Summary

Cancer screening involves testing for signs of cancer or precancerous conditions in people without obvious symptoms. The National Cervical Screening Program (NCSP) is one of Australia’s three population-based cancer screening programs. It aims to reduce cervical cancer cases, illness, and deaths by detecting precancerous abnormalities before any potential progression to cervical cancer.

The NCSP is a highly successful public health initiative in Australia, halving cervical cancer incidence and mortality since it was introduced in 1991. This has been achieved through organised, population-based cervical screening to detect precancerous changes, allowing treatment before any progression to cervical cancer, thereby preventing this disease.

A renewed NCSP was introduced on 1 December 2017 that included a change from 2-yearly Pap tests for the target age group 20–69 to 5-yearly Cervical Screening Tests (CST) for the target age group 25–74. A CST is a human papillomavirus (HPV) test, followed by a liquid-based cytology (LBC) test if oncogenic (cancer-causing) HPV is found.

Five years after its commencement, this is the fourth report to present data for the renewed NCSP. Data included in this report are for the calendar years 2018, 2019, 2020, and 2021.

Terminology

This report uses the terms ‘people’ and ‘participants’ when referring to data collected under the NCSP. These data are not restricted by sex or gender, with all participants in cervical screening included in these data. For NCSP data, ‘people’ is defined as any person with a cervix. This may include women, transgender men, intersex people, and non-binary people.

This report uses the term 'women' to mean ‘female' when referring to data collected outside the NCSP as these other data sources are based on sex assigned at birth. These include cancer incidence data, and cancer mortality data. However, it should be noted that some people may not identify with this term.

Participation

Participation is measured over the same number of years as the screening interval. This is 5 years for the renewed NCSP. However, as 5 years have not yet passed since it was introduced, 5-year participation cannot yet be reported. In the interim, participation and coverage have been estimated for the years that are available, 2018–2021.

Over the 4 years 2018–2021, more than 4.2 million people aged 25–74 had a screening HPV test (primary screening or 12-month repeat HPV test). Participation has been estimated to be 62% of the eligible population.

Over the 4 years 2018–2021, more than 4.7 million people aged 25–74 had an HPV or LBC test for any reason. Coverage has been estimated to be 70% of the eligible population.

Response to invitation

Of the people aged 25–74 who were invited to screen or rescreen in 2021, 9% had an HPV test within 6 months. This means that 9% of people responded to an invitation to screen.

These data do not currently include people aged 30–74 whose previous Pap test was normal. While transitioning from 2-yearly to 5-yearly screens, this group are sent a reminder to rescreen after they are overdue, not an invitation to rescreen.

Screening results

Risk refers to the risk of significant cervical abnormality, and is determined by the primary screening episode result (a primary screening HPV test and (if indicated) an LBC test).

Of the 502,158 primary screening episodes in 2021 in participants aged 25–74:

  • 89% were low risk
  • 8% were intermediate risk
  • 3% were higher risk
  • fewer than 1% could not be assigned a risk (due to unsatisfactory or incomplete tests).

Correlation of screening results

In 2020, 70% of primary screening episodes in participants aged 25–74 that had an LBC that predicted a high-grade or glandular abnormality were followed within 6 months by histology with a result of high-grade abnormality or cervical cancer.

Screening HPV test positivity

Screening HPV test positivity is the proportion of valid primary screening HPV tests that detected oncogenic HPV. Of the 501,281 valid primary screening HPV tests performed in 2021 in participants aged 25–74:

  • 2% were positive for oncogenic HPV types 16 or 18 (the two types of HPV that cause most cervical cancers)
  • 9% were positive for oncogenic HPV types other than 16 or 18.

Self-collection

Participants who self-collect their cervical screening sample and whose primary screening HPV test detects oncogenic HPV types need to return to a practitioner for an LBC or attend for a colposcopy, depending on the oncogenic HPV types detected.

In 2021, of the 327 participants aged 30–74 whose self-collected primary screening HPV test detected an oncogenic HPV type other than 16 or 18, 60% had an LBC within 6 months.

In 2021, of the 130 participants aged 30–74 whose self-collected primary screening HPV test detected oncogenic HPV type 16 or 18, 69% had a colposcopy within 6 months.

Follow-up results

Participants with an intermediate risk primary screening episode have a 12-month repeat screening episode to determine if their risk changes to low risk or higher risk, or if it remains as intermediate risk.

Of the participants aged 25–74 who had a primary screening episode in 2020 of intermediate risk, 54% had a 12-month repeat screening HPV test between 9 and 15 months.

Of the 127,839 repeat screening episodes in 2021 in participants aged 25–74:

  • 43% were low risk
  • 43% were intermediate risk
  • 13% were higher risk
  • fewer than 1% could not be assigned a risk (due to unsatisfactory or incomplete tests).

Colposcopy

Participants with a higher risk primary or repeat screening episode are referred for colposcopy, which is the examination of the cervix using a magnifying instrument called a colposcope, and is the first step in the assessment stage of the screening pathway.

  • Of the participants aged 25–74 who were referred for colposcopy in 2020, 55% had a colposcopy within 3 months. The median time to colposcopy was 62 days.
  • A biopsy was performed in 39% of colposcopies for participants aged 25–74 in 2021.
  • Of the participants aged 25–74 who had a colposcopy in 2020 following a higher risk screening test, 17% had a high-grade abnormality or cervical cancer detected on histology within 6 months of the colposcopy.
  • The positive predictive value of colposcopies performed in 2020 for participants aged 25–74 was 63%.

High-grade cervical abnormality detection rate

Detection of high-grade abnormalities provides an opportunity for treatment before cancer can develop. The NCSP aims to detect high-grade abnormalities in line with its broader aim to reduce the incidence of cervical cancer.

In 2021, the high-grade detection rate for participants aged 25–74 was 17 participants with a high-grade abnormality detected by histology per 1,000 participants screened.

This means that, for every 1,000 participants screened, 17 had a high-grade abnormality detected, providing an opportunity for treatment before possible progression to cancer.

In contrast, for every 1,000 participants screened, 1 had a cervical cancer detected.

Cervical cancer incidence

In 2018, there were 851 women aged 25–74 diagnosed with cervical cancer, which is an incidence rate of 11 new cases per 100,000 women in the population.

Over the 5 years 2014–2018, there were 161 Aboriginal and Torres Strait Islander women aged 25–74 diagnosed with cervical cancer, which is an incidence rate of 19 new cases per 100,000 Indigenous women in the population.

Over the 5 years 2014–2018, the age-standardised incidence rate among Aboriginal and Torres Strait Islander women was 2.0 times the rate of non-Indigenous Australians.

Cervical cancer mortality

In 2020, there were 165 women aged 25–74 who died from cervical cancer, which is a mortality rate of 2 deaths per 100,000 women in the population.

Over the 5 years 2016–2020, there were 62 Aboriginal and Torres Strait Islander women aged 25–74 who died from cervical cancer, which is a mortality rate of 7 deaths per 100,000 Indigenous women in the population.

Over the 5 years 2016–2020, the age-standardised mortality rate among Aboriginal and Torres Strait Islander women was 3.8 times the rate of non-Indigenous Australians.