Breast density, sometimes called mammographic density, is a crucial yet often overlooked aspect of breast health. It indicates the level of glandular and fibrous tissue relative to fat in your breasts and can be a strong indicator of your risk of developing breast cancer.
Despite this, many women have never even heard the term dense breast tissue. And while scientists know it matters, they’re still learning exactly why it increases risk. That’s why we’ve teamed up with Cheryl Cruwys from Breast Density Matters UK to explain what dense breasts actually are, why they can make breast cancer harder to detect, and what you can do if you have them.
What is Dense Breast Tissue?
Breasts are made up of a mix of glandular tissue, fibrous connective tissue, and fat. If you have dense breasts, it simply means you’ve got more glandular and fibrous tissue than fatty tissue. It’s completely normal – in fact, about 4 in 10 women over 40 fall into this category.
The challenge is that dense breast tissue does two things. First, it slightly raises your chances of developing breast cancer – the denser the tissue, the greater the risk. Secondly, it makes mammograms trickier to read. On a mammogram, both dense tissue and cancerous tumours appear white, a bit like trying to spot a snowball in a snowstorm. This can make it harder to spot cancers early.
Dense Breasts vs Fatty Breasts
You can’t tell if you have dense breasts by touch – dense breasts aren’t necessarily firmer, and there are no obvious outward signs. The only way to know you have dense breasts is through a mammogram, which will classify your breast density into one of four categories:
- A – Fatty
- B – Scattered fibroglandular density
- C – Heterogeneously dense
- D – Extremely dense
Categories C and D are classed as dense breasts. Women in these categories are more likely to need additional screening, as mammography alone may not detect small tumours.
Mammograms are still the best screening tool we have and have saved countless lives, but they’re less effective for women with dense tissue. That’s why in countries like France and Austria, women with high breast density are often offered extra screening, such as ultrasound or MRI, to give doctors a clearer picture.
Currently, awareness about the need for education on the topic is raised by Breast Density Matters UK who recommends medically-sourced DenseBreast-info as an educational resource. Equipped with their density composition, women can discuss appropriate screening with health professionals and make informed decisions on their breasts.
Should I Worry About Dense Breast Tissue?
Dense breast tissue isn’t something to panic about, but it is worth knowing about. It’s one of several factors that can increase your breast cancer risk, and being aware of it means you can make better decisions about screening.
The problem is, in the UK, most women aren’t told about their breast density after a mammogram. Without that information, it’s harder to have informed conversations with your GP or screening provider about whether you might need extra checks. At Prevent Breast Cancer, we believe every woman has the right to know her density – and what it means for their health.
What Causes Dense Breast Tissue?
A few different things can influence breast density.
- Genetics – If your mother or sisters have dense breasts, you may too.
- Age – Younger women are more likely to have dense breast tissue, which often becomes less dense with age.
- Hormones – Hormone replacement therapy (HRT) and menstrual cycle stages can increase density.
- Pregnancy and breastfeeding history – Can affect tissue composition.
How is Prevent Breast Cancer Helping?
We’re committed to raising awareness about breast density and funding research to better understand it. Our scientists are investigating the exact makeup of dense breast tissue, the genetic changes that may lead to cancer in dense breasts, and whether it’s possible to develop preventative treatments that reduce density – and therefore lower breast cancer risk.
Working with Breast Density Matters UK, we also promote medically sourced resources like DenseBreast-info.org to help both patients and healthcare professionals understand the impact of breast density. Thanks to funding from the Tim Bacon Foundation, we’re making progress towards more personalised screening strategies that could make a real difference for women with dense breasts.
The Key Takeaway
Dense breasts are normal, but they matter for your breast cancer risk and screening. They can’t be identified by touch, and there are no outward symptoms of dense breasts – only a mammogram can tell you if you have them. Understanding your density could help you and your healthcare team choose the right screening plan for you.
If you’re unsure about your breast density, we recommend asking your healthcare provider for your mammogram report and starting the conversation. Awareness is the first step towards prevention.
About Prevent Breast Cancer
Prevent Breast Cancer is the only UK charity entirely dedicated to the prediction and prevention of breast cancer – we’re committed to freeing the world from the disease altogether. Unlike many cancer charities, we’re focused on preventing, rather than curing. Promoting early diagnosis, screening and lifestyle changes, we believe we can stop the problem before it starts. And being situated at the only breast cancer prevention centre in the UK, we’re right at the front-line in the fight against the disease. Join us today and help us create a future free from breast cancer. If you have any questions or concerns, email us today.
