Abstract 2787
Background
Neoadjuvant studies in breast cancer (BC) patients have well-demonstrated that attaining pathological complete response (pCR) is associated with improved event-free survival (EFS) and overall survival (OS); and the association is strong in triple negative BC (TNBC) subtype. This study aimed to comprehensively evaluate the association of pCR and survival outcomes in TNBC by incorporating most recent studies; and to explore the impact of different study settings, thresholds of hormone receptor positivity defining TNBC and adjuvant chemotherapy usage on this association.
Methods
A literature search of neoadjuvant studies in TNBC was conducted up to October 2018. Clinical trials (CTs), real-world evidence (RWE) studies and meta-analyses (MA) with EFS/OS reported by pCR outcome were included. Main analyses were restricted to pCR definition of absence of tumor in the breast and axillary nodes, which is aligned with FDA guidance. Hazard ratios (HRs) evaluating the association between pCR and EFS/OS were derived from meta-analyses using fixed-effect and random-effects models. To further quantify the association, meta-analyses were conducted to synthesize the published survival curves by pCR outcome. A random-effects frailty model was utilized to account for between-study variation.
Results
Four randomized CTs, 2 single-arm CTs, 18 RWE studies and 1 MA for a total of 4,330 patients with TNBC were included in this study. Achieving pCR was strongly associated with improved survival outcomes (HR of EFS: 0.26, 95% CI: 0.22-0.30; and HR of OS: 0.20, 95% CI: 0.16-0.25). HR results were similar across study settings of CTs, RWE and MA. TNBC definition and adjuvant chemotherapy use did not have significant impact on HR results. The meta-analyses showed numerically longer survival in studies that reported adjuvant chemotherapy usage compared with those which did not, irrespective of attainment of pCR.
Conclusions
This study confirms the strong association between pCR and survival outcomes in TNBC based on evidence synthesis from both clinical and real-world settings. In addition, this study suggests potential survival benefit of subsequent adjuvant therapy for TNBC patients who received neoadjuvant therapy.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
Merck & Co., Inc.
Funding
Merck & Co., Inc.
Disclosure
P.A. Fasching: Advisory / Consultancy: Merck & Co., Inc. M. Huang: Full / Part-time employment: Merck & Co., Inc. J. Cortés: Advisory / Consultancy: Merck & Co., Inc. J. Zhao: Full / Part-time employment: Merck & Co., Inc. J. O’Shaughnessy: Advisory / Consultancy: Merck & Co., Inc. P. Hu: Full / Part-time employment: Merck & Co., Inc. A. Haiderali: Full / Part-time employment: Merck & CO., Inc. V. Karantza: Full / Part-time employment: Merck & Co., Inc. G. Aktan: Full / Part-time employment: Merck & Co., Inc. A. Briggs: Advisory / Consultancy: Merck & Co., Inc. S. Ramsey: Advisory / Consultancy: Merck & Co., Inc. C.Z. Qi: Advisory / Consultancy, Employee of Analysis Group, Inc., which has received consulting fees from Merck & Co., Inc.: Merck & Co., Inc. J. Xie: Advisory / Consultancy, Employee of Analysis Group, Inc., which has received consulting fees from Merck & Co., Inc.: Merck & Co., Inc. C. Gu: Advisory / Consultancy, Employee of Analysis Group, Inc., which has received consulting fees from Merck & Co., Inc.: Merck & Co., Inc. K. Qian: Advisory / Consultancy, Employee of Analysis Group, Inc., which has received consulting fees from Merck & Co., Inc.: Merck & Co., Inc. M. Yuan: Advisory / Consultancy, Employee of Analysis Group, Inc., which has received consulting fees from Merck & Co., Inc.: Merck & Co., Inc. E.Q. Wu: Advisory / Consultancy, Employee of Analysis Group, Inc., which has received consulting fees from Merck & Co., Inc.: Merck & Co., Inc.
Resources from the same session
4331 - STING Agonist, ADU-S100, Yields Potent Antitumor Activity and Therapeutically Favorable Immune Profile in an Esophageal Adenocarcinoma Model
Presenter: Ali Zaidi
Session: Poster Display session 2
Resources:
Abstract
1770 - Increased assessment of HER2 in metastatic gastroesophageal cancer patients: a nationwide population-based cohort study
Presenter: Willemieke Dijksterhuis
Session: Poster Display session 2
Resources:
Abstract
3755 - A new docetaxel (DOC)-based triplet regimen does not improve the outcome of metastatic (M) or locally advanced (LA) gastric cancer (GC) as compared with an epirubicin (EPI) standard triplet regimen: a GISCAD trial.
Presenter: Roberto Labianca
Session: Poster Display session 2
Resources:
Abstract
2439 - The analysis of T cell subsets and clinical efficacy of immune checkpoint blockades in patients with advanced gastric cancer using multiplex immunohistochemistry
Presenter: Tae-yong Kim
Session: Poster Display session 2
Resources:
Abstract
2211 - First-line pembrolizumab (P), trastuzumab (T), capecitabine (C) and oxaliplatin (O) in HER2-positive metastatic esophagogastric adenocarcinoma.
Presenter: Yelena Janjigian
Session: Poster Display session 2
Resources:
Abstract
3046 - Monitoring patient-specific mutation in ctDNA and CTC for tumor response evaluation after neoadjuvant chemotherapy in locally advanced gastric cancer (NCT03425058)
Presenter: Tao Fu
Session: Poster Display session 2
Resources:
Abstract
4628 - Gastric cancer screening in BRCA 2 gene mutation carriers: should it be recommended?
Presenter: Inês Oliveira
Session: Poster Display session 2
Resources:
Abstract
2127 - Interim analysis of an observational/translational study for nivolumab treatment in advanced gastric cancer: JACCRO GC-08 (DELIVER trial)
Presenter: Yu Sunakawa
Session: Poster Display session 2
Resources:
Abstract
2264 - Prediction of S-1 adjuvant chemotherapy efficacy in Stage II/III gastric cancer treatment based on comprehensive gene expression analysis
Presenter: Masanori Terashima
Session: Poster Display session 2
Resources:
Abstract
2444 - Assessing the clinical utility of circulating tumour DNA through longitudinal liquid biopsy sampling in Oesophageal adenocarcinoma
Presenter: Emma Ococks
Session: Poster Display session 2
Resources:
Abstract