TY - JOUR
T1 - Transcriptomic profiling reveals three molecular phenotypes of adenocarcinoma at the gastroesophageal junction
AU - OCCAMS Consortium
AU - Bornschein, Jan
AU - Wernisch, Lorenz
AU - Secrier, Maria
AU - Miremadi, Ahmad
AU - Perner, Juliane
AU - MacRae, Shona
AU - O'Donovan, Maria
AU - Newton, Richard
AU - Menon, Suraj
AU - Bower, Lawrence
AU - Eldridge, Matthew D
AU - Devonshire, Ginny
AU - Cheah, Calvin
AU - Turkington, Richard
AU - Hardwick, Richard H
AU - Selgrad, Michael
AU - Venerito, Marino
AU - Malfertheiner, Peter
AU - Fitzgerald, Rebecca C
AU - Goh, Vicky
N1 - © 2019 The Authors. International Journal of Cancer published by John Wiley & Sons Ltd on behalf of UICC.
PY - 2019/12/15
Y1 - 2019/12/15
N2 - Cancers occurring at the gastroesophageal junction (GEJ) are classified as predominantly esophageal or gastric, which is often difficult to decipher. We hypothesized that the transcriptomic profile might reveal molecular subgroups which could help to define the tumor origin and behavior beyond anatomical location. The gene expression profiles of 107 treatment-naïve, intestinal type, gastroesophageal adenocarcinomas were assessed by the Illumina-HTv4.0 beadchip. Differential gene expression (limma), unsupervised subgroup assignment (mclust) and pathway analysis (gage) were undertaken in R statistical computing and results were related to demographic and clinical parameters. Unsupervised assignment of the gene expression profiles revealed three distinct molecular subgroups, which were not associated with anatomical location, tumor stage or grade (p > 0.05). Group 1 was enriched for pathways involved in cell turnover, Group 2 was enriched for metabolic processes and Group 3 for immune-response pathways. Patients in group 1 showed the worst overall survival (p = 0.019). Key genes for the three subtypes were confirmed by immunohistochemistry. The newly defined intrinsic subtypes were analyzed in four independent datasets of gastric and esophageal adenocarcinomas with transcriptomic data available (RNAseq data: OCCAMS cohort, n = 158; gene expression arrays: Belfast, n = 63; Singapore, n = 191; Asian Cancer Research Group, n = 300). The subgroups were represented in the independent cohorts and pooled analysis confirmed the prognostic effect of the new subtypes. In conclusion, adenocarcinomas at the GEJ comprise three distinct molecular phenotypes which do not reflect anatomical location but rather inform our understanding of the key pathways expressed.
AB - Cancers occurring at the gastroesophageal junction (GEJ) are classified as predominantly esophageal or gastric, which is often difficult to decipher. We hypothesized that the transcriptomic profile might reveal molecular subgroups which could help to define the tumor origin and behavior beyond anatomical location. The gene expression profiles of 107 treatment-naïve, intestinal type, gastroesophageal adenocarcinomas were assessed by the Illumina-HTv4.0 beadchip. Differential gene expression (limma), unsupervised subgroup assignment (mclust) and pathway analysis (gage) were undertaken in R statistical computing and results were related to demographic and clinical parameters. Unsupervised assignment of the gene expression profiles revealed three distinct molecular subgroups, which were not associated with anatomical location, tumor stage or grade (p > 0.05). Group 1 was enriched for pathways involved in cell turnover, Group 2 was enriched for metabolic processes and Group 3 for immune-response pathways. Patients in group 1 showed the worst overall survival (p = 0.019). Key genes for the three subtypes were confirmed by immunohistochemistry. The newly defined intrinsic subtypes were analyzed in four independent datasets of gastric and esophageal adenocarcinomas with transcriptomic data available (RNAseq data: OCCAMS cohort, n = 158; gene expression arrays: Belfast, n = 63; Singapore, n = 191; Asian Cancer Research Group, n = 300). The subgroups were represented in the independent cohorts and pooled analysis confirmed the prognostic effect of the new subtypes. In conclusion, adenocarcinomas at the GEJ comprise three distinct molecular phenotypes which do not reflect anatomical location but rather inform our understanding of the key pathways expressed.
KW - Siewert classification
KW - esophageal adenocarcinoma
KW - gastric cancer
KW - gastroesophageal junction
KW - gene expression profiling
UR - http://www.scopus.com/inward/record.url?scp=85066026956&partnerID=8YFLogxK
U2 - 10.1002/ijc.32384
DO - 10.1002/ijc.32384
M3 - Article
C2 - 31050820
SN - 0020-7136
VL - 145
SP - 3389
EP - 3401
JO - International Journal of Cancer
JF - International Journal of Cancer
IS - 12
ER -