Starvation prior to chemotherapy could make it more
effective, shielding healthy cells as it destroys the malignant cells, research
suggests.
Although the new method was applied only in animal research,
it is encouraging news for humans too.
Researchers led by Valter Longo at the University of Southern California
have found that lab tests on mice, not eating for 48 hours before chemo gives
healthy cells an edge.
“Starvation tells that, all the cells too, in an organism, go
to protective mode. Right? The cancer cells, because of their characteristics
of not being able to respond to that, just continue on their normal pro-growth
track,” Longo said in his study.
According to the study on living mice, of 28 mice starved for 48-60 hours
before chemotherapy, only 1 died. On the other hand, of 37 mice that were not
starved prior to treatment, 20 mice died from chemotherapy toxicity.
By using the starvation response to differentiate normal and
cancerous cells, researchers say healthy cells may be able to withstand higher
doses of existing cancer chemotherapy drugs, but further studies in humans are
needed to confirm these effects.
“We had found that healthy cells have a 'shield mode' -- a kind of
protective strategy that allows the organism to be resistant to not just one
but dozens of threats and stresses, including starvation. So we thought this
characteristic might be a way to distinguish between normal cells and cancer
cells when applying chemotherapy. And it turns out that it works for yeast, for
human cells in test tubes, and here, in mice,” Longo said.
Other cancer researchers welcomed the findings of the study.
Prof Pinchas Cohen, University of California, Los Angeles, UCLA,
commented upon the findings, saying, “This is very important paper. It defines
a novel concept in cancer biology. In theory, it opens up new treatment
approaches that will allow higher doses of chemotherapy. It’s a direction that’s
worth pursuing in clinical trials in humans.”
Dr. Longo and his team are preparing to test the method on a
small group of bladder cancer patients. The pilot clinical study is planned at
the university’s Norris Cancer Centre within six months.
“We hope this works with patients, and we ave reason to
think it will. I think I’m more enthusiastic about this than anything else I’ve
done. And you can see the potential for this being turned into something very,
very useful. But we won’t know until we do it,” Dr. Longo said.
The findings were published in the March 31 online issue of
the Proceedings of the National Academy of Science.