How often are mammograms (breast x-rays) done in Australia?

Mammography Screening Frequency in Australia

In Australia, mammography screening is recommended every 2 years for women aged 50-74 years through the national BreastScreen Australia program. 1

Screening Recommendations by Age Group

• For women aged 50-74 years, biennial (every 2 years) mammography screening is the standard recommendation in Australia 1
• Women aged 40-49 years can access the program but are not actively invited to participate in the national screening program 1
• Women aged 75 and older can continue screening but are not actively recruited 2
• The participation rate in the BreastScreen Australia program is approximately 56-60% 1, 3

Special Considerations for Higher Risk Groups

• Women with a family history of breast cancer (having at least one first-degree relative diagnosed with breast cancer) may benefit from annual rather than biennial screening 4
• Annual screening for women with family history has been shown to increase the odds of being diagnosed with smaller, node-negative tumors compared to biennial screening 4
• Women with genetic mutations such as BRCA1 and BRCA2 may require earlier and more frequent screening than the general population 5

Effectiveness of the Australian Screening Program

• Since the introduction of BreastScreen Australia in 1991, there has been a 28% reduction in age-standardized breast cancer mortality 6
• Studies suggest that mammography screening through BreastScreen Australia has contributed to a 21-30% reduction in breast cancer mortality 3
• However, some research indicates that improvements in treatment, particularly adjuvant hormonal and chemotherapy, may account for a significant portion of the mortality reduction 6

Comparison with International Guidelines

• Australian recommendations align closely with Canadian guidelines, which also recommend screening every 2-3 years for women aged 50-74 years 5
• This differs from some American organizations like the American Cancer Society, which recommends annual mammography starting at age 40 7
• The American College of Physicians recommends stopping screening in women aged 75 or older, or those with a life expectancy of less than 10 years 2

Potential Harms and Benefits

• Benefits include reduced breast cancer mortality through early detection 8, 3
• Potential harms include discomfort during examination, anxiety related to false-positive results, and possible overdiagnosis 2, 1
• Overdiagnosis in Australia has been estimated to be as low as 8% of detected cancers, though some research suggests it could be up to 30% 1

Screening Participation Considerations

• Participation rates are lower among Aboriginal and Torres Strait Islander women, women in remote areas, and women with lower socio-economic status 1
• Increased screening participation is associated with greater mortality reduction, with studies showing that achieving the program target of 70% participation could result in a 25-34% reduction in breast cancer mortality 3

Follow-up of Abnormal Results

• Quality guidelines recommend a delay of no more than 60 days between screening and diagnosis for abnormal results 5
• Longer delays (>180 days) between a positive screening result and diagnosis are associated with poorer outcomes 5