Chemotherapy can cause damage to healthy cells which triggers them to secrete a protein that sustains tumor growth and resistance to further treatment, a new study said Sunday.
Around 90% of patients with solid cancers, such as breast, prostate, lung and colon, that spread - metastatic disease - develop resistance to chemotherapy.
Treatment is usually given at intervals, so that the body is not overwhelmed by its toxicity. But that allows time for tumor cells to recover and develop resistance.
In this study, by researchers at the Fred Hutchinson Cancer Research Center in Seattle looked at fibroblast cells, which normally play a critical role in wound healing and the production of collagen, the main component of connective tissue such as tendons.
But chemotherapy causes DNA damage that causes the fibroblasts to produce up to 30 times more of a protein called WNT16B than they should.
The protein fuels cancer cells to grow and invade surrounding tissue - and to resist chemotherapy.
It was already known that the protein was involved in the development of cancers - but not in treatment resistance.
Researchers in the United States made the "completely unexpected" finding while seeking to explain why cancer cells are so resilient inside the human body when they are easy to kill in the lab.
Peter Nelson, who led the research, said: "Cancer therapies are increasingly evolving to be very specific, targeting key molecular engines that drive the cancer rather than more generic vulnerabilities, such as damaging DNA.
"Our findings indicate that the tumor microenvironment also can influence the success or failure of these more precise therapies."
The researchers said they confirmed their findings with breast and ovarian cancer tumors.
The result paves the way for research into new, improved treatment, said Nelson. "For example, an antibody to WNT16B, given with chemotherapy, may improve responses (kill more tumor cells)," he said in an email exchange.
"Alternatively, it may be possible to use smaller, less toxic doses of therapy."
So tell us, does this change your opinion of chemotherapy as an effective cancer treatment?
Labels: Chemotherapy Cancer Study, Chemotherapy grows cancer, New Research