Stomach cancer, one of the leading causes of cancer death worldwide, actually falls into three broad subtypes that respond differently to currently available therapies, say researchers at Duke-NUS Graduate Medical School Singapore.
The finding could greatly improve patient care with the development of a genetic test to classify tumors and match them to the therapies that offer the best outcomes.
"One of the features that makes gastric cancer so lethal is that it arises from many genetic alterations, creating differences in how the tumors respond to therapies," said Steve Rozen, Ph.D., director of the Centre for Computational Biology at Duke-NUS. Rozen is senior author of the study published in the September issue of the journal Gastroenterology
. "What our study has shown is that there are actually three distinct molecular classifications that appear to be biologically and therapeutically meaningful."
Worldwide, only lung cancer is more lethal than stomach cancer. Rates in all countries have been dropping for decades, and are much lower in the United States than in Asia, but the malignancy still afflicts more than 21,000 people in the U.S. a year, according to the National Cancer Institute.
Despite differences in the way their tumors respond to treatments, patients often receive a "one-size-fits-all" treatment approach, resulting in a five-year survival rate of about 27 percent in the United States.
"There has been an urgent need for improved classification of gastric cancer that provides insight into the biology of the tumors that might help predict treatment response," said co-senior author Patrick Tan, M.D., PhD., professor in the Cancer and Stem Cell Biology Program at Duke-NUS.