Abstract 4989
Background
Gastric cancer (GC) is one of the most common lethal malignancies worldwide. Signet ring cell carcinoma (SRCC) is a poorly differentiated gastric cancer. The molecular characteristics and prognostic of SRCC are not well studied.
Methods
Formalin fixed paraffin embedded (FFPE) samples of 64 Chinese solid tumor patients were collected for next‐generation sequencing (NGS) based 450 genes panel assay. Genomic alterations including single base substitution, short and long insertions/deletions, copy number variations, gene fusions and rearrangement were assessed. Microsatellite stable (MSS) status and TMB (tumor mutational burden) were also acquired by an NGS algorithm.
Results
A total of 64 patients were identified as GC-SRCC through SRCC histology. The most frequently mutated genes were TP53(48%), CDH1(31%), ARID1A(14%), CDKN2A(9%), LRP1B(9%), KMT2D(6%), NF1(6%), ERBB2(9%) and GLI3(8%). Meanwhile, the copy numbers of FGFR2(14%), FGF3(8%), FGF19(8%), FGF4(8%), MYC(8%), CCND1(6%) and CDKN2A(9%) were frequently altered in SRCC.FGFR2 and 11q13 amplification is the first time reported in Chinese SRCC. Moreover, FGFR2 rearrangement (FGFR2/VTI1A and FGFR2/TACC2) was detected in 4% tumor samples. 34 cases had received chemotherapy, 4 cases had confirmed partial responses (PR); 14 cases had reached the stability of disease (SD). Noticeably, patients harboring gene rearrangement (N = 9) were observed a much shorter overall survival time (OS) in comparison with patients without any gene rearrangement (N = 14) (13.2 months vs 24.2 months, P < 0.05). Additionally, patients with CDH1 mutation (N = 9) showed a shorter OS than CDH1 wide type (N = 25) (14.2 months vs 25.3 months, P = 0.11), although the difference was not statistically significant.
Conclusions
Our observation reveals the molecular characteristics of SRCC. Gene rearrangements might associate to shorter OS. FGFR2 and 11q13 region amplification were newly observed in SRCC. It might provide new possibilities for the treatment of SRCC. Due to the limitations of the number of samples, the results may require further research and validation.
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
1571 - Thyroid Lobectomy versus Total Thyroidectomy among Early-Stage Papillary Thyroid Carcinoma Patient
Presenter: Sara Ahmed
Session: Poster Display session 2
Resources:
Abstract
5051 - Classification of thyroid nodule using DNA methylation profiling on tissue and circulating tumor DNA
Presenter: Shubin Hong
Session: Poster Display session 2
Resources:
Abstract
4155 - Durvalumab plus Tremelimumab for the Treatment of Patients (pts) with Refractory and Progressive Advanced Thyroid Carcinoma. A Phase II Multicohort Trial (DUTHY / GETNE T1812)
Presenter: Jorge Hernando Cubero
Session: Poster Display session 2
Resources:
Abstract