New approach to cancer treatment boosts radiotherapy’s effectiveness
London: A new approach to cancer treatment
which radically increases the effectiveness of radiotherapy
has been identified by researchers.
The study, published in the journal Cancer Research,
showed that treating mice with certain drugs improved the
stability of blood vessels in the tumours.
Normally, blood vessels in tumours are badly developed,
weak and twisted, and as a result cancer cells have lower
oxygen levels than normal cells. But by using drugs to improve
the blood vessels, the scientists at the Gray Institute for
Radiation Oncology & Biology of the University of Oxford
increased the oxygen concentration inside the tumour, an
effect that boosts tumours` sensitivity to radiotherapy.
A better, more stable blood supply in the tumour also
enables better delivery of chemotherapy drugs to the cancers.
"We are very excited to have uncovered this brand new
approach to cancer treatment, where the drugs prime the cancer
cells for radiotherapy," said professor Gillies McKenna,
director of the Gray Institute.
"It`s a counterintuitive technique because you might
expect that by increasing an oxygen supply to tumour cells you
would help them grow, but actually by oxygenating the cell
with a better blood supply we enable radiotherapy and
chemotherapy to do a better job of killing them."
The scientists tested the effects of four drugs which are
in clinical use or under development for cancer therapy. The
drugs block a cell signalling pathway which is commonly
activated in cancer cells.
The drugs were given to the mice at doses which did not
alter tumour growth but the effects of them acted to increase
the blood supply to the tumours.
"Previous work by our group had shown that treatment with
some of these types of drugs could improve radiotherapy, but
it was not understood how. Now with the new understanding,
strategies could be developed to use these drugs to soften up
tumour cells before treating them with radiotherapy,"
Professor McKenna added.