The National Cervical Screening Program

This information relates to the National Cervical Screening Program in Australia which has just been updated to support 5-yearly primary HPV ± reflex liquid-based cytology (LBC) testing for sexually active women starting from age 25 and ending at the time of a cervical screening test (CST) between ages 70 and 74.

HPV vaccination and testing has changed the cervical screening environment. Because of the good efficiency and uptake of HPV vaccination and because of the high sensitivity and specificity of HPV testing, the interval to cervical screening has been safely extended to five year intervals starting, in sexually active women, from age 25. When GPs order a cervical screening test (CST) — performed as for liquid-based cytology — primary testing for oncogenic HPV strains 16 and 18 (and 12 other lesser oncogenic strains) is performed and automatically supplemented with reflex liquid-based cytology (LBC) for all positive tests.

Results will trigger one of the following responses, respectively:

• Negative CST (no oncogenic HPV detected) → rescreen in 5 years
• Positive CST with HPV strains 16 or 18 detected → colposcopy
• Positive CST with lesser oncogenic HPV strains → triage according to reflex LBC and clinical history
• Unsatisfactory CST (HPV and/or LBC) → repeat CST in 6-12 weeks

The rationale for the changes are based on the understanding that of 40 genital HPV strains, 14 are oncogenic with strains 16 and 18 accounting for 70-80% of all cervical cancer. The immune system, however, generally clears any HPV within two years of infection and that only “persistent infection with oncogenic HPV (especially type 16) is associated with a significantly elevated risk of developing high grade cellular abnormalities of the cervix”. That persistent infection is established within 5-10 years in less than 10% of cases. Furthermore, HPV vaccination has dramatically reduced the rates of HPV infection inclusive of oncogenic strains 16 and 18. Moreover, there is limited overall benefit to screening women under 25 because of the effect of over-investigation and treatment; “evidence links treatment of the cervix with a small but important increased risk of preterm delivery”. Finally, a select group of women will be allowed to self-collect via a vaginal swab.

---

Reference

• The renewed National Cervical Screening Program is here!, Dr Lara Roeske, Liaison Physician for Victorian Cytology Service (VCS) available at https://www.healthed.com.au/clinical-articles/renewed-national-cervical-screening-program/. Accessed on Tuesday, 5 December 2017.

Further Reading:

Click on pdf icon to access file directly

• Sisters doing it for themselves: a safe and acceptable self-collection model for cervical cancer screening. VCS wall-chart.
• Hammond, I., Canfell, K. and Saville, M. (2017), A new era for cervical screening in Australia: Watch this space!. Aust N Z J Obstet Gynaecol, 57: 499–501.

Featured Image

• Woman [Wikimedia Commons]