A commonly used HIV drug could be used to prevent cervical
cancer, UK researchers believe.
Early lab tests show the antiviral drug lopinavir attacks the
virus that causes cervical cancer - HPV - as well as HIV.
The University of Manchester team envisage that the oral drug
could be made into a simple cream or pessary to apply to the
cervix.
This would mean thousands of women could avoid surgery to remove
early cancers, they told Antiviral Therapy.
Cervical cancer vaccines are already being developed, but these
will only be effective in people who have not already caught the
HPV virus.
Women who already have the virus currently have to have regular
checks for cancer. If there are very early warning signs of a
possible tumour, doctors advise a 'watch and wait' policy because
many of these abnormalities disappear on their own.
However, some progress to become cancerous and have to be cut
out.
Each year in the UK alone about 50,000 women have early cervical
cancers removed, say the researchers.
In the laboratory study, small doses of the liquid protease
inhibitor selectively killed HPV-infected cervical cancer cells.
Dr Ian Hampson and his team are hopeful that the HIV drug will do
the same in real life and plan to carry out clinical trials in
women soon.
The test treatment will be a cream or a pessary because the doses
that reach the cervix after passing through the body when
lopinavir is taken orally would not be strong enough.
Fast-track
However, the actual concentration needed in the lab was a
millionth of that used orally to treat HIV.
And because the drug has already been approved and checked for
treating HIV, the researchers believe it could be available as a
treatment for HPV in a few years.
Dr Hampson's team tested the drug against the most common
cancer-causing strain of human papilloma virus, HPV 16.
They are confident that it will also work against other HPV
strains that cause cervical cancer.
Dr Hampson explained: "The drug works as a selective proteosome
inhibitor. It allows cellular proteins that are detrimental to
the virus to persist."
Normally, HPV would remove these from the cell so it could
flourish, he said.
"At the moment, we can't really offer anything to women with HPV
and low-grade cervical disease.
"We are talking about 200,000 women in the UK alone. This
treatment, if it works, could provide an alternative," he said.
Future hope
Michael Carter, of the HIV organisation Aidsmap, said: "This
latest finding is extremely welcome. Many HIV-positive
individuals are infected with high-risk strains of HPV. Anal and
cervical cancer caused by HPV is a real concern for people with
HIV."
He said other research suggested certain anti-HIV drugs could be
used to treat hepatitis B.
HIV makes people susceptible to HPV-related cancers and many
other diseases because it attacks the body's immune system.
A spokesman from the HIV charity Avert said: "Cervical cancer
kills 250,000 people each year, and most of these deaths occur in
developing countries where there is little access to surgery.
"The prospect of a simple, non-surgical treatment for HPV is very
exciting. However, we'll have to wait for the results of human
trials."
Dr Laura-Jane Armstrong of Cancer Research UK said: "This is an
interesting study but the research has only been done on cells in
the laboratory and we don't yet know if it will work in humans.
"Currently, the best thing women can do to prevent cervical
cancer developing is to go for regular cervical smear tests when
invited."
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