BreastScreen Australia changed its reporting in 2023 — every screening mammogram now includes the patient's breast density category (BI-RADS A through D). Category C ('heterogeneously dense') and D ('extremely dense') reduce the sensitivity of mammography for cancer detection.
The number that should change the conversation
Around 43% of Australian women aged 50-74 have category C or D breast density (BreastScreen Australia 2023 data). For these women, a standard mammogram has a sensitivity of around 70%, compared to 95% in women with predominantly fatty tissue. The cancers it misses tend to be the masses that ultrasound or MRI would catch.
What the report actually says
BreastScreen reports the density category but does not, in most states, recommend supplemental screening. The patient is left with a result that says 'no abnormality detected' alongside a density category that, in clinical research, is associated with both reduced sensitivity AND increased breast-cancer risk.
Whether the patient understands this depends entirely on the GP conversation. Most don't have it.
What the conversation should cover
- Explanation of what density means — and that it's NOT the same as breast cancer risk, though it correlates with it.
- Acknowledgement that mammographic sensitivity is reduced in dense tissue.
- Discussion of supplemental imaging options (ultrasound, MRI) — what they cost, what they detect, who pays.
- The patient's personal risk assessment using a validated tool like Gail or Tyrer-Cuzick.