One Cancer - Many Diseases

Stomach cancer subtypes identified that could become therapeutic targets

(RxWiki News) Stomach cancer is not one disease, but many. Understanding the different types of this complex cancer could lead to improved treatments.

Scientists have identified a number of new types of stomach cancer. These new types are caused by environmental factors.

Understanding the biology of these cancers unlocks the possibility of developing new and better treatments. 

"Eat more fresh green vegetables."

Researchers at the Duke-NUS Graduate Medical School in Singapore conducted the study, and Patrick Tan, MD, PhD was the lead author. Patients with stomach cancer, which was diagnosed in an estimated 21,321 Americans in 2012, respond very differently to the same treatments, according to Tan.

In addition to genetic mutations, gastric (stomach) cancer can also be caused by onslaughts from the outside, such as smoking, heavy drinking and exposure to certain chemicals. These environmental factors are called epigenetic alterations that affect the way a gene behaves.

Dr. Tan’s team worked with 240 gastric tumors and cell lines to see how external factors changed the genetic landscape. Researchers were looking for DNA changes caused by something other than genetics.The focus was finding new targets that could be treated with existing or new medicines.

What was being explored is called methylation, a process that changes how a gene behaves without changing the gene itself. In this study, the scientists found that methylation plays a major role in the development of stomach cancer.

Confirming earlier research, the investigators found a subtype of stomach cancers that have very high levels of methylation. The CIMP subgroup is now associated with poor outlook, especially in younger patients.

Dr. Tan says CIMP tumors may become targets for existing or new therapies, including so-called DNA demethylating drugs.

“Improving gastric cancer clinical outcomes will require molecular approaches capable of subdividing patients into biologically similar subgroups, and designing subtype-specific therapies for each group,” Dr. Tan said in a statement.

This research was published October 17 in the journal Science Translational Medicine.

Review Date: 
December 10, 2012