Abstract 4557
Background
Genomic instability as characteristic for malignant transformation can be identified by quantitative sequencing. Cell-free tumor DNA (cfDNA) is a minimal invasive biomarker that can be used for tumor and therapeutic monitoring. This study evaluates quantitative cfDNA in patients (pts) with pancreatic cancer (PDAC) as an early therapeutic outcome marker.
Methods
In this prospective study plasma samples of 59 PDAC pts were collected in two centers throughout treatment with either FOLFIRINOX (n = 35) or Gemcitabine/nab-paclitaxel (n = 24). Additionally in 17 pts with FOLFIRINOX samples were collected during and 8 hours after treatment initiation. CNI scoring assays were used to quantify cfDNA. The results were correlated to CT/MRT imaging (RECIST 1.1) after 8-12 weeks, or monthly CA 19-9 and CEA values.
Results
At base-line in 55 out of 59 samples cfDNA could be detected. The CNI scores in metastasized PDAC were significant higher in comparison to locally advanced tumors (p = 0.009), however no differences occurred between the centers, therapy regime or outcome. Results to sensitivity, specificity, PPV and accuracy of CNI scores after 3 month of treatment are given in the table. Especially in sensitivity and accuracy CNI score show an advantage above classical tumor marker. Moreover, a dramatic cytolytic burst with subsequent significant increased CNI score 8 hours after treatment initiation with FOLFIRINOX was observed in 3/4 pts with PR, 1/4 pts with SD, compared to 0/9 pts with PD. This makes the CNI sore a very early predictor of treatment failure sensitive during first administration of chemotherapy.Table:
717P CNI and CA19-9 for prediction of therapy outcome
FOLFIRINOX CNI | FOLFIRINOX CA19-9 | Gem/nab CNI | Gem/nab CA19-9 | |
---|---|---|---|---|
Sens PD (%) | 73 | 36 | 50 | 18 |
Spec PD (%) | 88 | 88 | 93 | 62 |
PPV (%) | 89 | 100 | 86 | 40 |
Conclusions
Determination of cfDNA in the serum predicts treatment outcome more precise and earlier compared to classical tumor marker such as imaging or CA19-9 in PDAC patients. Prediction of non responsivness to therapy might even be possible after the first administration of FOLFIRINOX.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
The authors.
Funding
Has not received any funding.
Disclosure
All authors have declared no conflicts of interest.
Resources from the same session
1619 - Meta-analysis of KRAS Mutation as prognostic factor in patients (pts.) with resection of colorectal (CRC) liver metastases: Tumor burden and Sideness analysis.
Presenter: Maria Romina Luca
Session: Poster Display session 2
Resources:
Abstract
2104 - Clinical implications of regorafenib-induced hypothyroidism in metastatic colorectal cancer refractory to standard therapies: A prospective evaluation
Presenter: Jwa Hoon Kim
Session: Poster Display session 2
Resources:
Abstract
2143 - Clinical impact of BRAF V600E mutations in patients (pts) with resectable solitary colorectal liver metastases (CRLM)
Presenter: Shin Kobayashi
Session: Poster Display session 2
Resources:
Abstract
3136 - Trifluridine/tipiracil in metastatic colorectal cancer: an updated multicentre real-world analysis on efficacy, safety and predictive factors.
Presenter: Chara Stavraka
Session: Poster Display session 2
Resources:
Abstract
4234 - Correlation between p53 expression and clinical outcome in RAS/BRAF wild type metastatic colorectal cancer patients receiving later-line irinotecan-cetuximab
Presenter: Eleonora Lai
Session: Poster Display session 2
Resources:
Abstract
4287 - Safety and effectiveness of aflibercept + FOLFIRI for the treatment of patients with metastatic colorectal cancer (mCRC): OZONE secondary analyses
Presenter: Ian Chau
Session: Poster Display session 2
Resources:
Abstract
1820 - A Phase Ib study of the safety and efficacy of atezolizumab (atezo) + bevacizumab (bev) + cobimetinib (cobi) in patients (pts) with metastatic colorectal cancer (mCRC)
Presenter: Johanna Bendell
Session: Poster Display session 2
Resources:
Abstract
5644 - Development and validation of a metastasis-associated immune prognostic model for concurrent metastatic colorectal cancer
Presenter: Zhiwen Luo
Session: Poster Display session 2
Resources:
Abstract
5697 - Prognostic role of blood cell count-based immuno-inflammatory parameters in the Valentino trial
Presenter: Giovanni Fuca
Session: Poster Display session 2
Resources:
Abstract
4704 - Evaluation of safety, immunogenicity and preliminary efficacy of PolyPEPI1018 vaccine in subjects with metastatic colorectal cancer (mCRC) with a predictive biomarker
Presenter: Joleen Hubbard
Session: Poster Display session 2
Resources:
Abstract