Abstract 6P
Background
Neoadjuvant chemotherapy (NAC) results in a pathologic complete response (pCR) and is associated with disease-free survival and overall survival. The apparent diffusion coefficient (ADC) indicates the stability of water molecules and is used to predict the response of solid tumors to chemotherapy. Therefore, we evaluated the changes in ADC using diffusion-weighted breast magnetic resonance imaging (MRI) to predict pCR in patients with breast cancer treated with NAC.
Methods
From August 2013 to April 2019, 50 patients (mean age, 55 years; age range, 31–75 years) were treated with nanoparticle albumin-bound paclitaxel (nab-PTX) (260 mg/m2) every 3 weeks for four cycles ± concurrent trastuzumab (8 mg, 6 mg/kg) every 3 weeks for four cycles in human epidermal growth factor receptor 2 (HER2)-positive patients followed by FEC (5-fluorouracil/epirubicin/cyclophosphamide, 500/100/500 mg/m2) every 3 weeks for four cycles. pCR was defined as the absence of any residual invasive cancer or ductal carcinoma in situ in the breast. Changes in ADC (Δnab-PTX: post nab-PTX – pre nab-PTX, ΔFEC: post FEC – pre nab-PTX) were also calculated.
Results
The tumor phenotypes were triple negative (TN) (n = 25) and HER2 positive (n = 25). pCR was achieved in 27 patients [54%] (11 with TN disease and 16 with HER2-positive disease). The mean pre nab-PTX ADC and ΔFEC ADC in pCR patients were 0.718±0.157 × 10-3 mm2 and 0.621±0.357 × 10-3 mm2, respectively, and they were not associated with pCR (p = 0.06 and p = 0.248, respectively). However, the mean post nab-PTX ADC and Δnab-PTX ADC were 1.117±0.303 × 10-3 mm2 and 0.400±0.311 × 10-3 mm2, respectively, and they were associated with pCR (p < 0.01 and p = 0.01, respectively). Using receiver operating characteristic (ROC) analysis with Δnab-PTX ADC, the area under the curve was 0.691 [95% confidence interval: 0.54–0.841] in all patients. Δnab-PTX ADC and pCR were significantly correlated (p = 0.00463).
Conclusions
High Δnab-PTX ADCs in diffusion-weighted breast MRI may be promising findings for the successful prediction of pCR in patients treated with NAC using nab-PTX followed by FEC.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
The author.
Funding
Has not received any funding.
Disclosure
The author has declared no conflicts of interest.
Resources from the same session
490P - Outcomes of sequential epidermal growth factor receptor tyrosine (EGFR) tyrosine kinase inhibitor (TKI) therapy in patients with advanced non-small cell lung carcinoma (NSCLC)- a real-world institutional experience
Presenter: Yvonne Ang
Session: Poster display session
Resources:
Abstract
498P - An observational retrospective study to evaluate the incidence of acquired EGFR T790M resistance in NSCLC patients with EGFR mutation following progression after at least one prior EGFR TKI treatment in Taiwan: ARISE study
Presenter: Shang-gin Wu
Session: Poster display session
Resources:
Abstract
501P - Clinical characteristics and efficacy in non-small cell lung cancer patients with EGFR exon 20 insertion and EGFR amplification
Presenter: Xin Gao
Session: Poster display session
Resources:
Abstract
502P - Epidermal growth factor receptor tyrosine kinase inhibitor treatment response in advanced non-small cell lung cancer with uncommon mutations: A multicenter observational study
Presenter: Masaki Kanazu
Session: Poster display session
Resources:
Abstract
482P - Interim analysis from a phase IIIb, open-label study of afatinib in EGFR TKI-naïve patients (pts) with EGFR mutation-positive (EGFRm+) NSCLC
Presenter: Filippo De Marinis
Session: Poster display session
Resources:
Abstract
483P - A phase IIIb, open-label study of afatinib in EGFR TKI-naïve patients with EGFR mutation-positive NSCLC: A biomarker analysis
Presenter: Rafael Rosell
Session: Poster display session
Resources:
Abstract
484P - Activity of afatinib in patients (pts) with EGFR mutation-positive (EGFRm+) NSCLC and baseline brain metastases: Pooled analysis of three large phase IIIb trials
Presenter: Maya Gottfried
Session: Poster display session
Resources:
Abstract
491P - Clinical outcomes of leptomeningeal metastases in EGFR-mutant lung adenocarcinoma
Presenter: Chia-I Shen
Session: Poster display session
Resources:
Abstract
510P - Paclitaxel as continuation maintenance therapy in patients with advanced non-small cell lung cancer
Presenter: Suzy Gohar
Session: Poster display session
Resources:
Abstract
496P - Higher osimertinib introduction rate achieved by multiple repeated re-biopsy after acquired resistance to first/second generation EGFR-TKIs
Presenter: Taira Ninomaru
Session: Poster display session
Resources:
Abstract