A cervical smear test involves a gentle internal examination to collect cells from around the
cervix. We put these in a solution and then send them off to the lab where they can be
processed and the pathologist has a look to see whether any of the cells look abnormal.
It's a bit strange when you first have an internal examination. It feels a little bit
stretchy, but if it's done expertly and carefully, it shouldn't be uncomfortable at all. There's
a new device available called a PapCone, which hurts a lot less than the traditional brush
that is used throughout the UK. These are available at a small number of centres and
we've managed to get some ourselves here at the McIndoe centre. In terms of frequency
of smears, a lot of women have the smears every year. The NHS suggests that every three
years is enough, but sometimes that's a little bit too infrequent. We know that smear tests
aren't terribly accurate and sometimes they miss abnormalities. So particularly if you
haven't had many smears, it's not a bad idea to have a smear more frequently than every
three years.
The NHS recommend women start having their first smears at 25 years of age, but frighteningly,
the peak incidence of cancer of the cervix which of course is what we're trying to prevent
is between 25 and 30 years of age. The NHS increased their age that women first have
smears from 20 to 25 about 15 years ago and since then we've seen a 50% increase in women
between the ages of 25 and 30 getting a cancer. And if you think about it, that's an absolute
disaster for these young women, because it may be possible to cure the cancer, but it
affects their chances of having babies. So, if you want to stop cancers between 25 and
30, the age to screen obviously is 20 to 25. Because we're trying to pick up abnormalities
which if left might become a cancer. We're not trying to detect actual cancers. The reason
the NHS shifted their screening age is that a statistician argued that smear tests between
20 and 25 didn't seem to work, because a single smear test alone doesn't necessarily protect
women from cancer. But the problem is that smear tests are only about 50% sensitive.
And so, they do miss quite a number of precancerous abnormalities. So, what you need to do is
to do a number of smears between 20 and 25 to pick up the important abnormalities and
to treat those. There's a new test being introduced to the NHS, an HPV test, which probably will
pick up a few more precancerous abnormalities than the smear test. And that is a real hope
for the future. The other thing that's a hope for the future is HPV vaccination; which has
been rolled out as most of you will know I'm sure to young girls across the country and
seems to be reducing the incidence of cancer the cervix quite dramatically.
An abnormal smear test suggests that there are some cells in the skin of the cervix which
are growing a bit faster than they should do. Which if left, might become a cancer.
We divide the abnormalities into low grade and high grade. Low grade changes represent
very minor abnormalities which most of the time will just go away by themselves. So,
what we tend to do with low-grade abnormalities is just watch and wait with the expectation
that the cervix will clear. With high-grade abnormalities, these are ones that are much
more likely to become a cancer over time. And so these are the ones that we tend to
treat. Treatment's relatively straightforward. We can just remove the little area of skin
that's abnormal. And the smear test should go back to normal. If a woman presents with
a low-grade abnormality, it's important that she then goes for a colposcopy, because about
1 in 10 women with a low-grade abnormality on their smear test will actually have a high-grade
abnormality when we look with the colposcope. So, the point of the first examination of
the colposcope is to identify those women that have an unexpected high-grade abnormality.
By far and away the most likely finding is a low-grade change which as I said will go
away by itself over one to two maybe three years.
An abnormal smear test usually doesn't indicate cancer. In fact, very rarely will an abnormal
smear test result from cancer. The vast majority of abnormalities we see when the smear test
is abnormal is relatively minor changes in the skin of the cervix, which if left most
of them will just go away by themselves. Occasionally, it's a slightly more serious abnormality.
Still a precancerous change which we can remove quite simply. It's vanishingly rare that the
smear test will actually show that you have a cancer.
So if a woman has an abnormal smear test, she will be sent for colposcopy. This involves
a careful examination of the cervix. It's a bit like a smear test but takes just slightly
longer. We use the same speculum as we do for a smear test, but with the colposcope,
we put some solutions on the cervix which make it apparent whether any of the cells
look abnormal. Interestingly, with an abnormal smear test, the cervix looks completely normal
to the naked eye. And it's only when we put solutions on and use the magnification about
10 times with the colposcope that we can see these abnormalities. And what we're looking
for is to try and decide whether the abnormalities are low-grade; in which case we tend to be
very conservative and just watch and wait with the expectation that it will go back
to normal by itself. If the abnormality is high-grade, then we'll often take a biopsy
from the cervix just to be absolutely sure what it is that we're treating. But if we
confirm that there's a high-grade abnormality, then the usual treatment is just to remove
that with a wire loop or a needle to take away the bit of skin that's abnormal. And
after that, for the vast majority of women, that's all that will be needed. Just a single
treatment. Very occasionally, women require a second treatment but that's not common at
all. One of the tests that we use to help decide between low grade and high grade is
an HPV test. And we can look at that to see whether there's any high-risk HPV types which
are associated with the more serious abnormalities. If the HPV test is negative then that can
be very reassuring that there's nothing very serious going wrong with the cervix.