Gastric cancer can be divided into two molecular subtypes that are associated with differing levels of patient survival and response to standard chemotherapy treatments, researchers from several research institutes in Singapore reported this week.
In the study, published this Monday in Gastroenterology, researchers from the National University of Singapore and elsewhere claimed to be the first to show that a molecular classification of gastric cancer can identify subtypes that respond differently different therapies, a crucial step in the push to personalize cancer treatment.
The researchers, led by Patrick Tan of the Genome Institute of Singapore, identified two intrinsic genomic subtypes of gastric cancer. They found that cell lines belonging to one subtype were significantly more sensitive to the drugs 5-fluorouracil and oxaliplatin, while cell lines belonging to the other subtype were more sensitive to cisplatin.
Tan wrote in an e-mail to PGx Reporter that this is not the first genomic analysis of gastric cancer. It has long been known that gastric cancers are histologically heterogeneous, and several cellular, genomic, and proteomic classifications have been made previously in this setting. However, according to Tan, no previous genomic classification systems have been able to provide reliable independent prognostic prediction or an association with specific treatment options.
“Most previous studies have been limited by analyses of small data sets and focused on analyzing primary tumors that are very complex entities,” Tan wrote. “Here, we hypothesized that adopting a different approach, starting our analysis with a panel of gastric cancer cell lines … we might be able to derive cleaner molecular signatures that can then be extrapolated to primary cancers.”
Tan wrote that the researchers took a three-step approach. “First, we analyzed the expression profiles of a large panel of gastric cancer cell lines… to identify highly distinct patterns of gene expression,” he said. “This … revealed the existence of two very distinct subgroups of gastric cancer cell lines, which could be clearly distinguished by a gene expression signature of about 170 genes.” Read more…