Research in mice has found that cancer cells often seek refuge in the thymus, escaping from chemotherapy.

Massachusetts Institute of Technology (MIT) biologists say these cancer cells often cause tumor relapses at a later stage.The team of researchers is now testing drugs that interfere with one of those protective growth factors.

They believe that using these drugs in combination with chemotherapy could offer a one-two punch that eliminates tumor cells and prevents relapse.

Study leader Michael Hemann, an assistant professor of biology, said in an MIT news release, that "Successful cancer therapy needs to involve a component that kills tumor cells as well as a component that blocks pro-survival signals. Current cancer therapies fail to target this survival response."

Scientists also believe there may be other places in the body, such as bone marrow, where cancer cells are protected from chemotherapy.

Researchers aren’t sure if the investigation would translate to human patients, but they do suggest several targets for investigation.

The study findings are published in the Oct. 29 issue of the journal Cell.