NSABP FB-10: a phase Ib/II trial evaluating ado-trastuzumab emtansine (T-DM1) with neratinib in women with metastatic HER2-positive breast cancer

BACKGROUND

We previously reported our phase Ib trial, testing the safety, tolerability, and efficacy of T-DM1 + neratinib in HER2-positive metastatic breast cancer patients. Patients with ERBB2 amplification in ctDNA had deeper and more durable responses. This study extends these observations with in-depth analysis of molecular markers and mechanisms of resistance in additional patients.

METHODS

Forty-nine HER2-positive patients (determined locally) who progressed on-treatment with trastuzumab + pertuzumab were enrolled in this phase Ib/II study. Mutations and HER2 amplifications were assessed in ctDNA before (C1D1) and on-treatment (C2D1) with the Guardant360 assay. Archived tissue (TP0) and study entry biopsies (TP1) were assayed for whole transcriptome, HER2 copy number, and mutations, with Ampli-Seq, and centrally for HER2 with CLIA assays. Patient responses were assessed with RECIST v1.1, and Molecular Response with the Guardant360 Response algorithm.

RESULTS

The ORR in phase II was 7/22 (32%), which included all patients who had at least one dose of study therapy. In phase I, the ORR was 12/19 (63%), which included only patients who were considered evaluable, having received their first scan at 6 weeks. Central confirmation of HER2-positivity was found in 83% (30/36) of the TP0 samples. HER2-amplified ctDNA was found at C1D1 in 48% (20/42) of samples. Patients with ctHER2-amp versus non-amplified HER2 ctDNA determined in C1D1 ctDNA had a longer median progression-free survival (PFS): 480 days versus 60 days (P = 0.015). Molecular Response scores were significantly associated with both PFS (HR 0.28, 0.09-0.90, P = 0.033) and best response (P = 0.037). All five of the patients with ctHER2-amp at C1D1 who had undetectable ctDNA after study therapy had an objective response. Patients whose ctHER2-amp decreased on-treatment had better outcomes than patients whose ctHER2-amp remained unchanged. HER2 RNA levels show a correlation to HER2 CLIA IHC status and were significantly higher in patients with clinically documented responses compared to patients with progressive disease (P = 0.03).

CONCLUSIONS

The following biomarkers were associated with better outcomes for patients treated with T-DM1 + neratinib: (1) ctHER2-amp (C1D1) or in TP1; (2) Molecular Response scores; (3) loss of detectable ctDNA; (4) RNA levels of HER2; and (5) on-treatment loss of detectable ctHER2-amp. HER2 transcriptional and IHC/FISH status identify HER2-low cases (IHC 1+ or IHC 2+ and FISH negative) in these heavily anti-HER2 treated patients. Due to the small number of patients and samples in this study, the associations we have shown are for hypothesis generation only and remain to be validated in future studies. Clinical Trials registration NCT02236000.

Phase II Clinical Trial of Pembrolizumab and Chemotherapy Reveals Distinct Transcriptomic Profiles by Radiologic Response in Metastatic Triple-Negative Breast Cancer

PURPOSE

A single arm, phase II trial of carboplatin, nab-paclitaxel, and pembrolizumab (CNP) in metastatic triple-negative breast cancer (mTNBC) was designed to evaluate overall response rate (ORR), progression-free survival (PFS), duration of response (DOR), safety/tolerability, overall survival (OS), and identify pathologic and transcriptomic correlates of response to therapy.

PATIENTS AND METHODS

Patients with ≤2 prior therapies for metastatic disease were treated with CNP regardless of tumor programmed cell death-ligand 1 status. Core tissue biopsies were obtained prior to treatment initiation. ORR was assessed using a binomial distribution. Survival was analyzed via the Kaplan-Meier method. Bulk RNA sequencing was employed for correlative studies.

RESULTS

Thirty patients were enrolled. The ORR was 48.0%: 2 (7%) complete responses (CR), 11 (41%) partial responses (PR), and 8 (30%) stable disease (SD). The median DOR for patients with CR or PR was 6.4 months [95% confidence interval (CI), 4-8.5 months]. For patients with CR, DOR was >24 months. Overall median PFS and OS were 5.8 (95% CI, 4.7-8.5 months) and 13.4 months (8.9-17.3 months), respectively. We identified unique transcriptomic landscapes associated with each RECIST category of radiographic treatment response. In CR and durable PR, IGHG1 expression was enriched. IGHG1high tumors were associated with improved OS (P = 0.045) and were concurrently enriched with B cells and follicular helper T cells, indicating IGHG1 as a promising marker for lymphocytic infiltration and robust response to chemo-immunotherapy.

CONCLUSIONS

Pretreatment tissue sampling in mTNBC treated with CNP reveals transcriptomic signatures that may predict radiographic responses to chemo-immunotherapy.

Radiomic predicts early response to CDK4/6 inhibitors in hormone receptor positive metastatic breast cancer

The combination of Cyclin-dependent kinase 4/6 inhibitors (CDK4/6i) and endocrine therapy (ET) is the standard of care for hormone receptor-positive (HR + ), human epidermal growth factor receptor 2-negative (HER2-) metastatic breast cancer (MBC). Currently, there are no robust biomarkers that can predict response to CDK4/6i, and it is not clear which patients benefit from this therapy. Since MBC patients with liver metastases have a poorer prognosis, developing predictive biomarkers that could identify patients likely to respond to CDK4/6i is clinically important. Here we show the ability of imaging texture biomarkers before and a few cycles after CDK4/6i therapy, to predict early response and overall survival (OS) on 73 MBC patients with known liver metastases who received palbociclib plus ET from two sites. The delta radiomic model was associated with OS in validation set (HR: 2.4; 95% CI, 1.06-5.6; P = 0.035; C-index = 0.77). Compared to RECIST response, delta radiomic features predicted response with area under the curve (AUC) = 0.72, 95% confidence interval (CI) 0.67-0.88. Our study revealed that radiomics features can predict a lack of response earlier than standard anatomic/RECIST 1.1 assessment and warrants further study and clinical validation.

NCCN Guidelines® Insights: Breast Cancer, Version 4.2023

The NCCN Clinical Practice Guidelines in Oncology (NCCN Guidelines) for Breast Cancer address all aspects of management for breast cancer. The treatment landscape of metastatic breast cancer is evolving constantly. The therapeutic strategy takes into consideration tumor biology, biomarkers, and other clinical factors. Due to the growing number of treatment options, if one option fails, there is usually another line of therapy available, providing meaningful improvements in survival. This NCCN Guidelines Insights report focuses on recent updates specific to systemic therapy recommendations for patients with stage IV (M1) disease.

Abstract OT2-10-02: Phase I trial of an alpha-lactalbumin vaccine in patients with operable triple-negative breast cancer (TNBC)

Background: Triple-negative breast cancer (TNBC) is the subtype of breast cancer with the worst prognosis and is the subtype most often associated with germline mutations of BRCA1 as well as other genes. Alpha-lactalbumin (aLA) is a milk protein expressed in lactating breasts but not at other times or in other normal tissues. Expression of aLA is found in approximately 70% of TNBC (Cancers PMID: 27322324) so is an attractive immunologic target for TNBC based on the “retired protein hypothesis” (Semin Immunol PMID: 31926646). Pre-clinical studies have shown that vaccination with aLA inhibits the growth of established breast tumors and provides potent protection from development of autochthonous tumors in transgenic murine models of breast cancer and against 4T1 transplantable breast cancer in BALB/c mice (Nat Med PMID: 20512124). Specific Aims: We are conducting a Phase I trial of vaccination with an aLA vaccine in patients with early stage TNBC to demonstrate the safety of this approach and to document the ability to produce a relevant immunologic response to aLA. Trial Design: Patients are being entered into a Phase I trial of alpha-lactalbumin with GMP-grade zymosan adjuvant in Montanide ISA 51 VG vehicle. Subjects receive a total of 3 vaccinations administered once every 2 weeks. Toxic events of Common Terminology Criteria for Adverse Events (CTCAE) grade 2 or greater are considered dose-limiting. Dose levels being tested in the current protocol are alpha-lactalbumin/zymosan 0.01/0.01, 0.1/0.01, 0.5/0.01, 0.5/0.03, and 0.5 mg/0.06 mg. Patients are being monitored for toxicity until 84 days after the first vaccination or resolution of toxicity, whichever is later. Blood is being drawn prior to therapy and 14, 28, and 56 days after the first vaccination to assess cellular response using enzyme-linked immunosorbent spot (ELISpot) assays of interferon-gamma and interleukin-17 production in response to aLA. Humoral response to aLA vaccination is being assessed by enzyme-linked immunosorbent assay (ELISA). Eligibility Criteria: Patients with ER-negative, PR-negative, HER2-negative breast cancer of pathologic stage II-III or who had residual disease after standard pre-operative systemic therapy. Participants must be within 3 years of initiation of treatment and have no evidence of recurrence. Dose Selection: Doses are being escalated using a 3+3 trial design to determine the maximum tolerated dose, the lowest immunologic dose and the optimal immunologic dose Present Accrual and Target Accrual: Dependent on toxicity, 18-30 patients will be treated. Future Plans and Contact Information: After identification of the maximum tolerated dose and expansion of the dose levels associated with effective tumor immunity we plan to enroll 2 additional cohorts of patients: 1) patients who have completed pre-operative chemo-immunotherapy and are receiving pembrolizumab as standard of care therapy, and 2) patients without cancer planning to undergo prophylactic bilateral mastectomy. Interested parties may contact Dr. Budd at buddg@ccf.org. Funding Source: Department of Defense (W81XWH-17-1-0592 and W81XWH-17-1-0593)

Citation Format: George Budd, Justin M. Johnson, Emily Rhoades, Halle Moore, Megan L. Kruse, Erin Roesch, Jame Abraham, Brenna Elliott, Elena Haury, Vincent K. Tuohy. Phase I trial of an alpha-lactalbumin vaccine in patients with operable triple-negative breast cancer (TNBC) [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 OT2-10-02.

Development of a shared decision-making intervention to improve drug safety and to reduce polypharmacy in frail elderly patients living at home

Objectives

For patients with geriatric frailty, reducing inappropriate medication is an important goal to improve patient safety in primary care. GP-side barriers include knowledge gaps, legal concerns, and lack of communication between the actors involved. The aim was to develop a multi-faceted intervention to facilitate deprescribing and shared prioritisation among frail elderlies with polypharmacy living at home.

Methods

Mixed methods study including: 1) scoping review on family conferences, expert panels; 2) group discussions with GPs, mapping of needs and challenges in Primary Care; 3) workshops and expert interviews with GPs, patient advocates, researchers as a basis for a theoretical intervention model; 4) piloting.

Results

A major challenge for GPs is to conduct a productive discussion with patients and family cares on deprescribing and drug safety. A guideline for a structured family conference with a medication check and geriatric assessment was developed and proved to be feasible in the pilot study.

Conclusion

The intervention developed to facilitate deprescribing and shared prioritisation of drug therapy based on family conferences seems suitable to be tested in a subsequent cRCT.

Innovation

Adapting family conferences to primary care for frail patients with polypharmacy.

Optimizing adjuvant and post-neoadjuvant therapy in HER2-positive early breast cancer

INTRODUCTION

Treatment advances have improved outcomes in human epidermal growth factor receptor 2 (HER2)-positive early-stage breast cancer (eBC) but certain patients remain at high risk of recurrence. Neoadjuvant therapy (NAT) has comparable outcomes to adjuvant therapy with the advantage of surgical down-staging, response assessment, informing prognosis, and tailoring adjuvant treatment. Thus, the standard of care for the majority of HER2-positive eBC has become a combination of chemotherapy and HER2-targeted agents given in the neoadjuvant setting.

AREAS COVERED

Mounting evidence suggests that pathologic complete response after NAT translates to a favorable long-term prognosis. The efficacy and tolerability of post-NAT are key, particularly for patients with residual disease. This is demonstrated, for example, by the use of trastuzumab emtansine in the appropriate clinical setting and various new drugs under investigation. This review summarizes the current clinical management and exciting future directions to optimize outcomes in HER2-positive eBC.

EXPERT OPINION

Targeted therapies such as trastuzumab deruxtecan, tucatinib, and immunotherapy have demonstrated impressive responses in metastatic breast cancer, including CNS disease. Incorporating these agents in the post-neoadjuvant space may improve the prognosis of HER2-positive eBC. Future research should prioritize the identification of biomarkers that personalize treatments to achieve maximum benefit and less toxicity.

Immune checkpoint inhibition in early-stage triple-negative breast cancer

INTRODUCTION

Breast cancer cells can evade immune recognition by upregulating programmed death-ligand 1 (PD-L1) leading to decreased T cell function. Anti-PD-1 agents, like pembrolizumab, and anti-PD-L1 agents, such as atezolizumab and durvalumab, in combination with chemotherapy were found to have efficacy in metastatic triple-negative breast cancer (TNBC). With sub-optimal long-term outcomes in early-stage TNBC, this combination of immune checkpoint inhibition with chemotherapy was subsequently investigated. A robust immune microenvironment and extensive tumor antigen exposure in early-stage breast cancer is believed to facilitate response to checkpoint inhibitors.

AREAS COVERED

This review focuses on studies that assess the role of neoadjuvant immune checkpoint inhibition along with chemotherapy. The results of key phase I, II and III trials using checkpoint inhibitors in early-stage breast cancer (ESBC) are reviewed along with foundational data from metastatic TNBC, including the role of biomarkers in predicting response to immunotherapy.

EXPERT OPINION

Despite a clear role for neoadjuvant immune checkpoint inhibition in TNBC, many questions remain. The benefit of these agents in the neoadjuvant versus adjuvant setting is unclear and immune-related toxicity is a major concern. Additional studies are needed to elucidate which immune checkpoint inhibitor is most efficacious and best tolerated in early-stage TNBC.

Novel Radiomic Measurements of Tumor-Associated Vasculature Morphology on Clinical Imaging as a Biomarker of Treatment Response in Multiple Cancers

PURPOSE

The tumor-associated vasculature (TAV) differs from healthy blood vessels by its convolutedness, leakiness, and chaotic architecture, and these attributes facilitate the creation of a treatment-resistant tumor microenvironment. Measurable differences in these attributes might also help stratify patients by likely benefit of systemic therapy (e.g., chemotherapy). In this work, we present a new category of computational image-based biomarkers called quantitative tumor-associated vasculature (QuanTAV) features, and demonstrate their ability to predict response and survival across multiple cancer types, imaging modalities, and treatment regimens involving chemotherapy.

EXPERIMENTAL DESIGN

We isolated tumor vasculature and extracted mathematical measurements of twistedness and organization from routine pretreatment radiology (CT or contrast-enhanced MRI) of a total of 558 patients, who received one of four first-line chemotherapy-based therapeutic intervention strategies for breast (n = 371) or non-small cell lung cancer (NSCLC, n = 187).

RESULTS

Across four chemotherapy-based treatment strategies, classifiers of QuanTAV measurements significantly (P < 0.05) predicted response in held out testing cohorts alone (AUC = 0.63-0.71) and increased AUC by 0.06-0.12 when added to models of significant clinical variables alone. Similarly, we derived QuanTAV risk scores that were prognostic of recurrence-free survival in treatment cohorts who received surgery following chemotherapy for breast cancer [P = 0.0022; HR = 1.25; 95% confidence interval (CI), 1.08-1.44; concordance index (C-index) = 0.66] and chemoradiation for NSCLC (P = 0.039; HR = 1.28; 95% CI, 1.01-1.62; C-index = 0.66). From vessel-based risk scores, we further derived categorical QuanTAV high/low risk groups that were independently prognostic among all treatment groups, including patients with NSCLC who received chemotherapy only (P = 0.034; HR = 2.29; 95% CI, 1.07-4.94; C-index = 0.62). QuanTAV response and risk scores were independent of clinicopathologic risk factors and matched or exceeded models of clinical variables including posttreatment response.

CONCLUSIONS

Across these domains, we observed an association of vascular morphology on CT and MRI-as captured by metrics of vessel curvature, torsion, and organizational heterogeneity-and treatment outcome. Our findings suggest the potential of shape and structure of the TAV in developing prognostic and predictive biomarkers for multiple cancers and different treatment strategies.

Association of Bariatric Surgery With Cancer Risk and Mortality in Adults With Obesity

IMPORTANCE

Obesity increases the incidence and mortality from some types of cancer, but it remains uncertain whether intentional weight loss can decrease this risk.

OBJECTIVE

To investigate whether bariatric surgery is associated with lower cancer risk and mortality in patients with obesity.

DESIGN, SETTING, AND PARTICIPANTS

In the SPLENDID (Surgical Procedures and Long-term Effectiveness in Neoplastic Disease Incidence and Death) matched cohort study, adult patients with a body mass index of 35 or greater who underwent bariatric surgery at a US health system between 2004 and 2017 were included. Patients who underwent bariatric surgery were matched 1:5 to patients who did not undergo surgery for their obesity, resulting in a total of 30 318 patients. Follow-up ended in February 2021.

EXPOSURES

Bariatric surgery (n = 5053), including Roux-en-Y gastric bypass and sleeve gastrectomy, vs nonsurgical care (n = 25 265).

MAIN OUTCOMES AND MEASURES

Multivariable Cox regression analysis estimated time to incident obesity-associated cancer (a composite of 13 cancer types as the primary end point) and cancer-related mortality.

RESULTS

The study included 30 318 patients (median age, 46 years; median body mass index, 45; 77% female; and 73% White) with a median follow-up of 6.1 years (IQR, 3.8-8.9 years). The mean between-group difference in body weight at 10 years was 24.8 kg (95% CI, 24.6-25.1 kg) or a 19.2% (95% CI, 19.1%-19.4%) greater weight loss in the bariatric surgery group. During follow-up, 96 patients in the bariatric surgery group and 780 patients in the nonsurgical control group had an incident obesity-associated cancer (incidence rate of 3.0 events vs 4.6 events, respectively, per 1000 person-years). The cumulative incidence of the primary end point at 10 years was 2.9% (95% CI, 2.2%-3.6%) in the bariatric surgery group and 4.9% (95% CI, 4.5%-5.3%) in the nonsurgical control group (absolute risk difference, 2.0% [95% CI, 1.2%-2.7%]; adjusted hazard ratio, 0.68 [95% CI, 0.53-0.87], P = .002). Cancer-related mortality occurred in 21 patients in the bariatric surgery group and 205 patients in the nonsurgical control group (incidence rate of 0.6 events vs 1.2 events, respectively, per 1000 person-years). The cumulative incidence of cancer-related mortality at 10 years was 0.8% (95% CI, 0.4%-1.2%) in the bariatric surgery group and 1.4% (95% CI, 1.1%-1.6%) in the nonsurgical control group (absolute risk difference, 0.6% [95% CI, 0.1%-1.0%]; adjusted hazard ratio, 0.52 [95% CI, 0.31-0.88], P = .01).

CONCLUSIONS AND RELEVANCE

Among adults with obesity, bariatric surgery compared with no surgery was associated with a significantly lower incidence of obesity-associated cancer and cancer-related mortality.

Breast Cancer, Version 3.2022, NCCN Clinical Practice Guidelines in Oncology

The therapeutic options for patients with noninvasive or invasive breast cancer are complex and varied. These NCCN Clinical Practice Guidelines for Breast Cancer include recommendations for clinical management of patients with carcinoma in situ, invasive breast cancer, Paget disease, phyllodes tumor, inflammatory breast cancer, and management of breast cancer during pregnancy. The content featured in this issue focuses on the recommendations for overall management of ductal carcinoma in situ and the workup and locoregional management of early stage invasive breast cancer. For the full version of the NCCN Guidelines for Breast Cancer, visit NCCN.org.

Phase I trial of an alpha-lactalbumin vaccine in patients with moderate- to high-risk operable triple-negative breast cancer (TNBC)

TPS1125

Background: Triple-negative breast cancer (TNBC) is the subtype of breast cancer with the worst prognosis and is the subtype most often associated with germline mutations of BRCA1 and certain other genes. Alpha-lactalbumin (aLA) is a milk protein that is expressed in lactating breasts but not at other times or in other normal tissues. Expression of aLA is found in approximately 70% of TNBC (Cancers PMID: 27322324) so is an attractive immunologic target for TNBC based on the “retired protein hypothesis” (Semin Immunol PMID: 31926646). Pre-clinical studies have shown that vaccination with aLA provides treatment of established and, more potently, protection from development of autochthonous tumors in transgenic murine models of breast cancer and against 4T1 transplantable breast cancer in BALB/c mice (Nat Med PMID: 20512124). We are conducting a Phase I trial in patients with early stage TNBC to demonstrate the safety of this approach and to document the ability to produce a meaningful immunologic response to aLA. Methods: Patients with ER-negative, PR-negative, HER2-negative breast cancer of pathologic stage I-III or who had residual disease after standard pre-operative systemic therapy are being entered into a Phase I trial of alpha-lactalbumin with a GMP-grade zymosan adjuvant in Montanide ISA 51 VG vehicle. Participants must be within 3 years of initiation of treatment and have no evidence of recurrence. Patients receive a total of 3 vaccinations administered once every 2 weeks with doses escalated using a 3+3 trial design. Toxic events of Common Terminology Criteria for Adverse Events (CTCAE) grade 2 or greater are considered dose-limiting. Dose levels being tested are alpha-lactalbumin/zymosan 0.01 mg/0.01 mg, 0.1 mg/0.1 mg, and 1 mg/1 mg. Patients are being monitored for toxicity until 84 days after the first vaccination or resolution of toxicity, whichever is later. Blood is being drawn prior to therapy and 14, 28, and 56 days after the first vaccination to assess cellular response using enzyme-linked immunosorbent spot (ELISpot) assays of interferon-gamma and interleukin-17 production in response to aLA. Humoral response to aLA vaccination is being assessed by enzyme-linked immunosorbent assay (ELISA). After identification of the Maximum Tolerated Dose we will expand the dose levels associated with effective tumor immunity and enroll a cohort of patients without cancer planning to undergo prophylactic bilateral mastectomy. Funding Source: Department of Defense (W81XWH-17-1-0592 and W81XWH-17-1-0593). Clinical trial information: NCT04674306.

Increased Drug Intoxications Seen in Heart Transplant Donors During COVID-19 Pandemic

Purpose

The majority of heart transplant centers decline heart donors with known or suspected COVID-19. In addition to impacting donor utilization, we hypothesize that the COVID pandemic is associated with increased number of drug intoxication in heart donors.

Methods

The COVID pandemic was declared on March 11^th, 2020. The Scientific Registry of Transplant Recipient was analyzed during two 15-month eras: era 1 was defined as January 1^st2019 - March 30^th, 2020 and era 2 was defined as March 31^th, 2020 - June 30th 2021. Donor populations are described by era and UNOS region. T-test was used for trend analysis.

Results

Era 1 identified 7,649 donor hearts and era 2 identified 8,475 donor hearts. There was a significant increase of 577 (45.2%) heart donors with drug intoxication identified as the cause of death from era 1 to era 2 (p<0.0001, Figure 1). There was an increase in heart donors from drug intoxication cross all UNOS regions, but the greatest increase was seen in UNOS region 5 (120.3%) followed by region 7 (69.1%) and region 4 (61.4%) (Figure 2).

Conclusion

More donor hearts were recovered for transplantation during the COVID-19 pandemic, with a notable increase in those who died from drug intoxication. This finding may reflect a psychosocial effect of the pandemic on the general population that has impacted the field of heart transplantation.

Abstract P5-13-27: Post-treatment vascularity and vessel shape are associated with survival and response to CDK4/6 inhibitors in hormone receptor-positive metastatic breast cancer (MBC)

Background: CDK 4/6 inhibitors (CDKI) with Endocrine therapy (ET) is mainstay treatment for hormone receptor-positive (HR+) Her2- metastatic breast cancer (MBC). Despite excellent efficacy, most patients develop resistance to CDKI limiting its utility. CDK4/6 are thought to act by upregulating VEGF causing tortuous angiogenesis and promoting cancer progression. Recent studies have shown aggressive tumors possess a higher density and tortuous vasculature. In this study, we evaluated if vascular radiomic features computationally extracted from liver CT scans pre- and post CDKI treatment could predict patient survival and treatment response. Method: From a registry of 350 patients on treatment with CDKI at institution 1(S1), 51 pts with HR+, Her2-, MBC patients with evidence of liver mets and disease progression (PFS) data were identified. 30 pts discontinued treatment due to progression or death, with a median time to progression of 195 days. Pre-treatment and first post-treatment CT exams were analyzed from 25 and 34 patients, respectively. Median time between scans was 128 days. To validate the prognostic value of our signature, a cohort of 29 patients with available OS data was identified from institution 2 (S2). A publicly available pre-trained deep learning model was applied to isolate liver metastases and vessels. Next, fast marching algorithm was applied to reduce vessels to their centerlines and divide the vasculature into constituent branches. 7 quantitative metrics were computed measuring vascularity of metastases and 3-D shape of hepatic vessels. First, the number (f1) and percentage (f2) of hepatic vessels arising from the tumor were computed. Vessel tortuosity - measuring the degree of twisting across a vessel - was computed separately for each branch. The mean (f3), standard deviation (f4), maximum (f5), skewness (f6), and kurtosis (f7) tortuosity values were calculated to summarize these measurements at patient level. The features were individually assessed at pre- and post-treatment for association with PFS at S1 in univariable Cox proportional hazards models. Features found to be associated in S1 were evaluated for association with OS in S2. Results: On the initial post-treatment scan, features of both tumor vascularization (f6 - HR=1.115 [1.039-1.196]; f7 - HR=10.646 [2.539-44.641]), as well as two features of vessel tortuosity (f3 - HR=0.011 [0.001-0.199]; f4 - HR=0.545 [0.313-0.949]) were significantly associated with PFS. Both tortuosity features were also significantly associated with OS in S2 (f3 - HR=0.085 [0.009-0.780]; f4 - HR=0.331 [0.130-0.842]). In addition the percentage (f7 - HR=6.445 [2.001-20.753]]),of vessels feeding the lesions was also significant in S2 while the number (f6 - HR=1.070 [0.966-1.184]), of vessels was not. No vessel metrics from the pre-treatment baseline exam were significantly associated with OS. Conclusions: Radiomic analysis of tumor vascularity and vessel tortuosity on CT scans post-CDK treatment was associated with patient survival and treatment response.

Table 1.Association of vessel features with PFS in Institution 1(S1)and OS in Institution 2(S2)S1- Pretreatment CT (n=25)S1 - Post-Treatment CT (n=34)S2 - Post-treatment CT - Validation (n=29)f1Tortuosity - Mean0.9912702470.852294696–f2Tortuosity - St. Dev0.7563942230.273115373–f3Tortuosity - Max0.1387051870.0022517550.02931473f4Tortuosity - Skewness0.254463710.0318270370.02022882f5Tortuosity - Kurtosis0.3058266760.108967601–f6Number of vessels feeding lesions0.419096650.0025747910.19306052f7Percentage of vessels feeding lesions0.0517942660.0012205950.00179103

Citation Format: Vidya Sankar Viswanathan, Nathaniel Braman, Priyanka Reddy, Siddharth Kunte, Jame Abraham, Alberto J Montero, Anant Madabhushi. Post-treatment vascularity and vessel shape are associated with survival and response to CDK4/6 inhibitors in hormone receptor-positive metastatic breast cancer (MBC) [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr P5-13-27.

Determining degradation kinetics, byproducts and toxicity for the reductive treatment of Nitroguanidine (NQ) by magnesium-based bimetal Mg/Cu

Energetic-laden process water from industrial munition facilities can be treated by zero-valent metals (ZVMs) or zero-valent iron (ZVI) to remove residual energetics. This reduction-based treatment is significantly enhanced with the addition of a secondary catalytic metal (i.e. forming a bimetal reagent). The reagent is further enhanced by using a more reductive base metal, such as Mg. In this work, the reductive degradation of nitroguanidine (NQ) in aqueous solutions by Mg/Cu bimetal is investigated. Two initial pH conditions (unadjusted and pH 2.7) were studied. Under unadjusted initial pH conditions, 90% of NQ degraded within 30 min reaction time. After 150 min, NQ degradation generated a suite of products including guanidine (44%), cyanamide (31%), formamide (15%), aminoguanidine (AQ) (6%), urea (2%) and cyanoguanidine (0.03%), leading to 100.0% carbon closure when accounting for residual NQ. The experimentally-derived degradation reaction pathway consisted of two parallel reactions: nitroreduction led to formation of AQ with further degradation to urea, cyanamide and formamide, or reductive cleavage of the N-N bond led to guanidine formation. Toxicological assessments indicated only cyanamide and AQ were toxic to S. obliquus at certain concentrations. A lowered initial pH promoted AQ transformation to benign formamide, thus reducing toxicity and complexity of products.

Adrenal-permissive HSD3B1 genetic inheritance and risk of estrogen-driven postmenopausal breast cancer

BACKGROUND

Genetics of estrogen synthesis and breast cancer risk has been elusive. The 1245A→C missense-encoding polymorphism in HSD3B1, which is common in White populations, is functionally adrenal permissive and increases synthesis of the aromatase substrate androstenedione. We hypothesized that homozygous inheritance of the adrenal-permissive HSD3B1(1245C) is associated with postmenopausal estrogen receptor–positive (ER-positive) breast cancer.

METHODS

A prospective study of postmenopausal ER-driven breast cancer was done for determination of HSD3B1 and circulating steroids. Validation was performed in 2 other cohorts. Adrenal-permissive genotype frequency was compared between postmenopausal ER-positive breast cancer, the general population, and postmenopausal ER-negative breast cancer.

RESULTS

Prospective and validation studies had 157 and 538 patients, respectively, for the primary analysis of genotype frequency by ER status in White female breast cancer patients who were postmenopausal at diagnosis. The adrenal-permissive genotype frequency in postmenopausal White women with estrogen-driven breast cancer in the prospective cohort was 17.5% (21/120) compared with 5.4% (2/37) for ER-negative breast cancer (P = 0.108) and 9.6% (429/4451) in the general population (P = 0.0077). Adrenal-permissive genotype frequency for estrogen-driven postmenopausal breast cancer was validated using Cambridge and The Cancer Genome Atlas data sets: 14.4% (56/389) compared with 6.0% (9/149) for ER-negative breast cancer (P = 0.007) and the general population (P = 0.005). Circulating androstenedione concentration was higher with the adrenal-permissive genotype (P = 0.03).

CONCLUSION

Adrenal-permissive genotype is associated with estrogen-driven postmenopausal breast cancer. These findings link genetic inheritance of endogenous estrogen exposure to estrogen-driven breast cancer.

FUNDING

National Cancer Institute, NIH (R01CA236780, R01CA172382, and P30-CA008748); and Prostate Cancer Foundation Challenge Award.

Real-World Outcomes of Everolimus and Exemestane for the Treatment of Metastatic Hormone Receptor-Positive Breast Cancer in Patients Previously Treated With CDK4/6 Inhibitors

PURPOSE

Everolimus with exemestane (EVE+EXE) was FDA-approved to treat metastatic hormone receptor-positive breast cancer (mHRBC) based on BOLERO-2. However, none of those patients received prior CDK4/6 inhibitors. The purpose of this study is to evaluate the efficacy of EVE+EXE in mHRBC after CDK4/6 inhibitors.

METHODS

A retrospective review of patients ≥18 years old with mHRBC treated with EVE+EXE, for ≥30 days, at our institution from January 1, 2012, to April 1, 2020 was conducted. Primary objective was to compare progression free survival (PFS) for EVE+EXE between patients with and without prior exposure to CDK4/6 inhibitors. Secondary outcomes included overall survival and safety.

RESULTS

192 patients were included in the study (n = 79, prior CDK4/6 inhibitor use; n = 113, no prior CDK4/6 inhibitor use). Baseline patient characteristics were similar between groups. Greater number of prior therapies before EVE+EXE use increased risk of disease progression (P = .017). Patients with prior CDK4/6 inhibitor use had a lower median PFS of 3.8 months (95% CI: 3.4-4.7) vs. 5.4 months (95% CI: 3.9-6.2) for patients without prior CDK4/6 inhibitor use, with a HR for progression of 1.46 (95% CI: 1.08 to 1.97, P = .013). Overall survival between groups was not significantly different.

CONCLUSION

Patients who received a prior CDK4/6 inhibitor had a lower median PFS benefit from EVE+EXE compared to those who did not, without differences in overall survival. Although PFS is expected to decrease with subsequent lines of therapy, it is reasonable to use EVE+EXE after CDK4/6 inhibitors in selected patients, recognizing that additional benefit is modest.

Pseudocirrhosis in Breast Cancer - Experience From an Academic Cancer Center

Background

Pseudocirrhosis is characterized by radiological changes in the liver that resemble cirrhosis, but with more rapid onset and progression. Though reported most frequently in patients with metastatic breast cancer, little is known about its prognostic factors and impact on breast cancer outcomes.

Methods

In this observational study, we reviewed abdominal CT and/or MRI scan reports of all patients with invasive breast cancer diagnosed at our center, during a ten-year period, to identify patients with pseudocirrhosis. Exclusion criteria included lack of baseline imaging, pre-existing cirrhosis, hepatitis B or C, other chronic liver diseases, or heavy alcohol use. Routine descriptive statistical measures were used. Survival distributions were estimated using Kaplan-Meier method, and Cox regression was used for multivariate analysis. Two-tailed p < 0.05 was considered significant.

Results

Eighty-six patients were included - all were females, median age was 57.5 years, and 90% were Caucasian; 86% of primary tumors were hormone-receptor positive and 17% were HER2 positive. Most patients (98%) had metastatic disease with liver involvement (94%), and were heavily pre-treated - 97% with chemotherapy, 85% with hormonal therapy, and 19% with anti-HER2 agents. Median interval from breast cancer diagnosis to pseudocirrhosis was 75.4 months (IQR 35.2-115.3 months). Thirty-six percentage of patients had ≥1 signs of portal hypertension and 49% had ≥1 signs of hepatocellular failure. Pseudocirrhosis led to permanent discontinuation of chemotherapy, endocrine therapy, and all systemic therapies in 29%, 31%, and 20% patients, respectively. Median overall survival from diagnosis of pseudocirrhosis was 10.0 months (95%CI 5.2-14.8 months). On multivariate analysis, coagulopathy, hyperbilirubinemia, hypoalbuminemia, and cancer progression were independently predictive of mortality.

Conclusions

In this largest series, to date, of breast cancer with pseudocirrhosis, the latter was often complicated by portal hypertension and hepatocellular failure, and markedly impacted breast cancer management. Survival was shorter for patients who developed hepatocellular failure.

Adrenal-permissive HSD3B1 genetic inheritance and risk of estrogen-driven postmenopausal breast cancer

10503

Background: Genetic factors that contribute to endogenous estrogen synthesis and postmenopausal breast cancer risk are unknown. We set out to test the hypothesis that homozygous inheritance of the common 1245A→C missense-encoding polymorphism in HSD3B1, which is common (8-10%) in White populations, functionally adrenal permissive and increases synthesis of the aromatase substrate, androstenedione, is associated with postmenopausal estrogen receptor-positive breast cancer. Methods: A prospective single institution study of postmenopausal estrogen receptor-driven breast cancer for determination of HSD3B1 genotype, circulating steroid concentrations, and adrenal-permissive genotype frequency compared with the genotype frequency in the general population and in estrogen receptor-negative breast cancer. Validation was performed in 2 breast cancer genomic studies with estrogen receptor documentation. The primary outcome is the adrenal-permissive genotype frequency in postmenopausal estrogen receptor-positive breast cancer and the general population. Genotype comparisons were also done with postmenopausal estrogen receptor-negative breast cancer and the association with circulating adrenal androgen concentrations determined. Results: The prospective and validation studies had 199 and 1628 women, respectively. The adrenal-permissive genotype frequency in postmenopausal White women with estrogen-driven breast cancer in the prospective cohort was 17.5% (21/120) compared with 9.6% (429/4451) in the general population [p = 0.0077]. The adrenal-permissive genotype frequency for estrogen-driven postmenopausal breast cancer was validated using the Cambridge and TCGA genomic datasets together: 14.4% (56/389) compared with 6.0% (9/149) for estrogen receptor-negative breast cancer (p = 0.007) and the general population (p = 0.005). Circulating androstenedione concentration was significantly higher for women with the adrenal-permissive genotype compared with the other genotypes (p = 0.03). Conclusions: The adrenal-permissive genotype is associated with estrogen-driven postmenopausal breast cancer. These findings link genetic inheritance of endogenous estrogen exposure to estrogen-driven breast cancer and have broad implications for risk stratification, prevention, potential biomarkers for hormonal therapy response and possibly other clinical outcomes related to estrogen physiology in postmenopausal women.

NCCN Guidelines® Insights: Breast Cancer, Version 4.2021

The NCCN Guidelines for Breast Cancer include up-to-date guidelines for clinical management of patients with carcinoma in situ, invasive breast cancer, Paget disease, phyllodes tumor, inflammatory breast cancer, male breast cancer, and breast cancer during pregnancy. These guidelines are developed by a multidisciplinary panel of representatives from NCCN Member Institutions with breast cancer-focused expertise in the fields of medical oncology, surgical oncology, radiation oncology, pathology, reconstructive surgery, and patient advocacy. These NCCN Guidelines Insights focus on the most recent updates to recommendations for adjuvant systemic therapy in patients with nonmetastatic, early-stage, hormone receptor-positive, HER2-negative breast cancer.

Abstract PS5-42: Change in intra-lesion heterogeneity on CT predicts long-term survival following treatment with CDK4/6 inhibitors in hormone receptor-positive metastatic breast cancer (MBC)

Background: CDK 4/6 inhibitors are currently standard of care for patients CDK 4/6 inhibitors but currently lack validated predictive markers. We evaluated whether changes in intra-lesional heterogeneity, extracted computationally from routine computed tomography (CT) of MBC could predict survival following treatment with CDK 4/6 inhibitors.

Methods: 33 patients with ER+ breast cancer metastasized to the liver who received palbociclib in combination with anti-estrogen therapy were identified from a registry. For each patient, CT exams were acquired prior to treatment and following initiation of treatment (median time between scans of 106 +/- 48.6 days). Liver metastases were manually delineated on all scans with consultation of radiology reports. On each scan, gray level co-occurrence matrix (GLCM) entropy, a computational measure of intra-lesional heterogeneity, was calculated and averaged across all metastatic lesions and its change over treatment was computed. For comparison, response was also assessed via RECIST v1.1: 65% of patients had objective response/stable disease, while 35% had progressive disease on scan following initiation of treatment. Imaging metrics were assessed individually and in a multivariate comparison including clinical features for association with overall survival (OS) via a cox proportional hazards model.

Results: Change in intra-lesion heterogeneity was associated with OS with a hazard ratio [HR] of 2.82 (p=0.019). An increase in entropy between the pre- and treatment scan was associated with poorer viability on treatment including CDK inhibitors, indicating that a favorable response can be distinguished by a decrease in intra-lesion heterogeneity. RECIST response was also associated with OS (HR=0.24, p&lt;0.001). In a multivariable comparison with clinical variables, change in GLCM entropy and response per RECIST criteria both demonstrated multivariate significance. Neither the heterogeneity measure on the pre-treatment scan (HR=0.56, p=0.23) nor the scan acquired during treatment (HR=1.51, p=0.27) treatment scans alone were significantly associated with overall survival.

Conclusions: The change in lesion heterogeneity on clinical imaging following the initiation of treatment was found to offer independent value in distinguishing patients with favorable survival following CDK 4/6 inhibitor treatment.

Multivariate association of imaging features and clinical variables with overall survivalHazard ratio (HR)p-valueChange in Heterogeneity4.670.019RECIST response0.160.003PR status1.010.99HER2 status1.130.92Age1.040.26Pathology0.770.39Line of Treatment1.360.12

Citation Format: Nathaniel Braman, Siddharth Kunte, Kaustav Bera, Jame Abraham, Albert Montero, Anant Madabhushi. Change in intra-lesion heterogeneity on CT predicts long-term survival following treatment with CDK4/6 inhibitors in hormone receptor-positive metastatic breast cancer (MBC) [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 PS5-42.

Abstract PS12-16: Pilot study of carboplatin, nab-paclitaxel and pembrolizumab for metastatic triple-negative breast cancer

Background. Given the significant clinical activity of the anti-PD1 inhibitor pembrolizumab as either a single agent or in combination with cytotoxic chemotherapy in the treatment of patients with metastatic triple-negative breast cancer (mTNBC), as well as the favorable cytotoxic and immunomodulatory properties of carboplatin and nab-paclitaxel, we identified a strong rationale to treat patients with mTNBC with the combination of carboplatin (C), nab-paclitaxel (N) and pembrolizumab (P) (CNP).

Material and Methods. We undertook a prospective, single-arm pilot study of 30 patients with mTNBC treated at two institutions. Inclusion criteria included: radiographically measurable mTNBC, ECOG performance status of 0-1, &lt;2 prior therapies for mTNBC, and willingness to undergo a primary pre-treatment biopsy of a metastatic focus for research purposes. A second post-treatment research biopsy was encouraged but not mandated. Eligible patients received 3 cycles of CNP, with each cycle initially consisting of C (AUC 6 on days 1 of a 21-day cycle), N (100 mg/m2 IV on days 1, 8 and 15 of a 21-day cycle), and P (200 mg IV on day 15 of each cycle). Because of significant bone marrow toxicity, C was subsequently reduced to AUC 4.2 and N was reduced to 75 mg/m2. After completing 3 cycles of CNP, patients with either responding or stable disease by RECIST 1.1 criteria were eligible for additional cycles of CNP. The primary objective of this study was to determine overall response rate (ORR) in patients treated with CNP. The true response rate of therapy was estimated based on the number of responses using a binomial distribution and its confidence intervals were estimated using Wilson's method. Secondary objectives included: determine progression-free survival (PFS) and safety/tolerability of CNP. The Kaplan-Meier method was used to estimate PFS and OS. The probability of PFS at 6, 12, and 18 months were 51.8%, 24.7%, and 6.2%, respectively. The median PFS was 6.1 (95% CI: 5.1, 11) months. The probability of OS at 6, 12, and 18 months were 79%, 47%, and 5.9%, respectively. The median OS was 11.5 (95% CI: 8, 14.1) months. Correlative biopsy analyses will be undertaken to identify pathologic and genomic correlates of response to CNP. Factors including pathologic and genomic correlates that predict survival outcomes will be identified by Cox model or extensions of the Cox model.Results. Twenty nine patients have completed treatment and 1 remains on single-agent P. ORR was 53% (2 CRs and 14 PRs). Four patients had SD. The most common toxicity was infection (10 patients, grade 3) .The most common immune-related adverse events were pneumonitis (1 patient, grade 3) and hepatitis (1 patient, grade 3). There was only 1 grade 4 toxicity (increased creatinine).

Conclusions. CNP demonstrated significant activity in patients with mTNBC. Studies are underway to identify pathologic and genomic correlates of clinical response to CNP.

Citation Format: Joseph Baar, Jame Abraham, G. Thomas Budd, Paula Silverman, Alberto Montero, Halle Moore, Pingfu Fu, Vinay Varadan, Kara Ladaika, Lauren Hricik. Pilot study of carboplatin, nab-paclitaxel and pembrolizumab for metastatic triple-negative breast cancer [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 PS12-16.

Reducing time to treatment and patient costs with breast cancer: the impact of patient visits

BACKGROUND

The purpose of this study was to evaluate the impact of processes aimed at reducing time to treatment initiation (TTI) on minimizing the days spent to complete pretreatment visits and the associated costs for patients with nonmetastatic breast cancer.

METHODS

System-wide initiatives were implemented in 2014 to minimize TTI, by incorporating multiple strategies (eg, creation of teams, patient liaisons, process mapping) and enhanced communication to increase coordinated visits. Average number of days spent to complete visits, TTI, and associated patient costs including driving expenses, parking, food, childcare, and lost wages were calculated and compared between the years 2015 and 2018.

RESULTS

In 2015, the median TTI was 43.5 days and the average number of separate days spent to attend multidisciplinary visits prior to first treatment was 1.86. These were reduced to 29 days and 1.52 visits, respectively, in 2018 (p < 0.0001 for both). When evaluating treatment visits by surgical procedure, the average number of visits was reduced regardless of surgical procedure. The average number of visits was highest for patients undergoing mastectomy with reconstruction (2.34 in 2015, reduced to 1.65 in 2018, p < 0.0001). A single visit to complete treatment planning was associated with patient costs of $249 as compared with multiple trips costing $491 for 2 visits and up to $1,226 for 5 visits.

CONCLUSIONS

In breast cancer patients, implementing processes to reduce time to treatment was associated with fewer visits required prior to treatment initiation, resulting in lower patient costs.

Machine Learning-Based Risk Assessment for Cancer Therapy-Related Cardiac Dysfunction in 4300 Longitudinal Oncology Patients

Background The growing awareness of cardiovascular toxicity from cancer therapies has led to the emerging field of cardio-oncology, which centers on preventing, detecting, and treating patients with cardiac dysfunction before, during, or after cancer treatment. Early detection and prevention of cancer therapy-related cardiac dysfunction (CTRCD) play important roles in precision cardio-oncology. Methods and Results This retrospective study included 4309 cancer patients between 1997 and 2018 whose laboratory tests and cardiovascular echocardiographic variables were collected from the Cleveland Clinic institutional electronic medical record database (Epic Systems). Among these patients, 1560 (36%) were diagnosed with at least 1 type of CTRCD, and 838 (19%) developed CTRCD after cancer therapy (de novo). We posited that machine learning algorithms can be implemented to predict CTRCDs in cancer patients according to clinically relevant variables. Classification models were trained and evaluated for 6 types of cardiovascular outcomes, including coronary artery disease (area under the receiver operating characteristic curve [AUROC], 0.821; 95% CI, 0.815-0.826), atrial fibrillation (AUROC, 0.787; 95% CI, 0.782-0.792), heart failure (AUROC, 0.882; 95% CI, 0.878-0.887), stroke (AUROC, 0.660; 95% CI, 0.650-0.670), myocardial infarction (AUROC, 0.807; 95% CI, 0.799-0.816), and de novo CTRCD (AUROC, 0.802; 95% CI, 0.797-0.807). Model generalizability was further confirmed using time-split data. Model inspection revealed several clinically relevant variables significantly associated with CTRCDs, including age, hypertension, glucose levels, left ventricular ejection fraction, creatinine, and aspartate aminotransferase levels. Conclusions This study suggests that machine learning approaches offer powerful tools for cardiac risk stratification in oncology patients by utilizing large-scale, longitudinal patient data from healthcare systems.

Real-world Outcomes of Cyclin-dependent Kinase Inhibitors Continued Beyond First Disease Progression in Hormone Receptor-positive Metastatic Breast Cancer

BACKGROUND

CDK4/6 inhibitors (CDK4/6i), in combination with aromatase inhibitors, are United States Food and Drug Administration-approved for the treatment of hormone receptor-positive (HR⁺)/human epidermal growth factor receptor 2-negative (HER2^-) metastatic breast cancer (MBC). The effectiveness of continuing them beyond first disease progression (PD) is currently unknown. This retrospective study evaluated the impact of the continuation of CDK4/6i beyond first PD in HR⁺/HER2^- MBC using real-world experience.

PATIENTS AND METHODS

A single-institution retrospective review of patients with HR⁺ MBC who received CDK4/6is from 2015 to 2018 and where CDK4/6is were continued beyond first PD. The primary outcome was progression-free survival (PFS) after initial PD on CDK4/6i therapy.

RESULTS

Thirty women with HR⁺/HER2^- MBC met eligibility criteria. Patients were identified from a prospective database of patients at the Cleveland Clinic Foundation who were prescribed CDK4/6is. The median age and follow-up duration were 47.5 years and 27 months, respectively. Most patients received palbociclib (PA)/letrozole as initial therapy (67%), followed by PA/fulvestrant (23%), and PA/other aromatase inhibitor (20%), and abemaciclib with either fulvestrant or letrozole (6%). As of January 31, 2019, 25 (83.3%) patients were still alive, and 19 (63%) patients had progressed. The estimated median PFS for continued CDK4/6i use beyond the first PD was 11.8 months (95% confidence interval, 5.34-13.13 months).

CONCLUSIONS

Among a small cohort of patients with HR⁺ MBC in a non-clinical trial setting, continuation of CDK4/6i-endocrine treatment post initial PD was associated with a median PFS of about 12 months. Formal randomized clinical trials evaluating the continuation of CDK4/6is beyond the first PD are currently ongoing and will provide more answers to this important clinical question.

Stereotactic radiosurgery with concurrent HER2-directed therapy is associated with improved objective response for breast cancer brain metastasis

BACKGROUND

Patients with breast cancer positive for human epidermal growth factor receptor 2 (HER2) remain at high risk of intracranial relapse following treatment and experience increased rates of intracranial failure after stereotactic radiosurgery (SRS). We hypothesized that the addition of concurrent lapatinib to SRS would improve intracranial complete response rates.

METHODS

Patients with newly diagnosed HER2-amplified breast cancer brain metastases from 2005-2014 who underwent SRS were included and divided into 2 cohorts based on timing of treatment with lapatinib. Outcome variables included the proportion of patients who achieved an intracranial complete response or progressive disease according to the RECIST 1.1 criteria, as well as individual lesion response rates, distant intracranial failure, and radiation necrosis.

RESULTS

Eighty-four patients with 487 brain metastases met inclusion criteria during the study period. Over 138 treatment sessions, 132 lesions (27%) were treated with SRS and concurrent lapatinib, while 355 (73%) were treated with SRS without lapatinib. Compared with patients treated with SRS alone, patients treated with concurrent lapatinib had higher rates of complete response (35% vs 11%, P = 0.008). On a per-lesion basis, best objective response was superior in the concurrent lapatinib group (median 100% vs 70% reduction, P < 0.001). Concurrent lapatinib was not associated with an increased risk of grade 2+ radiation necrosis (1.0% with concurrent lapatinib vs 3.5% without, P = 0.27). Lapatinib had no protective effect on distant intracranial failure rates (48% vs 49%, P = 0.91).

CONCLUSION

The addition of concurrent lapatinib to SRS was associated with improved complete response rates among patients with HER2-positive brain metastases.

Novel HER2-targeted therapies for HER2-positive metastatic breast cancer

Human epidermal growth factor receptor 2 (HER2) is overexpressed in approximately 20% of all breast cancers. Before the development of HER2-directed monoclonal antibodies, HER2-positive breast cancer was associated with a rather poor prognosis. With the advent of monoclonal HER2-targeting antibodies (trastuzumab and pertuzumab) and antibody-drug conjugates (trastuzumab emtansine [T-DM1] and trastuzumab deruxtecan), clinical outcomes for HER2-positive breast cancer have dramatically changed, and a greater proportion of patients in the nonmetastatic setting are cured. However, in the metastatic setting, resistance to anti-HER2 treatments still remains a major therapeutic challenge, underscoring the importance of developing novel HER2-directed therapies. Over the last year, there has been a dramatic shift in the current treatment paradigms for HER2-positive metastatic breast cancer, with recent U.S. Food and Drug Administration approvals of trastuzumab deruxtecan (DS-8201), neratinib, and tucatinib in combination with trastuzumab and capecitabine. The authors summarize recent phase 3 data with novel HER2-targeted therapies as well as phase 1 and 2 data with other novel HER2-targeting agents.

NCCN Guidelines Insights: Breast Cancer, Version 3.2018

These NCCN Guidelines Insights highlight the updated recommendations for use of multigene assays to guide decisions on adjuvant systemic chemotherapy therapy for women with hormone receptor-positive, HER2-negative early-stage invasive breast cancer. This report summarizes these updates and discusses the rationale behind them.

Novel targeted therapies for metastatic breast cancer

Metastatic breast cancer (mBC) continues to be a leading cause of cancer-related death in women. Even though mortality rates have improved over recent years, the 5-year survival rate of advanced BC is still at only 27%. As researchers and clinicians attempt to tackle this challenge, there has been extensive research and many trials studying treatment options for BC patients with metastatic disease, with numerous new therapies being discovered as a result. We review the most pertinent novel agents to enter the scope of BC treatment, including CDK4/6 inhibitors, PI3K inhibitors, mTOR inhibitors, immunotherapy, PARP inhibitors, and more.

Genetic Counseling and Germline Testing in the Era of Tumor Sequencing: A Cohort Study

BACKGROUND

The clinical impact of addressing potential germline alterations from tumor-only next-generation sequencing (NGS) is not well characterized. Current guidelines for cancer genetic testing may miss clinically actionable germline changes, which may have important implications for cancer screening, treatment, and prevention. We examined whether increasing involvement of the clinical genetics service during somatic tumor-only NGS review at Molecular Tumor Board (MTB) increases the detection of germline findings.

METHODS

In a retrospective evaluation of patients who underwent tumor-only NGS and were reviewed at MTB, we quantified genetic counseling (GC) referrals as well as germline testing uptake and results across three cohorts: before (C1) and after (C2) the addition of tumor-only NGS review and after (C3) instituting a formal process to coordinate NGS-based genetics referrals to preexisting oncology appointments. All statistical tests were two-sided.

RESULTS

From 2013 to 2017, 907 tumor-only NGS reports were reviewed at MTB (nC1 = 281, nC2 = 493, nC3 = 133); gastrointestinal (22.5%), lung (19.7%), genitourinary (14.8%), and breast (14.1%) were the most common index cancers. GC visits due to MTB increased with each successive cohort (C1 = 1.1%, C2 = 6.9%, C3 = 13.5%; P for trend [P trend] < .001), as did germline testing (C1 = 0.7%, C2 = 3.2%, C3 = 11.3%; P trend < .001). Diagnosis of germline pathogenic variants increased with each successive cohort (C1 = 1.4%, C2 = 2.0%, C3 = 7.5%; P trend = .003) and with germline pathogenic variants found by MTB review (C1 = 0.4%, C2 = 0.4%, C3 = 2.3%; P trend = .12).

CONCLUSIONS

Both review of tumor-only NGS by genetics and the institution of a process coordinating GC with oncology appointments increased the discovery of germline pathogenic variants from tumor-only NGS testing. Furthermore, this process identified germline pathogenic variant carriers who would not have otherwise met standard criteria for germline testing.

Reducing time to treatment and patient costs with breast cancer: The impact of patient visits

e19407

Background: The purpose of this study was to evaluate the impact of a continuous improvement process aimed at reducing time to treatment on minimizing the number of days spent to complete pre-treatment visits and the associated costs for patients with non-metastatic breast cancer. Methods: System-wide initiatives were implemented in 2015 to minimize time to treatment initiation (TTI), by incorporating lean process strategies and enhanced coordination. Patient and treatment information was obtained through an IRB-approved registry for the years 2015 and 2018. Average number of days spent to complete visits, TTI, and associated patient costs including driving expenses, parking, food, childcare, and lost wages were calculated and compared between the years 2015 and 2018. Results: In 2015, the median TTI was 43.5 days and the average number of separate days spent to attend multidisciplinary visits prior to first treatment was 1.86. These were reduced to 29 days and 1.52 visits, respectively, in 2018 (p < 0.0001 for both). When evaluating treatment visits by surgical procedure, the average number of visits was reduced regardless of surgical procedure. The average number of visits was highest for patients undergoing mastectomy with reconstruction (2.34 in 2015, reduced to 1.65 in 2018, p < 0.0001). A single visit to complete treatment planning was associated with patient costs of $249 as compared with multiple trips costing $491 for 2 visits and up to $1,226 for 5 visits. Conclusions: In breast cancer patients, implementing a continuous improvement process to reduce time to treatment was associated with fewer visits required prior to treatment initiation, resulting in lower patient costs.

SGNLVA-001: A phase I open-label dose escalation and expansion study of SGN-LIV1A administered weekly in breast cancer

TPS1104

Background: LIV-1 is a highly prevalent transmembrane protein in breast cancer cells. Ladiratuzumab vedotin (LV), SGN-LIV1A, is an investigational antibody-drug conjugate (ADC) that targets LIV-1 via a humanized IgG1 monoclonal antibody conjugated to monomethyl auristatin E (MMAE) by a protease-cleavable linker. LV is internalized when it binds LIV-1 on cell surfaces and MMAE is released, which binds tubulin and induces apoptosis. LV has been shown to be active and tolerable in metastatic breast cancer (mBC) at a recommended dose of 2.5 mg/kg every 21 days (Modi 2017). More frequent, fractionated dosing has improved the activity and/or safety of other ADCs. Thus, this study is actively accruing subjects with metastatic triple negative breast cancer (mTNBC; estrogen receptor (ER)/progesterone receptor (PR)/human epidermal growth factor receptor 2 (HER2) receptor-negative) and endocrine-resistant ER+ or PR+ (hormone receptor [HR+])/HER2-negative mBC to test weekly dosing of LV (Days 1, 8, and 15 of every 3-week cycle). Methods: This study is enrolling up to 82 subjects (42 HR+/HER2-negative and 40 mTNBC) into dose escalation and dose expansion cohorts (NCT01969643). Eligible subjects are females ≥18 years old with pathologically and radiologically confirmed metastatic HR+/HER2-negative or mTNBC with at least 1 measurable lesion per RECIST v1.1. Subjects with HR+/HER2-negative disease must have received no more than 1 prior line of cytotoxic chemotherapy in the locally advanced (LA)/mBC setting, either as single agent or combination therapy. Subjects with mTNBC must have received 1 prior line of cytotoxic chemotherapy in the LA/mBC setting. Progression within 6 months of completion of neoadjuvant or adjuvant therapy is considered an LA/mBC regimen. Subjects must have adequate organ function, ECOG status of ≤1, and no ≥ Grade 2 peripheral neuropathy. Subjects with brain lesions must have received definitive treatment of the lesions. Prior therapy with MMAE-containing agents is not allowed. Dose escalation follows the modified toxicity probability interval method (Ji 2010). Dose expansion cohorts will provide data about activity and tolerability. Tumor assessments will be conducted every 2 cycles per RECIST v1.1 and all subjects will be followed for safety. Pharmacokinetics and markers of pharmacodynamics will be assessed. Primary safety endpoint is the incidence of adverse events and dose-limiting toxicities. Key efficacy endpoints include confirmed overall response rate, duration of response, and progression-free survival. Clinical trial information: NCT01969643 .

Radiomics risk score (RRS) on CT to predict survival and response to CDK 4/6 inhibitors in hormone receptor (HR) positive metastatic breast cancer (MBC)

e13041

Background: The addition of CDK 4/6 inhibitors (CDK) to endocrine therapy (ET) is the standard of care for HR+ MBC. Currently, no robust predictive markers for CDK inhibitors exist. We hypothesized that baseline imaging features on pre-treatment CT scans using machine learning could correctly identify responders to CDK. Methods: From a retrospective pt registry, 46 pts with HR+ MBC who received palbociclib (palbo) plus ET and had liver metastases were identified, and divided at random into equally sized training and testing cohorts. Patients with objective response/stable disease per RECIST v1.1 were defined as ‘responders’ (65%), and those with progressive disease within 6 months were ‘non-responders’ (35%). The median age at diagnosis was 62. All pts were ER+ and 4% were HER2+. 65% pts received palbo as 1st or 2nd line tx. 503 radiomic texture features measuring subtle differences in lesion heterogeneity on a pixel level were extracted on pre-treatment CT within the first lesion measured for RECIST assessment. An elastic net Cox proportional hazards model was constructed within the training set to derive a Radiomics Risk Score (RRS), which was evaluated for association with prognosis and response within the testing set. A risk score threshold was chosen in the training set for stratifying patients into high and low risk groups. Results: The RRS consisted of 4 radiomic features indicating intratumoral heterogeneity to be associated with poor outcome. In the independent testing set (n = 23), RRS was continuously associated with survival (p = .0027) on multivariate analysis, along with age and RECIST response (Table). Categorical risk groups were similarly associated with survival in the testing set (p = .00491, HR = 4.03, CI = 0.6772). Median survival time in low and high risk groups were 2.33 and 0.673 years, respectively. When compared against RECIST response in the testing set, RRS was found to also be predictive of response with an ROC curve of 0.675. Conclusions: Radiomics analysis was able to predict response and survival in HR+ MBC pts prior to initiation of treatment with CDK. [Table: see text]

Improving Outcomes in HER2-Positive Breast Cancer: Analysis and Application of Evolving Data and Best Practices

Through expert, case-based discussion, Jame Abraham, MD, and Kelley Mayden, MSN, FNP, AOCNP®, presented existing and emerging data for current and investigational therapies for HER2-positive breast cancer and their associated adverse events, in addition to best practices for managing central nervous system metastases.

Breast Cancer, Version 3.2020, NCCN Clinical Practice Guidelines in Oncology

Several new systemic therapy options have become available for patients with metastatic breast cancer, which have led to improvements in survival. In addition to patient and clinical factors, the treatment selection primarily depends on the tumor biology (hormone-receptor status and HER2-status). The NCCN Guidelines specific to the workup and treatment of patients with recurrent/stage IV breast cancer are discussed in this article.