Intrinsic Subtypes of Gastric Cancer Linked to Survival
Patient survival, response to chemo associated with distinct patterns of gene expression
THURSDAY, Aug. 4 (HealthDay News) -- Intrinsic subtypes of gastric cancer (GC) with distinct gene expression patterns are correlated with patient survival and response to chemotherapy, according to a study published in the August issue of Gastroenterology.
Iain Beehuat Tan, M.B.B.S., from the National Cancer Centre Singapore, and colleagues analyzed gene expression profiles for 37 GC cell lines in primary tumors from 521 patients in four independent cohorts to identify intrinsic GC subtypes. Expression profiling or subtype-specific immunohistochemical markers (LGALS4, CDH17) were used to determine the subtypes. Additionally, in vitro sensitivity was assessed for 5-fluorouracil (5-FU), cisplatin, and oxaliplatin.
The investigators found that based on distinct patterns of gene expression there were two major intrinsic genomic subtypes, G-INT and G-DIF. In both univariate and multivariate analyses in multiple cohorts, the intrinsic subtypes were predictive of survival, but subtypes based on Lauren's histopathology were not. Compared to G-DIF cell lines, G-INT cell lines were more resistant to cisplatin and significantly more sensitive to 5-FU and oxaliplatin. Intrinsic subtypes were correlated with patient survival time following adjuvant 5-FU therapy.
"Intrinsic subtypes of GC, based on distinct patterns of expression, are associated with patient survival and response to chemotherapy. Classification of GC based on intrinsic subtypes might be used to determine prognosis and customize therapy," the authors write.