Trend data are available for females aged 50–69 years from 1996, and for females aged 50–74 years from 2014. From 1996 to 2020, the proportion of females in the 50-69-year target age range who were recalled to assessment after their first breast screen increased from 5.8% in 1996 to 12.2% in 2014, with marginal decreases to 11.7% in 2019 and 11.1% in 2021 (age-standardised data). The increase since 1996 was accompanied by an increase in the detection rate of invasive breast cancers. From 1996 to 2019, the proportion of females aged 50–69 years recalled to assessment after a subsequent screen remained relatively stable, in the range of 3.2-4.2% (age-standardised). This proportion appeared to be about 4.0% in 2014 and 2021.^1,4-9

Between 2014 and 2020, the recall to assessment rate for participants aged 50–74 years at the first screening round varied between 11.2% and 12.2%. Over the same period, the recall to assessment rate for subsequent screening rounds ranged between 3.5% and 4.0%.^1,4-9

International comparison

A comparison has been made between recall to assessment data for BreastScreen Australia and the NHS Breast Screening Programme (NHSBSP) in England.¹⁰ Caution should be applied to this comparison due to different age ranges and definitions. Data from the NHS Breast Screening Programme in England included females aged 45 and over. Women referred for assessment include those subsequently referred for cytology, core biopsy or open biopsy. Referred for assessment rate was calculated by different invitation types including 1st invitation for routine screening; routine invitations to previous non-attenders, and to previous attenders (last screen within and more than 5 years previously). In Breastscreen Australia¹, recall to assessment is reported for women aged 50-74 years and 50-69 years and is classified by first and subsequent screening rounds. Assessment of participants often included palpation, diagnostic mammography, ultrasound and, if required, a percutaneous biopsy.¹

Between 2019 to 2023, in the NHSBSP, the recall to assessment rate after the first breast screen remained stable from 6.2-7%. For subsequent screens to previous attenders with last screen within 5 years, the recall to assessment rate was in the range of 2.7-3.2%.¹⁰ By comparison, between 2019 and 2021, the recall to assessment rate in Australia remained stable from 11.1% to 11.7% for first screens and 3.7% to 4% for subsequent screens.  

Recall to assessment and breast cancer control in Australia

Since the introduction of BreastScreen Australia, the age-standardised incidence rate for female breast cancer increased from 100.2 per 100,000 in 1991, to 125.6 per 100,000 in 2019, and was projected to be 128.6 per 100,000 in 2023.¹¹ Meanwhile there was a significant decrease in the age-standardised breast cancer mortality rate in females from 31.2 per 100,000 in 1991 to 18.2 per 100,000 in 2021, and with a projected 18.1 per 100,000 for 2023.¹² An increase in 5-year relative survival was reported in females from 78.3% in 1990–1994 to 92.0% in 2015–2019.¹³

Changes to recall to assessment rates should be considered alongside corresponding invasive cancer detection rates, as a higher recall to assessment rate may be considered acceptable if it leads to higher breast cancer detection rates.¹ The increase in age-standardised recall to assessment rates of females in the target age range after their first breast screen has been accompanied by an increase in detection of invasive breast cancers and ductal carcinoma in situ in females screening. 

Between 2014 and 2021, the age-standardised invasive breast cancer detection rate for ages 50–74 for their first screening round ranged between 103.3 and 122.0 per 10,000 participants screened. By comparison, the equivalent rate for subsequent screening rounds stabilized between 49.0 and 51.2 participants with an invasive breast cancer detected per 10,000 participants screened.¹

In 2021, for every 10,000 participants aged 50–74 screened through BreastScreen Australia, 35.4 had a small (≤15 mm) invasive breast cancer detected. Over half (58.6%) of all invasive breast cancers detected through BreastScreen Australia in all screening rounds were small, whereas invasive breast cancers detected outside BreastScreen Australia were less likely to be small, with only 28% reported to be ≤15 mm by the AIHW in 2018.¹ Small breast cancers generally have increased treatment options (NBOCC 2009) and are associated with higher survival (AIHW & NBCC 2007).¹

Similarly, BreastScreen Australia participation has increased ductal carcinoma in situ (DCIS) detection, signalling women with an increased risk of later developing invasive breast cancer (AIHW 2010; IARC 2002). Between 2014 and 2021, the age-standardised DCIS detection rate for participants aged 50–74 years at their first screening round increased from 23.9 to 30.3 per 10,000 participants and from 11.6 and 14.8 per 10,000 participants screened at subsequent rounds.¹