A commonly used HIV drug could be used to prevent cervical cancer, UK researchers believe.
HPV infection increases the risk of cervical cancer
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.
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.
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."