HPV testing advances boost outcomes

SELF-collection for human papilloma virus (HPV) screening will play a key role in improving outcomes for unscreened and underscreened women, according to Australian researchers, however mainstream screening will remain the gold standard with substantially greater benefits for women.

Research published today in the MJA found that, compared with being unscreened, women offered even one round of self-collected HPV screening at age 30 would have 908 fewer cancer diagnoses and 364 fewer cancer deaths by the time they reached age 84 (NNT, 5.8).

The research also reinforced the effectiveness of the mainstream screening program, which showed substantially greater benefits for women, with about double the number of deaths averted over a lifetime after a single screen at age 30 (NNT, 4.9).

The findings come as Australia prepares to roll out significant changes to the Australian National Cervical Screening Program (NCSP) from May 2017. The changes – known as the “Renewal” – follow on from an extensive review of the program, and have been endorsed by the Medical Services Advisory Committee. 

The recommended changes include the introduction of 5-yearly HPV-based testing with partial genotyping; colposcopy referral for women testing positive for HPV16/18; liquid-base cytology triage for other oncogenic HPV types; and the provision of self-collection for women aged 30–74, who have never been screened or are overdue for screening by 2 years or more.

Speaking in an MJA podcast, Dr Julia Brotherton said Australia’s cervical cancer screening program had been “remarkably” successful, halving the rate of cervical cancer since its inception. However, she said, the existing program was based on old technology and the introduction of HPV DNA testing would enable less frequent but more effective screening.

• Podcast with Dr Julia Brotherton
• Video with Dr Julia Brotherton
  
• Related: MJA — Cervical screening rates for women vaccinated against human papillomavirus

“Australia is going to be one of the first countries in the world to roll this out to our populations and all the projections are that it’s going to … reduce cancer even more effectively and actually save us money,” she said.

Professor Karen Canfell, Director of Cancer Council Australia’s Cancer Screening and Immunisation Committee, said the transitional period would be challenging, but the key message for clinicians and women was to continue to adhere to the 2-yearly Pap smear program until the changes come into effect next year.

“We don’t want to see a decrease in screening participation either because women are anticipating the screening changes, or in the case of younger women because they may not be aware that if you’re vaccinated you still need to be screened,” she said.

Professor Canfell said the research looking at the comparative benefits of no screening, self-collection and participation in the mainstream program would highlight the importance of engaging with the NCSP.

“Even a single test using self-collection in an unscreened woman, can cut a woman’s risk by more than 40%, but it’s equally important to note that the benefit can be doubled if women instead participate in the mainstream screening program,” Professor Canfell told MJA InSight.

“So it’s better to have self-collection than nothing at all, but also that we really want to encourage women to participate in the mainstream program. We support the ongoing development of health promotion activities tailored to specific cultural group to help get this message out.”

Lead author of the MJA research, Dr Megan Smith, researcher at Cancer Council NSW, said one concern about self-collection was that women who participated in the mainstream program might shift to self-collection. However, the proposed model of restricting self-collection to unscreened and underscreened women through a screening provider was designed to address this issue.

“It will be important that the offer of self-collection is accompanied by suitable information and advice from a healthcare professional and the opportunity for women to ask questions,” Dr Smith told MJA InSight. 

• Related: MJA – Impact of HPV sample self-collection for underscreened women in the renewed Cervical Screening Program
• Related: MJA – HPV vaccine impact in Australian women: ready for an HPV-based screening program
• Related: MJA – Self-sampling HPV testing versus mainstream cervical screening and HPV testing

“It also ensures that there is a health care professional who can help follow-up women as required, for example, women who have a positive HPV test. Offering self-collection through health care professionals who also offer mainstream cervical screening also means there will already be mechanisms in place to send the self-collected samples to a laboratory for processing.”

In an accompanying MJA editorial, Adjunct Professor Annabelle Farnsworth, medical director of Douglass Hanly Moir, said the study results were important because self-sampling had received significant publicity in the mainstream media, which had fuelled many misconceptions.

“Headlines such as ‘Australian women will be able to do their own Pap smear’ and ‘You could soon be doing your own Pap smear’ have appeared online,” Professor Farnsworth wrote. “Such comments are confusing and misleading for both the general public and the medical profession.”

The MJA also published a short report today evaluating the impact of the HPV vaccine on the prevalence of high-grade cervical abnormalities. In an analysis of Victorian Cervical Cytology Registry data, researchers reported that the vaccine program was associated with a 17% drop in pre-cancerous lesions in women aged 25–29 years over the past 2 years.

They also identified the first signs of decline in the 30–34 year age group, which was significant because many of these women would have been sexually active before being vaccinated at 18–26 years.

Lead author, Dr Julia Brotherton said the continuing declines in cervical disease prevalence were in line with modelling studies and would underpin the new screening program.

“In terms of declines in HPV prevalence … now you’ll only find it in about 1% of women aged 16–18, whereas in the pre-vaccine era, it would have been 25%,” Dr Brotherton said. “It’s absolutely crashed through the floor.”