(RxWiki News) Why does cancer (so often) return after it's thought to have been killed and is no longer evident in the body? Scientists think they might know about why this happens - Cancer Stem Cells.
Three different research studies have concluded that cells that are impervious to chemotherapy and radiation lurk in the body during and after cancer treatment.
They remain dormant, until one day, they go to work forming new tumors.
"Learn what each cancer medication is targeting."
This means that to eradicate cancer once and for all, tumor cells and these lurking cells dubbed "cancer stem cells" are both going to have to be eliminated.
It will mean that the cancer stem cells are really in charge - they are the directors of the cancer motion picture. These stem cells can not only copy themselves, but they can make other types of tumor cells.
All of this is still conjecture, but these studies expand on the concept. Some proof of the cancer stem cell theory was seen in the 1990s, but has not been evident in other cancer types.
The three new studies - published in Nature and in Science - used what's known as cell-marking techniques to trace how cells multiply inside tumors induced in mice.
In one study, Cédric Blanpain, a stem cell researcher at the Université Libre de Bruxelles in Belgium, and colleagues worked with papilloma tumors, which are precursors to squamous cell skin cancer.
This team found that new tumors were driven by a relatively few cells, which behaved very much like healthy cells.
The second paper, conducted by developmental biologist Luis Parada and his colleagues at the University of Texas Southwestern Medical Center (UTSMC) in Dallas, discussed the findings surrounding a glioma - a form of brain cancer.
Researchers found the same phenomenon - only a few cells were driving the growth of tumors. Scientists also found that these cells remain dormant during and are unfazed by chemotherapy and radiation.
The third study by Dutch researchers at the Hubrecht Institute in Utrecht looked at intestinal tumors.
Again, just a few cells are involved and they are quite close to normal cells. One of the lead authors, Hugo Snippert, PhD, said, "The tumor is really like a caricature of normal tissue."
The authors admit limitations with these studies and, of course, what occurs in mice doesn't necessarily happen in humans.
And there are many, many, many questions that will probably take years to to answer before this information can be turned into treatment therapies.
That said, knowing that different types of cells may be involved in cancer recurrence opens the possibility of developing new ways to stamp out the disease for good.