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