Check your breasts

Breast cancer does occur in younger women

Breast cancer is the most commonly diagnosed cancer in women in Australia.
About 20,000 women in Australia are diagnosed with breast cancer each year, of which over 3,500 women are aged below 50 years.¹ All women, regardless of age, should be breast aware.²

What are the main subtypes of breast cancer?

There are three main subtypes of breast cancer:³

Hormone receptor positive
HER2 (human epidermal growth factor receptor 2) positive
Triple negative breast cancer

What is hormone receptor positive breast cancer?

Hormone receptor positive (HR+) breast cancer cells have receptors for the hormones oestrogen or progesterone, or both.³ Worldwide, most breast cancers are HR+.^3,4

What is HER2 positive breast cancer?

HER2 positive breast cancer cells have higher than normal levels of the HER2 protein.³ Worldwide, about 15–20% of breast cancers are HER2 positive.^3,5

What is triple negative breast cancer?

Triple negative breast cancer (or TNBC) means the cancer cells do not have receptors for the hormones oestrogen and progesterone, and also do not make any of the HER2 protein.⁶

Triple negative breast cancer is considered an aggressive form of breast cancer because it can grow quickly, is more likely to have spread at the time it is found and is more likely to come back within 5 years of diagnosis than other types of breast cancer.^6,7

Worldwide, around 10–15% of all breast cancer cases are triple-negative breast cancers.^6,7

Signs and symptoms of breast cancer

Early detection of breast cancer is important.⁸ Get to know your breasts—learn what is normal for you in terms of how your breasts look, their feel and shape.⁹

Check your breasts regularly. If you notice any changes, talk to your doctor for advice.

Most breast changes are not caused by breast cancer but it is important to check with your doctor.⁹

Learn how to check your breasts →

Watch out for:⁹

What are the risk factors for breast cancer?

Many factors can affect your risk of breast cancer. Having risk factors does not mean you will develop breast cancer; on the other hand, people with breast cancer may not have any known risk factors. Some factors are related to lifestyle and therefore can be changed while other factors cannot be changed.^10,11

Note: The below is only general information and not an exhaustive list of risk factors. Please talk to your doctor for advice about your risk of breast cancer.

Examples of risk factors (expand for more information):

Being a woman is a risk factor for breast cancer.¹¹Age over 50 years is also a risk factor.¹¹ This doesn’t mean that breast cancer doesn’t occur in younger women but the risk increases with age.¹

Having a close relative, such as a mother, sister, or daughter, diagnosed with breast cancer or ovarian cancer before the age of 50, may increase your risk of breast cancer. The importance of family history also rises with the number of family members affected by breast cancer or ovarian cancer. Talk to your doctor if you have a family history of breast cancer or ovarian cancer.^12-14

Only about 5% of breast cancers can be explained by an inherited gene fault (mutation).¹⁰ A type of rare genetic mutation called the BReast CAncer (BRCA) gene is linked to a higher risk of triple negative breast cancer. However, most triple negative breast cancers are not caused by a BRCA gene mutation.^7,15 Also, if you have a BRCA gene mutation, it does not mean you will develop cancer.¹⁶

Examples of lifestyle factors that can increase the risk of breast cancer include the following:^10,11

being overweight or living with obesity in women who have experienced menopause (postmenopausal women)
drinking alcohol daily

Breast screening (mammograms)

In Australia, women aged 50–74 years are invited to participate in a free breast screen (mammogram; a scan using X-Rays) every 2 years through BreastScreen Australia. Women aged 40–49 years or 75 years and older and with no breast cancer symptoms can also participate in screening.¹⁷

Some women may need different care and services that are not part of screening. This includes women who have:¹⁸

symptoms of breast cancer
a strong family history of breast or ovarian cancer
a previous diagnosis of breast cancer within the last five years

Talk to your doctor to see if breast screening is right for you.

How is breast cancer diagnosed?

If you have new breast changes or an abnormal breast screening, speak to your doctor. Your doctor will probably talk to you to find out more about your symptoms and your family history. They may also perform a clinical breast examination.

Your doctor may refer you for further tests, such as a mammogram if you haven’t had one, or an ultrasound (a scan using high-frequency sound waves).¹⁹

You may also be asked to have a biopsy, which involves a sample of the breast tissue taken and sent to a lab to check for cancer.¹⁹

Staging breast cancer

If you are diagnosed with breast cancer, your healthcare team will probably order tests to assess how big the cancer is and whether it has spread to your lymph nodes or other parts of your body. This information may help with treatment planning.

Your healthcare team may use the TNM system to describe the extent and spread of your cancer:

T: stands for tumour (cancer) and measures the tumour’s size and location

N: stands for node and shows if lymph nodes have cancer

M: stands for metastasis (whether the cancer has spread to other parts of the body)

Your healthcare team may use the numbers 0–5 to describe the stage of breast cancer:²⁰

Stage 0 – abnormal cells are detected but have not spread

Stage 1 and Stage 2 – also known as early breast cancer

Stage 3 – also known as locally advanced breast cancer

Stage 4 – also known as metastatic breast cancer. Breast cancer has spread to other parts of the body

The above information is general. Ask your doctor or healthcare team for information about your individual situation.

References:

Australian Institute of Health and Welfare. Cancer data in Australia (2023). https://www.aihw.gov.au/reports/cancer/cancer-data-in-australia (accessed February 2024)
Cancer Australia. https://www.canceraustralia.gov.au/resources/position-statements/early-detection-breast-cancer (accessed July 2024)
Breast Cancer Network Australia. Types of breast cancer. https://www.bcna.org.au/resource-hub/articles/types-of-breast-cancer (accessed April 2024).
Giaquinto AN et al. Breast cancer statistics, 2022. CA Cancer J Clin 2022; 72(6): 524–541.
American Cancer Society. Breast cancer HER2 status. https://www.cancer.org/cancer/types/breast-cancer/understanding-a-breast-cancer-diagnosis/breast-cancer-her2-status.html (accessed June 2024).
American Cancer Society. Triple negative breast cancer. https://www.cancer.org/cancer/types/breast-cancer/about/types-of-breast-cancer/triple-negative.html (accessed April 2024).
Breast Cancer Trials. Triple negative breast cancer: Symptoms, treatment & prevention. https://www.breastcancertrials.org.au/triple-negative-breast-cancer (accessed February 2024).
Australian Institute of Health and Welfare 2015. Leading cause of premature mortality in Australia fact sheet: breast cancer. Cat. no. PHE 196. Canberra: AIHW.
Australian Government Department of Health and Aged Care. Be breast aware. https://www.health.gov.au/our-work/breastscreen-australia-program/be-breast-aware (accessed April 2024).
Cancer Australia. Risk factors. https://www.breastcancerriskfactors.gov.au/risk-factors (accessed May 2024).
Breast Cancer Network Australia. Risk factors. https://www.bcna.org.au/resource-hub/articles/your-breast-cancer-risk (accessed May 2024).
National Breast Cancer Foundation. Breast cancer prevention and risk. https://nbcf.org.au/about-breast-cancer/prevention-and-risk (accessed February 2024).
National Breast and Ovarian Cancer Centre. Advice about familial aspects of breast cancer and epithelial ovarian cancer (December 2010). https://www.canceraustralia.gov.au/sites/default/files/publications/nbocc-bog-2010-web-a4-printable_504af02a673fd.pdf (accessed May 2024).
US Centers for Disease Control and Prevention. Breast and Ovarian Cancer and Family History Risk Categories. https://www.cdc.gov/breast-ovarian-cancer-hereditary/risk-factors/breast-and-ovarian-cancer-and-family-history-risk-categories.html (accessed May 2024).
Wong-Brown MW et al. Prevalence of BRCA1 and BRCA2 germline mutations in patients with triple-negative breast cancer. Breast Cancer Res Treat 2015; 150(1): 71-80.
US National Cancer Institute. BRCA gene mutations: Cancer risk and genetic testing. https://www.cancer.gov/about-cancer/causes-prevention/genetics/brca-fact-sheet (accessed June 2024).
BreastScreen Australia. BreastScreen and you. https://www.health.gov.au/resources/publications/breastscreen-and-you (accessed June 2024).
Australian Government Department of Health and Aged Care. Who should have a breast screen. https://www.health.gov.au/our-work/breastscreen-australia-program/having-a-breast-screen/who-should-have-a-breast-screen (accessed April 2024).
Cancer Australia. Tests for breast cancer. https://www.canceraustralia.gov.au/cancer-types/breast-cancer/symptoms-and-diagnosis/tests-breast-cancer (accessed May 2024).
Cancer Australia. Stages of breast cancer. https://www.canceraustralia.gov.au/cancer-types/breast-cancer/symptoms-and-diagnosis/stages-breast-cancer (accessed May 2024).

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