Breast screening

Breast self-examination

• Failed to show reduction in mortality amongst women of average risk
• De-emphasised in modern guidelines, but still should be valued

Clinical breast examination

• Effectiveness depends on technique and time spent on examination

Mammography

• See below for BreastScreen recommendations
• Primary imaging modality
• Mediolateral oblique projection and craniocaudal projection
• Appears to be most effective for 60-70 year olds
• Limitations
  • Radiation
  • Overdiagnosis
  • Doesn't work as well in younger women
    • Higher breast density - harder to screen as well as higher risk

MRI (gadolinium enhanced)

• Nearly all cancers are visible, but specificity is a bit low
• Screening with MRI is recommended for certain populations

USS

• Not currently useful - takes a long time and doesn't work that well, and operator-dependent
• USS + mammogram resulted in an additional 4.2 cancers per 1000 women compared to mammogram alone, but also more false positives and call-backs and biopsies

Molecular breast imaging

• Based on preferential uptake in cancer cells
• May eventually be found to be useful in women with denser breasts, but not currently recommended

BreastScreen (guidelines correct as of 2021)

• Two-yearly mammograms to those who are asymptomatic and age 50-74
• Patients aged 40-49 or 75+ are eligible too but won't be invited
• Diagnosed with breast cancer/DCIS >5 years ago: annual mammograms
• LCIS, ADH, ALH: annual mammogram up until age of 74
• Biennial screening should continue while a woman's life expectancy is >10 years

1. At or slightly above average risk

Covers more than 95% of the female population

As a group, risk of breast cancer up to age 75 is between 1 in 11 and 1 in 8. This risk is no more than 1.5 times the population average.

• No confirmed family history of breast cancer
• One 1° relative diagnosed with breast cancer at age 50 or older
• One 2° relative diagnosed with breast cancer at any age
• Two 2° relatives on the same side of the family diagnosed with breast cancer at age 50 or older
• Two 1° or 2° relatives diagnosed with breast cancer, at age 50 or older, but on different sides of the family (ie one on each side of the family)

2. Moderately increased risk

Covers less than 4% of the female population

As a group, risk of breast cancer up to age 75 is between 1 in 8 and 1 in 4. This risk is 1.5 to 3 times the population average.

• One 1° relative diagnosed with breast cancer before the age of 50 (without the additional features of the potentially high-risk group – refer to category 3)
• Two 1° relatives, on the same side of the family, diagnosed with breast cancer (without the additional features of the potentially high-risk group – refer to category 3)
• Two 2° relatives, on the same side of the family, diagnosed with breast cancer, at least one before the age of 50, (without the additional features of the potentially high-risk group – refer to category 3)

Mammogram annually from 40-49, then every two years 50-74.

3. Potentially high risk

Covers less than 1% of the female population

As a group, risk of breast cancer up to age 75 is between 1 in 4 and 1 in 2. Risk may be more than 3 times the population average. Individual risk may be higher or lower if genetic test results are known.

• Women who are at potentially high risk of ovarian cancer
• Two 1° or 2° relatives on one side of the family diagnosed with breast or ovarian cancer plus one or more of the following on the same side of the family:
  • additional relative(s) with breast or ovarian cancer
  • breast cancer diagnosed before the age of 40
  • bilateral breast cancer
  • breast and ovarian cancer in the same woman
  • Jewish ancestry
  • breast cancer in a male relative.
• One 1° or 2° relative diagnosed with breast cancer at age 45 or younger plus another 1° or 2° relative on the same side of the family with sarcoma (bone/soft tissue) at age 45 or younger.
• Member of a family in which the presence of a high-risk breast cancer gene mutation has been established.

Annual MRI until 40yo

Annual MRI + MMG 40-60

Annual MMG >60

Consider chemoprophylaxis, prophylactic mastectomy