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Breast cancer


Friday 11 September, 2020

About breast cancer

Breast cancer is the abnormal growth of the cells lining the breast ducts or lobules. These abnormal cells have the potential to spread to other parts of the body. Most breast cancers are found when they are invasive. This means the cancer has spread from the breast ducts or lobules into the surrounding breast tissue. Invasive breast cancer can be early, locally advanced or advanced (metastatic).

Anyone can develop breast cancer. While it is much more common in women, men can also get breast cancer. Breast cancer in  is usually diagnosed and treated in the same way for everyone. Find more information for men diagnosed with breast cancer, visit or download “ Men get breast cancer too” from Breast Cancer Network Australia.

Transgender and gender-diverse people can also get breast cancer.

A transgender woman who is taking medicines to boost female hormones and lower male hormones may have an increased risk of developing breast cancer.

A transgender man who has a mastectomy is still at risk of developing breast cancer. This is likely due to small amounts of breast tissue that may remain after surgery.

Cancer care pathways

For an overview of what to expect during all stages of your cancer care, read or download the What To Expect guide for breast cancer (also available in Arabic, Chinese, Greek, Hindi, Italian, Tagalog and Vietnamese – see details on the site). The What To Expect guide is a short guide to what is recommended for the best cancer care across Australia, from diagnosis to treatment and beyond.


The breasts

Everyone has breast tissue.

Female breasts are mostly made up of lobes, lobules and ducts:

  • lobes – each breast is divided into 12 to 20 sections called lobes
  • lobules  – each lobe contains glands that can produce milk; these milk glands are called lobules or glandular tissue
  • ducts  – the lobes and lobules are connected by fine tubes called ducts; the ducts carry milk to the nipples.

Male breast tissue has ducts but few or no lobes and lobules.

All breasts also contain fibrous and fatty tissue. Some breast tissue extends into the armpit (axilla). This is known as the axillary tail of the breast.

Most younger people who have been born female have dense breasts, because they have more glandular tissue than fat in them.

The lymphatic system

The lymphatic system is an important part of the immune system. It protects the body against disease and infection. It is made up of a network of thin tubes called lymph vessels that are found throughout the body. Lymph vessels connect to groups of small, bean-shaped structures called lymph nodes or glands.

Lymph nodes are found throughout the body, including in the armpits, neck, abdomen and groin, and behind the breastbone (sternum). The lymph nodes in the armpit (axillary lymph nodes) are often the first place cancer cells spread to outside the breast.

Different types of breast conditions

Non-invasive breast conditions

Non-invasion breast conditions are also called carcinoma in situ. These are a pre-cancerous condition where the cells look like cancer cells but have not invaded nearby tissues.

Ductal carcinoma in situ (DCIS)

Abnormal cells are in the ducts of the breast They may develop into invasive breast cancer. Ductal carcinoma in situ is treated in a similar way to invasive breast cancer, but chemotherapy is not used.

Lobular carcinoma in situ (LCIS)

The abnormal cells are in the lobules of the breast. If you have this condition, there is an increased risk of developing cancer in either breast. You will need to have regular mammograms or other scans.

Invasive breast cancer

There are two main types of invasive breast cancer. They are named after the area of the breast they start in. If invasive breast cancer spreads beyond the breast tissue and nearby lymph nodes, it is called advanced or metastatic breast cancer.

For more information, call Cancer Council 13 11 20, or visit Breast Cancer Network Australia or Cancer Australia.

Invasive ductal carcinoma (IDC) 

Invasive ductal carcinoma starts in the ducts and accounts for about 80 per cent of breast cancers.

Invasive lobular carcinoma (ILC) 

Invasive lobular carcinoma starts in the lobules and makes up about 10 per cent of breast cancers.

Other types

Less common types include inflammatory breast cancer, Paget’s disease of the nipple, medullary carcinoma, mucinous carcinoma and papillary carcinoma.

Risk factors

Many factors can increase your risk of breast cancer. But having risk factors does not mean that you will develop breast cancer.
For more information, visit or

Inherited breast cancer gene

Most people diagnosed with breast cancer don’t have a family history of the disease. But a small number of people may have inherited a gene fault that increases their breast cancer risk. Everyone inherits a set of genes from each parent, so they have two copies of each gene. Sometimes there is a fault in one copy of a gene. This fault is called a mutation or pathogenic variant.

The two most common gene mutations linked to breast cancer are the BRCA1 and BRCA2 genes. Other types include CDH1, PTEN, STK11, TP53, PALB2, ATM and CHEK2.

Women and trans-men in families with an inherited BRCA1 or BRCA2 change are at increased risk of breast and ovarian cancers.

Men and trans-women in families with an inherited BRAC2 change may be at an increased risk of breast and prostate cancers.

To find out if you have inherited a gene mutation, you can visit a family cancer clinic. Talk to your doctor or breast cancer nurse.

Female-specific factors

For people born with a female reproductive system, the main risk factors fall into these categories:

  • family history factors

– a family history of breast cancer or a particular type of ovarian cancer in your mother or a sister, or female relatives on the same side of the family, especially if diagnosed at a young age

  • lifestyle factors

– being overweight or gaining weight after menopause

– drinking alcohol every day

– not being physically active

  • medical factors

– using menopause hormone therapy (MHT) that contains both oestrogen and progestogen

– taking the pill for a long time (small increase)

– taking diethylstilboestrol (DES) during pregnancy

– having radiation therapy to the chest for Hodgkin lymphoma

– having atypical ductal hyperplasia or proliferative disease without atypia

– previous diagnosis of lobular carcinoma in situ (LCIS) or ductal carcinoma in situ (DCIS)

  • personal factors

– older age

– dense breast tissue as seen on a mammogram

  • reproductive factors

– starting first period younger than 12

– being older than 30 at the birth of first child

– not giving birth

– not having breastfed

– going through menopause after 55

Male-specific factors

For people born with a male reproductive system, the main risk factors fall into these categories:

  • family history factors

– a family history, with more than one parent or sibling who has had BRCA2 breast cancer

– a relative diagnosed with breast cancer under the age of 40

– several relatives diagnosed with ovarian, colon or prostate cancer

  • medical factors

– a rare genetic syndrome called Klinefelter syndrome. People with this syndrome have three sex chromosomes (XXY) instead of the usual two (XY).

  • personal factors

– older age. 


Some people have no symptoms and the cancer is found during a screening mammogram (a low-dose x-ray of the breast) or through the National Breast Cancer Screening Program.

If you do have symptoms, they could include one or more of the following:

  • a lump, lumpiness or thickening, especially if it is in only one breast
  • changes in the size or shape of a breast
  • changes to a nipple, such as a change in shape, crusting, sores or ulcers, redness, a clear or bloody discharge, or a nipple that turns in (inverted) when it used to stick out
  • a change in the skin of the breast, such as dimpling or indentation, a rash, a scaly appearance, unusual redness or other colour changes
  • swelling or discomfort in the armpit
  • ongoing, unusual pain that is not related to your normal monthly menstrual cycle, remains after your period and occurs in one breast only.

Most breast changes aren’t caused by cancer. If you have symptoms, see your doctor without delay.

Breast cancer rates

Breast cancer is the most common cancer in Australian women (apart from common skin cancers). About 17,000 women, according to statistics on breast cancer published by the Australian Institute of Health and Welfare in 2018, are diagnosed with breast cancer each year, and one in eight will be diagnosed by the age of 85.

Although breast cancer can occur at any age, it is more common in women over 40. Almost 70 per cent of breast cancers are diagnosed in women aged between 40 and 69, and about 25 per cent are diagnosed in women aged 70 or older. In rare cases, women are diagnosed during pregnancy.

About 150 men are diagnosed with breast cancer in Australia each year, and most of these men are over 50.

Health professionals you may see

You may be recalled for further tests after a screening mammogram or your general practitioner (GP) will arrange the first tests to assess your symptoms. If these tests do not rule out cancer, you will usually be referred to a specialist breast service for further tests.

If breast cancer is diagnosed, you will first see a breast surgeon, or in some cases a medical oncologist, who will consider your treatment options. Often these will be discussed with other health professionals at what is known as a multidisciplinary
team (MDT) meeting. During and after treatment, you will see a range of health professionals who specialise in different aspects
of your care. You may not need to see all members of the MDT.

general practitioner (GP) assists you with treatment decisions and works in partnership with your specialists in providing ongoing care
breast physician diagnoses breast cancer and coordinates treatment for breast cancer in some clinics
breast surgeon* specialises in surgery and performs biopsies; some breast surgeons also perform breast reconstruction and plastic surgery procedures
oncoplastic breast surgeon* specialises in using plastic surgery techniques to reconstruct breast tissue after surgery
reconstructive (plastic) surgeon* performs breast reconstruction for women who have had a mastectomy
anaesthetist* administers anaesthetic before surgery and monitors you during the operation
pathologist* examines cells and tissue samples that are removed from the breast to work out the type and extent of the cancer
breast care nurse provides information, support and referral to women affected by breast cancer during and after treatment
nurse administers drugs and provides care, information and support throughout treatment
radiologist* analyses x-rays, mammograms, ultrasounds and other scans
radiation oncologist* treats cancer by prescribing and coordinating a course of radiation therapy
radiation therapist plans and delivers radiation therapy
medical oncologist* treats cancer with drug therapies such as chemotherapy, hormone therapy, targeted therapy and immunotherapy
lymphoedema practitioner educates people about lymphoedema prevention and management, and provides treatment if lymphoedema occurs; often a physiotherapist
dietitian recommends an eating plan to follow during treatment and recovery
exercise physiologist prescribes exercise to help people with medical conditions improve their overall health, fitness,
strength and energy levels
physiotherapist, occupational therapist assist with physical and practical problems, including restoring movement and mobility after treatment, and recommending aids and equipment
social worker links you to support services and helps you with emotional, practical or financial issues
genetic counsellor provides advice for people with a strong family history of breast cancer or with a genetic condition linked to breast cancer
psychiatrist*, psychologist, counsellor help you manage your emotional response to diagnosis and treatment

*Specialist doctor

Expert content reviewers:

Professor Bruce Mann, Professor of Surgery, University of Melbourne, and Director, Breast Tumour Stream, Victorian Comprehensive Cancer Centre, Vic; Dr Marie Burke, Radiation Oncologist, and Medical Director GenesisCare Oncology, Qld; Dr Susan Fraser, Breast Physician, Cairns Hospital and Marlin Coast Surgery Cairns, Qld; Ruth Groom, Consumer; Julie McGirr, 13 11 20 Consultant, Cancer Council Victoria; Associate Professor Catriona McNeil, Medical Oncologist, Chris O’Brien Lifehouse, NSW; Dr Roya Merie, Staff Specialist, Radiation Oncology, Liverpool Cancer Therapy Centre, Liverpool Hospital, NSW; Dr Eva Nagy, Oncoplastic Breast Surgeon, Sydney Oncoplastic Surgery, NSW; Gay Refeld, Clinical Nurse Consultant – Breast Care, St John of God Subiaco Hospital, WA; Genny Springham, Consumer


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