drug partner and type of metastatic disease (HR =0.91, 95% CI =0.64 to 1.30, p =0.6 for high BMI group). Subgroup analysis of patients on an AI in the first line setting also did not show a significant difference in PFS with median PFS 19.3 and 18 months in the low and high BMI groups, respectively. Conclusions: In patients on an AI for metastatic HR-positive breast cancer, there was no statistically significant difference in PFS in patients with low versus high BMI. While BMI influences efficacy of AIs in the adjuvant setting, our results demonstrate that in the metastatic setting, BMI does not significantly impact the efficacy of AIs among our patient population. This discrepancy could be due to other differences in disease characteristics that make complete aromatase inhibition more important in the adjuvant setting when disease burden is the lowest. Additional larger studies are needed to confirm this finding. Citation Format: Rima Patel, Zhiqiang Li, Brittney S. Zimmerman, Marc Y. Fink, Jason D. Wells, Xiang Zhou, Kristin L. Ayers, Arielle Redfern, Scott Newman, Rong Chen, William K. Oh, Amy Tiersten. Impact of body mass index on the efficacy of aromatase inhibitors in patients with metastatic breast cancer [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 P1-17-06.

Abstract P1-08-26: Morphologic characterization of tumor-infiltrating lymphocytes and its relation with pathological response in a series of breast cancer patients treated with primary chemotherapy

Abstract Introduction: Tumor-Infiltrating Lymphocytes (TILS) is a well-known predictor of response to primary chemotherapy1,2 and a prognostic factor for improved survival in different breast cancer subtypes3. We present data on the association of the level of TILs and morphologic characteristics of such infiltrate with pCR. Material and methods: A series of 477 breast cancer patients (479 tumors) treated with primary chemotherapy at Catalan Institut of Oncolgy - H.U. Bellvitge between January 2009 and December 2016. Chemotherapy consisted on anthracyclines and taxanes (plus trastuzumab if Her-2 positive disease). Levels of percentage of TILs using hematoxylin-eosin-stained sections of diagnostic core-needle biopsy were evaluated according to international guidelines in a prospectively defined retrospective analysis. Characterization of TILS consisted on identification of plasma cells, intraepithelial infiltrate vs stromal infiltrate and homogeneous vs heterogeneous infiltrate. A sub-classification using levels of TILS and heterogeneity was done for statistical purposes. Levels of TILS and their morphological characteristics were examined for their associations with pCR adjusted for predictive clinic-pathological factors, by univariate and multivariate logistic regression, statistical significance set at 0.05. A ROC curve was performed to look for a cut-point of TILs to predict PCR. Results: The mean value of TILs was 23.79% (SD, 24%). TILs were significantly higher in ductal carcinomas (39.1% vs 0%, p=0.007), grade 3 (55.2 vs 17.7%p<0.001), ki 67 >30 (48.8% vs 24.5%, p<0.001), HER2 (56.6%) and triple negative tumors (TNBC)(56.6%) vs luminal (20%), p<0.001). The level of TILS was set in 20% to predict pCR by a ROC curve (S=62.3% E=71%). Characterization of TILs found plasma cells in 41.1% of the samples, intraepithelial infiltrate in 11.2% and homogeneous infiltrate in 60.1%. Homogeneously high infiltrate was found in 20% of the samples. In the univariate analysis pCR was higher in samples with TILs > 20% (15.2% vs 41.5%, OR: 3.96 [95%CI, 2.57-6.10]; P < 0.001); plasma cells (OR 6.61 [95%CI, 1.51-28.8]; P=0.01), intraepithelial TILS (OR: 10.34 [95%CI, 2.22-48.01]; P =0.003), homogeneous high infiltrate (OR: 13.6 [95%CI, 3.04-60.77]; P =0.001). In luminal tumors, TILs over 20% predicted pCR (OR 12.3 [95%CI, 4.0-37.7]; P < 0.001) as well as in TNBC (OR 4.32 [95%CI, 1.77-10.53]; P=0 .001) but not in those cases with HER2 positive tumors (luminalB HER2 + HER2) (OR 1.65 [95%CI, 0.88-3.07]; P=0.118). In the multivariate analyses, levels of TILs > 20% were associated with higher pCR rates (adjusted odds ratio, 2.44 [95%CI, 1.48-4.01]; P < .001). Conclusions: The presence of TILs over 20% at diagnosis is an independent, positive, predictive marker of pCR in early breast cancer treated with neoadjuvant chemotherapy. Interestingly, the predictive information added by TILs >20% was higher in luminal and triple negative tumors compared to HER2 positive cases. Careful morphological characterization of TILS may add valuable predictive information and can be done in current pathologic laboratories with a well-trained breast cancer pathologist.

Abstract P1-09-05: Baseline dietary patterns among women with newly diagnosed early-stage breast cancer enrolled in the Optimal Living Program

Abstract Background: Evidence-based recommendations support a dietary pattern rich in whole grains, fruits, and vegetables with limited consumption of added sugars to improve cancer risk and mortality. The Optimal Living Program (OLP) is a prospective multiparametric lifestyle intervention that engages early-stage breast cancer patients at the time of diagnosis in risk-stratified, personalized lifestyle management. Here, we report baseline dietary patterns among women enrolled in the OLP. Methods: Upon enrollment, patients complete a questionnaire that incorporates the National Cancer Institute (NCI) Dietary Screener Questionnaire (DSQ), which queries the consumption frequency of 26 food items over the past month. Based on standard NCI DSQ scoring procedures, we calculated total daily serving equivalents of all food items within a dietary factor group. This included: 1) total daily cup equivalents of fruit and vegetables from fruit, fruit juice, salad, potatoes, beans, other vegetables, tomato sauce, salsa, and pizza, 2) total daily ounce equivalents per day of whole grains from cereal, whole grain bread, popcorn, and whole grain rice, and 3) total daily teaspoon (tsp) equivalents of added sugars from cookies/cake/pie, doughnuts, ice cream, candy, cereals, and sugar-sweetened beverages including soda, fruit drinks, and sugar/honey in coffee/tea. Results: There were 100 patients enrolled in the OLP for whom baseline DSQ data were available. The median age at diagnosis was 58 and median BMI was 27.4 mg/m2. 69 patients were white (69.0%), 14 were Black (14.0%), and 7 were Asian (7.0%). 62 patients had stage I disease (62.0%), 22 patients had stage II disease (22.0%), and 15 patients had ductal carcinoma in situ (15.0%). 74 patients had hormone receptor-positive disease (74.0%), 3 had HER2-positive disease (3.0%), and 7 had triple-negative disease (7.0%). Daily frequency of consumption of dietary factor groups are shown in Table 1. Only 29 patients (29.0%) met the current dietary guideline of 4-5 cup equivalents of fruits and vegetables per day and no patients (0%) met the guideline of more than 3 ounce equivalents of whole grains per day. Added sugar intake ranged from 0 to 4.8 teaspoon equivalents per day. Conclusion: Most women in this cohort with newly diagnosed early-stage breast cancer did not consume the recommended daily intake of fruits, vegetables, and whole grains per the 2020-2025 Dietary Guidelines and the American Institute for Cancer Research. Our findings identify these dietary factors as important targets of intervention with personalized dietary guidance at the time of breast cancer diagnosis. Table 1.<1/day1 - 2/day2 - 3/day3 – 4/day>4/dayFruits and vegetables (cup equivalents)6 (6.0%)23 (23.0%)28 (28.0%)14 (14.0%)29 (29.0%)Whole grains (ounce equivalents)63 (63.0%)29 (29.0%)8 (8.0%)0 (0%)0 (0%)Added sugar (tsp equivalents)32 (32.0%)35 (35.0%)22 (22.0%)6 (6.0%)5 (5.0%)Sugar-sweetened beverages (tsp equivalents)62 (62.0%)21 (21.0%)15 (15.0%)2 (2.0%)0 (0%) Citation Format: Sherry Shen, Johnny Allsop, Erica Salehi, Cara Anselmo, Stacie Corcoran, Jill Clayton, Andrea Smith, Melissa Emerzian, Mark Robson, Neil Iyengar. Baseline dietary patterns among women with newly diagnosed early-stage breast cancer enrolled in the Optimal Living Program [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 P1-09-05.

Abstract ES1-2: Genomics of HER2+ breast cancer

Abstract Human epidermal growth factor receptor 2 (HER2) is amplified and overexpressed in about 20% ofall breast cancers and, when untreated, is the most aggressive breast cancer phenotype. The prognosis of patients with HER2-positive breast cancer has been markedly improved thanks to the effectiveness of anti-HER2 therapies. However, we still overtreat a high proportion of patients with toxic chemotherapy +antiHER2 combinations, while others still develop recurrent disease despite these complex regimens. Both the intrinsic complexity of HER2-positive tumors and the properties of its tumor microenvironment likely contribute to differences in response toanti-HER2 targeted therapies. HER2-positive breast cancer is highly heterogeneous, and all the intrinsic molecular subtypes can be identified within HER2-positive tumors by gene expression. HER2-enriched subtype has been systematically associated with higher pCR rates to anti-HER2 targeted therapies across multiple trials in early stages. Genomically, the HER2-enriched subtype is the most HER2 oncogene addicted of the subtypes, which likely explains the high sensitivity to anti-HER2 therapies. However, this may also explain why a HER2-enriched tumor with residual disease after anti-HER2 treatments carries a particularly poor prognosis. Conversely, both tumor-infiltrating lymphocytes (TILs) and RNA-based immune-signatures are significantly and independently associated with a higher likelihood of pCR and better survival outcomes in patients with HER2-positive disease. Thus, integrating the prognostic information provided by clinical factors, genomic subtype, and immune-related signatures is essential to improve the design of future clinical trials and establish new and better treatment algorithms for HER2-positive breast cancer treatment. Citation Format: C Perou. Genomics of HER2+ breast cancer. [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 ES1-2.

Abstract P2-13-07: Zanidatamab (ZW25), a HER2-targeted bispecific antibody, in combination with chemotherapy (chemo) for HER2-positive breast cancer (BC): Results from a phase 1 study

Abstract Background: Despite the availability of multiple HER2-targeted therapies, most patients (pts) with advanced HER2-positive BC experience disease progression, and an unmet medical need remains. Zanidatamab (zani) binds to HER2 across a range of expression levels and induces formation of receptor clusters, resulting in receptor internalization and downregulation that affect signal transduction. Zani potently activates antibody-dependent cellular cytotoxicity, antibody-dependent cellular phagocytosis, and complement-dependent cytotoxicity. In this ongoing phase 1 study (NCT02892123), data from BC pts treated with zani monotherapy have been previously reported. Here, we evaluated the safety and antitumor activity of zani in combination with chemo in HER2-positive BC pts. Methods: Pts with locally advanced and/or metastatic HER2-positive (immunohistochemistry [IHC] 3+ or IHC 2+/fluorescence in situ hybridization+) BC who received prior trastuzumab (tras), pertuzumab (pert), and T-DM1 were enrolled. Eligibility criteria included Eastern Cooperative Oncology Group performance status ≤1 and adequate organ function. Prior history of treated stable brain metastases was allowed. Zani (20 mg/kg Q2W or 30 mg/kg Q3W) was administered in combination with paclitaxel (pac), capecitabine (cap), or vinorelbine (vin). Zani + chemo was continued until disease progression or toxicity; if chemo was discontinued due to toxicity, zani treatment could be continued. Primary endpoints were safety and tolerability assessments; secondary efficacy endpoints included objective response rate (ORR) and disease control rate (DCR; complete response [CR] + partial response [PR] + stable disease [SD]) per RECIST v1.1, and progression-free survival (PFS). Clinical benefit rate (CBR) was defined as SD ≥24 weeks or best overall response of CR or PR. Results: As of 3 May 2021, 20 HER2-positive BC pts had enrolled (zani + pac, n=4; zani + cap, n=9; zani + vin, n=7). Ten pts were hormone receptor positive (data available for 19 pts), and 7 pts had a prior history of brain metastases. Median age was 53 years (range, 38-72), with median prior systemic therapies of 4.5 (range, 2-7) and median of 2 regimens in the metastatic setting. Pts received a median of 3 prior HER2 regimens; all pts received tras and T-DM1, 17 received pert, and 6 received tyrosine kinase inhibitors. In the 16 response evaluable (measurable disease and either post-baseline assessments or earlier death/progression) pts, confirmed ORR was 37.5% (with 1 additional response pending confirmation), CBR was 50%, and DCR was 81.3%. Median duration of response was not reached (range, 1.8+ to 16.8+ mo), with 4 of 6 confirmed responses ongoing. Among all pts (n=20), the most common (≥30% of pts) zani- and/or chemo-related adverse events (AEs) were diarrhea (65%), nausea (45%), peripheral neuropathy (35%), and fatigue (30%). One pt experienced grade 3 diarrhea leading to dose reduction of zani, and 1 pt discontinued zani due to AEs (abdominal pain and nausea, both grade ≤2). Four grade 4 AEs were observed in 4 (20%) pts: neutrophil count decreased (2 pts) and neutropenia (1 pt), all related to chemo, and hyponatremia (1 pt, not related to study treatment). Serious AEs were observed in 2 (10%) pts (pleural effusion, 1 pt; pneumonitis and upper respiratory tract infection, 1 pt), none related to zani. No grade 5 AEs were reported. Conclusions: Zani in combination with chemo is well tolerated, with encouraging and durable antitumor activity in heavily pretreated (including prior tras, pert, and T-DM1) pts with HER2-positive BC. These data support further investigation of zani as a novel therapeutic for these pts. The cap and vin cohorts continue to enroll, and additional cohorts are evaluating zani ± chemo in combination with tucatinib. Citation Format: Philippe L Bedard, Seock-Ah Im, Elena Elimova, Sun Young Rha, Rachel Goodwin, Cristiano Ferrario, Keun-Wook Lee, Diana Hanna, Funda Meric-Bernstam, Jose Mayordomo, Murali Beeram, Erika Hamilton, Jorge Chaves, Melody Cobleigh, Tony Mwatha, Joseph Woolery, Do-Youn Oh. Zanidatamab (ZW25), a HER2-targeted bispecific antibody, in combination with chemotherapy (chemo) for HER2-positive breast cancer (BC): Results from a phase 1 study [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 P2-13-07.

Abstract P2-13-06: Clinical implication of HER2 status change after neoadjuvant chemotherapy with Trastuzumab and Pertuzumab (HP) in patients with HER2-positive breast cancer

Abstract Background: Patients with early HER2-positive breast cancer (BC) and residual disease after HER2-targeted neoadjuvant chemotherapy (NAC) are at high risk of recurrence. It is estimated that 10-30% of HER2-positive breast cancers change HER2 status after trastuzumab alone, but the effects of adding pertuzumab on this phenomenon and clinical outcomes remain unclear. We previously reported a high rate (~50%) of HER2 status change after HP in a small subset of patients. Herein, we present an updated analysis incorporating pathological review of additional cases.Methods: We identified patients with HER2-positive BC who received NAC with pertuzumab and trastuzumab (NAC-HP) followed by surgery at our institution between September 1, 2013 to November 1, 2019. Patients with HER2 status performed either at MSKCC or outside institutions were included. Change in HER2 status on residual disease from baseline was evaluated. We defined HER2 positivity as immunohistochemistry (IHC) IHC3+ or IHC0-2+ FISH amplified (ratio ≥ 2 or ratio < 2 and HER2 copy number ≥ 6 signals/cell). HER2-low was defined as IHC 1+ or 2+, FISH non-amplified. Disease free survival (DFS) and overall survival (OS) were analyzed using the Kaplan-Meier method. Differences between patients with concordant and discordance HER2 status were assessed using the log-rank test.Results: Of 525 patients receiving NAC with HP, 229 (44%) patients had residual disease post NAC-HP. Among these 229 patients, 141 had both pre and post NAC-HP HER2 status available and were included in this analysis. HER2 status on biopsy specimens was determined at MSKCC in 35/141 (25%) and at external institution in 106/141 (75%). The majority of patients (84%) received dose-dense AC-THP; the remainder received TCHP or other HP-based regimens. Most (96%) of patients continued HP after surgery, and 2 patients received T-DM1. Of the 141 patients, 84/141(60%) were found to be HER2 concordant, while 57 (40%) were found to be HER2 discordant. In 13/57 (23%) patients, HER2 expression was lost (IHC 0), while in 44/57 (77%) patients, HER2-low profile was detected (IHC 1+ in 31, and IHC 2+, FISH non-amplified in 13). Further details are reported in the table. Patients with HER2 discordance after NAC-HP had similar survival outcome compared with patients who remained HER2 concordant (5-years DFS: 92.3% versus 88.7%, p=0.49 and 5-yr OS 93.6% versus 88.4%, p=0.70).Conclusions: In a single center cohort, discordant HER2 status after NAC-HP appeared frequently without statistically significant impact on survival outcome, although this finding may be due to the small size and hence low statistical power. Of these, HER2-low profile is the most frequent post treatment HER2 status change. This raises the possibility that patients with change in HER2 status may have heterogenous expression of HER2 at baseline, and HER2-loss or low sub-clones survive as residual disease due to the selection pressure of HP. Alternatively, anti-HER2 therapy may suppress HER2 expression in surviving cells. These findings could inform studies of tailored approaches in the post-neoadjuvant setting based on the biological profile of residual disease. Pre NAC-HP HER2 statusNPost NAC-HP HER2 statusNDiscordantN=57IHC 3+: 19IHC0: 4IHC1+: 9IHC2+ FISH not ampl: 6IHC 0-2+ FISH ampl: 38IHC0: 9IHC1+: 22IHC2+ FISH not ampl: 7Concordant N= 84IHC 3+: 59IHC 3+: 47IHC 0- 2+ FISH ampl: 12IHC 0-2+ FISH ampl: 25IHC 3+: 4IHC 0- 2+ FISH ampl: 21 Citation Format: Emanuela Ferraro, Anton Safonov, Hanna Y Wen, Edi Brogi, Mithat Gonan, Andrea V. Barrio, Pedram Razavi, Sarat Chandarlapaty, Shanu Modi, Andrew D. Seidman, Larry Norton, Mark E. Robson, Chau T. Dang. Clinical implication of HER2 status change after neoadjuvant chemotherapy with Trastuzumab and Pertuzumab (HP) in patients with HER2-positive breast cancer [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 P2-13-06.

Abstract P3-14-05: Racial/ethnic disparities in cancer mortality after a second breast cancer

Abstract Background: Eighteen percent of breast cancer survivors will develop a second cancer within 25 years of diagnosis, of which breast cancer is the most common type. We have previously reported a higher cancer mortality among survivors who had a second cancer compared to a first cancer. In this study, we examined whether the increased cancer mortality from a second breast cancer differs by race/ethnicity. Method: A prospective cohort study was conducted among breast cancer survivors who developed a second breast cancer using data collected from the Surveillance, Epidemiology, and End Results (SEER) 18 database between 2000 and 2016. Hazard ratio (HR) and 95% confidence interval (CI) for cancer mortality after second breast cancer were estimated from Cox proportional hazard regression, comparing Non-Hispanic Black (NHB), Non-Hispanic American Indian/Alaska Native (NHAIAN), Non-Hispanic Asian/Pacific Islander (NHAPI), and Hispanic women to Non-Hispanic White (NHW) women. Models were adjusted for age at diagnosis, year of diagnosis, tumor stage, tumor grade, estrogen receptor (ER) status, and treatments (surgery, radiotherapy, and chemotherapy) of the second breast cancer. Analyses were also stratified by second cancer ER status, tumor stage, age at diagnosis (<50, 50-75, and ≥75 years), and time since first breast cancer diagnosis (≤5 and >5 years). In a subgroup of women diagnosed of second cancer after 2010 (N=8,224), we also conducted the analysis stratified by breast cancer molecular subtype [luminal A, triple-negative, and human epidermal growth factor receptor 2 (HER2)-positive]. Results: There were 14,392 breast cancer survivors diagnosed with a second breast cancer, including 9,928 NHW, 1,975 NHB, 70 NHAIAN, 988 NHAPI, and 1,431 Hispanic during the study period. The median age at diagnosis of the second cancer ranged from 57 to 66 years and the median follow-up time from diagnosis to cancer death ranged from 52 to 62 months across racial and ethnic groups. Cancer mortality was increased among NHB (HR: 1.28, 95%CI: 1.15-1.43) and Hispanic survivors (HR: 1.17, 95%CI: 1.03-1.33) compared to NHW. There was no increased cancer mortality among NHAIAN (HR: 1.07, 95%CI: 0.61-1.90) and NHAPI survivors (HR: 0.94, 95%CI: 0.80-1.12). The increased cancer mortality in NHB was observed irrespective of second cancer ER status, tumor stage, age at diagnosis, and time since first breast cancer diagnosis. Increased cancer mortality in NHB was also observed for luminal A (HR: 1.26, 95%CI: 1.11-1.44) and triple-negative subtypes (HR: 1.42, 95%CI: 1.10-1.83), but not for HER2-positive (HR: 1.19, 95%CI: 0.88-1.60) disease. For Hispanic patients, increased cancer mortality was observed in women with ER-positive disease, regional stage disease, cancer diagnosed <50 years of age, and cancer developed after 5 years. Conclusion: Racial/ethnic disparities in cancer mortality are present even among NHB and Hispanic breast cancer survivors who developed a second breast cancer. Studies are needed to understand the drivers of these disparities and to test preventive strategies to mitigate them. Citation Format: Zhengyi Deng, Miranda R Jones, Mei-Cheng Wang, Kala Visvanathan. Racial/ethnic disparities in cancer mortality after a second breast cancer [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 P3-14-05.

Abstract P1-12-01: Dose-dense sequential adjuvant chemotherapy in the trastuzumab era: Final long-term results of the hellenic cooperative oncology group phase III HE10/05 trial

Abstract Background: Dose-dense sequential chemotherapy based on anthracyclines and taxanes has achieved an 18% reduction of recurrence risk in the adjuvant setting of early breast cancer (BC). However, the optimal chemotherapy schedule and the preferable interval between cycles are still under investigation. Methods: A total of 990 eligible BC patients were randomized to receive either 3 cycles of epirubicin (E,110 mg/m2) every 2 weeks followed by 3 cycles of paclitaxel (T, 200 mg/m2) every 2 weeks followed by 3 cycles of intensified CMF (Control Arm A, E-T-CMF; 333 patients) or three cycles of epirubicin followed by 3 cycles of CMF followed by 9 consecutive weekly cycles of docetaxel (wD) 35 mg/m2 (Experimental Arm B, E-CMF-wD; 331) or 9 consecutive weekly cycles of paclitaxel (wT) 80 mg/m2 (Experimental Arm C, E-CMF-wT; 326). Trastuzumab was administered for HER2-positive disease. The primary endpoint was disease-free survival (DFS). Results: At a median follow-up of 13.3 years, 330 DFS events (33.3%) had been reported. DFS and overall survival (OS) did not differ between patients in the combined B and C arms versus control arm A either in the entire cohort (HR=0.90, p=0.38 and HR=0.85, p=0.20) or among HER2-positive, trastuzumab-treated patients (HR=0.69, p=0.13 and HR=0.67, p=0.13). Thirty-four patients (3.4%) developed secondary neoplasms. Conclusions: Overall, no significant differences in DFS or OS were found amongst the studied regimens after a long-term observational period. Trial registration: Australian New Zealand Clinical Trials Registry ACTRN12610000151033 Citation Format: Flora Zagouri, Georgia-Angeliki Koliou, Foteinos Dimitrakopoulos, Christos Papadimitriou, Ioannis Binas, Angelos Koutras, Pavlos Papakostas, Christos Markopoulos, Vasileios Venizelos, Grigorios Xepapadakis, Charisios Karanikiotis, Amanda Psyrri, Dimitrios Bafaloukos, Paris Kosmidis, Gerasimos Aravantinos, Eleni Res, Davide Mauri, Anna Koumarianou, Kalliopi Petraki, Anna Tsipoura, Dimitrios Pectasides, Helen Gogas, George Fountzilas. Dose-dense sequential adjuvant chemotherapy in the trastuzumab era: Final long-term results of the hellenic cooperative oncology group phase III HE10/05 trial [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 P1-12-01.

Clinical features, treatment, and prognosis of 16 breast cancer patients with ocular metastases.

The incidence of ocular metastases in patients with disseminated breast cancer is increasing. This study aimed to investigate the clinical features, treatment, and prognosis of breast cancer patients with ocular metastases. For this purpose, a total of 16 patients were diagnosed with ocular metastases. Demographic, treatment, and other clinical data were obtained from patients' charts. The estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor-2 (HER2) statuses of the patients were obtained from the histopathologic reports. Demographic features were analyzed through descriptive statistics, and the Kaplan-Meier method was used for survival analysis. The results showed that among the 16 patients (median age: 41 years), 10 had ER-positive, 8 had PR-positive, and 3 had HER2-positive disease. The choroid was the most commonly involved structure (n = 8). Nine (56%) patients had blurred vision. Treatments for these patients included systemic therapy (six patients), radiotherapy (three patients), and combined therapy (seven patients). The median time from the diagnosis of breast cancer to the diagnosis of ocular metastasis was 52.9 months, and the median time from the diagnosis of metastatic breast cancer at any other site to the diagnosis of ocular metastasis was 21.3 months. The median overall survival (OS) was 136.5 months (95% confidence interval, 40.6-232.4 months), and the median survival duration after ocular metastasis was 32.4 months (95% confidence interval, 20.1-44.7 months). The OS of patients with unilateral eye involvement and bilateral eye involvement did not differ significantly (P = 0.573), nor did the OS of those diagnosed before 2000 and in 2000 or later (P = 0.409). In general, a breast cancer patient with ocular metastasis can have a good prognosis after therapy. However, large-scale clinical studies are needed to confirm our findings.