Abstract 5640
Background
The aim of this study was to assess the prognostic and predictive value of an untargeted assessment of tumor fractions in the plasma of metastatic breast cancer patients and to compare circulating tumor DNA (ctDNA) with circulating tumor cells (CTC) and conventional tumor markers.
Methods
Patients and methods: 29 patients with metastatic breast cancer were included in this single-institution observational cohort study. Blood samples were obtained at first diagnosis of metastases, during several lines of treatment, and/or at every further moment of progression/development of new metastases. We assessed tumor fractions in plasma using an untargeted mFAST-SeqS method. CTCs were captured using a sized-based microfilter and identified as nucleated, cytokeratin positive/CD45 negative cells. Resulting ctDNA z-scores were compared to tumor fractions established with the recently published ichorCNA algorithm and associated with the clinical outcome.
Results
We observed a close correlation between mFAST-SeqS z-scores and ichorCNA ctDNA quantifications. Patients with mFAST-SeqS z-scores above three (34.5%) showed significantly worse overall (p = 0.014) and progression-free survival (p = 0.018) compared to patients with lower values. Elevated z-score values were clearly associated with radiological proven progression. In contrast, baseline CTC count, CEA, and CA15-5 had no prognostic impact on the outcome of patients in the analyzed cohort.
Conclusions
This proof of principle study demonstrates the prognostic impact of ctDNA levels detected with mFAST-SeqS as a very fast and cost-effective means to assess the ctDNA fraction without prior knowledge of the genetic landscape of the tumor. Furthermore, mFAST-SeqS-based ctDNA levels provided an early means of measuring treatment response.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
The authors.
Funding
Krebshilfe Steiermark.
Disclosure
All authors have declared no conflicts of interest.
Resources from the same session
3716 - Prognostic factors for predicting early recurrence within the first year of surgery in pancreatic ductal adenocarcinoma
Presenter: Naru Kim
Session: Poster Display session 2
Resources:
Abstract
3947 - Integrated population pharmacokinetic modelling of liposomal irinotecan in patients with various tumour types, including untreated metastatic pancreatic cancer (mPC)
Presenter: Teresa Macarulla
Session: Poster Display session 2
Resources:
Abstract
2880 - Expression of long noncoding RNA and clinical outcomes of pancreatic cancer patients who received adjuvant chemotherapy by S-1 or GEM after curative resection.
Presenter: Mariko Kamiya
Session: Poster Display session 2
Resources:
Abstract
5029 - POLO: Time to treatment discontinuation and subsequent therapies following maintenance olaparib for patients (pts) with a germline BRCA mutation and metastatic pancreatic cancer (mPC)
Presenter: Eric Van Cutsem
Session: Poster Display session 2
Resources:
Abstract
4730 - Diagnostic Value of Digital Multiplexed Detection of Single Nucleotide Variants in Pancreatic Cancer Specimens Collected by Endoscopic Ultrasound Fine-Needle Aspiration
Presenter: Irina Cazacu
Session: Poster Display session 2
Resources:
Abstract
3303 - Phase I/II study of LDE225 in combination with gemcitabine and nab-paclitaxel in patients with metastatic pancreatic cancer
Presenter: Esther Pijnappel
Session: Poster Display session 2
Resources:
Abstract
2009 - Efficacy of platinum-containing chemotherapy and prognosis of pancreatic cancer patients with homologous recombination deficiency: meta-analysis of published clinical studies
Presenter: Elizeveta Polyanskaya
Session: Poster Display session 2
Resources:
Abstract
2164 - Plasmatic CXCL8 is a marker for TGFß-activated kinase 1 (TAK1) activation which may predict resistance to nanoliposomal irinotecan (nal-IRI) in gemcitabine-refractory pancreatic cancer (PC) patients
Presenter: Valeria Merz
Session: Poster Display session 2
Resources:
Abstract
2529 - A protein level signature of four selected genes associated with survival outcomes of patients with pancreatic ductal adenocarcinoma
Presenter: Jie Hua
Session: Poster Display session 2
Resources:
Abstract
4947 - Pre-treatment serum 25-hydroxyvitamin D levels and survival in a Danish cohort of patients with pancreatic cancer
Presenter: Louise Rasmussen
Session: Poster Display session 2
Resources:
Abstract