A new field of cancer research could explain why some cancers that appear to have been cured can rear their ugly head or spread to other organs.
The answer, believe researchers at the University of Michigan Comprehensive Cancer Center, lies with a small number of cells within a tumor, called cancer stem cells, that are responsible for fueling the tumor's growth.
A U-M Web site explains what cancer stem cells are and why they are the key to finding a cure. The site is at www.mcancer.org/stemcells.
"The identification of cancer stem cells means we have to fundamentally change how we approach cancer treatment. Up till now, cancer treatment has been designed to shrink cancers down. What we're finding is traditional cancer treatments are able to kill the bulk of the cells in a cancer, but the cancer stem cells are resistant to common treatments like chemotherapy and radiation therapy," says Max S. Wicha, M.D., Distinguished Professor of Oncology and director of the U-M Comprehensive Cancer Center.
"If we're going to kill the more common cancers, we have to find a way to eliminate the cancer stem cells," Wicha adds.
Researchers believe only 1 percent of cells in a tumor are cancer stem cells.
Wicha is one of the top experts worldwide in this area of cancer research. He was part of the team at U-M who first identified stem cells in a solid tumor, finding them in breast cancer. Since then, U-M researchers have also been first to report stem cells in pancreatic cancer and head and neck cancer.
More than a dozen groups at U-M are working on stem cell research in virtually all tumor types. Researchers recently began the first clinical trial designed specifically to target breast cancer stem cells. Another clinical trial is looking at a lymphoma drug to target multiple myeloma stem cells.
"We can now define what we believe are the important cells - the cells that determine whether the cancer will come back or be cured - and target treatment directly to those cells," Wicha says.