Disease Outcome Indicators

Cervical cancer incidence is the measure used by the WHO to determine whether elimination has been achieved (1).

In 2020, 982 women were diagnosed with cervical cancer in Australia, an incidence rate of 6.6 per 100,000. Cervical cancer incidence over the 5-year period 2016-2020 was 6.4 per 100,000 nationally (Figure 1.1). Incidence varied between groups, and rates (over the period 2016-2020) were three times as high as the elimination target among Aboriginal and Torres Strait Islander women (12.1 per 100,000 women), therefore a 67% reduction is need to achieve cervical cancer elimination.  Rates over the period 2016-2020 were at least twice as high as the elimination target in women living in outer regional or very remote areas. There is a socioeconomic gradient in cervical cancer incidence, with the incidence rates becoming higher with increasing levels of socioeconomic disadvantage.

Cervical cancer rates were similar in 2020 to those in 2019 (6.6 per 100,000, compared to 6.5 per 100,000 in 2019) (Figure 1.2). This is consistent with an anticipated transient increase in cancer diagnoses that was expected to occur from 2018 as a result of Australia transitioning from 2-yearly cytology-based screening to 5-yearly primary HPV screening on 1st December 2017 (2) (i.e. the increased sensitivity of the test will initially result in the detection of a greater number of prevalent cancers).

In most demographic groups, cervical cancer incidence rates in 2016-2020 were broadly similar to those in recent preceding 5-year periods, although in some groups there was an apparent increase (Queensland, South Australia, outer regional). Conversely, rates appear to have decreased over multiple recent time periods in some groups (people living in remote areas, Tasmania, ACT). Rates were not available for Aboriginal and Torres Strait Islander women for 5-year periods prior to 2016-2020, so comparisons were not possible.

The impact of HPV vaccination on cervical cancer incidence would be expected to occur gradually over time and affect younger age groups first. Cervical cancer incidence rates are extremely low in women aged less than 25, and the number of cases in women aged less than 25 is also extremely small (one case in 2020). This makes rates in these age groups unstable and difficult to interpret, especially in the context of the increase in the recommended start age for screening from 1st December 2017 from 20 to 25, and declining screening attendance among those aged 20-24 years in the years leading up to this. In other settings, a similar change in the recommended start age has led to an initial increase in cancer incidence in those aged 25-29 years, as screen-detection of some cancers shifts from occurring at age 20-24 to age 25, coinciding with their first screen (3). In spite of this, cervical cancer incidence has decreased over recent years in women aged 25-29 years (Figure 1.3).

Source: AIHW Australian Cancer Database, published in AIHW 2024 (4) for 2020 rates. All other rates supplied by AIHW.

In many population groups, very few cases occur in a year, and so rates are subject to random fluctuation. For this reason, in order to report on and compare cancer incidence across a range of population groups, most data are reported across a 5-year period. Age-standardised rates are lower than those reported elsewhere for Australia, for example in routine AIHW reports, because the age-standardising method and standard population recommended by WHO for measuring cervical cancer elimination has been used in this report (2015 World Female Population), to enable comparison with the WHO target and internationally (1,5). In previous elimination progress reports, cervical cancer incidence has been based on age-specific rates published in AIHW reports (6). This limited our capacity to report by state and territory, as the age-specific rates required to age-standardise to the WHO benchmark were not published for all age groups in every jurisdiction. The current report instead relies on age-standardised rates directly computed and supplied by AIHW according to the WHO methodology. These were recalculated for 5-year periods back to 2011-2015, and therefore age-standardised rates for earlier time periods may differ from those in earlier elimination progress reports, due to updated data.

Results by Indigenous status are based on six jurisdictions (NSW, Vic, Qld, WA, ACT and NT) where data quality was considered sufficient for analysis. Overall rates in these jurisdictions (6.3 per 100,000 women; including those whose Indigenous status was unknown) was slightly lower than the national rate (6.4 per 100,000 women). Following the release of the 2021 Census-based estimates of the Aboriginal and Torres Strait Islander population by the Australian Bureau of Statistics (ABS), the AIHW's First Nations Health and Welfare Group has been working with relevant agencies and advisory groups to examine options and agree on an approach for national reporting. To maintain national consistency across government reporting, the Productivity Commission, AIHW and ABS have collectively agreed to adopt the same approach on the use of a consistent denominator. The agreed approach is that 2021 Census-based backcast estimates and projections should generally be used as the denominator for rates. The AIHW has decided to limit analyses back to the year 2016 due to the extent of non-demographic change between Census population estimates. For this reason, the Aboriginal and Torres Strait Islander and non-Indigenous data for periods which include years prior to 2016 have not been published for incidence. 

Aboriginal or Torres Strait Islander identification was based on whether a person had ever self-reported their status, as recorded by six state and territory cancer registries (NSW, Vic, Qld, WA, ACT and NT) (6).

There is currently a delay of approximately four to five years in the availability of national cancer incidence data stratified by population groups in Australia. This delay limits our ability to conduct timely reporting of cervical cancer incidence in Australia against the primary WHO elimination target. In the context of this delay and reporting across a 5-year period (the period reported on here is 9-13 years after the vaccination program commenced), it is not surprising that cervical cancer rates in most population groups have not reduced substantially compared to the previous report.  More generally, it will take some time for all age rates to be impacted by HPV vaccination, due to the long time between a vaccine delivered in early adolescence, a prevented HPV infection, and the cancer which otherwise would have occurred. The period reported on (2016-2020) also straddles the change to the screening program, when there was expected to be a transient increase in detection of cancer, due to the more sensitive test detecting some prevalent cancers (noting this represents a success of the new program since earlier detection leads to downstaging of cancer and improved survival). In spite of these limitations, cervical cancer rates in those aged 25-29 years appear to have declined in recent years (although based on fewer than 60 cases in each year over 2016-2020).

1 World Health Organization. Global strategy to accelerate the elimination of cervical cancer as a public health problem. 2020. Available at: https://www.who.int/ publications/i/item/9789240014107.

2 Hall MT, Simms KT, Lew JB, et al. Projected future impact of HPV vaccination and primary HPV screening on cervical cancer rates from 2017-2035: Example from Australia. PLoS One 2018; 13(2): e0185332.

3 Sasieni P, Castanon A. Dramatic increase in cervical cancer registrations in young women in 2009 in England unlikely to be due to the new policy not to screen women aged 20-24. Journal of Medical Screening. 2012;19(3):127-132. doi:10.1258/jms/2012/012081

4 Australian Institute of Health and Welfare. Cancer data in Australia. Cat. no: CAN 122 Canberra: Australian Government. Available at: https://www.aihw.gov.au/reports/cancer/cancer-data-in-australia/data 

5  Canfell K, Kim JJ, Brisson M, et al. Mortality impact of achieving WHO cervical cancer elimination targets: a comparative modelling analysis in 78 low-income and lower-middle-income countries. Lancet 2020; 395(10224): 591-603.

6 Australian Institute of Health and Welfare. National Cervical Screening Program monitoring report 2023. Cat. no: CAN 157 Canberra: Australian Government. 

Reducing premature mortality from cervical cancer is the overarching aim of the WHO elimination strategy, so cervical cancer mortality has been identified as a key impact indicator in the global strategy to accelerate elimination (1). Cervical cancer mortality will capture two things that will not be reflected in cervical cancer incidence rates: downstaging (due to screening) and the WHO target of treating 90% of women diagnosed with cervical cancer.

In 2022, there were 269 deaths from cervical cancer. Cervical cancer mortality was 1.3 per 100,000 women in 2018-2022 with some variation in mortality across the population, most notably women living in very remote areas or in the Northern Territory, and a socioeconomic gradient (Figure 2.1). In the jurisdictions with sufficient data quality for Indigenous status, mortality rates among Aboriginal and Torres Strait Islander women were 4.0 per 100,000 women, 2.8 times higher than the overall rate for those jurisdictions (1.4 per 100,000). Mortality rates were at least 20% lower than the national rate in the least socioeconomically disadvantaged areas and the ACT. 

Source: National Mortality Database, extracted data supplied by AIHW (2024) and published in AIHW 2024 (2).

In many population groups, very few deaths occur in a year, and so rates are subject to random fluctuation. In order to report on cancer mortality across a range of population groups, data are reported across a 5-year period (the most recent 5-year period for which data are available). National age-specific rates were sourced from the most recent national report (2). Age-standardisation is performed across all ages using the 2015 World female population, consistent with the methodology recommended for incidence as part of the WHO elimination strategy (1,3). As a result of this difference in methodology, mortality rates in this report are not comparable to AIHW reports.

The Indigenous status variable is not of sufficient quality for analysis for records from Victoria, Tasmania or the ACT; therefore, data by Indigenous status are reported for NSW, Qld, WA, SA, and NT combined, and the overall total in those jurisdictions is also reported (which includes those whose Indigenous status was unknown). The populations used for the calculations were based on the 2021 Census estimates for 2016–2021 and projections for 2022. Following the release of the 2021 Census-based estimates of the Aboriginal and Torres Strait Islander population by the ABS, the AIHW's First Nations Health and Welfare Group has been working with relevant agencies and advisory groups to examine options and agree on an approach for national reporting. To maintain national consistency across government reporting, the Productivity Commission, AIHW and ABS have collectively agreed to adopt the same approach on the use of a consistent denominator. The agreed approach is that 2021 Census-based backcast estimates and projections should generally be used as the denominator for rates. The AIHW has decided to limit analyses back to the year 2016 due to the extent of non-demographic change between Census population estimates. For this reason, the Aboriginal and Torres Strait Islander and non-Indigenous data for periods which include years prior to 2016 have not been published for mortality.

Aboriginal or Torres Strait Islander identification was based on whether a person had ever self-reported their status, as recorded by five state and territory Births Deaths and Marriages registries (NSW, Qld, WA, SA and NT) (4). 

Cervical cancer mortality is relatively low in many groups but many of the groups with higher rates correspond with those with a higher incidence (increasing rates with increasing level of socioeconomic disadvantage). There is considerable overlap in the groups identified as having the highest mortality rates (Aboriginal and Torres Strait Islander women, women living in the NT and women living in very remote areas). Interpretation of trends is challenging due to small numbers, particularly in small areas such as the ACT, NT and Tasmania; and remote and very remote areas. 

Reductions in cervical cancer mortality over time will reflect a range of factors, including improved prevention, earlier detection (downstaging), improvements to treatment, and providing more women with optimal treatment.

National mortality data are reported more promptly than national cancer incidence data. 

1 World Health Organization. Global strategy to accelerate the elimination of cervical cancer as a public health problem. 2020. Available at: https://www.who.int/ publications/i/item/9789240014107.

2 Australian Institute of Health and Welfare. Cancer data in Australia. Cat. no. CAN 122, AIHW 2024. Available at: https://www.aihw.gov.au/reports/cancer/cancer-data-in-australia/data. 

3 Canfell K, Kim JJ, Brisson M, et al. Mortality impact of achieving WHO cervical cancer elimination targets: a comparative modelling analysis in 78 low-income and lower-middle-income countries. Lancet 2020; 395(10224):591-603. 

4 Australian Institute of Health and Welfare.. National Cervical Screening Program monitoring report 2023. AIHW National Mortality Database: https://www.aihw.gov.au/about-our-data/our-data-collections/national-mortality-database/deaths-data

Cervical screening aims to detect specific types of cervical disease (known as high-grade -see Methods tab for details), which are recognised as precursors of cervical cancer, so that women can have treatment to prevent progression to cancer. High-grade abnormalities of the cervix include cervical intraepithelial neoplasia (CIN) that has been graded as moderate (CIN 2) or severe (CIN 3), or for which the grade has not been specified, as well as endocervical dysplasia and adenocarcinoma in situ (1).

This indicator measures the proportion of women screened who are found to have high-grade disease as defined by a high-grade disease result on biopsy/histopathology. It will be determined by the underlying proportion with high-grade disease in the screened population, the accuracy of the screening method used, and the subsequent diagnostic steps and follow up undertaken with women found positive on the screening method.

Nationally, detection of high-grade cervical disease in 2022 was 14.2 per 1,000 screened women aged 25-74 years (age adjusted rate 13.1 per 1,000) (Figure 3.1). The rate of CIN3 detection was 8.5 per 1,000 (age adjusted 7.8 per 1,000 and 59.4% of all high-grade disease detected). Of note, crude and age adjusted rates for women aged 25-64 years for any high grade disease was 15.1 and 14.2 respectively and for CIN3 were 8.9 and 8.1 respectively. AIS was detected at a rate of 0.5 per 1,000 (3.3% of all high-grade disease) (Figure 3.2). Women residing in the least socioeconomically disadvantaged quintile had a high-grade detection rate lower than the national average (12.7 per 1,000 screened). The rate of high-grade detection per 1,000 screened women increased with increasing remoteness of residence, ranging from 12.7 in major cities to 19.8 in very remote areas (21.3 per 1000). NT had the highest detection rate at 17.6 per 1,000 screened women (Figure 3.1).

Detection of high-grade cervical disease overall, and of CIN3 was highest in the 30–34-year-old age group at 22.4 and 13.3 respectively, whereas AIS peaked in the 40-44 year old age group at 0.82 per 1,000 screened women (Figure 3.2). The age group with the highest proportion of high-grade disease that was CIN3 was the 70-74-year-old age group (76.4%) and the lowest proportion was those aged 25-29 at 55.7%. The age group with the highest proportion of high-grade disease that was AIS was the 45-49-year-old age group (at 6.8%).

High-grade detection rates by Indigenous status are presented for the first time in this report series. Amongst women who ever identified as Aboriginal and Torres Strait Islander aged 25-74 years, in 2022, the crude rate was 20.0 per 1,000. Because of the significantly younger age distribution of the Aboriginal and Torres Strait Islander population it is important to account for age differences in estimating overall rates. Crude and age-adjusted rates for women aged 25-64 years for any high-grade disease were 20.7 and 18.4, respectively, and for CIN3, were 13.6 and 12.1, respectively. Rates peaked in the 30-34 year old age group at 32.3 per 1,000 and were lowest in the 55-59 year old age group at 8.8 per 1000 (rates not published for those aged 65-74 due to small cell counts.)

Source: Analysis of NCSR data (NCSR RDE 06/01/2024); data prepared by the Screening Analysis and Monitoring Unit of the Australian Institute of Health and Welfare.

High-grade cervical disease was defined as a histology result of S3.1 (High-grade intraepithelial lesion (HSIL) not otherwise specified (CIN NOS)), S3.2 (HSIL (CIN 2)), S3.3 (HSIL (CIN 3)), E3.1 (Endocervical dysplasia), E3.2 (Adenocarcinoma in situ) or E3.3 (Mixed carcinoma in situ/adenocarcinoma in situ) (2).

Crude rates are presented, except for the national high grade and CIN3 rate, due to the small number of cases preventing calculation of age standardised rates. Cell suppression impacted some age groups for AIS and for stratifications by State/Territory, remoteness and socioeconomic status. Age-standardised rates were the number of women with a high-grade abnormality detected by histology per 1,000 women screened, age-standardised to the Australian 2001 Standard Population (3).

Aboriginal or Torres Strait Islander identification was based on whether a person had ever self-reported their status, as recorded in the National Cancer Screening Register (4).

In the last 6 month period where data were available for the previous Pap based screening program (January-June 2017), the crude high grade detection rate for women aged 25-74 years was 6.6 per 1,000 screened women and highest in the 25–29-year-old age group (at 14.4 per 1,000 screened) (5). In the first five year interval of the HPV screening program, rates peaked in 2020 and 2021 (at 16.5 per 1000 screened), as was predicted by modelling (6), both due to the move to HPV based screening with its higher sensitivity and because women attending were all at relatively higher risk of high-grade disease: women screening in 2020 and 2021 were either entering the program at age 25, were attending because they were under surveillance for a previous positive HPV test, or else were overdue for screening (due to the transition from the previous 2 yearly screening interval). In late 2022, those who started HPV screening in December 2017 when the program first commenced became eligible for their second round screen. Detection rates fell from the 2021 peak to 14.2 (13.1 age standardised) in 2022. Women offered HPV vaccination as catch up as adults (aged 18-26 in 2007) were aged 33 to 41 in 2022.

There is known under-enumeration of histopathology reports held in the NCSR, as safety net follow-up (and attempts to retrieve not yet notified histopathology) cease when an MBS item number consistent with cervical histology is located (indicating the woman has received further assessment). Additionally, due to teething issues during initial register implementation, 2018 data is known to be incomplete. It is likely that high grade rates estimated from the early years (2018-2019, age standardised high grade rate of 8.1 and 9.7 per 1000, peaking at age 25-29 years) may more significantly underestimate the true high-grade detection rate, with reporting to the register improving over time, so data for these years in particular should be interpreted with caution. 

There was evidence of variation in high grade detection rate by remoteness of residence, with women in remote areas having higher rates, and by socioeconomic quintile of residence, with women living in the least disadvantaged quintile having lower rates. Women residing in Queensland, Tasmania and NT had higher rates than in other jurisdictions in 2022.

National data by Aboriginal and Torres Strait Islander status are reported here in detail for the first time. When interpreting these data it is important to note that under identification of Aboriginal and Torres Strait Islander status remains a significant challenge for the NCSP. Identification in the NCSR is contingent upon Indigenous people being respectfully asked to identify as Aboriginal and/or Torres Strait Islander, feeling comfortable and safe to do so, agreeing to its recording in their Medicare record or as part of their cervical screening test request, inclusion of this field on the pathology request form, transmission of these data to the NCSR and its accurate recording therein. Indigenous status was not known for over a quarter of screening participants in 2022. Therefore the rates of high grade disease detection are representative only for those participants who identified as Indigenous rather than for being rates inclusive of all Aboriginal and Torres Strait Islander participants. If those who have identified are different in demographic or other characteristics to those who have not, then these rates will be non-representative of the actual rate.

The available data suggests higher rates of disease detection amongst those people attending cervical screening who identify as Aboriginal or Torres Strait Islander women compared with overall national estimates. However, comparisons should be interpreted cautiously since factors influencing the likelihood of developing high grade cervical disease, such as smoking, have not been controlled for. Some age-standardised rates are presented where they can be estimated given cell suppression rules but may not completely control for the strong influence of age on HPV prevalence and disease: the Aboriginal and Torres Strait Islander population has a notably younger age structure (median age of 24.0 years in 2021) than that of the overall population (median age of 38.4 years in 2021) (7). This finding is, however, consistent with available data from the previous cervical cytology program and with the higher rates of cervical cancer experienced by Indigenous people. (8,9) It is also an important finding as it suggests a greater potential to benefit from screening and underscores the critical importance of providing culturally appropriate and supportive screening services along the screening pathway. Now that self-collection offers a way to screen that may be more accessible and acceptable for many Indigenous people (10), priority needs to be given to ensuring the cultural safety and accessibility of follow-up care, including both public and private colposcopy services. Every gynaecologist and colposcopy provider in Australia must be appropriately trained and actively committed to providing culturally safe care for Aboriginal and Torres Strait Islander participants.

1 Australian Institute of Health and Welfare. National Cervical Screening Program monitoring report 2021. Cancer Series 134. Cat. no: CAN 141 Canberra: AIHW; 2021.

2 Australian Institute of Health and Welfare. National Cervical Screening Program data dictionary: version 1.1. Catalogue number CAN 146 Canberra: AIHW; 2022.

3 Australian Bureau of Statistics. Australia 2001 Standard Population for Use in Age-Standardisation. 2003. Available at: https://www.abs.gov.au/AUSSTATS/abs@.nsf/DetailsPage/3101.0Mar%202013?OpenDocument  

4 Australian Institute of Health and Welfare National Cervical Screening Program monitoring report 2023. Cat. no: CAN 157 Canberra: Australian Government. 

5 Australian Institute of Health and Welfare 2019. Cervical screening in Australia 2019. Cancer series no. 123. Cat. no. CAN 124. Canberra: AIHW

6 Hall MT, Simms KT, Lew JB, et al. Projected future impact of HPV vaccination and primary HPV screening on cervical cancer rates from 2017-2035: Example from Australia. PLoS One 2018; 13(2): e0185332.

7 Australian Bureau of Statistics. Estimates of Aboriginal and Torres Strait Islander Australians; 2021. Available from https://www.abs.gov.au/statistics/people/aboriginal-and-torres-strait-islander-peoples/estimates-aboriginal-and-torres-strait-islander-australians/30-june-2021  

8 Australian Institute of Health and Welfare (2023) National Cervical Screening Program monitoring report 2023, catalogue number CAN 157, AIHW, Australian Government.

9 Whop LJ, Baade P, Garvey G, Cunningham J, Brotherton JML, Lokuge K, Valery PC, O’Connell DL, Canfell K, Diaz A, Roder D, Gertig DM, Moore SP, Condon JR. Cervical abnormalities are more common among Indigenous than other Australian women: a retrospective record-linkage study, 2000-2011. PLoS One. 2016 Apr 11;11(4):e0150473. doi: 10.1371/journal.pone.0150473. eCollection 2016.

10 Whop L, Butler T, Lee N, Cunningham J, Garvey G, Anderson K, Condon J, Tong A, Moore S, Maher C, Mein J, Warren E, Brotherton J. Aboriginal and Torres Strait Islander women’s views of cervical screening by self-collection: a qualitative study. Australian and New Zealand Journal of Public Health. 2022 Apr;46(2):161-169. doi: 10.1111/1753-6405.13201.

The ability to achieve cervical cancer elimination is dependent upon the reduction in the prevalence of oncogenic HPV types through HPV vaccination. Monitoring infection prevalence in settings where this is feasible provides a direct measure of the extent to which this reduction is achieved and maintained over time.

In 2023, 1.4% of women aged 25-74 years who were screened were positive for HPV16 or 18, the most oncogenic HPV types prevented by vaccines utilised in the National HPV Vaccination Program. Positivity for HPV16 or 18 was 2.2% for Aboriginal and Torres Strait Islander women. Minor variations were observed across socioeconomic quintiles, remoteness areas, and States and Territories (Figure 4.1).

HPV16 or 18 positivity was marginally lower in 2023 than in previous years (2018 through 2022). This pattern was evident across socioeconomic quintiles, remote areas, and in most states and territories. By age group, 2023 positivity was lowest at 1.0% for women aged 25–29, decreasing from 2.0% in 2018. For older age groups, positivity was also very low and reasonably stable over time (although there were relative increases in 2020 and 2021, consistent with people attending in those years tending to be at higher risk of having an infection; Figure 4.2a).

Overall positivity for any oncogenic HPV type was 6.9% in 2023. Positivity for any oncogenic HPV type was 12.1% for Aboriginal and Torres Strait Islander women, 10.2% among women living in very remote areas and 10.4% among women in the NT. The positivity for oncogenic HPV was influenced by types other than HPV16 or 18 (Figure 4.1).

Among Aboriginal and Torres Strait Islander women, HPV16/18 positivity was also lowest in 2023, at 1.0%, for women aged 25–29, decreasing from 2.2% in 2018. For older women, positivity increased marginally to 3.3% among those aged 45-49 before falling with increasing age (Figure 4.2d). 

Positivity for oncogenic HPV types overall and oncogenic types other than HPV16 or 18 was lower in 2023 than in previous years. This pattern likely reflects the lower positivity among women taking part in their second round of screening. Across all years, positivity was similar across socioeconomic groups, but the highest positivity was evident for women living in very remote areas and the NT. By age group, positivity overall and for HPV (not 16/18) was highest among women aged 25–29 years and decreased with increasing age. This pattern was consistent within and between years (Figure 4.2b and Figure 4.2c).

In 2023, positivity rates for the additional five HPV types targeted by the nonavalent HPV vaccine (HPV31, 33, 45, 52 or 58) and the remaining HPV types not targeted by vaccination (HPV35, 39, 51, 56, 59, 66 or 68) were 2.1% and 3.7% respectively, with little variation over time. Positivity was generally highest for women aged 25-29 and decreased with increasing age (Figure 4.3 and Figure 4.4).

Source: Analysis of NCSR data (NCSR RDE 6/1/2024, extracted January 2024); data prepared by the Screening Analysis and Monitoring Unit of the Australian Institute of Health and Welfare.

Results were derived using the standard method for calculating population prevalence (positivity): the sum of women with at least one positive result for a given HPV group divided by the total count of participants with a primary screening HPV test.

Aboriginal or Torres Strait Islander identification was based on whether a person had ever self-reported their status, as recorded in the National Cancer Screening Register (1). 

In 2023, national HPV prevalence was lower than in 2021-22, primarily due to many individuals undergoing a timely second HPV screening round following a negative test five years earlier. Lower positivity rates were expected (and observed in previous trials) during the second round of screening, reflecting more recent infections, while the first round detects both recent and long-standing infections. The exception is the 25-29 age group, primarily consisting of individuals attending their first HPV screening round. As a result, positivity rates in this group are expected to reflect the background rates of HPV infection over time and may be more stable than in other age groups, particularly for non-vaccine targeted HPV types. 

The consistent decline in HPV16 and 18 in the 25-29 age group reflects the impact of Australia’s quadrivalent HPV vaccination program on reducing infections (2,3). The patterns for HPV16 or 18 in some other age groups may also reflect some impact of HPV vaccination. However, they are also influenced by screening effects, including extended intervals and people attending for their second round test. In 2023, women offered HPV vaccines in the catch-up program began to reach age 43 in the second half of the year, and those in the school-based program are aged up to 33 to 34 years. The impact of the nonavalent vaccine is not apparent because cohorts offered this vaccine at the target age 12-13 are not yet at screening age. 

Data for Aboriginal and Torres Strait Islander women suggests a higher prevalence of oncogenic HPV compared with national estimates. However, crude positivity comparisons should be interpreted cautiously since factors like age have not been controlled. HPV positivity peaks amongst young women in the years following sexual debut, and the Aboriginal and Torres Strait Islander population has a notably younger age structure (median age 24.0 years in 2021) than that of the overall population (median age 38.4 years in 2021) (4). Other contributing factors include potential differences in participation rates in cervical screening. There are also known differences in the prevalence of some other risk factors, such as smoking, due to the long-lasting impacts of colonisation, including the use of tobacco by colonial settlers as a form of payment for labour, goods and access to land (5). 

HPV16 and 18 positivity was very low for Aboriginal and Torres Strait Islander women in birth cohorts offered HPV vaccination, similar to the national population, highlighting the success of Australia's school-based HPV vaccination program in achieving comparable impacts.

Surveys before the start of the vaccination program among women attending cervical screening suggested a similar prevalence of HPV16/18 in Indigenous compared with non-Indigenous women at all ages but a higher prevalence of other oncogenic types among Indigenous women aged 31 to 40 years (6) that appeared to be driven by other risk factors such as smoking. A survey conducted after the vaccination program had begun found declines in prevalence similar to those observed in non-Indigenous women, with an HPV16/18 prevalence among Indigenous women aged 18–26 of 1.4% in 2014-15 (7). A study of women aged 18-35 years recruited in 2015–2018 found that the prevalence of HPV16/18 was very similar in Indigenous and non-Indigenous women (2.3% versus 1.9%, respectively) (8). These findings are supported by national monitoring data, which showed that in 2022, HPV16 and 18 positivity was very low among Indigenous participants in birth cohorts offered HPV vaccination and similar to their non-Indigenous peers (1.8% versus 1.5%, respectively) (8).   

Indigenous status was unknown for over a quarter of screening participants in each reporting year. Therefore, HPV positivity is representative only for those participants who ever identified as Aboriginal and/or Torres Strait Islander rather than being rates inclusive of all Aboriginal and Torres Strait Islander participants.  

Figure 4.3 and Figure 4.4 were derived from a small subset of women whose samples were tested on either of two assays that provide discrimination between non-16/18 oncogenic HPV types. This subset represents only 1% of all screening tests conducted in the program. 

Calculations for Figure 4.1 and Figure 4.2 were based on all data reported to the NCSR. The NCSP laboratory reporting guidelines specify that all available (primary and secondary) HPV test results are recorded. This means that when a test returns a positive result for HPV16/18 and a non-16/18 type, both results should be documented. However, since clinical management will be based solely on the HPV16/18 result, the secondary non-16/18 finding may be underreported, resulting in an underestimate of prevalence in the population.

Figure 4.3 and Figure 4.4 were derived from a small subset of women whose samples were tested on either of two assays that provide discrimination between non-16/18 oncogenic HPV types. This subset represents only 1% of all screening tests conducted in the program. Compared with national data for 2023, this group had slightly lower positivity for HPV16 and 18 (0.9% vs 1.4%) and oncogenic HPV types other than HPV16 or 18 (6.6% vs 6.9%).

1 Australian Institute of Health and Welfare. National Cervical Screening Program monitoring report 2023, catalogue number CAN 157, AIHW, Australian Government. 

2 Brotherton JM, Hawkes D, Sultana F, et al. Age-specific HPV prevalence among 116,052 women in Australia’s renewed cervical screening program: A new tool for monitoring vaccine impact. Vaccine 2019; 37(3): 412-6.

3 Machalek DA, Garland SM, Brotherton JML, et al. Very Low Prevalence of Vaccine Human Papillomavirus Types Among 18- to 35-Year Old Australian Women 9 Years Following Implementation of Vaccination. The Journal of Infectious Diseases 2018; 217(10): 1590-600.

4 Australian Bureau of Statistics. Estimates of Aboriginal and Torres Strait Islander Australians; 2021. Available at: https://www.abs.gov.au/statistics/people/aboriginal-and-torres-strait-islander-peoples/estimates-aboriginal-and-torres-strait-islander-australians/30-june-2021 

5 Greenhalgh, EM, Jenkins, S, van der Sterren, A, Knoche, D, & Winstanley, MH 8 Tobacco use among Aboriginal and Torres Strait Islander peoples. In Greenhalgh, EM, Scollo, MM and Winstanley, MH [editors]. Tobacco in Australia: Facts and issues. Melbourne: Cancer Council Victoria; 2023. Available at: https://www.tobaccoinaustralia.org.au/chapter-8-aptsi 

6 Garland SM, Brotherton JM, Condon JR, et al. Human papillomavirus prevalence among Indigenous and non-Indigenous Australian women prior to a national HPV vaccination program. BMC Medicine 2011; 9: 104.

7 McGregor S, Saulo D, Brotherton JML, et al. Decline in prevalence of human papillomavirus infection following vaccination among Australian Indigenous women, a population at higher risk of cervical cancer: The VIP-I study. Vaccine 2018; 36(29): 4311-6.

8 Shilling, H, Garland, SM, et al. Human papillomavirus prevalence and risk factors among Australian women 9-12 years after vaccine program introduction. Vaccine 2021, 39(34), 4856–4863.