BREAST CANCER RISK AND BREAST DENSITY: IS AGE A FACTOR?
Like the rest of your body, breast tissue changes with age. Changes in firmness and size are a normal part of aging, especially after menopause.
However, the risk of developing breast cancer increases with age. According to the Canadian Cancer Society, breast cancer will affect one in eight women in Canada. It typically occurs in women between 50 and 69 years of age, but can certainly occur in the younger age groups.
Some changes to the breast can be a sign of health problems. You should speak to your health care practitioner if you are experiencing any of the following changes to your breasts:
- New lump in your breast or your armpit.
- New redness or flaking skin on your breast or nipple.
- Thickening or swelling of your breast.
- Nipple discharge.
- Breast pain.
HOW DOES BREAST DENSITY AFFECT BREAST CANCER RISK?
Dense breast tissue increases the risk of breast cancer, especially in older women. For women with dense breast tissue in 75 percent or more of their breasts, their breast cancer risk is double relative to the general population.
You can't tell by look or feel, whether or not you have dense breasts. It is a diagnosis that can only be assessed by mammography. Dense breasts have less fat and more glandular and connective tissue. This makes a mammogram harder to read, so smaller cancers may be hidden.
Dense breasts are normal. Breast tissue can change with age, usually becoming less dense as you get older and go through menopause. However, some women continue to have dense breast regardless of age. Dense breasts may be affected by taking certain types of hormone therapies, such as hormone treatments for menopause.
It’s important to be aware of your breast density. At Mayfair, we explain your breast score after your mammogram and include your density level in the report that is sent to your referring doctor. Our mammography machines are equipped with the Volpara Health Technologies program which standardizes the density score from A to D:
- Almost entirely fatty: There is almost no dense tissue, which makes abnormalities easy to detect. About 10% of women are in this category.
- Scattered fibroglandular densities: Scattered areas of density, but the majority of tissue is fatty. About 40% of women are in this category.
- Heterogeneously dense: More than half the breast is dense tissue. About 40% of women are in this category.
- Extremely dense: Nearly all of the tissue is dense. About 10% of women are in this category. This may make it hard to see a cancer on a mammogram because the cancer can blend in with the normal tissue.
HOW DO I MITIGATE MY RISK OF BREAST CANCER?
The survival rates for breast cancer have been improving since the 1980s, thanks to earlier detection from regular mammogram screening and improvements in breast cancer treatments. When breast cancer is found at an early stage, it’s more easily treated and the survival rate is much higher.
The best way to detect breast cancer early is by having regular screening mammograms before you develop symptoms of breast cancer like lumps, changes to the breast, or even pain in certain instances. This is why educating women about early detection is often the main goal of breast awareness month and its associated fundraisers and campaigns.
Having regular mammograms makes it easier for a radiologist to compare your images and see changes or areas of concern over time. If you wait until you have symptoms, the breast cancer might be enlarged and more difficult to treat.
Mammography is a type of X-ray exam that takes an image of the inside of the breasts. All Mayfair Diagnostics’ mammography clinics use technology that provides traditional 2D images of the breast, as well as 3D images (tomosynthesis) of the breast that can then be viewed in slices. This provides a greater level of detail and a clearer view of the breast tissue with a very small dose of radiation – the same level of radiation as the 2D images require.
A diagnostic breast ultrasound or an automated breast ultrasound may be booked in addition to a screening mammogram for patients with extremely dense breast tissue (Volpara D score) or patients who have a other risk factors for breast cancer (such as first-degree relative diagnosed with breast or ovarian cancer) combined with heterogeneously dense breast tissue (Volpara C score).
Using both ultrasound and mammograms together helps provide a more complete picture of dense breast tissue. Ultrasound on its own is not recommended as a breast cancer screening tool by the College of Physicians and Surgeons.
WHEN SHOULD I START HAVING A MAMMOGRAM?
All women should have a mammogram. Many women start having regular mammograms every year at about age 40. Alberta Health Care covers one mammogram per year starting at that age. If you have a concern about your breasts earlier than that, you should see your doctor and arrange to have appropriate imaging of your breasts. This may be a mammogram, ultrasound, or both. To get a screening mammogram, you will need to speak to your doctor about your family history, when to start screening, and how frequently you should be screened.
Mayfair Diagnostics recommends screening mammography every year from age 40 to 49, then every two years between age 50 and 74, if there are no risks factors that would necessitate a shorter interval. After age 75, screening frequency will depend on a number of factors, including your medical history.
Women with the following risk factors are considered high risk and may be encouraged to start screening earlier and more frequently:
- Personal history of breast or ovarian cancer.
- First-degree relative (parent, sibling, child) diagnosed with breast or ovarian cancer.
- BRCA1, BRCA2 positive.
- Three or more second-degree relatives with breast or ovarian cancer.
- Volpara D (extremely dense) breast density* score.
- Chest wall radiation at an age younger than 30.
- History of lobular carcinoma in situ or atypical hyperplasia on previous breast biopsy.
NOTE: If you are at high risk, Mayfair recommends regular breast screening every year starting at any age above 40 or 10 years earlier than the age a first-degree relative was diagnosed with breast or ovarian cancer.
Across Canada the recommended age to start screening and the recommended screening intervals differ by province. Most provincial and federal breast screening guidelines are based on an evaluation of whether the benefits of regular screening mammograms outweigh the potential harms. Mayfair’s recommendations for breast screening are aligned with the Canadian Society of Breast Imaging and the Canadian Association of Radiologists.
WHAT ARE THE RISKS OF REGULAR BREAST SCREENING?
When deciding between the benefit of early detection of breast cancer and the potential harms associated with breast cancer screening there are two main thoughts that are often considered. The first is radiation exposure and the second is overdiagnosis.
Many women are concerned about the cumulative effects from radiation exposure during a mammogram. However, mammograms require a very small dose of radiation, less than the annual background environmental radiation exposure. Many women consider the risk of harm from this amount of radiation exposure to be low compared to the prognosis when breast cancer is detected early.
Overdiagnosis includes unnecessary treatment of cancer that would not have caused harm in a woman’s lifetime, as well as the physical and psychological consequences of false positives. Current research puts the risk of overdiagnosis at 10 percent, compared to research that shows not participating in screening mammography leads to a 60 percent higher chance of dying from breast cancer.
While the recommendations differ, the ultimate decision rests with women. Understanding the risks and benefits of regular mammogram screening and speaking with your doctor about your medical history is an important first step to decide what’s right for you.
Mayfair Diagnostics has 12 locations which offer mammography exams, including Mahogany Village, Market Mall, Mayfair Place, Cochrane, and Southcentre locations which have the new Pristina Dueta mammography system – which helps provide a more comfortable mammogram. Visit our breast imaging page for more information.
Advani, S. M., et al. (2021) “Association of Breast Density With Breast Cancer Risk Among Women Aged 65 Years or Older by Age Group and Body Mass Index.” JAMA Network Open. 2021;4(8). Accessed September 15, 2021.
Canadian Association of Radiologists (2016) “CAR Practice Guidelines and Technical Standards for Breast Imaging and Intervention.” www.car.ca. September 15, 2021.
Canadian Society of Breast Imaging (2018) "The Canadian Society of Breast Imaging response to the new CTFPHC Guidelines." www.csbi.ca. September 15, 2021.
Monticciolo, Dr. et al. (2018) “Current Issues in the Overdiagnosis and Overtreatment of Breast Cancer.” American Journal of Roentgenology. February 2018, 210 (2). September 15, 2021.
Tabar, L., et al. (2018) “The incidence of fatal breast cancer measures the increased effectiveness of therapy in women participating in mammography screening.” Cancer. September 15, 2021.