Everything you need to know about a mammogram

Mammograms screen for breast cancer. Learn more about what’s involved and what to expect on the day.

A mammogram is a low dose x-ray of your breasts. It can detect small changes that can’t be picked up by a physical examination, says Bupa GP Janice Tan.¹

Mammograms are good at detecting:

• Microcalcifications: tiny calcium deposits that can be an early sign of cancer often before any lump is detectable by touch or even on ultrasound.
• Small tumours: especially in fatty breast tissue, mammograms can pick up very small lumps years before they'd be felt.
• Architectural distortions: subtle changes in the structure of breast tissue that can indicate early cancer.

Mammograms are used to screen for breast cancer in people who do not have symptoms. They can also be used as a diagnostic tool for people who do have symptoms and may be done in conjunction with other tests, such as a breast ultrasound or MRI.

“Ultrasound is better at distinguishing fluid-filled cysts from solid lumps and is the preferred tool for women with very dense breast tissue,” says Janice. “MRI is more sensitive overall but is expensive and typically reserved for high-risk women."

"Mammography remains the gold standard for population-level screening because of its ability to detect early-stage disease at scale.”

As part of the national BreastScreen program, all Australian women aged 40 and over can access a screening mammogram every 2 years. Women aged between 50 and 74 will receive a letter in the mail inviting them to screen.

“If you have a first-degree relative (mother, sister, daughter) who had breast cancer, especially at a young age, you may be eligible for earlier and more frequent screening,” says Janice. “Women with a significant family history may be referred for a familial cancer risk assessment, which can lead to personalised screening recommendations, starting as early as 10 years before the age your relative was diagnosed. Don't wait for your GP to bring it up. If you have a family history, proactively ask about your options.”

If you have any signs or symptoms of breast cancer at any age you can see your GP who will refer you for the most appropriate tests.

A mammogram is performed by a radiographer in a clinic or hospital. All BreastScreen radiographers are female.

You will need to undress from the waist up. The radiographer will position your breast between two X-ray plates, which compress it during the screening. Each x-ray takes about 10 seconds, and each breast usually has 2 x-rays taken.

Having a mammogram can be uncomfortable, but it shouldn’t be painful. Tell your radiographer if you experience any pain.

After the appointment, you can leave immediately and resume all normal activities, such as work or exercise. There is no need to fast before a mammogram.

If your mammogram comes back with no abnormalities, you will receive a letter telling you your results. In 2 years, you will receive an invitation to attend your next mammogram.

If you notice any changes in your breasts at any time, see your doctor. You do not need to wait until your next mammogram is due.

If your mammogram shows any abnormalities, you will be asked to return for further investigation. This might mean another mammogram, an ultrasound or a biopsy.

Not all abnormalities are breast cancer. Benign cysts, dense breast tissue and harmless lumps can show up on a mammogram, and further testing will rule out anything serious.

If breast cancer is detected, a doctor will explain the results and what happens next.