Breast screening: What you need to know

Being breast aware and understanding the screening guidance that applies to you are important parts of looking after your breast health. Screening aims to find some breast cancers before signs or symptoms develop. Finding breast cancer early may provide more treatment options and can support better outcomes, but screening may also present certain limitations and potential downsides.

Mammography is the standard population screening test. Ultrasound, MRI and other tests have different roles depending on whether you have symptoms, your age, breast density, overall risk and clinical advice. It’s important to discuss the risks and benefits of getting a screening test with your doctor to make sure it is most appropriate for you.

Breast cancer is the second leading cause of cancer death in Australian women after lung cancer.¹

Screening helps diagnose breast cancer, often in the very early stages. The earlier the disease is detected, the more options there are available. “Breast cancer survival is strongly linked to the stage at which it's detected,” says Bupa GP Janice Tan. “Stage 1, meaning the cancer is localised and small, has a 5-year survival rate of above 95%.² Stage 4, where the cancer is metastatic and has spread to other organs, has a 5-year survival rate of around 30%.²”

Early detection doesn't just improve survival; it often means less aggressive treatment. “A small tumour caught early may require a lumpectomy – a breast-conserving surgery,” explains Janice. “The same cancer found later might require mastectomy – surgery to remove the whole breast, chemotherapy, and radiation.”

Breast awareness is important at every age. Routine screening recommendations depend on age and individual risk.

Depending on your age and individual risk, different types of breast screening are appropriate.

The benefits of a mammogram

A mammogram is an x-ray of the breast. “A mammogram can find breast cancer when it’s still very small, sometimes around the size of a grain of rice and too small to feel.” “Mammography screening has been shown to reduce breast cancer mortality. There is a 54-63% lower likelihood of breast cancers causing death when they are picked up by the BreastScreen Australia Program, as compared to breast cancers diagnosed in women who had never participated,³” says Janice.

Limitations and risks of a mammogram

A mammogram exposes your breasts to a very small amount of radiation. “Modern x-ray screening equipment uses the smallest amount of radiation possible while still getting a high-quality x-ray image,” explains Caitlin. “Research shows the benefits of a breast screen outweigh the risks of radiation exposure. Radiation exposure from a breast screen is about the same amount of radiation as you're exposed to in 18 weeks of normal day-to-day activity.³”

“Mammograms are less sensitive in women with dense breasts because dense tissue can mask breast tumours. Dense breasts are common and not abnormal,” says Caitlin. “However, dense breast tissue can make breast cancer more difficult to detect on a mammogram, and is associated with an increased risk of breast cancer. Women with questions about their breast density should speak with their GP about their individual risk and screening needs.”

What happens during a mammogram?

During the screening as part of BreastScreen Australia, a female radiographer will place each of your breasts between 2 x-ray plates. The plates will press your breast firmly for about 10 seconds during the x-ray. This can be uncomfortable but should not be painful. If you experience pain, tell your radiographer immediately.

Breast density⁴ is a measure of how much fibrous and glandular tissue there is in your breast, compared to fat tissue. It isn’t related to breast size or firmness. Breasts are made up of lobules, ducts, and fatty and fibrous connective tissue. Fibrous and glandular tissue are harder to see through on a mammogram, so your breast tissue may be called ‘dense’ if you have a lot of these tissues.

Women who have dense breast tissue may have a higher risk of breast cancer compared to women with less dense breast tissue. Dense breast tissue also makes it harder for radiologists to see cancer on mammograms.

If your mammogram report says that you have dense breast tissue, talk with your health care provider about what this means for you. Be sure that your doctor or nurse knows if there’s anything in your medical history that may increase your risk for breast cancer.

Ultrasound5

“An ultrasound uses soundwaves to create pictures of the breast and does not use radiation,” says Caitlin. “In younger women with a breast lump or other breast symptom, ultrasound is often the first imaging test used. Ultrasound can also be used to investigate an abnormality found on a mammogram.”

A gel is spread on your breast, and then a small device (transducer) is moved over the breast and armpit. This sends soundwaves that echo when they meet something dense, like a tumour. A computer creates a picture from these echoes. The scan usually takes around 15-20 minutes and should not be painful.

MRI scan5

“An MRI uses a large magnet and radio waves to take pictures of the breast tissue,” explains Caitlin. “It does not use radiation. It is mainly used for people at high risk of breast cancer, or who have very dense breast tissue or implants. An MRI may also be used if other imaging test results are unclear or to help plan surgery.”

Before a breast MRI scan, you will usually have an injection of a dye to help show any abnormal breast tissue. You will lie face down on a table, which slides into a large, cylinder-shaped machine. The scan can take up to 40 minutes. It is painless but loud, so most people are offered earplugs to wear.

Biopsy5

If additional testings are required, your doctor may suggest doing a biopsy, which is when a small sample of cells or tissue is taken from the area of concern. This is then examined by a specialist doctor called pathologist under a microscope to check for cancer cells.

A biopsy usually involves a thin needle being inserted into the tissue or lymph node. The biopsy may be done in a specialist’s rooms, at a radiology practice, in hospital or at a breast clinic.

The Cancer Council has resources to help understand more about breast cancer, its symptoms, diagnosis and treatment.

Breast Cancer Network Australia helps Australians who are affected by breast cancer receive the very best care, treatment and support.