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.

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 as a screening test).

Two vaccines against HPV are available in Australia (Gardasil and Cervarix). The initial free vaccination programme was designed to vaccinate all women under the age of 26 ( to June 2009) and now all schoolgirls at the age of 12. The vaccine appears to be completely effective in preventing future HPV infections if given prior to the start of sexual activity although the length of immunity is not yet known.

The vaccines appear to be very safe with few adverse events reported when viewed against the large number of women so far vaccinated.

The vaccine is licenced to be given to women up to the age of 45 but the effectiveness of the vaccine in those who are already sexually active is far less clear. The vaccines have no role in treating women with abnormal smears.

There is no Government programme to vaccinate boys although an argument could be made that this would further reduce the number of infections in the population and protect their future partners, particularly for those that enter same sex relationships.

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.

A review of the first 1000 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 1700 women have now received treatment and the results of this large group are the same.