Abstract 3182
Background
Clonal hematopoiesis (CH) leads to blood-derived somatic mutations in KRAS, NRAS and BRAF. Our aim is to identify the prevalence of CH-derived mutations in these three genes in metastatic colorectal cancer (mCRC) patients and reveal the practical clinical implication of these mutations on plasma cell-free DNA (cfDNA) genotyping.
Methods
We analyzed KRAS, NRAS and BRAF genotypes in plasma and matched tumor tissues of 236 mCRC patients through next-generation sequencing (NGS). Suspected CH mutations were defined as those only present in plasma with variant allelic frequencies (AFs) <5% and were confirmed by paired peripheral blood cells (PBCs) using droplet digital PCR (ddPCR). The hemopoietic lineage harboring a CH-derived mutation was analyzed through flow cytometry.
Results
We identified suspected CH mutations in twenty patients (8.4%, 20/236). Three of these patients (1.27%, 3/236) had a CH-derived KRAS mutation. Two of them had a KRAS G12X and the third had a KRAS Q61H. We did not detect CH-derived NRAS or BRAF mutations. Patients harboring a CH-derived mutation previously received chemotherapy treatment. In one CH-derived KRAS G12X case, the mutation was enriched in lymphocytes and persisted in cfDNA over the course of 4 months of therapy.
Conclusions
We confirmed the existence of CH-derived KRAS mutations in a small proportion of mCRC patients. This should be noted to prevent misclassification as tumor somatic mutations when performing cfDNA sequencing.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
The authors.
Funding
The National Natural Science Foundation of China (81572064, 81772263, 81772511, 81602038), the Key Developing Disciplines of Shanghai Municipal Commission of Health and Family Planning (2015ZB0201), the Projects from the Shanghai Science and Technology Commission (16411952100), the Projects from Zhongshan Hospital, Fudan University (2018ZSLC05).
Disclosure
All authors have declared no conflicts of interest.
Resources from the same session
3278 - Immune-Related Gene Expression Profiling after Neoadjuvant Chemotherapy (NACT) of Ovarian High-Grade Serous Carcinoma
Presenter: Luis Manso
Session: Poster Display session 2
Resources:
Abstract
4906 - Tumor-infiltrating lymphocytes (TILs) in patients with epithelial ovarian cancer undergoing neoadjuvant chemotherapy: A restrospective study
Presenter: Sara Giovannoni
Session: Poster Display session 2
Resources:
Abstract
3919 - Prognostic significance of elements of the adaptive immunity in the microenvironment of epithelial ovarian cancer.
Presenter: Periklis Foukas
Session: Poster Display session 2
Resources:
Abstract
5139 - Neutrophil-to-lymphocyte ratio predicts platinum sensitivity in epithelial ovarian cancer patients: a MITO24 retrospective study
Presenter: Alberto Farolfi
Session: Poster Display session 2
Resources:
Abstract
4212 - The prognostic impact of monocyte to lymphocyte ratio (MLR) in advanced epithelial ovarian cancer (EOC)
Presenter: Marc Cucurull Salamero
Session: Poster Display session 2
Resources:
Abstract
5123 - TP53 Hotspot mutations as immunoreactive neoantigens define a signature with differential survival outcomes in advanced ovarian cancer
Presenter: Marica Garziera
Session: Poster Display session 2
Resources:
Abstract
3795 - Use of bevacizumab (Bev) in real life for first-line (fl) treatment of ovarian cancer (OC)/ The GINECO ENCOURAGE cohort of 500 French patients
Presenter: Dominique Berton-Rigaud
Session: Poster Display session 2
Resources:
Abstract
2359 - Phase II study: Letrozole maintenance therapy after first line chemotherapy in patients with advanced serous and endometrioid ovarian cancer
Presenter: Alexandra Tyulyandina
Session: Poster Display session 2
Resources:
Abstract
3619 - Baseline IPI (Immune Prognostic Index) predicts survival in patients with advanced cervical cancer treated with immune checkpoint inhibitors (ICI).
Presenter: Felix Blanc-Durand
Session: Poster Display session 2
Resources:
Abstract
3474 - Preselecting tumor-infiltrating lymphocyte subsets to implement adoptive inmmunotherapy in ovarian cancer
Presenter: Diego Salas-Benito
Session: Poster Display session 2
Resources:
Abstract