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
2670 - Molecular subtypes of metastatic(met) gastric cancer(GC) (MoTriGastric): new biomarkers closer to the clinics
Presenter: Maria Alsina Maqueda
Session: Poster Display session 2
Resources:
Abstract
3797 - Exploring candidate signal transduction pathways for targeted therapy in esophageal cancer
Presenter: Aafke Creemers
Session: Poster Display session 2
Resources:
Abstract
5485 - Clinical implication of CLDN18, RhoGAP, and E-cadherin in gastric signet ring cell carcinoma
Presenter: Hyunho Kim
Session: Poster Display session 2
Resources:
Abstract
1970 - Identification of a spectrum of germline mutations for hereditary diffuse gastric cancer in the Russian population by next-generation sequencing.
Presenter: IRINA EFIMOVA
Session: Poster Display session 2
Resources:
Abstract
4989 - The molecular profiling and prognostic value of Chinese gastric signet ring cell carcinoma patients
Presenter: Jia Wei
Session: Poster Display session 2
Resources:
Abstract
7145 - A phase 2 basket study of MCLA-128, a bispecific antibody targeting the HER3 pathway, in NRG1 fusion-positive advanced solid tumors
Presenter: Alison Schram
Session: Poster Display session 2
Resources:
Abstract
1406 - Simultaneous Resection of Pancreatic Cancer and Liver Oligometastases After Induction Chemotherapy in Stage IV Patients:an Open-Label Prospective Randomized Multicenter phase 3 trial(CSPAC-1)
Presenter: Miaoyan Wei
Session: Poster Display session 2
Resources:
Abstract
1530 - Multicenter randomized phase II trial of 5-Fluorouracil/leucovorin (5-FU/LV) with or without liposomal irinotecan (nal-IRI) in metastatic biliary tract cancer (BTC) as second-line therapy after progression on gemcitabine plus cisplatin (GemCis): NIFTY trial
Presenter: Changhoon Yoo
Session: Poster Display session 2
Resources:
Abstract
1563 - A randomized phase II study of Maintenance therapy with multiepitope vaccine Tedopi (OSE2101) ± nivolumab or FOLFIRI after induction chemotherapy (CT) with FOLFIRINOX in patients (Pts) with advanced Pancreatic ductal adenocarcinoma (aPDAC) (TEDOPaM – PRODIGE 63 GERCOR study)
Presenter: Cindy Neuzillet
Session: Poster Display session 2
Resources:
Abstract
2780 - A phase 3, randomized, double-blind, placebo-controlled, international study of durvalumab in combination with gemcitabine plus cisplatin for patients with advanced biliary tract cancers: TOPAZ-1
Presenter: Do-Youn Oh
Session: Poster Display session 2
Resources:
Abstract