The National Cervical Screening Program commenced in 1991. The main objective of the Program is to reduce the incidence, morbidity and mortality of cervical cancer through organised cervical screening of women using the Papanicolaou (Pap) test (the terms Pap test and Pap smear are often used interchangeably). The Program targets women aged 20–69 years.
Cervical screening in Australia 2005–2006 is the 10th annual report on the performance of the National Cervical Screening Program. This report combines data provided by state and territory cervical screening programs, as well as data sourced from the National Cancer Statistics Clearing House and the AIHW Mortality Database, to present the most recent information on the six Program performance indicators that cover participation in cervical screening, rate of early re-screening, low- and high-grade abnormalities detected, and incidence and mortality of cervical cancer.
For the first time, additional participation data have been compiled. These include 3-year and 5-year participation to enable comparisons with overseas cervical screening programs, and participation by geographic region and socioeconomic status to monitor the extent to which the program is achieving universal access.
The outcome data indicate that prevention, detection and treatment programs continue to be successful in reducing cervical cancer incidence and mortality. In 1991, when the Program commenced, the incidence of cervical cancer in women aged 20–69 years was 17.1 new cases per 100,000 women and mortality in women aged 20–69 years was 4.0 deaths per 100,000 women. Incidence of cervical cancer declined to 8.9 new cases per 100,000 women in 2004, and mortality to 2.0 deaths per 100,000 women in 2005. The decline in mortality began prior to introduction of the organised screening program and has continued.
- In the 2-year period 2005–2006, there were 3,505,978 women who participated in the National Cervical Screening program. Women aged 20–69 years accounted for 98.5% of the women screened. The proportion of women aged 20–69 years participating in cervical screening was 60.6%.
- From 1996–1997, when reporting for the National Cervical Screening Program first commenced, to 2005–2006, there was a decline in participation among women aged less than 40 years, and an improvement in participation among women aged 55 years and over. For instance, participation of women aged 25–29 years fell from 64.5% in 1996–1997 to 56.3% in 2005–2006, and participation of women aged 55–59 years rose from 62.7% in 1996–1997 to 67.8% in 2005–2006.
- In the 3-year period 2004–2006, there were 4,119,929 women who participated in the National Cervical Screening Program, 98.4% aged 20–69 years.
- The 3-year participation rate for 2004–2006 was 73.1% for women aged 20–69 years. This is comparable to the 3-year participation rates of 73% reported for New Zealand for 2003 (National Cervical Screening Programme 2005), 69.4% for England for 2007 (National Health Service 2007), 63.6% for Wales for 2007 (Cervical Screening Wales 2007), and to the previously reported average for the European Union countries of 75% (van Ballegooijen et al. 2000).
- In the 5-year period 2002–2006, there were 4,824,166 women who participated in the National Cervical Screening Program, 98.1% aged 20–69 years.
- The 5-year participation rate for 2002–2006 was 85.9% for women aged 20–69 years. This is higher than the 5-year participation rates of 79.2% reported for England for 2007 (National Health Service 2007), 74.6% for Wales for 2007 (Cervical Screening Wales 2007), and 77% for the Netherlands for 2003 (Rebolj et al. 2007), but lower than a previously estimated 5-year participation rate of 90% for Finland (Antilla & Nieminen 2000).
Participation by region and socioeconomic status
- In 2005–2006, participation rates by geographic region were 62.1% for major cities, 59.3% for inner regional, 57.8% for outer regional, 56.9% for remote locations, and 53.0% for very remote locations. These differences are statistically significant.
- In 2005–2006, participation rates by socioeconomic status of area of residence were 71.5% for the first quintile, which corresponds to the highest level of socioeconomic status, 68.3% for the second quintile, 61.8% for the third quintile, 60.2% for the fourth quintile, and 57.3% for the fifth quintile, which corresponds to the lowest level of socioeconomic status. These differences are statistically significant.
The recommended screening interval is 2 years following a normal (negative) Pap test. Early re-screening is defined as a repeat Pap test within 21 months of a negative test.
- Of a cohort of women screened in February 2005 who had a normal Pap test result, 24.4% had a repeat Pap test within 21 months. It is not known what proportion of this early re- screening was justified on clinical grounds.
- There was a decline in the proportion of women being re-screened early from 32.0% in 1999 to 24.4% in 2005, indicating greater compliance with the recommended screening interval over time.
Detection of abnormalities
Low-grade abnormalities include atypia, warty atypia, possible cervical intraepithelial neoplasia (CIN), equivocal CIN, CIN 1, and endocervical dysplasia not otherwise specified. High-grade abnormalities include CIN 1/2, CIN 2, CIN 3 and adenocarcinoma in situ.
- In 2006, the screening program detected 29,532 histologically verified abnormalities of which 15,118 were low-grade and 14,414 were high-grade.
- The number of high-grade abnormalities detected per 1,000 women screened aged 20–69 years increased significantly from 6.4 in 1997 (at the start of reporting) to 7.3 in 2006.
- Detection of high-grade abnormalities was highest in the younger age groups. In 2006, for women aged 20–24 years, detection of high-grade abnormalities was 18.4 per 1,000 women screened; in contrast, for women aged 65–69 years the rate was 1.1 per 1,000 women screened.
Incidence and mortality
- The numbers and rates of new cases of cervical cancer have continued to decline. There were 718 new cases in Australia in 2004 (6.9 per 100,000 women of all ages) compared with 1,090 in 1991 (13.2 per 100,000 women of all ages) when the organised screening program commenced. The number of new cases of micro-invasive cervical cancers also fell from 166 (1.9 per 100,000 women of all ages) to 107 (1.1 per 100,000 women of all ages) over the same period. These differences are statistically significant.
- Cervical cancer was the 18th most common cause of cancer mortality in Australian women in 2005, accounting for 216 deaths in 2005 compared with 329 in 1991. The age-standardised mortality rate from cervical cancer halved between 1991 and 2005 from 4.0 deaths per 100,000 women to 1.9. During the same period, for women aged 20–69 years the rate fell from 4.0 to 2.0 per 100,000 women.
- Mortality rates for cervical cancer increase with age. The highest mortality rate in the 2002–2005 period was in women aged 85 years and over, with 14.3 deaths per 100,000 women.
Aboriginal and Torres Strait Islander women
Identification of Aboriginal and Torres Strait Islander peoples in cancer registry records of new cases is not complete as Indigenous status is not yet included in pathology forms, and reporting of Indigenous status is primarily sourced from hospital records.
- In 2000–2004, despite under-reporting, cervical cancer incidence in Aboriginal and Torres Strait Islander women was 16.9 new cases per 100,000 women for New South Wales, Victoria, Queensland, Western Australia and the Northern Territory combined, more than double the non-Indigenous rate of 7.1 new cases per 100,000 women (AIHW unpublished data).
Only Queensland, Western Australia, South Australia and the Northern Territory have Indigenous mortality registration data of sufficient quality to be published.
- For these jurisdictions in the period 2002–2005, for women aged 20–69 years the age-standardised mortality rate for Indigenous women was 8.3 per 100,000 women, more than four times as high as the rate of 2.0 per 100,000 women for non-Indigenous women.