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Hi.
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Today I'd like to talk to you about
HPV (human papilloma virus),
cervical cancer and screening.
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Let's talk a little bit about
human papilloma virus, HPV for short.
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The HPV genotype appears to be
the most important determinant
for the persistence and
progression of disease.
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There are two different oncogenic types.
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One type is human papilloma
virus 16 or HPV-16.
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It has the highest carcinogenic potential and
this is very important to remember for your test.
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It accounts for about 55 to 60% of all
cases of cervical cancer worldwide.
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The next most carcinogenic
type of HPV is HPV-18.
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It's responsible for a lot less,
10 to 15% of all cases of cervical cancer.
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There are risk factors for
cervical cancer besides just HPV infection.
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The known risk factors increase the
likelihood of persistence of HPV infection
which is normally cleared
by a young, healthy woman.
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However, if you're a smoker,
that incidence of clearing is reduced.
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Also, if you have a compromised immune system,
that is with years of taking glucocorticoids,
you can potentially have an
increased persistence of HPV.
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Also, we know that HIV infection
can also increase
the persistence of human papilloma virus
leading to cervical cancer.
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Let's talk a little bit about the
molecular pathogenesis of HPV.
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HPV belongs to the papillomavirus family and
is a group of double-stranded DNA viruses.
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HPV 6 and 11 which I have not
mentioned yet causes genital warts
while 16 and 18 are more likely
to cause cervical cancer.
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The progression to invasive
cervical cancer is characterized
by the viral DNA integrating
into the host DNA.
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HPV is very common.
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It's usually an infection that occurs in
teenagers and women in their twenties.
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Although the prevalence is not quite known,
it decreases as women age.
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The lifetime cumulative risk
though of acquiring it is about 80%.
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Most young women, especially those
under 21 have a very effective immune system
that can clear the infection in
about an average of eight months.
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There's some guidelines
that we now need to review.
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They're from the United States Preventive Service
Task Force, and they only apply to certain women.
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So this is important to remember.
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They apply to women who have
a cervix and who are of age,
greater than 21 years old,
regardless of their sexual history.
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It does not apply to women who have already
received a pre-cancer cervical lesion diagnosis
or have frank cervical cancer.
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It does not apply to women who've been
exposed to DES or diethylstilbestrol
It does not apply to women who are immunocompromised
such as women who are HIV-positive.
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Here are the guidelines.
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Again, women ages 21 to 65 should be
screened with cytology every three years.
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Women who are 30 to 65
who want to lengthen the screening
can have intervals of five years with a
combination of cytology and HPV screening.
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And there are other recommendations that we no
longer follow which are grade D recommendations.
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So if you are younger than 21 or older than 65 or
you already have had a hysterectomy due to cancer,
or you are younger than 30,
we don't do HPV testing alone
or in combination with cytology in
women again who are younger than 30.
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What about prevention?
So how can we prevent all of this morbidity
and potentially mortality with HPV.
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Well, now there is a vaccine that protects
women against nine strains of HPV.
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While it protects women, both boys
and girls should receive the vaccine
between the ages of 9 and 26 years old.
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Thank you for listening.