Lobular Neoplasia Diagnosed by MRI-Guided Breast Biopsy: Identifying Upgrade Rate to Malignancy and Outcomes of Clinical and Surgical Management

OBJECTIVE

The aim of this study was to determine surgical and clinical outcomes of lobular neoplasia (LN) diagnosed by magnetic resonance imaging (MRI) biopsy, including upgrade to malignancy, and to assess for characteristics associated with upgrade.

METHOD

A single-institution retrospective study, between 2013 and 2022, of patients with histopathological findings of LN via MRI-guided biopsy was performed using an institutional database and review of the electronic medical records. Decision for excision or surveillance was made by a multidisciplinary team per institutional practice. Patient demographics and imaging characteristics were summarized using descriptive analyses. Upgrade was defined as upgrade to cancer on surgical pathology for patients treated with excision or the development of cancer at the biopsy site during surveillance. The Wilcoxon rank-sum test and Fisher's exact test were used to compare features of the upgraded cohort with the remainder of the group.

RESULTS

Ninety-four MRI biopsies diagnosing LN were included. Median age was 57 years (range 37-78 years). Forty-six lesions underwent excision while 48 lesions were surveilled. The upgrade rate was 7.4% (7/94). Upgrades in the excised cohort consisted of pleomorphic lobular carcinoma in situ (LCIS; n = 1), ductal carcinoma in situ (DCIS; n = 3) and invasive lobular carcinoma (ILC; n = 2), while one interval development of DCIS was observed at the site of biopsy in the surveillance cohort. No MRI or patient variables were associated with upgrade.

CONCLUSIONS

In this contemporary cohort of MRI-detected LNs, the upgrade rate was low. Omission of surgery for MRI-detected LNs in carefully selected patients may be considered in a shared decision-making capacity between the patient and the treatment team. Larger cohorts are needed to determine factors predictive of upgrade risk.

Germline Testing in Patients With Breast Cancer: ASCO-Society of Surgical Oncology Guideline

PURPOSE

To develop recommendations for germline mutation testing for patients with breast cancer.

METHODS

An ASCO-Society of Surgical Oncology (SSO) panel convened to develop recommendations based on a systematic review and formal consensus process.

RESULTS

Forty-seven articles met eligibility criteria for the germline mutation testing recommendations; 18 for the genetic counseling recommendations.

RECOMMENDATIONS

BRCA1/2 mutation testing should be offered to all newly diagnosed patients with breast cancer ≤65 years and select patients >65 years based on personal history, family history, ancestry, or eligibility for poly(ADP-ribose) polymerase (PARP) inhibitor therapy. All patients with recurrent breast cancer who are candidates for PARP inhibitor therapy should be offered BRCA1/2 testing, regardless of family history. BRCA1/2 testing should be offered to women who develop a second primary cancer in the ipsilateral or contralateral breast. For patients with prior history of breast cancer and without active disease, testing should be offered to patients diagnosed ≤65 years and selectively in patients diagnosed after 65 years, if it will inform personal and family risk. Testing for high-penetrance cancer susceptibility genes beyond BRCA1/2 should be offered to those with supportive family histories; testing for moderate-penetrance genes may be offered if necessary to inform personal and family cancer risk. Patients should be provided enough pretest information for informed consent; those with pathogenic variants should receive individualized post-test counseling. Variants of uncertain significance should not impact management, and patients with such variants should be followed for reclassification. Referral to providers experienced in clinical cancer genetics may help facilitate patient selection and interpretation of expanded testing, and provide counseling of individuals without pathogenic germline variants but with significant family history.Additional information is available at www.asco.org/breast-cancer-guidelines.

Discordance of Oncotype DX scores in synchronous bilateral and unilateral multifocal breast cancers

PURPOSE

Oncotype DX, a 21-gene expression profiling test, has become standard of care in the management of estrogen receptor (ER)-positive breast cancer. In multifocal tumors, it is unclear whether testing of the different foci is necessary. We evaluated the concordance of Oncotype DX recurrence scores (RS) between 2 tumor foci in synchronous bilateral or unilateral multifocal tumors and characterized pathological predictors of discordance.

METHODS

We reviewed 713 ER+, HER2- primary invasive breast cancer patients with Oncotype RS and identified 17 bilateral synchronous patients (34 tumors) and 13 unilateral multifocal patients (26 tumors) with available Oncotype RS on all foci. Discordance in Oncotype RS between synchronous tumors was recorded and associations with clinicopathologic features including tumor size, histology, Nottingham histologic grade, progesterone receptor staining, and Ki67 index were analyzed.

RESULTS

Bilateral synchronous tumors were present in older patients (median age 59 years) and had larger tumor (median size 17 mm) and more discordant histology (10/17, 59%) as compared to unilateral multifocal tumors (median age 49 years, p < 0.01; median tumor size 12 mm, p = 0.01; discordant histology 2/13, 15%, p = 0.03). Oncotype RS were discordant in 47% (8/17) of bilateral and 54% (7/13) of unilateral multifocal tumors. Concordant Oncotype RS was associated with similar histologic grade and Ki67 index in 78% (7/9) of bilateral and 100% (6/6) of multifocal tumors. In contrast, only 25% (2/8) of bilateral (p = 0.06) and 14% (1/7) of unilateral multifocal (p < 0.01) cases with discordant Oncotype RS had concordant histology grades and Ki67 levels. In synchronous tumors with discordant Oncotype RS and Ki67 index, all (4/4) foci with higher RS had higher Ki67 index.

CONCLUSION

Discordance of Oncotype RS is common in both bilateral and unilateral multifocal breast cancer and is likely associated with discordant histologic grade or Ki67.

Association of Medicaid Expansion with Reduction in Racial Disparities in the Timely Delivery of up-front Surgical Care for Patients with Early-Stage Breast Cancer

OBJECTIVE

We evaluated the association between Medicaid expansion and time to surgery among patients with early-stage breast cancer (BC).

SUMMARY BACKGROUND DATA

Delays in surgery are associated to adverse outcomes. It is known that underrepresented minorities are more likely to experience treatment delays. Understanding the impact of Medicaid expansion on reducing racial and ethnic disparities in healthcare delivery is critical.

METHODS

This was a population-based study including women ages 40-64 with stage I-II BC who underwent upfront surgery identified in the National Cancer Database (2010-2017) residing in states that expanded Medicaid on January 1, 2014. Difference-in-difference (DID) analysis compared rates of delayed surgery (>90 d from pathological diagnosis) according to time period (pre-expansion [2010-2013] and post-expansion [2014-2017]) and race/ethnicity (White vs. racial and ethnic minority), stratified by insurance type (private vs. Medicaid/uninsured). Secondary analyses included logistic and Cox proportional hazards regression. All analyses were conducted among a cohort of patients in the non-expansion states as a falsification analysis. Finally, a triple-differences approach compared pre-expansion with the post-expansion trend between expansion and non-expansion states.

RESULTS

Among Medicaid expansion states, 104,569 patients were included (50,048 pre- and 54,521 post-expansion). In the Medicaid/uninsured subgroup, Medicaid expansion was associated with a -1.8% point (95% CI -3.5% to -0.1, P =0.04) reduction of racial disparity in delayed surgery. Cox regression models demonstrated similar findings (adjusted DID hazard ratio 1.12 [95% CI 1.05-1.21]). The falsification analysis showed significant racial disparity reduction among expansion states but not among non-expansion states, resulting in a triple-difference estimate of -2.5% points (95% CI -4.9% to -0.1%, P =0.04) in this subgroup.

CONCLUSIONS

As continued efforts are being made to increase access to healthcare, our study demonstrates a positive association between Medicaid expansion and a reduction in the delivery of upfront surgical care, reducing racial disparities among patients with early-stage BC.

To Dissect or Not to Dissect: Can We Predict the Presence of Four or More Axillary Lymph Node Metastases in Postmenopausal Women with Clinically Node-Negative Breast Cancer?

BACKGROUND

Axillary lymph node (ALN) involvement is important for prognosis and guidance of multidisciplinary treatment of breast cancer patients. This study sought to identify preoperative clinicopathologic factors predictive of four or more pathologically positive ALNs in patients with cN0 disease and to develop a predictive nomogram to inform therapy recommendations.

METHODS

Using an institutional prospective database, the study identified postmenopausal women with cN0 invasive breast cancer undergoing upfront sentinel lymph node biopsy (SLNB) with or without completion ALND (cALND) between 1993 and 2007. Logistic regression analyses identified factors predictive of four or more positive nodes in the cN0 population and patients with one, two, or more SLNs.

RESULTS

The study identified 2532 postmenopausal women, 615 (24.3%) of whom underwent cALND. In the univariate analysis, tumor size, lymphovascular (LVI), histology, estrogen receptor (ER)-positive status, and multifocality/multicentricity were predictive of four or more positive nodes (n = 63; p < 0.05), and all except ER status were significant in the multivariate analysis. Of the 2532 patients, 1263 (49.2%) had hormone receptor (HR)-positive, human epidermal growth factor receptor 2 (HER2)-negative disease, and 30 (2.4%) were found to have four or more positive nodes. Of the 130 patients with exactly one positive SLN who underwent cALND (n = 130, 5.4%), 7 had four or more positive nodes, with grade as the only predictive factor (p = 0.01). Of the 33 patients with two or more positive SLNs who underwent cALND, 9 (27.3%) had four or more positive nodes after cALND, but no factors were predictive in this subset.

CONCLUSION

Postmenopausal women with early-stage cN0 HR-positive, HER2-negative breast cancer with a single positive SLN had a very low risk (5%) of having four or more positive nodes on final pathology. With such a low risk of N2 disease, limited staging with SLNB may be sufficient to guide therapy decisions for this subset of patients.

Clinical outcome and therapeutic impact on neuroendocrine neoplasms of the breast: a national cancer database study

PURPOSE

Neuroendocrine neoplasms (NENs) of the breast are rare and not well-studied. NEN are subcategorized as well-differentiated neuroendocrine tumor (NET) and poorly differentiated neuroendocrine carcinoma (NEC). The objectives of the current study were to review the clinicopathologic features of NENs, therapeutic efficacy of current systemic therapy and clinical outcomes of NEN of the breast.

METHODS

Between 2004 and 2015, 420 NET, 205 NEC, 146 Adenocarcinoma with NE differentiation (ACNED) and 1,479,520 of invasive carcinoma, not otherwise specified (IC-NOS) of the breast were identified in the National Caner Database. Overall survival was compared among groups using Kaplan-Meier method and Log-rank test. Multivariate analyses were performed to identify prognostic factors.

RESULTS

After adjusting for other prognostic factors, both NET and NEC of the breast showed significantly worse OS than IC-NOS (HR (95% CI) = 1.41 (1.17, 1.72), p = 0.005 and HR (95% CI) = 2.11 (1.67, 2.67), p < 0.001, respectively). Both NET and NEC benefited from endocrine therapy if the tumors were hormonal receptor positive (median OS for treated with vs without: 125 vs 57 months in NET, not reached vs 29 months in NEC). NEC also benefited from chemotherapy (median OS for treated with vs without: 42 vs 34 months), but not NET.

CONCLUSION

NEN is a unique pathologic and clinical entity, which has worse clinical outcome compared to IC-NOS of the breast. Current therapeutics used in the treatment of IC-NOS improve, but do not fully mitigate, the poorer prognosis of NEN patients. More effective therapy for patients with this unique tumor type are needed.

Endocrine Therapy Synergizes with SMAC Mimetics to Potentiate Antigen Presentation and Tumor Regression in Hormone Receptor-Positive Breast Cancer

Immunotherapies have yet to demonstrate significant efficacy in the treatment of hormone receptor-positive (HR+) breast cancer. Given that endocrine therapy (ET) is the primary approach for treating HR+ breast cancer, we investigated the effects of ET on the tumor immune microenvironment (TME) in HR+ breast cancer. Spatial proteomics of primary HR+ breast cancer samples obtained at baseline and after ET from patients enrolled in a neoadjuvant clinical trial (NCT02764541) indicated that ET upregulated β2-microglobulin and influenced the TME in a manner that promotes enhanced immunogenicity. To gain a deeper understanding of the underlying mechanisms, the intrinsic effects of ET on cancer cells were explored, which revealed that ET plays a crucial role in facilitating the chromatin binding of RelA, a key component of the NF-κB complex. Consequently, heightened NF-κB signaling enhanced the response to interferon-gamma, leading to the upregulation of β2-microglobulin and other antigen presentation-related genes. Further, modulation of NF-κB signaling using a SMAC mimetic in conjunction with ET augmented T-cell migration and enhanced MHC-I-specific T-cell-mediated cytotoxicity. Remarkably, the combination of ET and SMAC mimetics, which also blocks prosurvival effects of NF-κB signaling through the degradation of inhibitors of apoptosis proteins, elicited tumor regression through cell autonomous mechanisms, providing additional support for their combined use in HR+ breast cancer.

SIGNIFICANCE

Adding SMAC mimetics to endocrine therapy enhances tumor regression in a cell autonomous manner while increasing tumor immunogenicity, indicating that this combination could be an effective treatment for HR+ patients with breast cancer.

Chimeric RNAs reveal putative neoantigen peptides for developing tumor vaccines for breast cancer

Introduction

We present here a strategy to identify immunogenic neoantigen candidates from unique amino acid sequences at the junctions of fusion proteins which can serve as targets in the development of tumor vaccines for the treatment of breastcancer.

Method

We mined the sequence reads of breast tumor tissue that are usually discarded as discordant paired-end reads and discovered cancer specific fusion transcripts using tissue from cancer free controls as reference. Binding affinity predictions of novel peptide sequences crossing the fusion junction were analyzed by the MHC Class I binding predictor, MHCnuggets. CD8+ T cell responses against the 15 peptides were assessed through in vitro Enzyme Linked Immunospot (ELISpot).

Results

We uncovered 20 novel fusion transcripts from 75 breast tumors of 3 subtypes: TNBC, HER2+, and HR+. Of these, the NSFP1-LRRC37A2 fusion transcript was selected for further study. The 3833 bp chimeric RNA predicted by the consensus fusion junction sequence is consistent with a read-through transcription of the 5'-gene NSFP1-Pseudo gene NSFP1 (NSFtruncation at exon 12/13) followed by trans-splicing to connect withLRRC37A2 located immediately 3' through exon 1/2. A total of 15 different 8-mer neoantigen peptides discovered from the NSFP1 and LRRC37A2 truncations were predicted to bind to a total of 35 unique MHC class I alleles with a binding affinity of IC50<500nM.); 1 of which elicited a robust immune response.

Conclusion

Our data provides a framework to identify immunogenic neoantigen candidates from fusion transcripts and suggests a potential vaccine strategy to target the immunogenic neopeptides in patients with tumors carrying the NSFP1-LRRC37A2 fusion.

Isolated Flat Epithelial Atypia: Upgrade Outcomes After Multidisciplinary Review-Based Management Using Excision or Imaging Surveillance

Objective

To compare flat epithelial atypia (FEA) upgrade rates after excision versus surveillance and to identify variables associated with upgrade.

Methods

This single-institution retrospective study identified isolated FEA cases determined by percutaneous biopsy from April 2005 through July 2022 with excision or ≥2 years surveillance. All cases were recommended for excision or surveillance based on multidisciplinary discussion of clinical, imaging, and pathologic variables with emphasis on sampling adequacy and significant atypia. Truth was determined by pathology at excision or the absence of cancer on surveillance. Upgrade was defined as cancer occurring ≤2 cm from the biopsy site. Demographic, imaging, and biopsy variables were compared between those that did and did not upgrade.

Results

Among 112 cases of isolated FEA, imaging findings included calcifications in 81.3% (91/112), MRI lesions in 11.6% (13/112), and distortions or masses in 7.1% (8/112). Excision was recommended in 12.5% (14/112) and surveillance in 87.5% (98/112) of cases. Among those recommended for excision, 28.6% (4/14) of cases were upgraded, all to ductal carcinoma in situ. In those recommended for surveillance, 1.0% (1/98) were upgraded to invasive cancer. Overall, FEA had a 4.5% (5/112) upgrade rate, and 2.7% (3/112) also developed cancer >2 cm from the FEA. There were no significant differences in demographic, imaging, and biopsy variables between those that did and did not upgrade to cancer.

Conclusion

Multidisciplinary management of isolated FEA distinguishes those at higher risk of upgrade to cancer (28.6%) in whom surgery is warranted from those at low risk of upgrade (1.0%) who can be managed non-operatively.

Radiomic and deep learning characterization of breast parenchyma on full field digital mammograms and specimen radiographs: a pilot study of a potential cancer field effect

Purpose

In women with biopsy-proven breast cancer, histologically normal areas of the parenchyma have shown molecular similarity to the tumor, supporting a potential cancer field effect. The purpose of this work was to investigate relationships of human-engineered radiomic and deep learning features between regions across the breast in mammographic parenchymal patterns and specimen radiographs.

Approach

This study included mammograms from 74 patients with at least 1 identified malignant tumor, of whom 32 also possessed intraoperative radiographs of mastectomy specimens. Mammograms were acquired with a Hologic system and specimen radiographs were acquired with a Fujifilm imaging system. All images were retrospectively collected under an Institutional Review Board-approved protocol. Regions of interest (ROI) of 128×128  pixels were selected from three regions: within the identified tumor, near to the tumor, and far from the tumor. Radiographic texture analysis was used to extract 45 radiomic features and transfer learning was used to extract 20 deep learning features in each region. Kendall's Tau-b and Pearson correlation tests were performed to assess relationships between features in each region.

Results

Statistically significant correlations in select subgroups of features with tumor, near to the tumor, and far from the tumor ROI regions were identified in both mammograms and specimen radiographs. Intensity-based features were found to show significant correlations with ROI regions across both modalities.

Conclusions

Results support our hypothesis of a potential cancer field effect, accessible radiographically, across tumor and non-tumor regions, thus indicating the potential for computerized analysis of mammographic parenchymal patterns to predict breast cancer risk.

Phase II Trial of Nelipepimut-S Peptide Vaccine in Women with Ductal Carcinoma In Situ

NeuVax is a vaccine comprised of the HER2-derived MHC class I peptide E75 (nelipepimut-S, NPS) combined with GM-CSF. We completed a randomized trial of preoperative vaccination with NeuVax versus GM-CSF alone in patients with ductal carcinoma in situ (DCIS). The primary objective was to evaluate for NPS-specific cytotoxic T lymphocyte (CTL) responses. Patients with human leukocyte antigen (HLA)-A2-positive DCIS were enrolled and randomized 2:1 to NeuVax versus GM-CSF alone and received two inoculations prior to surgery. The number of NPS-specific CTL was measured pre-vaccination, at surgery, and 1 and 3 to 6 months post-operation by dextramer assay. Differences in CTL responses between groups and between pre-vaccination and 1-month post-operation were analyzed using a two-sample t test or Wilcoxon rank sum test. The incidence and severity of adverse events were compared between groups. Overall, 45 patients were registered; 20 patients were HLA-A2 negative, 7 declined participation, 1 withdrew, and 4 failed screening for other reasons. The remaining 13 were randomized to NeuVax (n = 9) or GM-CSF alone (n = 4). Vaccination was well-tolerated with similar treatment-related toxicity between groups with the majority (>89%) of adverse events being grade 1. The percentage of NPS-specific CTLs increased in both arms between baseline (pre-vaccination) and 1-month post-operation. The increase was numerically greater in the NPS+GM-CSF arm, but the difference was not statistically significant. NPS+GM-CSF is safe and well-tolerated when given preoperatively to patients with DCIS. In patients with HLA-A2-positive DCIS, two inoculations with NPS+GM-CSF can induce in vivo immunity and a continued antigen-specific T-cell response 1-month postsurgery.

PREVENTION RELEVANCE

This trial showed that vaccination of patients with HLA-A2-positive DCIS with NeuVax in the preoperative setting can induce a sustained antigen-specific T-cell response. This provides proof of principle that vaccination in the preoperative or adjuvant setting may stimulate an adaptive immune response that could potentially prevent disease recurrence.

Efficacy of Alternative Dose Regimens of Exemestane in Postmenopausal Women With Stage 0 to II Estrogen Receptor-Positive Breast Cancer: A Randomized Clinical Trial

Importance

Successful therapeutic cancer prevention requires definition of the minimal effective dose. Aromatase inhibitors decrease breast cancer incidence in high-risk women, but use in prevention and compliance in adjuvant settings are hampered by adverse events.

Objective

To compare the noninferiority percentage change of estradiol in postmenopausal women with estrogen receptor-positive breast cancer given exemestane, 25 mg, 3 times weekly or once weekly vs a standard daily dose with a noninferiority margin of -6%.

Design, Setting, and Participants

This multicenter, presurgical, double-blind phase 2b randomized clinical trial evaluated 2 alternative dosing schedules of exemestane. Postmenopausal women with estrogen receptor-positive breast cancer who were candidates for breast surgery were screened from February 1, 2017, to August 31, 2019. Blood samples were collected at baseline and final visit; tissue biomarker changes were assessed from diagnostic biopsy and surgical specimen. Biomarkers were measured in different laboratories between April 2020 and December 2021.

Interventions

Exemestane, 25 mg, once daily, 3 times weekly, or once weekly for 4 to 6 weeks before surgery.

Main Outcomes and Measures

Serum estradiol concentrations were measured by solid-phase extraction followed by liquid chromatography-tandem mass spectrometry detection. Toxic effects were evaluated using the National Cancer Institute terminology criteria, and Ki-67 was assessed by immunohistochemistry.

Results

A total of 180 women were randomized into 1 of the 3 arms; median (IQR) age was 66 (60-71) years, 63 (60-69) years, and 65 (61-70) years in the once-daily, 3-times-weekly, and once-weekly arms, respectively. In the intention-to-treat population (n = 171), the least square mean percentage change of serum estradiol was -89%, -85%, and -60% for exemestane once daily (n = 55), 3 times weekly (n = 56), and once weekly (n = 60), respectively. The difference in estradiol percentage change between the once-daily and 3-times-weekly arms was -3.6% (P for noninferiority = .37), whereas in compliant participants (n = 153), it was 2.0% (97.5% lower confidence limit, -5.6%; P for noninferiority = .02). Among secondary end points, Ki-67 and progesterone receptor were reduced in all arms, with median absolute percentage changes of -7.5%, -5.0%, and -4.0% for Ki-67 in the once-daily, 3-times-weekly, and once-weekly arms, respectively (once daily vs 3 times weekly, P = .31; once daily vs once weekly, P = .06), and -17.0%, -9.0%, and -7.0% for progesterone receptor, respectively. Sex hormone-binding globulin and high-density lipoprotein cholesterol had a better profile among participants in the 3-times-weekly arm compared with once-daily arm. Adverse events were similar in all arms.

Conclusions and Relevance

In this randomized clinical trial, exemestane, 25 mg, given 3 times weekly in compliant patients was noninferior to the once-daily dosage in decreasing serum estradiol. This new schedule should be further studied in prevention studies and in women who do not tolerate the daily dose in the adjuvant setting.

Trial Registration

ClinicalTrials.gov Identifier: NCT02598557; EudraCT: 2015-005063-16.

Current Trends in the Utilization of Preoperative Breast Magnetic Resonance Imaging Among Women With Newly Diagnosed Breast Cancer

PURPOSE

The clinical benefit of preoperative breast magnetic resonance imaging (MRI) for early-stage breast cancer (BC) remains controversial. We examined trends and the associated factors of preoperative breast MRI use.

METHODS

This study cohort, constructed from Optum Clinformatics database, included women with early-stage BC who had a cancer surgery between March 1, 2008, and December 31, 2020. Preoperative breast MRI was performed between the date of BC diagnosis and index surgery. Multivariable logistic regressions, one for elderly (65 years and older) and the other for non-elderly patients (younger than 65 years), were performed to examine factors associated with the use of preoperative MRI.

RESULTS

Among 92,077 women with early-stage BC, the crude rate of preoperative breast MRI increased from 48% in 2008 to 60% in 2020 for nonelderly and from 27% to 34% for elderly women. For both age groups, non-Hispanic Blacks were less likely (odds ratio [OR]; 95% CI, younger than 65 years: 0.75, 0.70 to 0.81; 65 years and older: 0.77, 0.72 to 0.83) to receive preoperative MRI than non-Hispanic White patients. Across Census divisions, the highest adjusted rate was observed in Mountain division (OR compared with New England; 95% CI, younger than 65 years: 1.45, 1.27 to 1.65; 65 years and older: 2.42, 2.16 to 2.72). Other factors included younger age, fewer comorbidities, family history of BC, axillary node involvement, and neoadjuvant chemotherapy for both age groups.

CONCLUSION

The use of preoperative breast MRI has steadily increased. Aside from clinical factors, age, race/ethnicity, and geographic location were associated with preoperative MRI use. This information is important for future implementation or deimplementation strategies of preoperative MRI.

Abstract 5262: Avasimibe abolishes the breast cancer preventative efficacy of statin in a spontaneous mouse model of breast cancer

Background: The cholesterol biosynthesis pathway plays a central role in the normal cellular development and carcinogenesis. Relevant to breast cancer prevention, the breast epithelium in women with atypical hyperplasia has been shown to have increased in cholesterol levels and oxidative products of cholesterol. Additionally, cholesterol pathway genes such as HMGCR and HMGCS1 are known to be upregulated during progression of breast cancer in patients. We have previously shown in SV40C3TAg mice that the cholesterol lowering drug-fluvastatin reduces breast tumor incidence and burden by 50% and have noted that the efficacy of statin is reduced due to the tight regulation of the cholesterol biosynthesis pathway through multiple restorative feedback loops, thus bypassing the effect of statin blockade.

Hypothesis: We hypothesize that fluvastatin efficacy can be improved by co-targeting the restorative feedback pathways that are involved in resistance to statins.

Methodology: RNA seq data from statin resistant MCF10.AT1-R cell clones was compared to the statin sensitive parental MCF10.AT1 cells in order to identify pathways and targets involved in statin resistance. Genes that were also found to be upregulated in the statin non-responders mice mammary tumors relative to responders mice were tested for dual targeting. Efficacy of avasimibe, an ACAT inhibitor, to sensitize MCF10.DCIS cells to statin therapy was studied by the colony formation assay. In vivo validation of the statin + avasimibe dual therapy was performed in SV40C3TAg mice that spontaneously develop triple negative breast cancer.

Results: We found ACAT1 and ACAT2 to be overexpressed in statin resistance cell clones and non-responder mouse breast tumors. ACATs are involved in cholesterol esterification that is required for storing cholesterol in lipid droplets. Cholesterol esterification in conjunction with cholesterol synthesis and export constitute key mechanisms involved in maintaining cholesterol homeostasis. Thus, we tested if avasimibe treatment potentiates the fluvastatin efficacy to inhibit colonizing ability. Avasimibe and fluvastatin combination completely abolished the ability of MCF10.DCIS cells to form colonies. Next, we tested the efficacy of combination treatment to prevent breast tumors in SV40C3TAg mice. The treatments started at the age of 6 weeks, prior to the onset of cancer and continued until 22 weeks of age. We found fluvastatin and avasimibe combination to be completely ineffective and 90% mice developed tumors. In addition, tumor burden was not reduced with dual treatment.

Conclusions: We postulate that avasimibe enhanced metabolism of fluvastatin in mouse system and thus completely abolishing the chemopreventive effects of statin. Genomically derived rationale drug combinations may result in unanticipated interactions and/or ancillary effects that limit efficacy in vivo/in patients.

Citation Format: Anjana Bhardwaj, Zhenlin Ju, Alexander Koh, Rhea Bhala, Jing Wang, Isabelle Bedrosian. Avasimibe abolishes the breast cancer preventative efficacy of statin in a spontaneous mouse model of breast cancer. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 5262.

Temporal Machine Learning Analysis of Prior Mammograms for Breast Cancer Risk Prediction

The identification of women at risk for sporadic breast cancer remains a clinical challenge. We hypothesize that the temporal analysis of annual screening mammograms, using a long short-term memory (LSTM) network, could accurately identify women at risk of future breast cancer. Women with an imaging abnormality, which had been biopsy-confirmed to be cancer or benign, who also had antecedent imaging available were included in this case-control study. Sequences of antecedent mammograms were retrospectively collected under HIPAA-approved guidelines. Radiomic and deep-learning-based features were extracted on regions of interest placed posterior to the nipple in antecedent images. These features were input to LSTM recurrent networks to classify whether the future lesion would be malignant or benign. Classification performance was assessed using all available antecedent time-points and using a single antecedent time-point in the task of lesion classification. Classifiers incorporating multiple time-points with LSTM, based either on deep-learning-extracted features or on radiomic features, tended to perform statistically better than chance, whereas those using only a single time-point failed to show improved performance compared to chance, as judged by area under the receiver operating characteristic curves (AUC: 0.63 ± 0.05, 0.65 ± 0.05, 0.52 ± 0.06 and 0.54 ± 0.06, respectively). Lastly, similar classification performance was observed when using features extracted from the affected versus the contralateral breast in predicting future unilateral malignancy (AUC: 0.63 ± 0.05 vs. 0.59 ± 0.06 for deep-learning-extracted features; 0.65 ± 0.05 vs. 0.62 ± 0.06 for radiomic features). The results of this study suggest that the incorporation of temporal information into radiomic analyses may improve the overall classification performance through LSTM, as demonstrated by the improved discrimination of future lesions as malignant or benign. Further, our data suggest that a potential field effect, changes in the breast extending beyond the lesion itself, is present in both the affected and contralateral breasts in antecedent imaging, and, thus, the evaluation of either breast might inform on the future risk of breast cancer.

Abstract 6521: Subtype-specific molecular signatures of field cancerization in patients with sporadic breast cancer

Background: We have previously shown the presence of molecular field cancerization in patients with sporadic breast cancer. Given the heterogeneity of breast cancer, we hypothesized that such field cancerization is likely to be subtype-specific.

Methods: RNA exome sequencing was performed on 360 samples obtained from 75 breast cancer patients undergoing mastectomy; 25 cases were selected from each subtype: hormone receptor (HR) positive, Her2 positive, triple negative (TN) breast cancer. Four sites were sampled from each patient: primary tumor (A), adjacent normal parenchyma within 2cm of the tumor (B), 2 separate, histologically normal sites at least 2cm away from the tumor (C &D) or, if available, tissue from the unaffected contralateral breast (E). Normal breast tissue (N) from cancer-free controls was obtained from reduction mammoplasty. Tumor-associated genes (TAGs) were identified by comparison of primary tumor to tissue from cancer free controls. We estimated tumor content that was shared across samples B-E by applying deconvolutional analysis to the tumor associated genes, to calculate indices that ranged from 0, indicating normal, to 1, indicating tumor. Molecular field-associated genes and pathways were identified by Spearman’s correlation coefficient analysis between the differential genes/pathways and ISTC.

Results: Across all subtypes, the proportion of tumor content present in the histologically normal breast tissue samples (samples B, C, D, E) obtained from cancer patients ranged from 80% in tissue adjacent to the tumor to approximately 50% in tissue obtained from the contralateral breast. We found over 600 deregulated genes to constitute the molecular field across all of the 3 major subtypes tested (Her2+, HR, and TNBC), of which approximately 20% were shared in the molecular field of all 3 subtypes of breast cancer. Among the 664 genes noted to be part of the molecular field in TNBC, 23.8% were unique to this subtype. In contrast, only 13% of the genes that constituted the field cancerization in the Her2 and HR+ subtypes were subtype-specific. PIP3-AKT, TCR signaling, and DNA synthesis were among the top pathways specifically activated in the molecular field of the Her2+ subtype of breast cancer. The molecular field of HR+ breast cancer was uniquely characterized by upregulation in the mitotic cell cycle, G1- S transition, and RB pathway. The field of cancerization in the TNBC subtype showed an upregulation in MEK-MAPK, mTOR, and JNK-JUN-TAK1 pathways.

Conclusions: Our study suggests the presence of a breast cancer molecular field effect that extends beyond the adjacent normal breast tissue and includes the entire mammary gland. A substantial proportion of this field cancerization is subtype specific with uniquely deregulated pathways within each subtype. These findings provide new opportunities for developing subtype-specific chemoprevention strategies.

Citation Format: Anjana Bhardwaj, Zhenlin Ju, Constance Albarracin, Celestine Trinidad, Preethi Gunaratne, Jing Wang, Randa El-Zein, Isabelle Bedrosian. Subtype-specific molecular signatures of field cancerization in patients with sporadic breast cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 6521.

Prospective, early longitudinal assessment of lymphedema-related quality of life among patients with locally advanced breast cancer: The foundation for building a patient-centered screening program

BACKGROUND

We examined how breast cancer-related lymphedema (BCRL) affects health-related quality of life (HRQOL), productivity, and compliance with therapeutic interventions to guide structuring BCRL screening programs.

METHODS

We prospectively followed consecutive breast cancer patients who underwent axillary lymph node dissection (ALND) with arm volume screening and measures assessing patient-reported health-related quality of life (HRQOL) and perceptions of BCRL care. Comparisons by BCRL status were made with Mann-Whitney U, Chi-square, Fisher's exact, or t tests. Trends over time from ALND were assessed with linear mixed-effects models.

RESULTS

With a median follow-up of 8 months in 247 patients, 46% self-reported ever having BCRL, a proportion that increased over time. About 73% reported fear of BCRL, which was stable over time. Further in time from ALND, patients were more likely to report that BCRL screening reduced fear. Patient-reported BCRL was associated with higher soft tissue sensation intensity, biobehavioral, and resource concerns, absenteeism, and work/activity impairment. Objectively measured BCRL had fewer associations with outcomes. Most patients reported performing prevention exercises, but compliance decreased over time; patient-reported BCRL was not associated with exercise frequency. Fear of BCRL was positively associated with performing prevention exercises and using compressive garments.

CONCLUSIONS

Both incidence and fear of BCRL were high after ALND for breast cancer. Fear was associated with improved therapeutic compliance, but compliance decreased over time. Patient-reported BCRL was more strongly associated with worse HRQOL and productivity than was objective BCRL. Screening programs must support patients' psychological needs and aim to sustain long-term compliance with recommended interventions.

Prospective Study of Pain Outcomes Associated With Breast Surgery in Women With Nonhereditary Breast Cancer

OBJECTIVE

To assess pain severity and interference with life in women after different types of breast cancer surgery and the demographic, treatment-related, and psychosocial variables associated with these pain outcomes.

SUMMARY OF BACKGROUND DATA

Data are conflicting regarding pain outcomes and quality of life (QOL) among women who undergo different types of breast surgery.

METHODS

Women with nonhereditary breast cancer completed the brief pain inventory before surgery and at 1, 6, 12, and 18 months postsurgery. We assessed associations between pain outcomes and CPM status and mastectomy status using multivariable repeated measures models. We assessed associations between pain outcome and QOL and decision satisfaction.

RESULTS

Of 288 women (mean age 56 years, 58% non-Hispanic White), 50 had CPM, 75 had unilateral mastectomy, and 163 had BCS. Mean pain severity scores were higher at one (2.78 vs 1.9, P = 0.016) and 6 months (2.79 vs 1.96, P = 0.031) postsurgery in women who had CPM versus those who did not, but there was no difference at 12 and 18 months. Comparing mastectomy versus BCS, pain severity was higher at 1 and 12 months. There was a significant interaction between pain severity and time point for CPM ( P = 0.006), but not mastectomy status ( P = 0.069). Regardless of surgery type, Black women had higher pain severity ( P = 0.004) than White women. Higher pain interference was associated with lower QOL ( P < 0.001) and lower decision satisfaction ( P = 0.034).

CONCLUSIONS

Providers should counsel women considering mastectomy about the potential for greater acute pain and its impact on overall well-being. Racial/ethnic disparities in pain exist and influence pain management in breast surgical patients.

Abstract P4-07-23: Results of a Phase 2 Trial of Combination Immunotherapy with Concurrent Nelipepimut-S + GM-CSF and Trastuzumab in High-risk HER2+ Breast Cancer Patients

INTRODUCTION: The HER2-targeted peptide vaccine nelipepimut-S + GM-CSF (NeuVax) has been shown to be safe, immunogenic, and potentially synergistic with trastuzumab. Here we present the results of a randomized phase 2 trial assessing the ability of nelipepimut-S/GM-CSF versus GM-CSF alone, added to the standard adjuvant Trastuzumab, to prevent recurrences in high-risk HER2-positive breast cancer patients. METHODS: The study was a multi-center, prospective, randomized, controlled, single-blinded, phase 2 trial. Enrolled patients had high risk HER2+ breast cancer defined by the presence of residual disease post neoadjuvant therapy or by the presence of positive lymph nodes after upfront surgery. Eligible patients had completed an approved trastuzumab-chemotherapy containing regimen and they were receiving adjuvant Trastuzumab monotherapy. Enrollment was limited to patients with HLA-A2, A3, A24, and/or A26 alleles. Patients received intradermal injections of nelipepimut-S + GM-CSF or placebo + GM-CSF every three weeks for six total vaccinations with concurrent, standard monotherapy with iv trastuzumab. After completion of the primary vaccine series, booster inoculations were administered every six months for four doses. The primary outcome measure was invasive disease-free survival (iDFS) at 36 months. Secondary outcome measures were distant recurrence-free survival (DRFS), toxicity assessment, and evaluation of immune response. RESULTS: 100 patients were enrolled and randomized 1:1 to nelipepimut-S/GM-CSF or GM-CSF alone. There were no significant clinicopathologic differences between the groups. There was no difference in related local (p=0.49) or systemic toxicities (p=0.41). Kaplan-Meier estimates of iDFS at 36 months were 79% in the nelipepimut-S arm and 92% in the placebo arm (log rank, p=0.11). DRFS at 36 months was estimated to be 90% in the nelipepimut-S arm and 95% in the placebo arm (log rank, p=0.40). Delayed type hypersensitivity (DTH) response to nelipepimut-S was measured and considered positive if there was more than 5 mm induration after 48 hours. DTH response converted from negative to positive in 11% of patients in the vaccine group versus 5% of patients in the placebo group (p=0.36). In both groups, iDFS at 36 months was 100% for those with a positive DTH response post-inoculation and 88% for those with a negative DTH response post-inoculation (log rank, p=0.29). CONCLUSION: Combination immunotherapy with concurrent nelipepimut-S + GM-CSF and trastuzumab is safe, however there was no difference in iDFS or DRFS among high-risk HER2+ breast cancer patients who received nelipepimut-S + GM-CSF compared to GM-CSF alone. We observed a trend towards improved iDFS in patients with a positive DTH response to nelipepimut-S, though it was not statistically significant.

Citation Format: Ankur Tiwari, Guy Clifton, Carmen Calfa, Gheath Alatrash, Jarrod Holmes, Isabelle Bedrosian, George Peoples, Elizabeth A. Mittendorf. Results of a Phase 2 Trial of Combination Immunotherapy with Concurrent Nelipepimut-S + GM-CSF and Trastuzumab in High-risk HER2+ Breast Cancer Patients [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 P4-07-23.

Effectiveness Without Efficacy: Cautionary Tale from a Landmark Breast Cancer Randomized Controlled Trial

Background: "Old" randomized controlled trials established breast conserving therapy (BCT) and total mastectomy (TM) equivalence for treating early breast cancer, whereas recent literature report improved survival with BCT. To reconcile this, we performed a simulation study and re-analyzed B-06 trial data. Methods: We estimated the distributions for overall survival (OS), cumulative incidence functions for breast-cancer-specific death (BCSD) and other causes-specific death (OCSD) by BCT and TM. The restricted mean survival time (RMST) difference and hazard ratio between the two arms were estimated. Given the estimated distributions, we simulated cause-specific death times from each arm, evaluating the power to test treatment difference in OS, BCSD, and OCSD with different sample sizes, follow-up times, and a modified setting by simulating BCT-arm OCSD times from the distribution of patients not receiving radiation. Results: With 200 months follow-up, the average BCT-over-TM gain measured by RMST was 3.7 months for OS and 4.5 months for BCSD. Increasing the trial size to 5,000 per arm, there is a 79.2% chance to detect the OS benefit with RMST and 92.4% for BCSD. A nonproportional increase of OCSD in BCT compared to TM was observed after 144 months, and particularly after 200 months post treatments. When OCSD times of BCT were simulated using patients not receiving radiation, the estimated OS gain increased to 4.4 months, and the power increased to 92.2%. Conclusions: The late excess other-cause-death, likely due to radiation, in the BCT arm and sample size constraints limited the power to report BCT superiority. Given radiation delivered in the era of B-06 trial, BCT and TM remain largely equivalent.

Evaluation of Sensitivity to Endocrine Therapy Index (SET2,3) for Response to Neoadjuvant Endocrine Therapy and Longer-Term Breast Cancer Patient Outcomes (Alliance Z1031)

PURPOSE

To evaluate prediction of response and event-free survival (EFS) following neoadjuvant endocrine therapy by SET2,3 index of nonproliferation gene expression related to estrogen and progesterone receptors adjusted for baseline prognosis.

EXPERIMENTAL DESIGN

A correlative study was conducted of SET2,3 measured from gene expression profiles of diagnostic tumor (Agilent microarrays) in 379 women with cStage II-III breast cancer from the American College of Surgeons Oncology Group Z1031 neoadjuvant aromatase inhibitor trial SET2,3 was dichotomized using the previously published cutoff. Fisher exact test was used to assess the association between SET2,3 and low proliferation at week 2-4 [Ki67 ≤ 10% or complete cell-cycle arrest (CCCA; Ki67 ≤ 2.7%)] and PEPI-0 rate in cohort B, and the association between SET2,3 and ypStage 0/I in all patients. Cox models were used to assess EFS with respect to SET2,3 excluding cohort B patients who switched to chemotherapy.

RESULTS

Patients with high SET2,3 had higher rate of pharmacodynamic response than patients with low SET2,3 (Ki67 ≤ 10% in 88.2% vs. 56.9%, P < 0.0001; CCCA in 50.0% vs. 26.2%, P = 0.0054), but rate of ypStage 0/I (24.0% vs. 20.4%, P = 0.4580) or PEPI = 0 (28.4% vs. 20.6%, P = 0.3419) was not different. Patients with high SET2,3 had longer EFS than patients with low SET2,3 (HR, 0.52, 95% confidence interval: 0.34-0.80; P = 0.0026).

CONCLUSIONS

This exploratory analysis of Z1031 data demonstrated a higher rate of pharmacodynamic suppression of proliferation and longer EFS in high SET2,3 disease relative to low SET2,3 disease. The ypStage 0/I rate and PEPI = 0 rate were similar with respect to SET2,3.

Survival outcomes after omission of surgery for ductal carcinoma in situ: A National Cancer Database (NCDB) analysis

e12574

Background: Clinical trials of active surveillance (AS) for Ductal Carcinoma in Situ (DCIS) are underway. We sought to understand the historical management of biologically favorable DCIS and to determine the long-term outcomes of patients who did not have surgery at time of diagnosis. We hypothesized that women who had biologically favorable DCIS and underwent AS would have excellent long-term outcomes. Methods: The NCDB was queried from 2004 to 2017 for women diagnosed with DCIS. This cohort was further refined to identify those with biologically favorable DCIS defined as grade 1 or 2 and hormone receptor (HR) positive. Women under age 40 were excluded. AS was defined as either no surgery or surgery >12 months from diagnosis. A Cochran-Armitage test was used to assess the trend of surgery omission over year of diagnosis. Multivariable logistic regression was used to assess association between baseline factors and AS. Kaplan-Meier curves were estimated to show overall survival (OS) in this biologically favorable DCIS group that underwent AS, stratified by age (<50, 50-65, >65). Univariate and multivariable Cox proportional hazard models were used to determine the effects of prognostic factors on survival distributions. Results: There were 74,868 women with grade 1 or 2, HR positive DCIS, of whom 2,384 (3.2%) were treated with AS. The proportion of patients with biologically favorable DCIS who underwent AS increased over time, peaking in 2017 with 4.2% of DCIS cases diagnosed that year treated with observation (p<0.001). Only 17% of the patients in the AS group received hormonal therapy. On multivariable analysis, increasing age (OR 1.02, p<0.001), black race (OR 1.7, p<0.001), and being uninsured (OR 2.2, p<0.001) were all associated with increased likelihood of AS. In an unadjusted analysis, receipt of surgery was associated with improved OS in the entire cohort. However, the OS benefit from surgery differed when stratified by age. In women <50 years of age, OS outcomes were similar, with 10-year OS of 97.4% in the immediate surgery cohort vs 99.1% in AS cohort (p=0.43). In contrast, in women >50 years of age, 10-year OS was higher for women undergoing surgery (85.3% vs 70.0% in AS group, p <0.001). This association with OS in this older cohort persisted even after adjusting for age, race and comorbidity as well as facility demographics. Conclusions: The proportion of patients with low or intermediate grade, hormone receptor positive DCIS not treated with surgery has remained small but is increasing over time. AS of biologically favorable DCIS in younger, healthier women is not associated with adverse survival. In older women, the finding of benefit of surgery over AS is very likely confounded by underlying health factors that are not fully captured with co-morbidity scores.

A phase 3 study to determine the breast cancer risk reducing effect of denosumab in women carrying a germline BRCA1 mutation (BRCA-P Study)

TPS10616

Background: Women with BRCA1 mutations have a 50-70% lifetime risk of developing breast cancer. Currently, prophylactic mastectomy is the only strategy that significantly reduces breast cancer risk. Recent evidence suggests that the RANK/RANKL signaling pathway plays a pivotal role in the development of BRCA1-mutated tumors. Targeting the RANK pathway has been shown to attenuate breast epithelial proliferation in vitro and in vivo, and to profoundly reduce mammary tumor formation in mouse models. The RANKL inhibitor, denosumab, an FDA approved drug for the treatment of osteoporosis, is potentially an ideal chemopreventive agent for women with a germline BRCA1 mutation because it: (a) could potentially reduce breast cancer risk, and (b) concomitantly protect bone health in women who have already undergone bilateral salpingo-oophorectomy or in naturally postmenopausal women. The BRCA-P study will evaluate the reduction in the risk of any breast cancer (invasive or DCIS) in women with a germline BRCA1 mutation who are treated with denosumab compared to placebo. Sub-studies include measurement of bone turnover markers; epigenetic profiling of tumor tissues; measuring denosumab’s effect on bone and breast density; measurement of serum RANK, RANKL, OPG, progesterone, LH and FSH; and measurement of quality of life. Methods: This is a randomized, double-blind, placebo-controlled, multi-center international phase 3 study to determine the breast cancer risk reducing effect of denosumab in women carrying a germline BRCA1 mutation. Eligibility: Women with a confirmed BRCA1 germline mutation; ages ≥ 25 years and ≤ 55 years; no evidence of breast or ovarian cancer; no preventive breast surgery planned at randomization; ECOG performance status 0-1. Eligible participants will be randomized 1:1 to receive 120 mg of subcutaneous denosumab or placebo every 6 months for 5 years. Thereafter, all participants will be followed up for 5 years. Primary endpoints: Time to the occurrence of any breast cancer (invasive or DCIS). Secondary endpoints: Time to invasive triple negative breast cancer; time to other BRCA1 mutation associated malignancies, time to clinical fractures. Statistically, a 35% reduction in breast cancer risk would be detected with an 80% power and a two-sided significance level of 5% if 167 breast cancer cases are observed. We expect to observe the number of events needed if 1459 subjects per group (2918 in total) are randomized. The study is currently enrolling participants in Austria, Australia, Israel and Spain. The study will shortly begin accrual in Germany, United Kingdom, and at more than 30 sites across the United States. Globally, the trial is coordinated by the Austrian Breast & Colorectal Cancer Study Group and by the Alliance for Clinical Trial in Oncology in the US. EudraCT: 2017-02505-35. Clinical trial information: NCT04711109.

A randomized presurgical trial of alternative dosing of exemestane in postmenopausal women with early-stage ER-positive breast cancer

519

Background: Successful therapeutic cancer prevention requires definition of the minimal effective dose of the proposed agent. Aromatase inhibitors substantially decreased breast cancer incidence in high risk postmenopausal women in phase III trials but their clinical use in prevention and adherence in adjuvant setting is limited by adverse events. We conducted a randomized presurgical phase IIb trial to evaluate two alternative doses of exemestane. Methods: We conducted a multi-center, pre-surgical, double-blind, 3-arm, non-inferiority phase IIb study in postmenopausal women with histologically confirmed estrogen receptor (ER)-positive breast cancer. Patients were randomized to receive either exemestane 25 mg/day (QD), or 25 mg/three times/week (TIW), or 25 mg once a week (QW) for 4-6 weeks before surgery. Blood and tissue biomarkers were collected at baseline and final visit. The primary aim was a non-inferiority percent change of circulating estradiol relative to the standard dose. Secondary endpoints were the change in Ki-67 and PgR expression in cancer tissue, blood sex hormones, lipid profile, toxicity and menopausal symptoms. For the power calculation we assumed a non-inferiority difference of 6% in the percentage change of estradiol among arms, using a one-sided, two-sample t-test. Assuming a 10% drop-out rate, a total sample size of 180 participants (60 per arm) had 80% power to detect a 6% margin of equivalence. The significance level for the main endpoint was 0.025 to account for multiple comparisons and 0.05 for secondary endpoints. Results: A total of 230 women were screened, 180 agreed to participate and 173 were evaluable for response. The median percent change of estradiol was -98%, -98%, and -70% for exemestane QD (n = 56), TIW (n = 57), and QW (n = 60), respectively, showing no significant difference between QD and TIW arms (p = 0.9). Similarly, no differences were observed for estrone, total estrone and estrone sulfate between QD and TIW arms. The QW arm showed some modulation in all hormones, even though less significantly so. Among the secondary endpoints, Ki-67 and PgR were reduced in all arms, with a median change of -5% vs -7.5% for Ki-67(p = 0.124), and -9 vs -17 for PgR (p = 0.246) in the TIW vs QD arms, respectively. SHBG and HDL-cholesterol had a more favorable profile with the TIW dose compared to the daily dose. Adverse events, measured according to the CTCAE (v4), and menopausal symptoms according to MENQOL were similar in all arms, but the short treatment time may not be representative. Conclusions: Exemestane 25 mg TIW retains a comparable activity than 25 mg QD. This activity was similar in both arms throughout the primary and the main secondary endpoints. This new schedule should be further assessed in prevention studies and in women on adjuvant treatment who do not tolerate the daily dose. Clinical trial information: NCT02598557.

Helping Patients Understand and Cope with BRCA Mutations

Purpose of Review

Individuals carrying germline mutations in BRCA1/2 have unique psychosocial and educational needs that must be met to ensure informed clinical decision-making. In this review, we highlight the strategies used in clinical practice to support patients’ needs as well as currently available pre- and post-disclosure support interventions.

Recent Findings

Clinical risk communication is complicated by the uncertainty associated with gene penetrance, inconclusive results, variable effectiveness of surgical and screening interventions, and inadequate awareness of clinical genetics. Interventions to support patients’ psychosocial needs, and strategies for effective and scalable clinical risk communication are in routine use and largely effective at meeting patients’ needs. Research is underway to develop newer supportive resources; however, the inadequate representation of all mutation carriers persists.

Summary

Effective clinical risk communication strategies, decision support aids, written educational materials, and supportive psychosocial tools can together have a large impact on meeting BRCA carriers’ supportive needs.

Gene signature associated with resistance to fluvastatin chemoprevention for breast cancer

Background

Although targeting of the cholesterol pathway by statins prevents breast cancer development in mouse models, efficacy is not absolute. Therefore, the goal of this study is to investigate if the upregulation in the cholesterol biosynthesis pathway genes associates with response to statin chemoprevention and may potentially be used as response biomarkers.

Methods

Expression of cholesterol biosynthesis pathway genes was initially derived from the RNA sequencing of MCF10A cell line- based breast cancer progression model system and subsequently validated by quantitative PCR assay. Response to fluvastatin was assessed in vitro using the MCF10A cell line model system, including a statin resistant cell line that was generated (MCF10.AT1-R), and measured using colony forming assays. In vivo efficacy of statin for chemoprevention was assessed in the SV40C3 TAg mouse model. Mammary tumors were identified by histologic analysis of the mammary glands. Mammary glands without histologic evidence of high-grade lesions (in situ and/or invasive carcinoma) were considered responsive to statin treatment.

Results

We found more than 70% of a published multi-gene fluvastatin resistance signature to be significantly upregulated during breast cancer progression and inversely correlated with statin inhibition of cellular growth and proliferation. This inherent statin resistance gene signature was also largely shared with the signature of acquired resistance to fluvastatin in MCF10.AT1-R cell line model of acquired statin resistance. These inherent resistance genes and genes exclusive to acquired statin resistance map to steroid-, and terpenoid backbone- biosynthesis pathway. We found upregulation of ~ 80% of cholesterol biosynthesis pathway genes in the tumor bearing mammary glands of SV40 C3TAg transgenic mouse model of TNBC, suggesting the involvement of cholesterol biosynthesis pathway in resistance to statin chemoprevention in vivo. A panel of 13-genes from the pathway significantly associated with response to statin treatment, as did the expression level of HMGCR alone in a mouse model of breast cancer suggesting their utility to predict the efficacy of statin chemoprevention.

Conclusions

High basal level, or restorative upregulation, in the cholesterol biosynthesis pathway genes appear to be strongly associated with resistance to statin chemoprevention for breast cancer and may serve as a biomarker to tailor statin treatment to individuals who are most likely to benefit.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-022-09353-2.

Abstract P2-11-10: Heterogeneity of preneoplastic breast tissues drives efficacy of therapeutic agents

Introduction: Little is known about the evolution of proteomic aberrations during TNBC tumorigenesis and whether the timing of intervention for prevention and treatment during this tumorigenic progression impacts efficacy. We hypothesized that the targeted therapies for TNBC is likely to be context specific, with specific transition points where such therapy is likely to be most effective based on presence of proteomic aberrations. Methods: MCF10A cell line-based model of triple negative breast cancer progression was used. This model system comprises of non-cancer MCF10A (P), preneoplastic MCF10.AT1 and MCF10.NeoT, premalignant ductal carcinoma in situ MCF10.DCIS and invasive MCF10.CA1D cells. Global proteomic patterns were studied by performing RPPA assay. Growth inhibitory effects drugs were studied by measuring inhibition in cell proliferation by MTT assay. Results: RPPA analysis revealed a majority of protein alterations (n=48) were acquired early on during TNBC progression, specifically during normal to preneoplastic (atypia) transition, with only 6 aberrations acquired in later stages of tumorigenesis. To assess the effects of this heterogeneity on efficacy of treatment, we selected 2 aberrant pathways that were up-regulated early in the breast tumorigenesis and compared efficacy of targeted intervention to drugs without pathway selectivity. Targeting upstream oncogenic pathways with small molecule inhibitors (AKT pathway with LY294002- a PI3 kinase inhibitor and MEK pathway with MEK1/2 inhibitors PD032590 or GSK1120212) showed PI3K inhibitor to be equally effective in suppressing the cell proliferation in both preneoplastic and DCIS state, consistent with upregulation of the underlying AKT pathway aberration early in tumorigenesis. MEK pathway inhibitors were preferentially more effective in preneoplastic state than DCIS state, consistent with continued activation of MEK pathway in the DCIS state relative to preneoplastic state. Similarly, fluvastatin (a cholesterol lowering drug) was more effective in inhibiting the cell proliferation in preneoplastic cells relative to DCIS cells. However, a broad spectrum drug aspirin (an AMPK activator) that is known to have pleotropic effects showed no differential effects across the cell lines tested. Conclusions: The preponderance of proteomic alterations occur in the very earliest stages of TNBC tumorigenesis. Effectiveness of targeted drug therapies in this model of breast tumorigenesis correlated. with deregulation of the associated pathway. This implies that accounting for heterogeneity of the preneoplastic breast and stage of tumorigenic progression will be important when considering targeted strategies for prevention.

Citation Format: Anjana Bhardwaj, Raniv Rojo, Zhenlin Ju, Jing Wang, Isabelle Bedrosian. Heterogeneity of preneoplastic breast tissues drives efficacy of therapeutic agents [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 P2-11-10.

Outcomes After Breast Radiation Therapy in a Diverse Patient Cohort With a Germline BRCA1/2 Mutation

PURPOSE

BRCA1/2 pathogenic variant (PV) mutations confer radiation sensitivity preclinically, but there are limited data regarding breast cancer outcomes after radiation therapy (RT) among patients with documented BRCA1/2 PV mutations versus no PV mutations.

METHODS AND MATERIALS

This retrospective cohort study included women with clinical stage I-III breast cancer who received definitive surgery and RT and underwent BRCA1/2 genetic evaluation at the The University of Texas MD Anderson Cancer Center. Rates of locoregional recurrence (LRR), disease-specific death (DSD), toxicities, and second cancers were compared by BRCA1/2 PV status.

RESULTS

Of the 2213 women who underwent BRCA1/2 testing, 63% self-reported their race as White, 13.6% as Black/African American, 17.6% as Hispanic, and 5.8% as Asian/American Indian/Alaska Native; 124 had BRCA1 and 100 had BRCA2 mutations; and 1394 (63%) received regional nodal RT. The median follow-up time for all patients was 7.4 years (95% confidence interval [CI], 7.1-7.7 years). No differences were found between the groups with and without BRCA1/2 PV mutations in 10-year cumulative incidences of LRR (with mutations: 11.6% [95% CI, 7.0%-17.6%]; without mutations: 6.6% [95% CI, 5.3%-8.0%]; P = .466) and DSD (with mutations: 12.3% [95% CI, 8.0%-17.7%]; without mutations: 13.8% [95% CI, 12.0%-15.8%]; P = .716). On multivariable analysis, BRCA1/2 status was not associated with LRR or DSD, but Black/African American patients (P = .036) and Asians/American Indians/Alaska Native patients (P = .002) were at higher risk of LRR compared with White patients, and Black/African American patients were at higher risk of DSD versus White patients (P = .004). No in-field, nonbreast second cancers were observed in the BRCA1/2 PV group. Rates of acute and late grade ≥3 radiation-related toxicity in the BCRA1/2 PV group were 5.4% (n = 12) and 0.4% (n = 1), respectively.

CONCLUSIONS

Oncologic outcomes in a diverse cohort of patients with breast cancer who had a germline BRCA1/2 PV mutation and were treated with RT were similar to those of patients with no mutation, supporting the use of RT according to standard indications in patients with a germline BRCA1/2 PV mutation.

Breast Radiation Therapy-Related Treatment Outcomes in Patients With or Without Germline Mutations on Multigene Panel Testing

PURPOSE

Multigene panel testing has increased the detection of germline mutations in patients with breast cancer. The implications of using radiation therapy (RT) to treat patients with pathogenic variant (PV) mutations are not well understood and have been studied mostly in women with only BRCA1 or BRCA2 PVs. We analyzed oncologic outcomes and toxicity after adjuvant RT in a contemporary, diverse cohort of patients with breast cancer who underwent genetic panel testing.

METHODS AND MATERIALS

We retrospectively reviewed the records of 286 women with clinical stage I-III breast cancer diagnosed from 1995 to 2017 who underwent surgery, breast or chest wall RT with or without regional nodal irradiation, multigene panel testing, and evaluation at a large cancer center's genetic screening program. We evaluated rates of overall survival, locoregional recurrence, disease-specific death, and radiation-related toxicities in 3 groups: BRCA1/2 PV carriers, non-BRCA1/2 PV carriers, and patients without PV mutations.

RESULTS

PVs were detected in 25.2% of the cohort (12.6% BRCA1/2 and 12.6% non-BRCA1/2). The most commonly detected non-BRCA1/2 mutated genes were ATM, CHEK2, PALB2, CDH1, TP53, and PTEN. The median follow-up time for the entire cohort was 4.4 years (95% confidence interval, 3.8-4.9 years). No differences were found in overall survival, locoregional recurrence, or disease-specific death between groups (P > .1 for all). Acute and late toxicities were comparable across groups.

CONCLUSION

Oncologic and toxicity outcomes after RT in women with PV germline mutations detected by multigene pane testing are similar to those in patients without detectable mutations, supporting the use of adjuvant RT as a standard of care when indicated.

Impact of the early COVID-19 pandemic on Breast Surgical Oncology fellow education

INTRODUCTION

The early COVID-19 pandemic rapidly transformed healthcare and medical education. We sought to evaluate the professional and personal impact of the pandemic on 2019-2020 Breast Surgical Oncology (BSO) fellows in Society of Surgical Oncology approved programs to capture the experience and direct future changes.

METHODS

From July 15, 2020 to August 4, 2020 a survey was administered to the American Society of Breast Surgeons' fellow members. The survey assessed the impact of the pandemic on clinical experience, education/research opportunities, personal health/well-being, and future career. Responses were collected and aggregated to quantify the collective experience of respondents.

RESULTS

Twenty-eight of fifty-seven (54%) eligible fellows responded. Twenty-one (75%) indicated the clinical experience changed. Twenty-seven (96%) reported less time spent caring for ambulatory breast patients and sixteen (57%) reported the same/more time spent in the operating room. Fourteen (50%) stated their future job was impacted and eight (29%) delayed general surgery board examinations. Stress was increased in 26 (93%). Personal health was unaffected in 20 (71%), and 3 (10%) quarantined for COVID-19 exposure/infection.

CONCLUSION

The COVID-19 pandemic altered the clinical experience of BSO fellows; however, the operative experience was generally unaffected. The creation of frameworks and support mechanisms to mitigate potential challenges for fellows and fellowship programs in the ongoing pandemic and other times of national crisis should be considered.

Evaluation of overall survival and barriers to surgery for patients with breast cancer treated without surgery: a National Cancer Database analysis

Surgery remains the foundation of curative therapy for non-metastatic breast cancer, but many patients do not undergo surgery. Evidence is limited regarding this population. We sought to assess factors associated with lack of surgery and overall survival (OS) in patients not receiving breast cancer surgery. Retrospective cohort study of patients in the US National Cancer Database treated in 2004-2016. The dataset comprised 2,696,734 patients; excluding patients with unknown surgical status or stage IV, cT0, cTx, or pIS, metastatic or recurrent disease resulted in 1,192,294 patients for analysis. Chi-square and Wilcoxon rank-sum tests were used to assess differences between groups. OS was analyzed using the Kaplan-Meier method with a Cox proportional hazards model performed to assess associated factors. In total 50,626 (4.3%) did not undergo surgery. Black race, age >50 years, lower income, uninsured or public insurance, and lower education were more prevalent in the non-surgical cohort; this group was also more likely to have more comorbidities, higher disease stage, and more aggressive disease biology. Only 3,689 non-surgical patients (7.3%) received radiation therapy (RT). Median OS time for the non-surgical patients was 58 months (3-year and 5-year OS rates 63% and 49%). Median OS times were longer for patients who received chemotherapy (80 vs 50 (no-chemo) months) and RT (85 vs 56 (no-RT) months). On multivariate analysis, age, race, income, insurance status, comorbidity score, disease stage, tumor subtype, treatment facility type and location, and receipt of RT were associated with OS. On subgroup analysis, receipt of chemotherapy improved OS for patients with triple negative (HR 0.66, 95% CI 0.59-0.75, P < 0.001) and HER2+ (HR 0.74, 95% CI 0.65-0.84, P < 0.001) subgroups while RT improved OS for ER+ (HR 0.72, 95% CI 0.64-0.82, P < 0.001) and favorable-disease (ER+, early-stage, age >60) (HR 0.61, 95% CI 0.45-0.83, P = 0.002) subgroups. Approximately 4% of women with breast cancer do not undergo surgery, particularly those with more aggressive disease and lower socioeconomic status. Despite its benefits, RT was underutilized. This study provides a benchmark of survival outcomes for patients who do not undergo surgery and highlights a potential role for use of RT.

Abstract 2589: Gene signature of fluvastatin resistance for prevention of breast cancer and predicting resistance to statins

Introduction: Cholesterol biosynthesis pathway is highly regulated and inhibition of the pathway with statins is known to cause restorative upregulation of several genes in the pathway. The goal of this study is to investigate if the statin mediated upregulation in the cholesterol biosynthesis pathway genes associates with the resistance to fluvastatin in a model of hormonally insensitive breast cancer

Methods: A published gene signature of statin resistance was validated 1) a cell line based model of breast cancer progression consisting of inherently fluvastatin sensitive and inherently fluvastatin resistant cell lines and also compared to our experimentally derived acquired signature of fluvastatin resistance using 2) an isogenic set of cell lines consisting of a fluvastatin sensitive cell line (MCF10.AT1), and an acquired resistant cell line (MCF10.AT- R) and lastly validated using 3) SV40 C3 tag, a mouse model of hormone receptor negative breast cancer. Clariom RNA profiling were processed and mined by IPA analysis to identify the fluvastatin resistance signature that were validated by qPCR. Fluvastatin resistance was determined in vitro by colony formation assay and in vivo in a mouse model of breast cancer.

Results: We found more than 75% of the published 17 gene panel fluvastatin resistance gene signature (consisting of cholesterol biosynthesis pathway genes) to be significantly upregulated in an inherently resistant cell line, DCIS cell line, relative to fluvastatin sensitive preneoplastic, MCF10.AT1 cell line. We found this inherent statin resistance gene signature to be also relevant in the MCF10.AT-R resistant cells as we found 13 of these genes to map to top 3 upregulated pathways that are steroid biosynthesis, steroid hormone biosynthesis and terpenoid backbone biosynthesis pathway. Next, we tested if 17 gene statin resistance signature associates with presence of tumors in the mammary glands of fluvastatin treated mice and found upregulation of more than 50% of the genes in the resistance signature in the tumor bearing mammary glands. Lastly, we studied if a 10-day period of fluvastatin treatment to SV40C3 Tag mice, a spontaneous mouse model of breast cancer, can also trigger the upregulation of these cholesterol biosynthesis pathway genes and provide an early signal of statin resistance. These experiments showed that a 10-day period is not long enough to cause a feedback upregulation in steroid biosynthesis pathway genes and thus can't be used a surrogate timepoint to detect resistance to fluvastatin.

Conclusions: Upregulation of multiple steroid biosynthesis pathway genes after fluvastatin treatment suggests an opportunity of dual targeting of the cholesterol biosynthesis pathway in order to sensitize the fluvastatin resistant breast cancer cells.

Citation Format: Anjana Bhardwaj, Zhenlin Ju, Matthew Embury, Jing Wang, Isabelle Bedrosian. Gene signature of fluvastatin resistance for prevention of breast cancer and predicting resistance to statins [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 2589.

The Influence of Vitamin D on Mammographic Density: Results from CALGB 70806 (Alliance) a Randomized Clinical Trial

Current therapies for breast cancer prevention only prevent estrogen receptor positive (ER+) disease and toxicity limits use of these agents. Vitamin D is a potential prevention therapy for both ER+ and ER- disease and is safe with few side effects. This study evaluates the effect of 1-year of vitamin D supplementation on mammographic density (MD), a biomarker of breast cancer risk in a multicenter randomized controlled trial. Premenopausal women with ≥25% MD and no history of cancer were randomly assigned to 2,000 international units (IU) of vitamin D or placebo orally daily for 1 year. Change in percent MD was evaluated using Cumulus software after all participants completed treatment. Three hundred women enrolled between January 2011 and December 2013 with a mean age of 43 and diverse ethnicity [14% Hispanic, 12% African American (AA)]. Supplementation significantly increased vitamin D levels compared with placebo (14.5 ng/mL vs. -1.6 ng/mL; P < 0.0001) with all participants on the vitamin D arm achieving vitamin D sufficiency at 12 months. Vitamin D was safe and well tolerated. After adjustment for baseline MD, the mean between-arm difference (vitamin D vs. placebo) at 1 year was -0.75 (-0.26, 1.76; P = 0.56). A greater effect was seen for women with ≥50% MD and AA women, although neither reached significance. This randomized controlled trial demonstrated significant improvement in vitamin D levels with 2,000 IU for 1 year, with 100% of supplemented women achieving sufficiency. However, a null effect was seen regarding change in MD for premenopausal women (the primary outcome of the study). PREVENTION RELEVANCE: Current therapies for breast cancer prevention only prevent estrogen receptor positive (ER+) disease and are underutilized due to toxicity and side effects. Vitamin D is a potential prevention therapy for both ER+ and ER- disease and is safe with few side effects.

Contralateral Axillary Metastasis in Patients with Inflammatory Breast Cancer

BACKGROUND

Nearly one-third of patients with inflammatory breast cancer (IBC) present with de novo stage IV disease. There are limited data on frequency and clinical outcomes of contralateral axillary metastasis (CAM) in IBC with no consensus diagnostic and treatment guidelines.

PATIENTS AND METHODS

Frequency of synchronous CAM was calculated in unilateral IBC patients at a single center (10/2004-6/2019). Clinicopathologic variables, diagnostic evaluation, treatment received, and overall survival (OS) were assessed and compared.

RESULTS

Of 588 unilateral IBC patients, 49 (8.3%) had synchronous CAM. Of these, 32 (65.3%) also presented with metastatic disease at another distant site. CAM was not associated with age, tumor laterality, breast cancer subtype, grade, or cN stage (p > 0.05). The sensitivity/specificity to detect CAM was as follows: mammography (18.2%/99.2%), ultrasound (92.3%/95.5%), PET (90.1/99.1%), and MRI (76.0%/98.6%). Following systemic therapy, 22 patients had contralateral axillary surgery, and 18 received adjuvant contralateral nodal radiation. On multivariable analysis including tumor receptor subtypes, patients with stage IV-isolated CAM has statistically similar survival to stage III patients (HR 1.37, 95% CI 0.70-2.69, p = 0.36). Patients with Stage IV non-CAM (HR 2.18, 95% CI 1.66-2.85, p < 0.001) and stage IV-CAM plus other distant metastasis (HR 2.57, 95% CI 1.59-4.16, p < 0.001) had higher risk of death (reference: stage III disease).

CONCLUSIONS

CAM in IBC was diagnosed in 8.3% of patients at presentation and was best identified by ultrasound and PET. We recommend routine contralateral axillary ultrasound as part of staging for all IBC patients. Diagnosis of CAM is a key first step toward much-needed prospective clinical trials evaluating management and outcomes of CAM in IBC.

Evaluation of sensitivity to endocrine therapy index (SET2,3) for response to neoadjuvant endocrine therapy (NET) and subsequent prognosis

580

Background: Patients (pts) in Cohort A of the American College of Surgeons Oncology Group Z1031 (Alliance) trial of NET for cStage II-III breast cancer were randomized to anastrozole [ANA], letrozole [LET] or exemestane [EXE] for 16-18 weeks (wks). In Cohort B, pts chose between ANA and LET and switched to chemotherapy or surgery if a tumor biopsy after 2-4 wks of NET had Ki67 >10%. Treatments after surgery were not defined by the trial protocol. SET2,3 measures nonproliferation gene expression related to estrogen and progesterone receptors adjusting for a baseline prognostic index that combines clinical tumor and nodal stage and a 4-gene molecular subtype (RNA4) defined by ESR1, PGR, ERBB2 and AURKA. High SET2,3 in a pre-treatment biopsy using cStage information is defined as SET2,3 >1.77. Methods: 379 pts had gene expression data from a research tumor biopsy prior to NET (Agilent 44K microarrays). A bioinformatician blinded to pt treatment and clinical outcomes determined SET2,3. The trial statistician then examined the association between SET2,3 and pharmacodynamic response at 2-4 wks (N=141, Cohort B): Ki67 ≤10% and complete cell cycle arrest (CCCA Ki67 ≤2.7%); pathologic outcomes in pts who completed NET: ypStage 0/1 (N=329, Cohorts A&B), PEPI-0 rate (N=155, Cohort B); and event-free survival (EFS) post-registration (N=244, Cohorts A&B). We used Fisher’s exact tests to assess whether responses, and Cox modeling to evaluate whether EFS, differed with respect to SET2,3 status. Results: High SET2,3 in 48% of pts (183/379) was associated with older age (median: 66 vs 63 years; p=0.012); cStage II (95% vs 75%; p <0.001); and pre-NET Ki67 ≤10% (37% vs 20%; p< 0.001) in pts with low SET2,3. In Cohort B, pts with high SET2,3 had a higher rate of pharmacodynamic response in their tumor at wk 2-4 than pts with low SET2,3 (Table). In the subset of Cohort B pts with wk 2-4 Ki67 ≤10%, pre-treatment SET2,3 trended numerically higher in pts who achieved PEPI-0 score (p=0.049) but the proportion achieving PEPI-0 did not differ by SET2,3 high/low status (Table). EFS was significantly longer for pts with high SET2,3 than pts with low SET2,3 (HR[H/L]: 0.52; 95% CI: 0.34-0.80; p=0.003). Conclusions: An exploratory analysis of Z1031 data demonstrated that the rate of pharmacodynamic suppression of proliferation by NET at 2-4 wks was greater and EFS was longer for pts with breast cancer expressing high SET2,3 disease than pts with low SET2,3. Support: U10CA180821, U10CA180882, U24CA196171; https://acknowledgments.alliancefound.org ; Clinical trial information: NCT00265759. [Table: see text]

Utilization of preoperative breast MRI among women with newly diagnosed breast cancer

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Background: The use of preoperative (pre-op) breast MRI remains controversial. Current practice may rely on patient characteristics and providers’ clinical judgment. This national study examined factors associated with pre-op breast MRI among women with newly diagnosed breast cancer (BC) and explored sources of variations. Methods: We applied the Nattinger algorithm to identify women with incident BC diagnosed between Mar 2008 and Dec 2018 from OPTUM Clinformatics database. Patients who had 26 months of full enrollment, 14 months before and 12 months after the first (index) BC surgery, and no pre-op radiotherapy were included. We defined pre-op MRI as patients who had an MRI between the date of BC diagnosis and date of index surgery. We conducted multivariable logistic regression models to examine factors associated with pre-op MRI and performed separate analyses for elderly (age > = 65) and non-elderly (age < 65) women. Results: 61,865 women (non-elderly: 27,309, elderly: 34,556) were included in the analysis. The crude rate of pre-op MRI increased from 7.4% in 2008 to 14.6% in 2018 (p-value <.001). For the non-elderly, women who were older (adjusted rates: 60-64, 10% vs 20-49, 12.1%), had no distant metastasis (10.6% vs. 12.3% with metastasis), no neoadjuvant chemotherapy (9.9% vs 15.0% with neoadjuvant), and 2 or more comorbidities (9.0% vs. 11.1% with zero comorbidity) were less likely to undergo pre-op MRI (all p-value <.001). Compared to white women (adjusted rate 10.6%), African Americans were more likely to have pre-op MRI (12.7%, p <.001) and Hispanics were less likely (8.14%, P <.001). There was no association between Health Management Organization (HMO) status and receipt of pre-op MRI among non-elderly. For elderly women, older age, more comorbidities, no distant metastasis, and no neoadjuvant chemotherapy were similarly associated with less pre-op MRI use. There was no significant association between race and receipt of pre-op MRI. Moreover, elderly women with HMO insurance were less likely to receive pre-op MRI. In both age groups, we observed wide geographic variations, with significant interaction between census division and HMO enrollment among elderly group only (Table). Conclusions: The use of pre-op MRI nearly doubled from 2008 and 2018. In addition to demographic and clinical characteristics, regional practice pattern variations and insurance type played a key role in the receipt of pre-op MRI among newly diagnosed breast cancer patients. Future study to understand this phenomenon is warranted.[Table: see text]

HER2 testing in breast cancers: comparison of assays and interpretation using ASCO/CAP 2013 and 2018 guidelines

PURPOSE

HER2 overexpression and gene amplification are routinely tested by immunohistochemistry (IHC) and fluorescence in situ hybridization (FISH), respectively. In addition, HER2 mRNA expression is also tested by the Oncotype DX assay. Discordance between laboratories among the different assays remains a problem. To improve the routine HER2 reporting, the American Society of Clinical Oncology (ASCO) and the College of American Pathologists (CAP) updated their guidelines in 2018. Our study will compare concordance of HER2 status by IHC and FISH using ASCO/CAP 2013 and 2018 guidelines with Oncotype DX.

METHODS

We retrospectively reviewed 657 estrogen receptor positive primary breast cancer cases with available Oncotype DX tests between 2011 and 2018. Medical records were reviewed for HER2 results by IHC, FISH, and Oncotype DX. The HER2 results by different assays and between 2013 and 2018 guidelines were compared.

RESULTS

Of the 657 cases, 280 were tested by IHC, FISH, and Oncotype DX. HER2-equivocal cases by IHC 2013 guidelines were all negative (67/67, 100%) by FISH 2018 guidelines and by Oncotype DX. HER2-equivocal cases by FISH 2013 guidelines were all negative (16/16, 100%) by FISH 2018 guidelines, while 15/16 (93.8%) negative and 1/16 (6.2%) equivocal by Oncotype DX. The HER2-equivocal and HER2-negative groups were similar in age, gender, histology, grade, and Ki67 score.

CONCLUSIONS

HER2 concordance was highest between Oncotype DX (99.6%) and FISH per 2018 guidelines. This suggests that the ASCO/CAP 2018 guidelines improved the accurate stratification of HER2-equivocal cases.

Technical Validity of a Customized Assay of Sensitivity to Endocrine Therapy Using Sections from Fixed Breast Cancer Tissue

BACKGROUND

We translated a multigene expression index to predict sensitivity to endocrine therapy for Stage II-III breast cancer (SET2,3) to hybridization-based expression assays of formalin-fixed paraffin-embedded (FFPE) tissue sections. Here we report the technical validity with FFPE samples, including preanalytical and analytical performance.

METHODS

We calibrated SET2,3 from microarrays (Affymetrix U133A) of frozen samples to hybridization-based assays of FFPE tissue, using bead-based QuantiGene Plex (QGP) and slide-based NanoString (NS). The following preanalytical and analytical conditions were tested in controlled studies: replicates within and between frozen and fixed samples, age of paraffin blocks, homogenization of fixed sections versus extracted RNA, core biopsy versus surgically resected tumor, technical replicates, precision over 20 weeks, limiting dilution, linear range, and analytical sensitivity. Lin's concordance correlation coefficient (CCC) was used to measure concordance between measurements.

RESULTS

SET2,3 index was calibrated to use with QGP (CCC 0.94) and NS (CCC 0.93) technical platforms, and was validated in two cohorts of older fixed samples using QGP (CCC 0.72, 0.85) and NS (CCC 0.78, 0.78). QGP assay was concordant using direct homogenization of fixed sections versus purified RNA (CCC 0.97) and between core and surgical sample types (CCC 0.90), with 100% accuracy in technical replicates, 1-9% coefficient of variation over 20 weekly tests, linear range 3.0-11.5 (log2 counts), and analytical sensitivity ≥2.0 (log2 counts).

CONCLUSIONS

Measurement of the novel SET2,3 assay was technically valid from fixed tumor sections of biopsy or resection samples using simple, inexpensive, hybridization methods, without the need for RNA purification.

Impact of adjuvant endocrine therapy in older patients with comorbidities and estrogen receptor-positive, node-negative breast cancer-A National Cancer Database analysis

BACKGROUND

Data are lacking about the benefit of adjuvant endocrine therapy (ET) in older patients with multiple comorbidities. The authors sought to determine the effect of ET on the survival of older patients who had multiple comorbidities and estrogen receptor (ER)-positive/human epidermal growth factor receptor 2 (HER2)-negative, pathologic node-negative (pN0) breast cancer.

METHODS

Women aged ≥70 years in the National Cancer Database (2010-2014) with Charlson/Deyo comorbidity scores of 2 or 3 who had pathologic tumor (pT1)-pT3/pN0, ER-positive/HER2-negative breast cancer were divided into 2 cohorts: adjuvant ET and no ET. Propensity scores were used to match patients based on age, comorbidity score, facility type, pT classification, chemotherapy, surgery, and radiation therapy. A Cox proportional hazards model was used to estimate the effect of ET on overall survival (OS).

RESULTS

In the nonmatched cohort (n = 3716), 72.8% of patients received ET (n = 2705), and 27.2% did not (n = 1011). The patients who received ET were younger (mean age, 76 vs 79 years; P < .001) and had higher rates of breast conservation compared with those who did not receive ET (lumpectomy plus radiation: 43.4% vs 23.8%, respectively; P < .001). In the matched cohort (n = 1972), the median OS was higher in the ET group (79.2 vs 67.7 months; P < .0001). In the adjusted analysis, ET was associated with improved survival (hazard ratio, 0.70; 95% CI, 0.59-0.83).

CONCLUSIONS

In older patients who have pN0, ER-positive/HER2-negative breast cancer with comorbidities, adjuvant ET was associated with improved OS, which may have been overestimated given the confounders inherent in observational studies. To optimize outcomes in these patients, current standard recommendations should be considered stage-for-stage based on life expectancy and the level of tolerance to treatment.

Predicted sensitivity to endocrine therapy for stage II-III hormone receptor-positive and HER2-negative (HR+/HER2-) breast cancer before chemo-endocrine therapy

BACKGROUND

We proposed that a test for sensitivity to the adjuvant endocrine therapy component of treatment for patients with stage II-III breast cancer (SET2,3) should measure transcription related to estrogen and progesterone receptors (SET_ER/PR index) adjusted for a baseline prognostic index (BPI) combining clinical tumor and nodal stage with molecular subtype by RNA4 (ESR1, PGR, ERBB2, and AURKA).

PATIENTS AND METHODS

Patients with clinically high-risk, hormone receptor-positive (HR+), human epidermal growth factor receptor 2 (HER2)-negative (HR+/HER2-) breast cancer received neoadjuvant taxane-anthracycline chemotherapy, surgery with measurement of residual cancer burden (RCB), and then adjuvant endocrine therapy. SET2,3 was measured from pre-treatment tumor biopsies, evaluated first in an MD Anderson Cancer Center (MDACC) cohort (n = 307, 11 years' follow-up, U133A microarrays), cut point was determined, and then independent, blinded evaluation was carried out in the I-SPY2 trial (n = 268, high-risk MammaPrint result, 3.8 years' follow-up, Agilent-44K microarrays, NCI Clinical Trials ID: NCT01042379). Primary outcome measure was distant relapse-free survival. Multivariate Cox regression models tested prognostic independence of SET2,3 relative to RCB and other molecular prognostic signatures, and whether other prognostic signatures could substitute for SET_ER/PR or RNA4 components of SET2,3.

RESULTS

SET2,3 added independent prognostic information to RCB in the MDACC cohort: SET2,3 [hazard ratio (HR) 0.23, P = 0.004] and RCB (HR 1.77, P < 0.001); and the I-SPY2 trial: SET2,3 (HR 0.27, P = 0.031) and RCB (HR 1.68, P = 0.008). SET2,3 provided similar prognostic information irrespective of whether RCB-II or RCB-III after chemotherapy, and in both luminal subtypes. Conversely, RCB was most strongly prognostic in cancers with low SET2,3 status (MDACC P < 0.001, I-SPY2 P < 0.001). Other molecular signatures were not independently prognostic; they could effectively substitute for RNA4 subtype within the BPI component of SET2,3, but they could not effectively substitute for SET_ER/PR index.

CONCLUSIONS

SET2,3 added independent prognostic information to chemotherapy response (RCB) and baseline prognostic score or subtype. Approximately 40% of patients with clinically high-risk HR+/HER2- disease had high SET2,3 and could be considered for clinical trials of neoadjuvant endocrine-based treatment.

Abstract PD11-09: Vadis trial: Phase II trial of nelipepimut-s peptide vaccine in women with DCIS of the breast

Background: Peptide cancer vaccines may be most effective when used in earlier stage cancers or pre-cancers where systemic and tumor microenvironmental immune suppression are less profound. Nelipepimut-S (NPS) plus granulocyte-macrophage colony-stimulating factor (GM-CSF) is a vaccine comprised of a human leukocyte antigen (HLA) restricted peptide from the extracellular domain of the HER2 protein (E75) combined with GM-CSF. We have completed a randomized phase II trial of preoperative vaccination with NPS+GM-CSF vs. GM-CSF alone with the primary outcome being NPS-specific cytotoxic T lymphocyte (CTL) responses.

Methods: HLA-A2 positive, DCIS patients were enrolled and randomized to either NPS+GM-CSF vs GM-CSF alone. The patients received two vaccinations prior to surgery at 2-week intervals. The number of NPS-specific CTL was measured at specified intervals (pre-vaccination, time of surgery, 1 month (+/- 7 days) post-op, and 3 months (+/- 7 days) post-op) using a flow cytometry-based dextramer assay. Differences in NPS-specific CTL responses between the two groups and between baseline pre-vaccination and 1-month post-op were analyzed using either a two-sample t-test or Wilcoxon rank sum test, when appropriate. The incidence and severity of adverse events, graded according to Common Terminology Criteria for Adverse Events (CTCAE) version (v) 4.03, were recorded and compared between treatment groups.

Results: 45 patients were registered; 7 withdrew consent, 1 opted for surgery at an external facility, 20 were ineligible due to negative HLA-A2, and 4 failed screening for other reasons, leaving 13 patients enrolled. The 13 patients were randomized (2:1) into treatment groups, with nine patients receiving NPS+GM-CSF and four patients receiving GM-CSF alone. The two groups were well-matched for age; however, the GM-CSF alone group had higher percentages of African American (50% vs. 22%) and Hispanic (25% vs. 11%) patients as compared to the NPS+GM-CSF group. In general, vaccination was well-tolerated with similar treatment-related toxicity profiles in the NPS+GM-CSF vs GM-GSF groups (Grade 1 - 93.3% vs. 89.3%, Grade 2 - 6.7% vs. 10.7%, respectively). The mean NPS-specific CTL% in the NPS+GM-CSF group at 1-month post-op was double that of the GM-CSF alone group (0.10 +/- 0.12% vs. 0.05 +/- 0.08, p=0.70). In addition, between baseline pre-vaccination and 1-month post-op, the NPS+GM-CSF group experienced an 11-fold increase in percentage of NPS-specific CTL (0.01 +/- 0.02% vs. 0.11 +/- 0.12%) as compared to only a 2.25-fold increase of NPS-specific CTL in the GM-CSF alone group (0.04 +/- 0.07% vs. 0.09 +/- 0.15%).

Conclusions: NPS+GM-CSF is safe and well-tolerated when given preoperatively to patients with DCIS. In HLA-A2 positive patients with DCIS, a single inoculation with NPS+GM-CSF can induce in vivo immunity and a continued antigen-specific T-cell response one month post-surgery. This data provides support for further testing of NPS+GM-CSF in the neoadjuvant and adjuvant settings in an attempt to prevent invasive recurrence in DCIS.

Citation Format: Anne E O'Shea, Guy T Clifton, Na Qiao, Brandy Heckman-Stoddard, Malgorzata Wojtowicz, Eileen Dimond, Isabelle Bedrosian, Diane Weber, Alex Husband, Ricardo Pastorello, Lana Vornik, George Peoples, Elizabeth A Mittendorf. Vadis trial: Phase II trial of nelipepimut-s peptide vaccine in women with DCIS of the breast [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 PD11-09.

Association of Chemotherapy With Survival in Elderly Patients With Multiple Comorbidities and Estrogen Receptor-Positive, Node-Positive Breast Cancer

Importance

Breast cancer risk and comorbidities increase with age. Data are lacking on the association of adjuvant chemotherapy with survival in elderly patients with multiple comorbidities and node-positive breast cancer.

Objective

To examine the association of chemotherapy with survival in elderly patients with multiple comorbidities and estrogen receptor-positive, node-positive breast cancer.

Design, Setting, and Participants

This retrospective cohort study included patients in the US National Cancer Database who were 70 years or older; had a Charlson/Deyo comorbidity score of 2 or 3; had estrogen receptor-positive, ERBB2 (formerly HER2 or HER2/neu)-negative breast cancer; and underwent surgery for pathologic node-positive breast cancer from January 1, 2010, to December 31, 2014. Propensity scores were used to match patients receiving adjuvant chemotherapy with those not receiving adjuvant chemotherapy based on age, comorbidity score, facility type, facility location, pathologic T and N stage, and receipt of adjuvant endocrine and radiation therapy. Data analysis was performed from December 13, 2018, to April 28, 2020.

Exposures

Chemotherapy.

Main Outcomes and Measures

The association of adjuvant chemotherapy with overall survival was estimated using a double robust Cox proportional hazards regression model.

Results

Of a total of 2 445 870 patients in the data set, 1592 patients (mean [SD] age, 77.5 [5.5] years; 1543 [96.9%] female) met the inclusion criteria and were included in the initial nonmatched analysis. Of these patients, 350 (22.0%) received chemotherapy and 1242 (78.0%) did not. Compared with patients who did not receive chemotherapy, patients who received chemotherapy were younger (mean age, 74 vs 78 years; P < .001), had larger primary tumors (pT3/T4 tumors: 72 [20.6%] vs 182 [14.7%]; P = .005), and had higher pathologic nodal burden (75 [21.4%] vs 81 [6.5%] with stage pN3 disease and 182 [52.0%] vs 936 [75.4%] with stage pN1 disease; P < .001). More patients who received chemotherapy also received other adjuvant treatments, including endocrine therapy (309 [88.3%] vs 1025 [82.5%]; P = .01) and radiation therapy (236 [67.4%] vs 540 [43.5%]; P < .001). In the matched cohort, with a median follow-up of 43.1 months (95% CI, 39.6-46.5 months), no statistically significant difference was found in median overall survival between the chemotherapy and no chemotherapy groups (78.9 months [95% CI, 78.9 months to not reached] vs 62.7 months [95% CI, 56.2 months to not reached]; P = .13). After adjustment for potential confounding factors, receipt of chemotherapy was associated with improved survival (hazard ratio, 0.67; 95% CI, 0.48-0.93; P = .02).

Conclusions and Relevance

This cohort study found that in node-positive, estrogen receptor-positive elderly patients with breast cancer and multiple comorbidities, receipt of chemotherapy was associated with improved overall survival. Despite attempts to adjust for selection bias, these findings suggest that physicians carefully selected patients likely to derive treatment benefit from adjuvant chemotherapy based on certain unmeasured variables. A standardized, multidisciplinary approach to care may be associated with long-term treatment outcomes in this subset of the population.

Validation of prognostic significance of the proposed uniform classification framework in neuroendocrine neoplasms of the breast

PURPOSE

A uniform classification framework for neuroendocrine neoplasms (NENs) in all the organ systems has been recently proposed by an International Agency for Research on Cancer (IARC) and World Health Organization (WHO) expert panel. Based on the new classification system, the NENs of the breast are divided into well-differentiated neuroendocrine tumors (NETs) and poorly differentiated neuroendocrine carcinomas (NECs). This study is aimed to analysis the prognostic differences between NENs and invasive ductal carcinomas of no special type (IDCs-NST).

METHODS

The surveillance, epidemiology, and end results (SEER) database released on November 2018 was used for this study. Between 2003 and 2016, 361 NENs (NET = 239, NEC = 122) of the breast and 491,908 of IDCs-NST were identified. Survival analysis was performed for disease-specific survival (DSS) and overall survival (OS).

RESULTS

The 5-year DSS of NET, NEC, and IDC-NST was 63.39%, 46.00%, and 89.17%, respectively. And the 5-year OS of NET, NEC, and IDC-NST was 55.66%, 38.87%, and 83.17%, respectively. Within the same clinical stage or grade, NETs and NECs of the breast had worse DSS and OS than corresponding stage or grade IDCs-NST (all P < 0.050). In univariate and multivariate survival analysis, NENs of the breast had significantly worse DSS and OS than IDCs-NST (P < 0.001).

CONCLUSION

The universal classification framework for NEN allowed us to further refine the breast carcinoma with neuroendocrine differentiation as a unique pathologic and clinical entity, which has worse clinical outcome compared to IDC-NST.

Prospective Registry Trial Assessing the Use of Magnetic Seeds to Locate Clipped Nodes After Neoadjuvant Chemotherapy for Breast Cancer Patients

BACKGROUND

Targeted axillary dissection (TAD) involves locating and removing both clipped nodes and sentinel nodes for assessment of the axillary response to neoadjuvant chemotherapy (NAC) by clinically node-positive breast cancer patients. Initial reports described radioactive seeds used for localization, which makes the technique difficult to implement in some settings. This trial was performed to determine whether magnetic seeds can be used to locate clipped axillary lymph nodes for removal.

METHODS

This prospective registry trial enrolled patients who had biopsy-proven node-positive disease with a clip placed in the node and treatment with NAC. A magnetic seed was placed under ultrasound guidance in the clipped node after NAC. All the patients underwent TAD.

RESULTS

Magnetic seeds were placed in 50 patients by 17 breast radiologists. All the patients had successful seed placement at the first attempt (mean time for localization was 6.1 min; range 1-30 min). The final position of the magnetic seed was within the node (n = 44, 88%), in the cortex (n = 3, 6%), less than 3 mm from the node (n = 2, 4%), or by the clip when the node could not be adequately visualized (n = 1, 2%). The magnetic seed was retrieved at surgery from all the patients. In 49 (98%) of the 50 cases, the clip and magnetic seed were retrieved from the same node. Surgeons rated the transcutaneous and intraoperative localization as easy for 43 (86%) of the 50 cases. No device-related adverse events occurred.

CONCLUSIONS

Localization and selective removal of clipped nodes can be accomplished safely and effectively using magnetic seeds.

Effectiveness and Safety of Magseed-localization for Excision of Breast Lesions: A Prospective, Phase IV Trial

OBJECTIVE

A prospective, phase IV study was conducted to assess the effectiveness of Magseed to localize breast lesions requiring surgical excision.

BACKGROUND

Since FDA approval in 2016, Magseed has been increasingly used to localize non-palpable lesions due to advantages over wires or radioactive seeds. This is the first prospective, post marketing trial of Magseed.

METHODS

From 1/2017-2/2018, 107 women with lesions requiring localization were enrolled at a single institution. Primary endpoint was Magseed retrieval rate. Secondary endpoints were adverse events, accuracy of placement, surgery duration and positive margin rate. Clinicians were surveyed for ease of use using a Likert scale. Descriptive statistics and Fisher's exact test were performed to assess univariable associations with positive margins.

RESULTS

There were 124 Magseeds placed including one marker in 93 subjects, 2 markers in 11 and 3 markers in 3. The majority of lesions were masses (63%) followed by calcifications (24%). All 124 Magseeds were placed within 10mm of the target lesion and surgically retrieved with median operative time of 15min (range 4-47). No device-related adverse events occurred. Of the 98 malignant lesions, 9 had positive margins and 7 of them underwent a second surgery for additional margins. On univariable analysis, age ≤ 50 (25.0% vs 6.4%, p=0.04), lesion histology (p = 0.03), and pathologic T-stage (p = 0.04) were significantly associated with positive margins. Clinicians rated the Magseed very or fairly easy to use in most cases.

CONCLUSIONS

The Magseed system for localization of non-palpable lesions was effective and safe; all markers were successfully retrieved with margin-negative resections in 91%. This study supports use of Magseed for localization of breast lesions.