The new national cervical cancer screening program has received a boost, with a large clinical trial showing screening for the human papillomavirus (HPV) is significantly better at detecting potential pre-cancerous cells than the traditional Pap smear.
"We found that the HPV test was substantially more effective at picking up high-grade abnormalities compared to the Pap test," said co-lead investigator Professor Karen Canfell, Director of Research at Cancer Council NSW.
The results, published in international journal PLOS Medicine, have been released less than three months ahead of the transition to the new national cervical cancer screening program that eliminates the need for women to have a Pap smear every two years.
From December, women from the age of 25, instead of 18, will be required to have a five-yearly HPV test, replacing the two-yearly Pap test.
Previous estimates have suggested the new screening program would lower cervical cancer incidence and mortality by at least 20 per cent due to the more accurate test.
However until now it had not been tested among women with a high uptake of the HPV vaccine.
To examine its effectives, researchers at Cancer Council NSW and the Victorian Cytology Service compared the detection rates of high grade cervical abnormalities with the Pap test among 5000 women aged 25 to 64.
The women attended a routine screening at 47 participating clinics in Victoria.
They were randomly assigned to either have a five-yearly HPV screening test or a 2.5-yearly liquid based cytology screening (Pap test).
The study found that compared to the Pap test, HPV screening "significantly" increased detection of high grade precancerous cervical lesions among those who had been vaccinated. The overall detection rate was 0.1 per cent versus 1.0 per cent, respectively.
"These findings provide initial support for the implementation of primary HPV screening in vaccinated populations," the authors wrote.
Prof Canfell says increased detection means greater longer-term protection against the development of the invasive cancer.
"This adds to existing evidence about how much more accurate and effective HPV screening is," she said.
While the woman's experience of cervical screening will be very similar, with a cervical smear still taken, the big difference is the way the sample is analysed in the lab.
"Instead of looking for changes in cells through a microscope, HPV testing is actually molecular testing for the presence of the presence of HPV itself which we know causes almost all cervical cancers," explained Prof Canfell.
"So it's a much more sensitive and earlier means of detecting the presence of the virus which could put women over the long term at increased risk of cervical cancer," she told AAP.
Prof Canfell says the new screening program is a "win,win" for women.
"With the Pap smear it requires testing every two years, so women have to be screened 26 times in a life time, women now only have to be nine to 10 times a life time but they still get better protection," Prof Canfeel said.
