Women under the age of 25 gain little benefit from Pap smears according to a study that supports the federal government's decision to scrap cervical screening in younger women.
But there has been a dramatic decline in cervical cancer among women over the age of 25 since the universal Pap smear program was rolled out in 1991.
Cancer Council NSW researchers investigated the incidence of cervical cancer among different age groups for the first time since the introduction of the National Cervical Screening Program to conclude that it has had a dramatic impact.
The incidence of cervical cancer among women over 25 has reduced by 50 per cent, but there has been little change in the younger group where the disease was very rare to begin with.
Cervical cancer is almost always caused by the human papilloma virus [HPV], and the disease is likely to become rare as women who received the HPV vaccine as teenagers graduate into riskier age groups.
The HPV vaccine has been provided free to 12-year-old and 13-year-old school students since 2007.
Cancer Council NSW program manager Megan Smith said there was some evidence that women who had abnormal cells cut out of the cervix had a higher chance of giving birth prematurely, so the risks of Pap smears potentially outweighed the benefits for women aged 18 to 25.
"Once you find something, you want to treat it but most of these things when found in young women will treat themselves," Ms Smith said.
"Most people who have it will never know they had it."
The federal government announced last year that cervical cancer screening would start being offered to women aged over the age of 25 from 2017, increasing the age at which it was first offered by five years.
It would also be offered only every five years as opposed to every two, and it would include an HPV test. Only women who tested positive to HPV would have their cervical cells analysed for abnormalities.
Some researchers have raised concerns about the increased age at which women will start having Pap smears, with claims that there was an increase in cervical cancer among 25 to 29-year-olds when the age of commencement rose from 21 to 25 in England.
But the Cancer Council NSW research, published in The Medical Journal of Australia on Monday, said this would be less likely in Australia as a result of the HPV vaccination program.
"Women under 25 years of age in 2017 will have been offered HPV vaccination at school before they were 15 years old, and the three-dose vaccine uptake rate in these women exceeds 70 per cent," the article said.
Between 1988 and 1990, 18 women in every 100,000 aged 20 to 69 developed cervical cancer. By 2008 to 2010 the rate was cut to 9.3 per 100,000.
Among women aged 20 to 24, only 2.6 per 100,000 had cervical cancer in 1988-1990, and this had reduced to 1.8 cases per 100,000 in 2008-2010.
