About Abnormal Smears
All cancers of the cervix and most cancers of the vagina and vulva are preceded
by a precancerous change in the skin, detection and treatment of which can
prevent their development. Regular smear tests and examinations can detect
most of these precancerous changes. The consequence of this is that these
cancers can be generally thought to be preventable.
In the case of cervix cancers, it is thought that the precancerous state
can be present for a considerable period of time (an average of ~ 20 years)
giving women many chances of detecting these changes before cancer
develops. Women who have regular 2 yearly smear tests have a protection
against cervix cancer of 90-95%.
Smear tests can be taken by most GP's, women's health clinics, family
planning clinics and gynaecologists. Smear
testing should commence at the age of 20 or when women become sexually
active, whichever is the earlier.
Abnormal smears can arise from either the skin of the surface of the
cervix (squamous abnormalities) or from the skin
lining the cervical canal (glandular abnormalities). Precancerous changes
of the squamous cells are called squamous dysplasia or
Cervical Intraepithelial Neoplasia (CIN) and
graded 1, 2or 3 depending on severity. CIN 3 is not yet cancerous but is
the closest change to squamous cervical cancer.
Similarly, precancerous changes of the endocervical
glandular cells are called glandular dysplasia.
The most significant glandular dysplasia is
called adenocarcinoma in situ (ACIS).
Sometimes, the changes in the smear fall short of dysplasia
and the smear is reported as atypical. This often is a reflection of
infection of the cervix by a virus - the human papilloma
virus (HPV) and will often go away without treatment, particularly in young
women.
Occasionally, the reporting pathologist sees changes which are not
specific to CIN or ACIS, but which he or she thinks may be associated with
an underlying CIN or ACIS. These smears are reported as inconclusive and
are as significant as a smear labelled CIN or
ACIS.
It is important to remember that smear tests are not highly accurate in
making a diagnosis and that their job is just to identify those women who
are at increased risk of developing cervix cancer and who should therefore
be further investigated.
Can I Do Anything to Stop Getting an Abnormal Smear?
The most important associations with the development of abnormal smears
are with smoking and infection with the human papilloma
virus. Women who smoke are 5-10 times more likely to have an abnormal smear
than women who don't and either not taking it up or giving the habit away
are very positive ways to decrease risk. The by-products of tobacco smoking
can be found in the cervical mucus of smokers with the potential to cause
the same sort of damage as is done to lung tissue. As well, smoking
decreases the body's immune system and lowers the natural protection
against these abnormal cells.
HPV infection is very common in the community with the majority of women
infected by adulthood. Most infections are transitory with the virus
disappearing from the skin probably as a result of immunity development.
Persisting infections are the ones associated with abnormal smears and
occur in some women for reasons that are not understood. Some particular
members of the HPV family are more often associated with persistent
infection and abnormal smears and a test is available to detect these
(although unfortunately not rebated by Medicare). A vaccine against these
HPV types is currently being assessed in clinical trials and may be
available in 5 years.
Treatment Options
The treatment of the precancerous abnormalities
of the cervix can be accomplished by several means. The
commonest are laser treatment, surgical excision, large loop excision of
the transformation zone (LLETZ) or Fischer cone excision.
LLETZ and Fischer cone excision are the
preferred methods at ABSU because the treatment is simply done under local anaesthetic, removes the minimum of normal tissue and
allows the pathologists to check the adequacy of treatment when the removed
specimen is submitted for assessment.
All aspects of the assessment and treatment are
checked by sending all samples to the pathology service for reporting.
Treatment Outcome
A review of the first 403 women treated by ABSU showed successful
eradication of the precancerous cells in more than 99% of women with a
single treatment. 5% of women had some continuing minor changes in their
smear tests at 12 months of followup and only 1%
required retreatment. Women treated at the Unit
should be very meticulous in ensuring that they have their subsequent
smears at the correct intervals.
Over 850 women have now received treatment and the results of this large
group are the same.
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