Cervical screening changes in depth: what, why and how

The federal budget announced changes to the government’s national cervical screening program, so what are the changes and what do they mean for patients?

The test

All Pap tests are currently performed in pathology laboratories and this will be the same with the new test, which will come into effect in 2017.

The sample will be collected in the same way as the current Pap test. Cells are collected from the cervix using a spatula or ‘brush’ device.

What has changed is the test performed on the sample once it reaches the pathology lab, and what the sample is being testing for.

The current test looks for abnormal cells in the sample which may indicate cancer, precancerous cells, or these cells could result from other changes in the body, a virus or infection.

This is done by a pathology professional looking at the sample under a microscope.

The new test detects the presence of the Human Papillomavirus (HPV) and is conducted using a machine operated by highly skilled pathology staff. It is more sensitive and has good accuracy in specifically detecting HPV. There are over 100 types of HPV but two of these are heavily associated with cancer; HPV 16 causes 55-60% of cervical cancers and HPV 18 causes 10-15%. In the unvaccinated population, HPV is very common as both men and women can be affected and it can be easily passed between sexual partners.

Why?

Identifying HPV allows doctors to know if a woman is at higher risk of cervical cancer prior to abnormal cells appearing.

The introduction of the HPV vaccination program in 2007 for young women, and in 2012 for young men, means younger generations of Australian women have a much lower risk of cervical cancer.

It has been predicted that rates of cervical cancer could fall a further 15% with this new type of screening, combined with the new landscape of many more people being vaccinated against HPV.

Due to the test’s ability to detect HPV, testing frequency will drop to every 5 years. However, like all tests there can be false negative results and if there are any worrying symptoms or signs then a woman should see her doctor.

What this means for women

It is important that all women continue to be tested regularly, even those who have been vaccinated.

There is currently no anti-viral drug available that can treat HPV and although the vaccine protects against HPV 16 and 18, it does not provide immunity to all types of HPV.

“Current Pap testing has dramatically reduced the mortality rate of cervical cancer in Australia and it is hoped that this new testing method will be able to identify those at high risk of developing cancer even earlier,” said A/Prof Annabelle Farnsworth, a specialist in cytopathology and gynaecological pathology.

What next?

  • Even women who have not been vaccinated will be tested every 5 years once the new test is implemented. However, women with any symptoms or signs of potential cervical disease such as abnormal vaginal bleeding can be tested as needed.
  • The test in the new screening program will specifically identify all types of HPV, including types 16 and 18. There is currently no anti-viral drug for HPV, so vaccination and screening are imperative preventative measures.
  • If a woman is found to have HPV, a cytology sample (cells to be examined under a microscope) will be prepared immediately. Depending on the nature of the HPV found and the cytology result she will be referred for further investigation. Many HPV infections are dealt with naturally by the body but persistent HPV infections could be a problem and the new test will help to identify these.
  • The type of HPV test used in screening has little bearing on whether the woman may have had HPV in the past and her current immunity so vaccination cannot be administered for all women who test negative. However, if a woman is interested in vaccination at any time she should discuss this with her doctor.
  • The change is due to be implemented on 1st May 2017 and until then current cervical screening provisions remain in place. All women must continue to have their regular Pap smear checks.

To find out how Pap tests were created, listen to Dr Clare Hampson’s engaging Laborastory presentation on George and Mary Papanicolaou.

1 Australian Government Department of Health –

http://www.cancerscreening.gov.au/internet/screening/publishing.nsf/Content/future-changes-cervical