Questions and Answers with NAM and Edwin J Bernard, editor, Aids Treatment Update
I’ve heard about an HPV vaccine that can prevent cervical cancer
in women. When can I get it?
There have been a lot of stories in the news recently about the very promising
results of two HPV (human papilloma virus) vaccines that can prevent infection
with ‘high-risk’ strains of HPV.
These are strains associated with the development of cervical cancer. They
should be approved in the US next year, but there’s no news on UK availability.
However, these are preventative vaccines, which mean they only work if you’re
not already infected with the particular ‘high-risk’ strains these
vaccines prevent: HPV 16 and 18. Unfortunately, most sexually active adults
are probably already infected with at least one of them, although the immune
system usually keeps HPV under control.
So what can I do to make sure I don’t get cervical cancer?
HIV positive women are more likely to have been infected with ‘high-risk’
HPV than the general population and because HIV affects the immune system,
are less likely to keep it under control. That’s why, in 1993, cervical
cancer became an Aids-defining illness. But being infected with ‘high-risk’
HPV alone isn’t enough for it to develop into cancer. Researchers have
found quite a few other ‘co-factors’ are necessary. These include
a family history of cervical cancer, smoking, increased age, and lower CD4
counts. Because of the risks to HIV positive women, you should visit your
gynaecologist regularly and often. Regular screening for pre-cancerous abnormalities
can identify and treat the disease before it becomes cancer. The good news
is that a recent US study found women on HIV treatment who received regular
screening had the same the risk for cervical cancer as their HIV negative
counterparts.
What about genital and anal warts. Are they risky?
There are over 100 different varieties of HPV. Only between 30 and 40 are
sexually transmitted. The majority of sexually transmitted HPV cause genital
and/or anal warts, and these are considered ‘low-risk’ for the
development of cervical or anal cancer. However, since genital warts are the
only visible signs of HPV infection, you could have the invisible ‘high-risk’
HPV as well.
Sometimes you can see genital or anal warts. They usually look like small
red or white bumps that are either one-offs, or clump together in cauliflower-like
bunches. However, sometimes they are hidden inside and invisible. Although
these warts occasionally cause pain, particularly during sex or when going
to the toilet, mostly they don’t cause physical symptoms. However, some
people who know they have genital warts feel anxious, ashamed and depressed.
How do I avoid warts?
You can’t, unless you avoid sex and close physical contact. Last year,
around 80,000 people were diagnosed with genital warts, making HPV the second
most frequently diagnosed STI in the UK.
HPV can be caught during vaginal, oral or anal sex, but it can also be caught
through close physical contact with someone who has it (and they don’t
have to have warts, since it is the virus and not the warts that is infectious).
Condoms reduce the risk but do not prevent it, and the more sexual partners
you have, the more likely you are to be infected with one or more strains
of HPV.
If I have anal warts, does that mean I’ll get anal cancer?
Not necessarily. The HPV that causes warts isn’t the same HPV that causes
cancer. Fortunately, anal cancer is still quite rare, but it is becoming more
common, particularly amongst HIV positive gay and bisexual men. HIV combination
therapy doesn’t seem to stop it occurring.
What about anal cancer screening?
The idea of screening men and women at high risk of anal cancer is gaining
popularity. The people at highest risk are HIV positive. Because HPV is so
easily spread, it can move from genital areas or the fingers to the anus.
In fact, one study found almost 50 per cent of HIV positive heterosexual men
who had never had anal sex had HPV in their anus. About 95 per cent of HIV
positive gay or bisexual men, and 75 per cent of HIV positive women have anal
HPV infection.
A national screening programme, similar to that for cervical cancer might
start soon in the UK, and HIV positive people will be first in line. But if
you want to be tested for anal cancer, you should mention this to you HIV
clinic doctor next time you see them.
• NAM provides information to help you think about your use of HIV treatments,
but this is not intended to replace discussion with your doctor.
