Abstract 4803
Background
Hereditary diffuse gastric cancer (HDGC) is closely related to germline mutation of CDH1. In addition, potential pathogenic germline variants in other candidate genes were detected in FGC and HDGC families. However, comprehensive genetic profile of HDGC predisposing gene variants in Chinese Familial gastric cancer (FGC) and HDGC patients are yet to be elucidated.
Methods
We collected peripheral blood from 28 early-onset DGC patients and from a first degree relative DGC patient who was diagnosed at age of 50. All 29 patients fulfilled IGCLC 2015 criteria for HDGC clinical diagnosis and genetic testing. Genomic DNA was extracted from peripheral blood followed by Whole Exome Sequencing (WES) with average sequencing depth of at least 100X. Gastric ancer predisposing SNV and Indel candidates were filtered based on population allele frequencies in public nucleotide polymorphism databases and corresponding functional impact was predicted by in silico tools.
Results
Among previously reported gastric cancer susceptibility genes, CDH1, BRCA2, MAP3K6 expressed the most predisposing SNV and Indel candidates. In addition, a novel splice-site variant, c.2165-1G>A, in CDH1 was detected in a Chinese early-onset HDGC patient who developed ovarian metastasis. Moreover, BCR gene exhibited as the most prevalent gastric cancer predisposing gene with filtered variants primarily enriched in RhoGAP domain. Pathway enrichment analysis showed that the top three predisposing variant candidates were enriched in the following signalling pathway: ECM-receptor interaction (P-Value: 0.001), focal adhesion (P-Value: 0.02) and protein digestion and absorption (P-Value: 0.002).
Conclusions
This study suggested that CDH1, BRCA2, MAP3K6 may act as potential gastric cancer susceptibility genes in Chinese early-onset HDGC patients. Further study may be required to investigate the functional role of BCR abnormality, especially in its RhoGAP domain, in the tumorigenesis of gastric cancer. Moreover, to further investigate molecular mechanisms of early-onset gastric cancer, one may consider genes involved in three signalling pathways: ECM-receptor interaction, focal adhesion and protein digestion and absorption.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
Peking University Cancer Hospital.
Funding
Has not received any funding.
Disclosure
All authors have declared no conflicts of interest.
Resources from the same session
4304 - A user-friendly nomogram to predict relapse-free survival (RFS) in western patients with resected gastric cancer (GC)
Presenter: Massimiliano Salati
Session: Poster Display session 2
Resources:
Abstract
4546 - Efficacy and toxicity of weekly carboplatin and paclitaxel as induction or palliative treatment in advanced esophageal cancer patients
Presenter: Femke de Man
Session: Poster Display session 2
Resources:
Abstract
5908 - Perioperative chemotherapy with Docetaxel, Oxaliplatin, Fluorouracil and Leucovorin (FLOT) versus Epirubicin, Platinum and Capecitabine or Flourouracil (EOX/ECF) in Resectable Gastric or Gastroesophageal Junction Adenocarcinoma- Safety and response data from India.
Presenter: Tanuj Chawla
Session: Poster Display session 2
Resources:
Abstract
937 - Phase II Study of Preoperative Radiotherapy Combined with S-1 plus Cisplatin in Clinically Resectable Type 4 or Large Type 3 Gastric Cancer: OGSG1205
Presenter: Shunji Endo
Session: Poster Display session 2
Resources:
Abstract
1119 - Observational Study of the Peritoneal Washing Cytology Positive Gastric Cancer without Gross Peritoneal Metastasis Underwent Radical D2 Gastrectomy.
Presenter: Jun Eul Hwang
Session: Poster Display session 2
Resources:
Abstract
3744 - Primary results of multicenter phase II study of neoadjuvant chemotherapy with S-1 and oxaliplatin for locally advanced gastric cancer (Neo G-SOX PII)
Presenter: Akira Miki
Session: Poster Display session 2
Resources:
Abstract
5091 - Multicenter Phase I/II Feasibility Study of Adjuvant Treatment with S-1 in Patients after R0-Resection of Adenocarcinoma of the Stomach and Esophagogastric Junction (GMBH-STO-0114)
Presenter: Kathrin Heinrich
Session: Poster Display session 2
Resources:
Abstract
2891 - A phase I study of Docetaxel/Oxaliplatin/S-1 (DOS) combination neoadjuvant chemotherapy for patients with locally advanced adenocarcinoma of the esophagogastric junction
Presenter: Kei Hosoda
Session: Poster Display session 2
Resources:
Abstract
2994 - Apatinib combined with docetaxel in second-line treatment of advanced gastric cancer: a prospective clinical study (Data updated)
Presenter: Mudan Yang
Session: Poster Display session 2
Resources:
Abstract
3000 - A multicenter phase II study of TAS-114 in combination with S-1 in patients with pre-treated advanced gastric cancer (EPOC1604)
Presenter: Daisuke Takahari
Session: Poster Display session 2
Resources:
Abstract