Neoadjuvant Trebananib plus Paclitaxel-based Chemotherapy for Stage II/III Breast Cancer in the Adaptively Randomized I-SPY2 Trial—Efficacy and Biomarker Discovery
Abstract Purpose: The neutralizing peptibody trebananib prevents angiopoietin-1 and angiopoietin-2 from binding with Tie2 receptors, inhibiting angiogenesis and proliferation. Trebananib was combined with paclitaxel±trastuzumab in the I-SPY2 breast cancer trial. Patients and Methods: I-SPY2, a phase II neoadjuvant trial, adaptively randomizes patients with high-risk, early-stage breast cancer to one of several experimental therapies or control based on receptor subtypes as defined by hormone receptor (HR) and HER2 status and MammaPrint risk (MP1, MP2). The primary endpoint is pathologic complete response (pCR). A therapy “graduates” if/when it achieves 85% Bayesian probability of success in a phase III trial within a given subtype. Patients received weekly paclitaxel (plus trastuzumab if HER2-positive) without (control) or with weekly intravenous trebananib, followed by doxorubicin/cyclophosphamide and surgery. Pathway-specific biomarkers were assessed for response prediction. Results: There were 134 participants randomized to trebananib and 133 to control. Although trebananib did not graduate in any signature [phase III probabilities: Hazard ratio (HR)-negative (78%), HR-negative/HER2-positive (74%), HR-negative/HER2-negative (77%), and MP2 (79%)], it demonstrated high probability of superior pCR rates over control (92%–99%) among these subtypes. Trebananib improved 3-year event-free survival (HR 0.67), with no significant increase in adverse events. Activation levels of the Tie2 receptor and downstream signaling partners predicted trebananib response in HER2-positive disease; high expression of a CD8 T-cell gene signature predicted response in HR-negative/HER2-negative disease. Conclusions: The angiopoietin (Ang)/Tie2 axis inhibitor trebananib combined with standard neoadjuvant therapy increased estimated pCR rates across HR-negative and MP2 subtypes, with probabilities of superiority >90%. Further study of Ang/Tie2 receptor axis inhibitors in validated, biomarker-predicted sensitive subtypes is warranted.
Abstract PD7-06: Trends in surgical resection for stage IV breast cancer: Less surgery more systemic treatment
Abstract Background: There is debate regarding the benefit of breast surgery in women with stage IV breast cancer, especially among those with oligometastatic disease and good response to systemic therapy. Although some retrospective studies have suggested that locoregional therapy may improve survival, this finding has not been universally replicated in randomized controlled trials (RCT) in India, Turkey, and recently the US. To assess need for dissemination of trial results by members of the Alliance/American College of Surgeons Clinical Research Program Dissemination and Implementation (ACS CRP D&I) committee, we sought to determine trends in surgical resection and other therapies for stage IV breast cancer in response to these findings. Methods: The National Cancer Database (NCDB) was queried to identify women diagnosed with clinical stage IV breast cancer of ductal, lobular, or metaplastic histology between 2004-2017. Trends in the rate of women who underwent surgery with breast-conserving surgery (BCS) or mastectomy, radiation, and/or systemic treatments were compared. Possible predictors of breast surgery were examined in univariable and multivariable analysis. Results: We identified 87,331 cases meeting inclusion criteria and assessed demographics for surgery versus no surgery. Of the 87,331 cases, 7,718 (9%) underwent BCS and 17,625 (20%) underwent mastectomy. Rates of breast surgical resection for women with clinically diagnosed stage IV breast cancer rose until 2009, reaching a peak at 37%, followed by a decline to a rate of 18% in 2017 (Table). The largest decline was seen in the hormone receptor positive (HR+) and HER2- subgroup with 71% of patients undergoing surgery in 2007 down to 15% in 2017. Concurrently, the mean number of days between chemotherapy initiation and definitive surgery has been on the rise, ranging from 52 days in 2004 up to 94 days in 2017. In 2004, the rate of systemic therapy alone was slightly more common than locoregional therapy (surgery and/or radiation) with or without systemic therapy (48% vs 37%). By 2017, systemic therapy alone was by far more frequently utilized (69% vs 20%, p<0.001). On multivariable analysis, factors associated with reduced odds of receiving surgery were older age, black race, higher comorbidity index, being uninsured, smaller tumors, lower histologic grade, multiple sites of metastasis, and treatment with chemo-endocrine therapy (all group p values ≤0.001). Factors associated with increased odds of receiving surgery were metaplastic histology, TN subtype, and radiation therapy (all group p values ≤0.001). Conclusions: Rates of surgical resection of the breast primary for stage IV breast cancer have been on the decline in recent years, especially for HR+/HER2- disease, suggesting that providers are responding to the lack of benefit demonstrated in RCTs. Higher rates of surgery in patients with HR-/HER2+ disease and the concurrent rise in the time interval between initiation of systemic therapy and definitive surgical intervention suggest that providers may still be selecting surgery for patients with certain subtypes or those with a durable response to systemic therapy. These areas of continued clinical equipoise could be a target for future studies or de-implementation strategies. OverallHR+/HER2-HER2+TNUnknownSurgery/Total%Surgery/Total%Surgery/Total%Surgery/Total%Surgery/Total%20041189/351334-55-30-50-3420051202/353834-65-35-23-3420061268/375834-54-36-31-3420071571/433636-71-41-32-3620081992/54203754/925926/544820/41491892/52333620092194/592437172/3604883/1525556/106531883/53063520102318/6419361162/331835554/134841352/80144250/9522620112322/6921341220/378932532/144137384/91542186/7762420122238/7110311177/393830587/163536339/85340135/6842020132147/7579281173/423128534/172831334/92536106/6951520142013/8033251086/442825496/185227306/99831125/7551720151805/794323914/434321517/198126288/9962986/6231420161609/819420829/464018459/196823247/10122474/5741320171477/813618722/467815421/190522256/10372578/51615Percent of women with stage IV breast cancer undergoing surgery by year and receptor subtype. Rows containing any number <10 are not reported by subtype to maintain confidentiality, per NCDB guidelines. Citation Format: Sasha R Douglas, Ingrid Lizarraga, Judy C Boughey, Anna Weiss, Kelly Hunt, Diana Dickson-Witmer, Preeti D Subhedar, Ko Un Park, Beiqun Zhao, Sarah Blair. Trends in surgical resection for stage IV breast cancer: Less surgery more systemic treatment [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 PD7-06.
Breast cancer—The catalyst of contemporary trials design
AbstractSurgical trials in breast cancer have catalyzed contemporary trial design for solid organ cancers and are a prime example of surgeons taking the lead in clinical trial design. Surgeons have lead trials that have improved patient outcomes and quality of life without sacrificing oncologic safety. We have evolved from radical mastectomy to breast conservation and sentinel node biopsy. Contemporary trial design in breast cancer now focus on personalizing care based on tumor genomics
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.
Extrapolation of ACOSOG Z0011 trial results—A survey of breast cancer providers
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.
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.