Breast cancer

14-minute read

Key facts

Breast cancer is the most common cancer diagnosed in females.
Risk factors for breast cancer include drinking alcohol, smoking, having a family history of breast cancer, having a genetic mutation and not being physically active.
Breast cancer screening aims to find breast cancers before you notice a lump.
Treatments for breast cancer include surgery, radiation therapy and different types of medicines including chemotherapy and hormone therapy.

What is breast cancer?

Breast cancer is the most commonly diagnosed cancer in females. It happens when cells in the breast grow abnormally. These cells can form a lump, known as a tumour. If the cancer spreads to other parts of the body, such as the bones, liver or lungs, it is known as metastatic (advanced) breast cancer.

Both males and females can get breast cancer, but it is rare in males.

There are 2 main categories of breast cancer:

pre-invasive or 'carcinoma in situ' breast conditions, when abnormal cells are inside the milk ducts or lobules of the breast
invasive breast cancers, which grow within normal breast tissue and may spread elsewhere in the body

The most common types include ductal carcinoma and lobular carcinoma. Other types include Paget's disease and inflammatory breast cancer.

Breast cancer is often defined by whether certain hormone receptors are found in the cancer. For example, hormone-receptor-positive breast cancer, HER2-positive breast cancer or triple-negative breast cancer (which tests negative for oestrogen, progesterone and HER2).

Illustration of the anatomy of the female breast. — Female breast anatomy.

What are the symptoms of breast cancer?

Symptoms of breast cancer can include:

a lump or area of thickened tissue in the breast
breast changes
a change in the shape or appearance of the nipple, inversion (where the nipple turns in instead of pointing out) or sometimes, nipple discharge
changes to the skin of the breasts, such as dimpling (similar to an orange peel), indents, rash or redness

Some people may have no symptoms and breast cancer is found only during routine screening.

Symptoms of breast cancer in males are similar to those in females.

If you notice any new or unusual breast changes, see your doctor as soon as possible.

CHECK YOUR SYMPTOMS — Use the Symptom Checker and find out if you need to seek medical help.

What causes breast cancer?

While there is no specific known cause for breast cancer, some lifestyle factors can increase your risk of developing it, including:

drinking alcohol — especially if you drink more than one drink per day
not being physically active
excessive weight — living with obesity is linked with an increased risk of breast cancer after menopause
smoking

Other factors that can't be changed also affect your likelihood of developing breast cancer, including:

being female — about 99% of breast cancers are in females
older age — most breast cancers are found in people after menopause and the risk increases after 50 years of age
hormone replacement therapy (HRT) — hormone medicine to manage menopausal symptoms
family history — having first-degree relatives with breast or ovarian cancer
gene mutations such as BRCA1, BRCA2 or PALB2
having dense breast tissue
previous radiation exposure

What's your risk?

Click here to learn about iPrevent — a breast cancer risk assessment tool to help you start a discussion with your GP about your risk.

When should I see my doctor?

See your doctor if you:

notice any new or unusual changes in your breasts
have any symptoms of possible breast cancer such as a lump, nipple discharge or dimpling
have any concerns about your breast cancer risk

Your doctor or another healthcare professional will assess you and work out if you need further tests. If needed, they can refer you to a local service and provide necessary follow-up care.

FIND A HEALTH SERVICE — The Service Finder can help you find doctors, pharmacies, hospitals and other health services.

How is breast cancer diagnosed?

Tests to confirm breast cancer

To find the cause of a breast change, your doctor will typically use a 3-step process called the 'triple test', which includes:

taking your medical history and performing a clinical breast examination
imaging tests, such as a diagnostic mammogram or ultrasound
a biopsy, which involves taking a sample of tissue cells and examining them under a microscope to check if there is cancer

Staging and further tests

If breast cancer is confirmed, your doctor will refer you for more tests, such as a computed tomography (CT) scan, blood tests, bone scans or a positron emission tomography (PET) scan, to confirm the stage of your cancer.

The most used staging method is the TNM system. It considers tumour size (T), nodal involvement (N) and the presence of metastasis (M).

The stages of breast cancer range from 0 to IV:

Stage 0 refers to pre-invasive breast conditions that are only in the milk ducts or lobules of the breast.
Stage I to III depends on the tumour size and the number of lymph nodes involved.
Stage IV cancer is when it has spread to other parts of the body.

There may also be other tests done on the biopsy sample. For example, your sample may be tested for hormone receptors (to see if your cancer cells have receptors for oestrogen or progesterone), HER2 (a protein that promotes cancer cell growth) or other genetic markers. These tests help you and your doctor determine the best treatment for your type of breast cancer.

ASK YOUR DOCTOR — Preparing for an appointment? Use the Question Builder for general tips on what to ask your GP or specialist.

How is breast cancer treated?

Treatment for breast cancer depends on the specific type and stage of the breast cancer that you have.

Genetic testing

Genetic testing can help to:

find people who may benefit from ways to lower their cancer risk, such as surgery, medicine or lifestyle changes
show if someone has a higher risk of other cancers linked to a gene change
identify gene changes that may help doctors choose targeted cancer treatments

Surgery

The most common surgery treatments for breast cancer are:

lumpectomy or partial mastectomy known as 'breast-conserving surgery'— removes the cancer and a small amount of surrounding healthy tissue, while keeping most of the breast
mastectomy — removes the whole breast affected by cancer
axillary lymph node dissection — removes lymph nodes from the armpit to check if the cancer has spread

Radiation therapy

Radiation therapy (radiotherapy) is often used to destroy any breast cancer cells left after a lumpectomy. It is sometimes used after a mastectomy if there is a risk of cancer recurring in the chest area.

Chemotherapy

Chemotherapy involves using anti-cancer medicines to kill any remaining cancer cells in the body. It may be used before or after surgery or radiation therapy, or together with other treatments.

Hormone therapy

Hormone therapy involves taking medicines that reduce or block your body's oestrogen and progesterone levels. It is used to stop or slow hormone-receptor-positive cancer cells from coming back.

Targeted therapy and immunotherapy

Targeted therapy and immunotherapy use medicines to specifically target cancer cells.

Currently, they are mainly used for HER2-positive breast cancers. Targeted therapy may be used before surgery.

A new type of medicine sometimes used if you have a BRCA gene mutation is poly (ADP-ribose) polymerase inhibitors — also known as PARP.

Palliative care

In some situations, especially if your cancer is advanced, your medical team will talk to you about palliative care. Palliative care aims to improve your quality of life by relieving your symptoms rather than aiming to cure the cancer.

Who will provide my breast cancer treatment?

Your medical team may include:

your GP
radiologists
medical and radiation oncologists
breast care nurses
a surgeon
a genetic counsellor
allied health professionals such as counsellors

Having a multidisciplinary team means you receive the best care possible. Sometimes, understanding the role of each health professional in your care team can be confusing. Ask your doctor if a cancer care coordinator is available. A cancer care coordinator is a health professional who coordinates your care, helps you communicate with all the health professionals involved in your treatment and supports you and your family throughout your cancer experience.

Living with breast cancer

Being diagnosed with breast cancer can be stressful and emotional. Common emotional concerns include fear that the cancer may return, uncertainty about the future and changes in self-image.

Physical issues can include early menopause, side effects from hormone therapy, tiredness, memory or concentration problems, and loss of bone strength. You may also gain weight during treatment.

It's important to give yourself time to adjust and ask for help when you need it. Staying active and maintaining a healthy weight can improve overall wellbeing. Regular visits to your GP are important for managing side effects and setting health goals after treatment.

There are many supports available, such as support groups, counsellors and care teams to help you through treatment and recovery. Read more on living with breast cancer.

What are the complications of breast cancer?

If you need to talk to someone about your mental health, call Beyond Blue on 1300 22 4636.

There are possible complications from breast cancer and its treatment:

Lymphoedema — in some cases, removing your lymph nodes may cause fluid to build up in your arm or breast, leading to swelling, discomfort and pain in the arm and upper body.
Early menopause or menopausal symptoms — chemotherapy and hormone therapy can cause symptoms such as hot flushes, muscle aches, pain or mood changes. Chemotherapy can permanently damage your ovaries leading to menopause. Hormone medicines usually cause temporary symptoms, but if your ovaries are removed menopause becomes permanent.
Anxiety and depression — common among people with breast cancer, it's understandable to have these feelings. Your medical team can help you with treatment options, so it's important to let them know how you are feeling.
Recurrence — when the cancer comes back in the same area, nearby, or in another part of the body such as the bones, lungs, brain or liver.

Can breast cancer be prevented?

Unfortunately, there isn't a way to prevent breast cancer completely. However, addressing any risk factors can help reduce your risk, such as by:

maintaining a healthy diet
keeping physically active
lowering your alcohol consumption

If you are at high risk of developing breast cancer, there may be measures you can take to reduce your risk. These may include taking hormone therapy (such as tamoxifen) or having a preventive mastectomy.

You can discuss with your doctor whether these options are suitable for you.

Early detection by mammogram allows for earlier treatment and can help prevent the cancer from spreading (metastasising). It is important that you are aware of how your breasts normally look and feel so that you can confidently report breast changes to your doctor or breast health nurse. Read more on breast checks to detect breast cancer.

Can I be screened for breast cancer?

BreastScreen Australia offers a free screening program.

If you're aged 50 to 74 years, you'll be invited to have a free mammogram every 2 years.
If you're aged 40 to 49 years or 75 years and older, you're also eligible but won't be automatically invited.

If you have a strong family history of breast cancer or carry a gene mutation, your doctor may refer you to a familial cancer clinic for further assessment, genetic testing and a personalised plan to reduce your risk.