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
3330 - Tumour-infiltrating lymphocytes and BRCA-like status in stage III breast cancer patients treated with intensified carboplatin-based chemotherapy
Presenter: Leonora De Boo
Session: Poster Display session 2
Resources:
Abstract
3971 - Unravelling the biological characteristics of MammaPrint extreme risk subgroups
Presenter: Rajith Bhaskaran
Session: Poster Display session 2
Resources:
Abstract
5871 - Residual Cancer burden as a prognostic factor in a large series of Neoadjuvant chemotherapy. Subgroup analysis per molecular surrogated subtypes
Presenter: Catalina Falo
Session: Poster Display session 2
Resources:
Abstract
5014 - Clinical validation of CanAssist Breast in a Spanish cohort
Presenter: Manjiri Bakre
Session: Poster Display session 2
Resources:
Abstract
2787 - Meta-analysis on association of pathological complete response with long-term survival outcomes in triple-negative breast cancer
Presenter: Peter A. Fasching
Session: Poster Display session 2
Resources:
Abstract
4301 - Immune infiltrate composition across intrinsic subtypes in hormone receptor (HR)+/HER2- early breast cancer (BC) enrolled in the prospective LETLOB trial
Presenter: Gaia Griguolo
Session: Poster Display session 2
Resources:
Abstract
3205 - Frequency of germline mutations in women's cancer susceptibility genes in a large cohort of Chinese breast cancer patients
Presenter: Ning Liao
Session: Poster Display session 2
Resources:
Abstract
4091 - Triple blinded Prospective Study assessing the Impact of Genomics & Artificial Intelligence Watson For Oncology (WFO) on MDT’s Decision of Adjuvant Systemic Therapy for Hormone Receptor Positive Early Breast Carcinoma-
Presenter: Somashekhar Sampige Prasannakumar
Session: Poster Display session 2
Resources:
Abstract
4359 - Prognostic significance of Progesterone Receptor levels in luminal-like Her2- early Breast Cancer patients. A retrospective single Cancer Center analysis.
Presenter: Anna Diana
Session: Poster Display session 2
Resources:
Abstract
1369 - PAM50 HER2-enriched subtype and pathological complete response in HER2-positive early breast cancer: a meta-analysis
Presenter: Francesco Schettini
Session: Poster Display session 2
Resources:
Abstract