From: GBurch1@aol.com
Date: Wed Jun 20 2001 - 15:16:05 MDT
>From Yahoo! News,
http://uk.news.yahoo.com/010616/17/bvg9w.html
-
Saturday June 16, 03:55 PM
Cancer cure is found
EARLY tests of a revolutionary drug and radiation cancer treatment invented
by British scientists have proved dramatically successful, it was revealed
yesterday.
Laboratory mice genetically engineered to grow human tumours were completely
cured in 85 per cent of cases.
More than nine months after the treatment was stopped there was no evidence
of any residual cancer in the animals.
One half of the treatment consists of a drug called Combretastatin - based
on a tree-bark extract used by Zulu warriors as a charm to ward off their
enemies - which targets newly-forming blood vessels that nourish tumours.
The other comprises antibodies tagged with a radioactive "warhead" which
they ferry into cancer cells.
The therapy was pioneered by Cancer Research Campaign scientists at the
Royal Free Hospital in London and the Gray Laboratory Cancer Research Trust
at Mount Vernon Hospital, Middlesex.
Human clinical trials are expected to begin next year. If successful they
could lead to the treatment being available in five years.
Professor Richard Begent, head of oncology at the Royal Free, said:
"Combretastatin has been given to patients on its own before but the
response has not been very good. In most cases the cancer continues to grow.
But when you put the two treatments together it's then possible in these
animals to cure the cancer completely with just a single treatment.
"It is rather exciting. We're now working towards carrying out some clinical
trials with the Cancer Research Campaign."
Tumours cannot live without blood and generate their own special network of
blood vessels to provide an adequate supply. Combretastatin specifically
targets and cuts off the cancer blood network by binding on to the dividing
cells creating the new capillaries.
Researchers found a ring of cells around the central tumour do not rely on
the cancer blood supply system - they use normal blood vessels instead - and
are thus free to keep growing.
The antibodies tackle these by zapping them with radioactive material.
The experiments at the Royal Free Hospital were led by Dr Barbara Pedley,
head of tumour biology at the Cancer Research Campaign's targeting and
imaging group.
Dr Pedley said: "We are excited by these results. These are human tumours
grown in mice.
"Although we have been mainly looking at colorectal cancer, it works on a
very wide range of cancers - all the solid tumours, which includes breast
cancer."
The key to the therapy is that it ensures that no residual cancer is left.
Combretastatin attacks the tumour from the inside out by cutting off its
blood supply. The radioactive antibodies work from the outside in.
Excitement about Combretastatin began four years ago when Cancer Research
Campaign scientists found it could kill up to 95 per cent of cells in solid
tumours in the laboratory. However, in patients, the small number of cancer
cells left behind allowed the disease to return.
Dr Lesley Walker, director of cancer information at the Cancer Research
Campaign, said: "This good news confirms what we have been saying all
along - that treatments that directly target cancers and spare normal tissue
will be the cancer therapies of the future.
"By combining radioimmunotherapy with Combretastatin, doctors could in the
future be able to launch a two-pronged attack on the cancer cells,
effectively delivering a `double-blow' and preventing tumours from
regrowing.
"As well as improving the effectiveness of treatment, it should greatly
reduce side-effects for the patient."
Dr Walker said patient trials involving Combretastatin were due to start
early next year and a number of trials were expected to use a combination of
the drug in conjunction with other chemotherapy agents and/or radiotherapy.
About 200 patients with a variety of different cancers would be recruited.
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