In the studies conducted by American, Belgian, British and Dutch researchers it was found that tumors contain their own pool of stem cells that can multiply and keep fueling the cancer, seeding regrowth. Studies were published on 1 August 2012 in the journals Nature and Science.
Stem cells in healthy tissues are known for their ability to produce any kind of cell. The new research deals with a different kind, cancer stem cells. Some researchers, but not all, believe they lurk as a persisting feature in tumors. The three studies used labeling techniques to trace the ancestry of cells within mouse tumors.