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What is breast cancer ?

Breast cancer is the most common cancer in women in Australia (apart from non-melanoma skin cancer) and the second most common cancer to cause death in women, after lung cancer.

Breast cancer is the abnormal growth of the cells lining the breast lobules or ducts. These cells grow uncontrollably and have the potential to spread to other parts of the body. Both men and women can develop breast cancer, although it is uncommon in men. Transwomen, non-binary people can also get breast cancer.

In Australia, the overall five year survival rate for breast cancer in females is 91%. If the cancer is limited to the breast, 96% of patients will be alive five years after diagnosis; this figure excludes those who die from other diseases. If the cancer has spread to the regional lymph nodes, five year relative survival drops to 80%.

In 2016, 17,354 women and 138 men were diagnosed with breast cancer in Australia. The risk of being diagnosed with breast cancer by age 85 is 1 in 8 for women and 1 in 651 for men.

In 2018, 2999 women and 35 men died of breast cancer in Australia.

The five year survival rate is 91%.

Learn more about how Cancer Council funded researchers are developing new treatments for hard to treat breast cancers.

Breast cancer symptoms

Some people have no symptoms and the cancer is found during a screening mammogram or a physical examination by a doctor.

If you do have symptoms, they could include:

  • new lumps or thickening in the breast or under the arm

  • nipple sores

  • nipple discharge or turning in

  • changes in the size or shape of the breast

  • skin of the breast dimpling

  • rash or red swollen breasts.

Pain is rare. 

Causes of breast cancer

Some factors that increase your risk of breast cancer include:

  • increasing age

  • family history

  • inheritance of mutations in the genes BRCA2, BRCA1  (more common with Ashkenazi Jewish heritage) and CHEK2

  • exposure to female hormones (natural and administered)

  • a previous breast cancer diagnosis

  • a past history of certain non-cancerous breast conditions.

Lifestyle factors that can also slightly increase the risk of breast cancer in men and women include:

  • being overweight
  • not enough physical activity
  • drinking alcohol.

There is also an association with some benign breast disease and past exposure to radiation.

Diagnosis of breast cancer

Tests to diagnose breast cancer may include:


A mammogram is an x-ray that can find changes that are too small to be felt during a physical examination.


If a mammogram picks up breast changes you may have an ultrasound. This is a painless scan using soundwaves to make a picture of your breast.


A doctor removes some of the breast tissue for examination under a microscope.

Other scans

If cancer is detected in your breast, you may have additional scans to see if the cancer has spread to other parts of your body, such as a CT scan or MRI scan.

After a diagnosis of breast cancer 

After finding out you have breast cancer, you may feel shocked, upset, anxious or confused. These are normal responses. Talk about your treatment options with your doctor, family and friends. Seek as much information as you need. It is up to you how involved you want to be in decisions about your treatment.  

 Find out more information after a diagnosis of breast cancer:

Treatment for breast cancer

Treatment depends on the extent of the cancer.


Staging involves assessing the size of the breast cancer and whether it has spread to the draining lymph nodes under the arm. A CT scan of the chest and liver and bone scan are done to check the sites to which breast cancers most commonly spread.


For localised breast cancer, the most extensive surgical option is to remove the breast and lymph nodes under the arm. When part of the breast is removed it is referred to as breast conserving surgery or a lumpectomy. Radiotherapy is generally recommended after breast conserving surgery.

When the whole breast is removed it is called a mastectomy.


Chemotherapy is usually given before radiation therapy. It may be used to help shrink the cancer before surgery, if the risk of cancer returning is high or if the cancer returns after surgery or radiation therapy. It may also be used if the cancer is HER2 positive or does not respond to hormone therapy.

Radiation therapy (radiotherapy)

Radiation therapy (radiotherapy) is recommended after breast-conserving surgery to help destroy any undetected cancer. It is also recommended if lymph nodes were removed from under the arm and there is a risk that the cancer will return to this area. Radiation therapy can sometimes be used after a mastectomy if there is a risk of the cancer returning to the chest area.

Hormone therapy

Hormone therapy uses drugs to reduce the levels of female hormones in the body. This helps to stop or slow the growth of hormone receptor positive cancer cells.

Palliative care

In some cases of breast cancer, your medical team may talk to you about palliative care. Palliative care aims to improve your quality of life by alleviating symptoms of cancer.

As well as slowing the spread of breast cancer, palliative treatment can relieve pain and help manage other symptoms. Treatment may include radiotherapy, chemotherapy or other drug therapies.

Treatment Team

Depending on your treatment, your treatment team may consist of a number of different health professionals, such as:
  • GP (General Practitioner)- looks after your general health and works with your specialists to coordinate treatment.
  • Radiologist- interprets diagnostic scans (including CT, MRI and PET scans).
  • Radiation oncologist- prescribes and coordinates radiation therapy treatment.
  • Radiation therapist- plans and delivers radiation therapy.
  • Medical oncologist- prescribes and coordinates the course of chemotherapy.
  • Breast care nurses- provide information and support to people affected by breast cancer during and after treatment.
  • Surgeon- surgically removes tumours and performs some biopsies.
  • Reconstructive (plastic) surgeon- performs any complex reconstructive surgery that restores or repairs the body's appearance and function.
  • Lymphoedema therapist- educates people about lymphoedema prevention and management, and provides treatment if lymphoedema occurs.
  • Other allied health professionals- such as social workers, pharmacists and counsellors.

Screening for breast cancer

Women aged between 50 and 74 are invited to access free screening mammograms every two years via the BreastScreen Australia Program.

Women aged 40-49 and 75 and over are also eligible to receive free mammograms, however they do not receive an invitation to attend.

It is recommended that women with a strong family history of breast or ovarian cancer, aged between 40 and 49 or over 75 discuss options with their GP, or contact BreastScreen Australia on 13 20 50.

Preventing breast cancer

There is no proven method of preventing breast cancer, however the risk of breast cancer can be reduced by lowering alcohol consumption and maintaining a healthy weight.

Women who are at high risk because of a very strong family history may benefit from hormones such as tamoxifen, usually administered over five years. Bilateral prophylactic mastectomy can be considered in women at high risk of breast cancer due to gene mutations.

Prognosis for breast cancer

It is not possible for a doctor to predict the exact course of a disease, as it will depend on each person's individual circumstances. However, your doctor may give you a prognosis, the likely outcome of the disease, based on the type of breast cancer you have, the test results, the rate of tumour growth, as well as your age, fitness and medical history.

The most common types of breast cancer have a very good long-term prognosis, especially if the cancer is found early.


Understanding Breast Cancer, Cancer Council Australia  © 2020. Last medical review of source booklet: July 2020. 

Australian Institute of Health and Welfare. ACIM (Australian Cancer Incidence and Mortality) Books. Canberra: AIHW.