BreastScreen Australia monitoring report 2025

Results

In 2023, 6,410 participants aged 50–74 had an invasive breast cancer detected through BreastScreen Australia. Of these, 1,142 were attending their first screen (equivalent to 99.4 participants diagnosed per 10,000 participants screened), and 5,268 were attending a subsequent screen (equivalent to 58.7 participants diagnosed per 10,000 participants screened).

In 2023, of the 6,410 participants aged 50–74 who had an invasive breast cancer detected through BreastScreen Australia, 3,705 had a small (≤15 mm) cancer detected. This equates to 36.6 per 10,000 participants screened.

In 2023, 57.8%, of all invasive breast cancers detected in participants aged 50–74 were small (≤15 mm).

Invasive breast cancer detection summary

The majority of participants who participate in BreastScreen Australia experience only the screening test. In 2023, of the 114,875 participants aged 50–74 who screened for the first time, 12,177 (10.6%) were recalled for further assessment (Table 4.1a). Of the 897,394 participants attending subsequent screens, 33,834 (3.8%) were recalled (Table 4.1b).

Most of the participants recalled to assessment did not have an invasive breast cancer detected. Of the 12,177 participants recalled to assessment after a first screen, 1,142 (9.4%) had an invasive breast cancer detected (Table 4.1a). Of the 33,834 participants recalled to assessment after a subsequent screen, 5,268 (15.6%) had an invasive breast cancer detected (Table 4.1b).

This means that in 2023, of the 114,875 participants aged 50–74 screened for the first time, 1.0% had an invasive breast cancer detected, and of the 897,394 participants attending subsequent screens, 0.6% had an invasive breast cancer detected through BreastScreen Australia (Table 4.1a and Table 4.1b).

Source: AIHW analysis of BreastScreen Australia data.

Invasive breast cancer detection trends

Between 2014 and 2023, the age-standardised invasive breast cancer detection rate for participants aged 50–74 for their first screening round ranged between 103.3 and 126.1 participants with an invasive breast cancer detected per 10,000 participants screened (Figure 4.1).

Over the same period, the equivalent rate for subsequent screening rounds for participants aged 50–74 was more stable and ranged between 49.0 and 52.4 participants with an invasive breast cancer detected per 10,000 participants screened (Figure 4.1).

Small cancers 

In 2023, for every 10,000 participants aged 50–74 screened through BreastScreen Australia, 36.6 had a small (≤15 mm) invasive breast cancer detected. As a proportion of all invasive breast cancers detected through BreastScreen Australia in participants aged 50–74, 45.3% were small in participants attending their first screen and 60.5% in participants attending subsequent screens. For all screening rounds combined, 57.8% of all breast cancers detected were small. Invasive breast cancers detected outside BreastScreen Australia are less likely to be small, with only 28% measuring ≤15 mm (AIHW 2018).

A participant is more likely to be diagnosed with a small cancer in subsequent screening visits than at their first visit, since their first screening mammogram detects prevalent cancers that might have been present for some time, whereas subsequent screens detect incident cancers that have grown between screens (Kavanagh et al. 1999). Because they have had less time to grow, incident cancers are more likely to be small. In contrast, invasive breast cancers detected at a first screen are less likely to be small because they are prevalent cancers that have had more time to grow.

Between 2014 and 2023 the proportion of small breast cancers detected for participants aged 50–74 varied between 57.6% and 59.8% (Figure 4.2). Of note, more than half of all invasive breast cancers detected through BreastScreen Australia are small. The high proportion of small breast cancers is a positive outcome, because small breast cancers tend to be associated with increased treatment options (NBOCC 2009) and improved survival (AIHW & NBCC 2007).

In 2023, the proportion of invasive breast cancers that were small was lower in younger age groups, comprising 41.9% of cancers detected for participants aged 40–49, compared with 54.5% for participants aged 75 and over and 57.8% for participants aged 50–74. The lower proportion of small invasive cancers in young women may be related to greater breast density in younger women, which makes small invasive breast cancers difficult to visualise with screening mammography (Irwig et al. 1997; Cancer in Australia 2015b).

Invasive breast cancer detection by age

In 2023, breast cancer detection rates increased with age. For the subsequent rounds the increase was from 18 per 10,000 participants screened for those aged 40–44, to 85 per 10,000 participants screened for those aged 70‍–‍74 (Figure 4.3). Breast cancer detection rates were highest for participants aged 75 and over, with 133 participants with invasive breast cancer detected through BreastScreen Australia for every 10,000 participants screened.

Over the same period the cancer detection rates for the first screening round increased to 236 per 10,000 participants screened for participants 70‍–‍74 and to 339 per 10,000 participants screened for participants aged 75 and over (Figure 4.3).

Invasive breast cancer detection by state and territory

In 2023, the breast cancer age-standardised detection rate for participants aged 50–74 for all screening rounds varied between the states and territories, from 54.8 to 67.6 per 10,000 participants screened.