Hidden harm

Latest research suggests that simply informing women about their breast density isn’t enough.

- Nicky Pellegrino

If a woman has a mammogram and happens to live in one of 38 of the 50 states in the US, there are rules in place to make sure she will be informed about her breast density. This is done because if you have dense breasts, which are composed of more fibro glandular tissue relative to fatty tissue, there is an increased risk of developing breast cancer.

Additionally, dense tissue can hide cancers - on a mammogram it shows up as a white mass, as does a tumour, making cancer more difficult to spot and potentially leading to a later diagnosis.

Armed with knowledge about how dense their breasts are, and particularly if they have other risk factors, women may choose to have additional screening. Ultrasound and MRI can both provide more detail.

In this country, if you have a mammogram at a private clinic, you may be told how dense your breasts are. However, women aged 45-69 who are signed up to the BreastScreen Aotearoa national screening programme won't be notified as a matter of course when they go for their two-yearly mammogram. Women in parts of Europe, in Western Australia and in much of the US are routinely notified (Listener, February 19, 2022).

Our approach aligns with the UK and the remainder of Australia, although the topic is on BreastScreen Aotearoa's work plan and it is keeping a close eye on new evidence and guidance as they emerge.

What the latest research from the US suggests is that simply informing women about their breast-density status isn't enough.

Christine Gunn, an assistant professor at the Dartmouth Institute in New Hampshire, has been interviewing women from a wide range of backgrounds about their understanding of breast cancer risk factors.