Abstract 1970
Background
Gastric cancer is the fifth most common malignancy in the world and the third leading cause of cancer death. Approximately 1–3% of gastric cancers are hereditary. Mutations of CDH1,the gene encoding E-cadherin, are the most common germline mutations detected in gastric cancer and cause hereditary diffuse gastric cancer (HDGC) syndrome. However, there has been no research previously conducted to identify candidate genes for predisposition to hereditary gastric cancer in the Russian population. The purpose of our research was to fill this gap.
Methods
For this study, we collected specimens of the venous blood of 40 patients (age up to 50 years) diagnosed with diffuse gastric cancer, and 80 gastric cancer tumor samples. To define the mutation in these patients we have used NGS with two panels -an Ion AmpliSeq Cancer Hot spot Panel v2, widely used for the analysis of «hot spots» in cancer related genes, and an in-house panel developed for sequencing the genes involved in gastric carcinogenesis (BMPR1A, SMAD4, CDH1, TP53, STK11, PTEN). All found mutations were verified in DNA obtained from peripheral blood lymphocytes, using polymerase chain reaction followed by Sanger sequencing.
Results
In total, with two panels, we have identified 16 genetic germline variants with exceptionally low general population frequencies (no higher than 0.00004 according to the gnomAD database), and 4 genetic variants that have never been reported previously. We detected 6 deleterious mutations in CDH1 gene. All found mutations were missense mutations (A2512G:p.S838G, c.G1234A:p.V412I, .G2635A:p.G879S, c.C8G:p.P3R, c.C670T:p.R224C). Among these 6 mutations, one (c.A907c:pT303P) was newly discovered in this study. Other deleterious germline variants were found in APC, CDKN2B, STK11, MET, SMO and two in RB1 genes. The mean age at diagnosis of gastric cancer patients with mutation was 46,1.
Conclusions
Identifying mutation carriers in families is extremely important. The identification of germline CDH1 mutations offers the opportunity for potentially lifesaving prophylactic gastrectomy, which is the standard of care for these individuals.
Clinical trial identification
Editorial acknowledgement
This work was supported by Russian Foundation for Basic Research (project No. 18-015-00333), Russian Foundation for Basic Research (project No. 18-29-09020).
Legal entity responsible for the study
The authors.
Funding
Russian Foundation for Basic Research (project No. 18-015-00333), Russian Foundation for Basic Research (project No. 18-29-09020).
Disclosure
All authors have declared no conflicts of interest.
Resources from the same session
3516 - Palbociclib Rechallenge in Hormone Receptor (HR)[+]/HER2[-] Advanced Breast Cancer (ABC). PALMIRA Trial
Presenter: Antonio Llombart Cussac
Session: Poster Display session 2
Resources:
Abstract
4616 - Alpelisib (ALP) + Endocrine Therapy (ET) by Last Prior Therapy in Patients (pts) With PIK3CA-Mutated Hormone-Receptor Positive (HR+) Human Epidermal Growth Factor Receptor-2-Negative (HER2–) Advanced Breast Cancer (ABC): Additional Study Cohort in BYLieve
Presenter: Eva Ciruelos
Session: Poster Display session 2
Resources:
Abstract
3592 - PRECYCLE: Impact of CANKADO-based eHealth-support on quality of life in metastatic breast cancer patients treated with palbociclib and endocrine therapy.
Presenter: Tom Degenhardt
Session: Poster Display session 2
Resources:
Abstract
4168 - Efficacy and safety of oral poly (ADP-ribose) polymerase inhibitor fluzoparib in patients with BRCA1/2 mutations and platinum sensitive recurrent ovarian cancer
Presenter: Ning Li
Session: Poster Display session 2
Resources:
Abstract
2785 - Effect of response to last platinum-based chemotherapy in patients (pts) with platinum-sensitive, recurrent ovarian carcinoma in the phase 3 study ARIEL3 of rucaparib maintenance treatment
Presenter: Jonathan Ledermann
Session: Poster Display session 2
Resources:
Abstract
3496 - Integrated safety analysis of the poly(ADP-ribose) polymerase (PARP) inhibitor rucaparib in patients (pts) with ovarian cancer in the treatment and maintenance settings
Presenter: Rebecca Kristeleit
Session: Poster Display session 2
Resources:
Abstract
2844 - Clinical factors associated with prolonged response and survival under olaparib as maintenance therapy in BRCA mutated ovarian cancers
Presenter: S.Intidhar Labidi-Galy
Session: Poster Display session 2
Resources:
Abstract
1955 - A Prospective Evaluation of Tolerability of Niraparib Dosing Based on Baseline Body Weight (BW) and Platelet (plt) Count: Blinded Pooled Interim Safety Data from the NORA Study
Presenter: Xiaohua Wu
Session: Poster Display session 2
Resources:
Abstract
2539 - Evaluation of Niraparib 200 mg/d as Maintenance Therapy in Recurrent Ovarian Cancer and Associated Thrombocytopenia in a Real-World US Setting
Presenter: Premal Thaker
Session: Poster Display session 2
Resources:
Abstract
1290 - Niraparib initial dose and its’ management in patients with recurrent high-grade serous ovarian cancer.
Presenter: Jacek Grabowski
Session: Poster Display session 2
Resources:
Abstract