Changes to the cervical cancer screening program
There are two types of tests for Cervical Cancer Screening: A Cytology-based Screening (Pap test or Pap smear) and a Human Papilloma Virus (HPV)-based Testing. The new cervical cancer screening program will be introduced to Australia in 2017, will discontinue the current Pap test (cytology) but will introduce the HPV test inviting women 25-74 years for screening every 5 years. This is due to commence 1 December 2017.
While the current Pap test can detect abnormal cell changes, the new cervical screening test will detect the persistent HPV infection that causes the abnormal cell changes, prior to the development of cancer. This new change is predicted to reduce the number of cervical cancers in Australia by at least an additional 15%, and save between $33 to $55 million in health care costs. More than 99 per cent of cases of Cervical Cancer are caused by HPV infection.
Instead of the specimen being collected on a glass slide, it will be collected in a liquid-filled container. The pathology institute will analyse the sample for HPV status first and will only proceed to analysing cytology [Liquid Based Cytology (LBC)] if the HPV sample indicates the presence of HPV (reflex LBC testing). If the cytology sample is also positive, patients will require a colposcopy.
Four to five times more women than currently will require a colposcopy because HPV testing is far more sensitive (but less specific) than cytology testing. Women under the age of 35 years will be most affected.
There has been a lot of speculation why changes are made to a successful screening program. There has even been an online petition against the new cervical screening program. However, there is also a lot of misinformation.
One of the greatest misinformation is that the changes were made to save costs. The change towards HPV testing and the decision to leave cytology-based testing is based on extensive national and international research evidence.
In an article published in the prestigious journal the Lancet, researchers reviewed four randomised controlled trials and found significantly lower rates of invasive cervical cancer in the HPV testing groups as compared with screening by PAP test cytology. In total across the four studies, 176 464 women aged 20–64 years were randomly assigned to HPV-based or cytology-based cervical cancer screening in Sweden, the Netherlands, England and Italy. The participants were followed up for a median of 6.5 years. In total, 107 invasive cervical carcinomas were detected. Rates of detection of invasive cancers was similar with the 2 screening methods for the first 2.5 years of follow-up. However, detection was significantly lower in the HPV screening group thereafter. At follow-up, women randomised to HPV screening had a cumulative incidence of invasive cervical cancer of 8.7 per 100,000 as compared with 36.0 per 100,000 among women randomised to screening cytology. Overall, the researchers found HPV-based screening provides 60–70% greater protection against invasive cervical carcinomas compared with cytology.
Change in screening intervals – every 5 years
A dominant concern from the general public is about prolonging the screening intervals from 2 years to 5 years. Remember, the new test will detect HPV before abnormal cell changes occur, rather than cytology testing for already formed abnormal changes. It usually takes around 5 to 10 years for changes to cervical cells caused by HPV to progress to cancer. But not all HPV will develop into cervical cancer. A HPV test once every five years is sensitive enough to identify changes before they become serious. The new test is much more sensitive than the old cytology-based PAP test. That’s why the screening intervals can be longer.
Simply, the pap smear is an old, outdated technique that did a terrific job for decades but should be replaced with a modern and far more effective test that prevents more cervical cancer.
Start of screening at age 25 years?
“Screening” is a technical term and means investigations in women who do not display any symptoms, such as irregular bleeding or bleeding after intercourse. Analysing the data from the last 50 years, it appears that cervical cancer in young women under 25 years is rare - around 1.7 in 100,000 Australian women under 25 years. Virtually all of these women see their doctor for symptoms (e.g., bleeding) and none are without symptoms.
While women under the age of 25 years will not be offered cervical cancer screening, those women with abnormal bleeding, (e.g. postcoital bleeding) a cervical cytology and/or HPV test is standard care and will still be government funded.
It will be very important to train our doctors that they do understand the screening program correctly. A young woman who complains about irregular bleeding or bleeding after intercourse to her GP will still require a PAP test. This will be a very important issue for the education of GP’s Australia-wide.
If you are a specialist or a GP, please consider attending the 4th QCGC Symposium. This symposium will educate O&G specialists and GPs on the new National Cervical Cancer Screening Program. The chair of the program, Prof Ian Hammond will be our guest speaker. If you are interested to attend, please drop me an email via my contact page.
Further information on the changes to the cervical cancer screening program can be found on the National Cervical Screening Program website here.
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