Breast Density: A Starter Guide

What is Breast Density?


Dense breasts contain more glandular tissue and less fat tissue. The NHS explain that having dense breasts is normal and isn't something that you can change. Dense breasts are not the same as having firm breasts and has no relation to the feel, shape and size of your breasts.
Breast tissue is typically classified into four categories labelled A, B, C & D, as shown in the image courtesy of My Density Matters. It ranges from A, categorised as Fatty Breast Tissue to D, categorised as Extremely Dense Tissue.

Who has Dense Breasts?


It is common for young women who haven't gone through the menopause to have dense breasts. Breast tissue often starts to become less dense as you get older, usually after the menopause. However, 50% of women at screening age still have dense breasts.


How can you find out your breast density?


Breast Density is identified from a mammogram, and is typically identified by the radiologist recording the amount of fatty tissue they can see in comparison to breast tissue. It can also be measured using some special software to extrapolate this information from the mammogram.

Dense Tissue & Breast Cancer Risk


Breast density is associated with breast cancer risk, with cancer being at least four times as likely in women with extremely dense breasts, when compared with women with fatty breast tissue.

Breast Density & Screening


Mammography remains the standard screening test for breast cancer and is proven to reduce deaths due to breast cancer. However, dense breasts can make breast cancer screening more challenging because the dense tissue can mask potential tumours on a mammogram. These tumours may not be discovered until they have grown and possibly spread.

Screening tests including MRI and ultrasound may also be used additionally to supplement mammography, this subsequently increases detection of breast cancer in women with dense breasts. Whether this is offered as part of screening will vary depending on your risk factors and the screening regime used in your country or state.

Micrima & Breast Density


Our MARIA® 7 system, a new breast imaging modality is currently in development and is planned for release to clinical sites later in 2022. The MARIA® 7 is based on radio-wave technology, scanning the breast with no ionising radiation exposure (X-rays) and without compression. It is the first time it will be possible to give a radiologist a breast density score without having a mammogram.

This means in the future it could scan and determine a woman’s breast density at a younger age. This density score could possibly be used to decide the right screening modalities to be used and/or to contribute information to a risk factor profile for each individual.

If you discover any symptoms of Breast Cancer, seek help from a medical professional and always go for your mammogram when invited by your healthcare provider. If you want to learn more about breast cancer and density, visit My Density Matters.

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