For the majority of cancer patients, it's not the primary tumor that is deadly, but the spread or "metastasis" of cancer cells from the primary tumor to secondary locations throughout the body that is the problem. That's why a major focus of contemporary cancer research is how to stop or fight metastasis.
Previous lab studies suggest that metastasizing cancer cells undergo a major molecular change when they leave the primary tumor a process called epithelial-to-mesenchymal transition (EMT). As the cells travel from one site to another, they pick up new characteristics. More importantly, they develop a resistance to chemotherapy that is effective on the primary tumor. But confirmation of the EMT process has only taken place in test tubes or in animals.
In a new study, published in the Journal of Ovarian Research, Georgia Tech scientists have direct evidence that EMT takes place in humans, at least in ovarian cancer patients. The findings suggest that doctors should treat patients with a combination of drugs: those that kill cancer cells in primary tumors and drugs that target the unique characteristics of cancer cells spreading through the body.
The researchers looked at matching ovarian and abdominal cancerous tissues in seven patients. Pathologically, the cells looked exactly the same, implying that they simply fell off the primary tumor and spread to the secondary site with no changes. But on the molecular level, the cells were very different. Those in the metastatic site displayed genetic signatures consistent with EMT. The scientists didn't see the process take place, but they know it happened.
"It's like noticing that a piece of cake has gone missing from your kitchen and you turn to see your daughter with chocolate on her face," said John McDonald, director of Georgia Tech's Integrated Cancer Research Center and lead investi
|Contact: Jason Maderer|
Georgia Institute of Technology