Australian Government - Department of Health and Ageing
Cancerscreening.gov.au

Policy for screening women vaccinated against HPV

Approved by the Australian Population Health Development Principal Committee - February 2007

Policy Statement

The National Cervical Screening Program recommends that all women aged 18 to 69 years, who have ever been sexually active, whether vaccinated or unvaccinated, should have cervical screening by Pap smears.

Key Points

  • Almost all cervical cancers are associated with persistent infection with oncogenic human papillomavirus (HPV) types.
  • HPV is a sexually transmitted infection, with the highest incidence rates in females seen in the 20 to 24 years age group. Most clear the infection, but in some cases infection persists leading to the development of cervical cancer after many years.
  • HPV strains 16 and 18 are responsible for an estimated 70% of all cervical cancers in Australia.
  • A vaccine, now available in Australia, has been shown to prevent infection, persistent infection and cervical abnormalities from two identified cancer causing strains of HPV, strains 16 and 18. The vaccine does not prevent persistent infection or cervical abnormalities in women who were already infected with the HPV strain before vaccination.
  • HPV vaccination will not prevent all cases of cervical cancer, therefore vaccinated women should continue to have two yearly Pap smears.
  • Women, whether vaccinated or unvaccinated, should be screened for cervical cancer in accordance with the policy of the National Cervical Screening Program1 and the NHMRC Screening to prevent cervical cancer: Guidelines for the management of asymptomatic women with screen detected abnormalities.2

Rationale

The current method of cervical cancer control in Australia is the National Cervical Screening Program (NCSP). Since the introduction of the NCSP, deaths from cervical cancer in the target age group (20-69 years) have fallen from 4.0 per 100,000 women (1991) to 1.8 per 100,000 women (2004).

Almost all cervical cancers are associated with persistent infection with the human papillomavirus (HPV), which is sexually transmitted. Over 100 strains of HPV have been identified, with approximately 40 strains affecting the genital tract. Of these, 15 high-risk strains of the virus have been associated with 99% of all invasive cervical cancers. Strains 16 and 18 are responsible for an estimated 70% of all cervical cancers in Australia.

It is estimated that 80% of the adult population will be exposed to HPV at some time in their life. Most healthy adults will clear the virus within two years. Persistent HPV infection may lead to cervical cancer after many years. Cervical cancer is a rare outcome of HPV infection.

A vaccine, now available in Australia, has been shown to prevent infection from two identified cancer causing strains of HPV, strains 16 and 18, if administered prior to infection. It also offers protection from two non-oncogenic strains of HPV, 6 and 11, which are responsible for the majority of genital wart lesions and for some low grade squamous intraepithelial lesion Pap smear results. This vaccine is licensed for use in Australia for females aged 9 to 26 years and males aged 9 to 15 years.5 The duration of immunity from vaccination is not yet known, but it is at least five years duration.3

HPV vaccine is best administered before sexual activity commences to prevent infection from HPV.3 As HPV vaccine does not protect against all cancer-causing HPV strains, vaccinated women will still need to have regular Pap smears through the NCSP to ensure early detection and treatment of cervical lesions.


1 The National Cervical Screening Program recommends women who have ever been sexually active should commence having Pap smears between the ages of 18 and 20, one or two years after first sexual intercourse, whichever is later. http://www.cancerscreening.gov.au/internet/screening/publishing.nsf/Content/cervical-1lp#policy_overview

2 National Health and Medical Research Council (2005). Screening to prevent cervical cancer: guidelines for the management of asymptomatic women with screen detected abnormalities.

3 National Centre for Immunisation Research and Surveillance (NCIRS) (2006) Fact Sheet: Human papillomavirus vaccines for Australians: Information for GPs and Immunisation Providers.

4 Australian Institute of Health and Welfare (2006). Cervical Screening in Australia 2003-2004.

5 http://www.tga.gov.au/docs/html/adec/adec0246.htm



Page currency, Latest update: 26 March, 2007