Self-collected vaginal samples

Only around five in 10 women participate in the National Cervical Screening Program (NCSP) at the recommended interval.^[1] Participation at the recommended interval is less than 50% in the Northern Territory, and in outer regional, remote, or very remote areas.^[1] Some of the groups of women and other people with a cervix who are underscreened include those who identify as Aboriginal and Torres Strait Islanders, are culturally and linguistically diverse, are socioeconomically disadvantaged, have experienced sexual assault, have a disability, identify as lesbian or bisexual, or are trans men and gender diverse people with a cervix who do not identify as women.

Data from the Victorian Cervical Cytology Register (VCCR) show that 74% of women diagnosed with invasive cervical cancer over 2012-2014 have never been screened or have participated in the screening program but were overdue for a recommended cytology test at the time of their cancer diagnosis.^[2,3,4] Self-collection of human papillomavirus (HPV) test samples has been shown to overcome some of the barriers to undergoing a screening test that some women experience. Providing HPV self-collection kits to never-screened and under-screened women has been shown to improve screening participation in international studies.^[5]

Under the renewed NCSP, HPV testing on self-collected samples with limited eligibility was introduced in December 2017. From 1 July 2022, HPV testing on self-collected samples will be available as a choice to all women eligible for routine screening or for a follow-up HPV test. The clinical guidelines define the pathways for people who have a positive self-collected sample. There are some groups of people who require co-testing and will therefore require a clinician- collected sample.

2013 MSAC systematic review

The MSAC evaluation assessed the comparative safety and effectiveness of including self-collected samples for HPV testing for never-screened and under-screened women, to supplement the organised screening program using clinician-collected samples for HPV testing, compared with the existing collection protocol.[7]

The MSAC assessment of accuracy of self-collected samples was based on 10 level III-2 diagnostic accuracy studies conducted in a screening setting, which were included in a systematic review.[5] Evidence for adherence rates was obtained from a randomised controlled trial[8] and two cohort studies.[9][10]

The 2013 MSAC systematic review made the following conclusions:[7]

• The accuracy of HPV testing using self-collected samples varies between different types of sampling devices and HPV tests.
• HPV tests using self-collected samples have moderate-to-high sensitivity and comparably high specificity for detecting cervical intraepithelial neoplasia grade 2 or higher (CIN2+), compared with clinic HPV testing in nine of 10 studies identified, with a relative sensitivity of 0.62–1.00 and relative specificity of 0.93–1.00.
• High rates of adherence to screening follow-up have been reported among previously unscreened women with a positive HPV test result from a self-collected sample.

Other evidence

A more recent meta-analysis[1] found that the sensitivity and specificity of HPV testing to detect CIN2+ in self-collected samples were similar to those for clinician-collected samples when using validated PCR-based HPV assays. When using signal amplification-based HPV assays, self-collected samples showed lower sensitivity than clinician-collected samples.[11][12]

Two studies conducted in Victoria suggest that offering self-collection is likely to be acceptable to Australian women who have not been screened recently.[13][14] One of these, a randomised controlled trial, additionally found that offering self-collection was more effective than a reminder letter in encouraging women who were unscreened or overdue for screening to undergo a round of screening.[15] Overall, 75.7% of women with a positive oncogenic HPV (any type) test result had the appropriate clinical follow-up within 6 months. Among 45 women with a positive oncogenic HPV (16/18) test result, 28 (62.2%) attended for colposcopy within 6 months, and attendance for colposcopy was lower among women with negative or LSIL cytology (18/27 attended) than among women with HSIL cytology (8/8 attended).[15] The authors suggested that medical practitioners may not have referred women for colposcopy when subsequent cytology was negative.[15] The trial protocol had recommended colposcopy referral for women with a positive oncogenic HPV (16/18) test result, and did not require or actively recommend that cytology be collected prior to referral (this was at the discretion of the healthcare professional), [16] however, cytology was collected from 35 of the 37 women who attended for any follow-up.[15]

A modelled analysis found that undergoing even one round of screening could substantially reduce an unscreened woman’s risk of cervical cancer over her lifetime, by around 41% if this occurred at age 30 or 40.[12] The authors noted that benefits of self-collection would be maximised by using a sufficiently accurate HPV test that had capacity to perform partial genotyping for HPV 16/18.[12

2021 MSAC review

In 2021, the Medical Services Advisory Committee (MSAC) reviewed an application from the National Cervical Screening Program requesting expansion of the eligibility to participate in cervical screening using self-collection. The Self-Collection Expert Advisory Group was convened to guide this review, and to provide advice on policy, implementation and consultation. [17]

MSAC noted the large body of evidence showing no material difference in the diagnostic accuracy of HPV testing between using self-collected and clinician-collected samples (relative sensitivity = 0.98; 95% CI: 0.96 to 1.01; relative specificity = 0.99; 95% CI: 0.98 to 1.01). [17]

MSAC concluded that HPV testing using self-collected samples is just as accurate as using clinician-collected samples, provided a PCR based assay was used. MSAC supported expanding access to self-collection to include everyone eligible for cervical screening, giving all eligible people a choice in screening method. MSAC considered self-collection to be safe and effective, and that it would likely increase participation in cervical screening.[17]

MSAC advised that expanding self-collection is an important option to increase access to screening, particularly for people who may feel uncomfortable with a clinician collecting their sample. People who choose to use self-collection would still access cervical screening through their healthcare provider, to allow for education and engagement.

2021 evidence review

A general review of the literature was undertaken to identify studies in Australia assessing the acceptability to women of screening on a self-collected sample (including uptake of this option) and adherence to follow-up among women in whom HPV is detected. Eight articles assessing acceptability were identified,18-25 six of which reported on findings for women who were under- or never-screened and who had used or been offered self-collection.18-23 Two other studies were among women with a mix of screening histories who were asked for opinions on self-collection but had not used it,24,25 and in one case were asked about home-based self-collection rather than the clinic-based model as has been adopted in Australia.24 In all studies where women had been offered or used self-collection there was a high level of acceptability of self-collection. The two studies among women with a mix of screening histories and who had not used self-collection reported that many women would prefer to continue to be screened on a clinician-collected sample, especially if they were screening regularly, but nevertheless there was high acceptability of self-collection being offered as an alternative option.24,25 Women who indicated they would prefer a healthcare professional to collect the sample expressed concerns about performing sample collection correctly. Most women who had used self-collection reported they found it easy to perform, less embarrassing, and a convenient option.

Only three studies provided information about adherence to recommended follow-up after a self-collected sample,18,20,21 all of which were undertaken with under-screened women. The findings of these studies may therefore have limited applicability to the general screening population. The number of women requiring follow-up was generally small (range: 14-140). Adherence to follow-up ranged from 52 to 82%. Study findings were inconsistent as to whether women with HPV (16/18) detected (colposcopy recommended) were more or less likely to have completed follow-up than women with HPV (not 16/18) detected.

The eight identified articles were reporting on six different studies or pilot studies of self-collection (for two studies there was both a quantitative and a qualitative paper). Three of these six studies were conducted in, or reported findings specifically for, Aboriginal or Torres Strait Islander women18,19, 25 (see Screening in Aboriginal and Torres Strait Islander women). Each of these studies reported a high level of acceptability of self-collection as an alternative option.

Flowchart 6.1. Cervical screening pathway for primary oncogenic HPV screening (HPV tests on clinician-collected or self-collected samples)

Women who are eligible for the self-collection pathway will benefit by participation in screening, especially if disease is detected and treated. They will also benefit by being reassured that they are at low risk of cervical cancer if oncogenic HPV is not detected.

Some women who choose to be screened using self-collection may be more anxious about cervical screening than other women and will need special consideration regarding reassurance and explanation of the screening pathway and the procedure. Women in whom HPV is detected will require a clinician-collected cervical sample for LBC and should be guided through this process in a sensitive and culturally appropriate manner. Women in whom HPV (16/18) is detected can have this sample collected at colposcopy. It is also important that health professionals communicate the meaning of HPV test results in a sensitive and culturally appropriate manner.

Providing flexibility for collection of a vaginal sample to occur in any setting the healthcare professional overseeing the test considers to be appropriate could further reduce barriers to cervical screening for under-screened and never-screened groups including rural and remote communities, people from diverse cultural and faith backgrounds, and LGBTIQ communities.

See Section 5. Benefits, harms and cost-effectiveness of cervical screening in the renewed NCSP.

Clinical practice

When deciding whether to choose self-collection or clinician collection, people must be given clear information by the supervising healthcare professional about the probability that HPV will be detected and, if so, what follow-up will be required. Among those attending for a routine screening test, approximately 2% have HPV16/18 detected and approximately 6% have HPV (not 16/18) detected, although the latter varies by age. If a person chooses self-collection then the healthcare professional should provide appropriately tailored information about how to collect the sample and how they will receive the test results.

Resourcing

If people who have been regular participants in the NCSP switch to using self-collection, they may require two visits to their healthcare provider, which will increase the costs of the program. However, this is only expected to affect people in whom HPV (not 16/18) is detected, around 6% of all participants attending for routine screening.

Barriers to implementation

Many people may be unaware of the self-collection option. Healthcare professionals who identify individuals who are never-screened or overdue for screening are encouraged to opportunistically offer cervical screening and the choice of self-collection or clinician-collection.

Women in whom HPV is detected may not undergo recommended further assessment, which includes taking a cervical sample for LBC and/or colposcopy.

It is possible that some healthcare professionals may choose to delay colposcopy referral for women with a positive oncogenic HPV (16/18) test result until after they have collected a cervical sample for LBC. However, women who have a positive HPV (16/18) test result should be referred directly to colposcopy and the cervical sample for LBC will collected by the colposcopist.

Key messages to educate women and healthcare professionals about the self-collection option and subsequent management of any abnormalities will be developed as part of implementation planning to support this updated guideline.

See the National Cervical Screening Program Policy.