From symptoms to screenings: Everything you need to know about checking your breasts.

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What is breast cancer?

Our breasts are a collection of lobes and ducts, with each lobe being further divided into lobules. The lobules are where milk is produced during breastfeeding and the ducts transport the milk to the nipple.

Breast cancer is where there is abnormal growth of the cells that line the breast lobules or ducts. These abnormal cells continue to divide and grow, and in some cases, can spread to other parts of the body (known as metastasis).

There are a few different ways in which breast cancer is categorised. The first is by location – either located in the ducts or in the lobules. The next step is whether breast changes are non-invasive or invasive:

• Ductal carcinoma in situ – the most common type of non-invasive carcinoma.

• Lobular carcinoma in situ – often referred to as 'pre-cancerous' or benign breast change.

• Invasive ductal carcinoma – approximately 80% of all diagnosed breast cancers.

• Invasive lobular carcinoma – approximately 10% of all diagnosed breast cancers.

Non-invasive refers to cancers that are confined to the duct or lobule, whereas invasive refers to cancers that have spread outside the duct or lobule into surrounding tissues. Non-invasive cancers are regarded as 'pre-cancerous' by some physicians. However, they must be treated so they don't progress to invasive cancers.

In addition to the above types of carcinoma, there are rarer types of breast cancer such as Paget's disease of the breast, phyllodes tumours and inflammatory breast cancers. 

Invasive breast cancers are further divided into subtypes once a biopsy has been taken and examined by a pathologist. 

1. Hormone receptor positive – these are cancers that grow in response to circulating oestrogen and progesterone. Approximately 75% of breast cancers are hormone receptor positive. 

2. HER2 positive – these cancers make up approximately 20% of all breast cancers and have increased levels of a protein known as HER2. It is a more aggressive form of breast cancer – however, the good news is that effective treatments are now available for this type of cancer.

3. Triple positive or negative – Triple positive is when a breast cancer is both hormone receptor positive as well as positive for HER2. Triple negative is when a breast cancer is negative for both hormone receptors and for HER2 proteins.

We unpack women's health issues with medical professionals and experts on Well, fcat sheet continues below.

Who does breast cancer most commonly affect, and what are the risk factors?

Recent estimates suggest one in seven women will be diagnosed with breast cancer by the age of 85 years, with the average age of diagnosis being 62 years. 

It is the second most commonly diagnosed cancer in Australia and the Cancer Council reports that almost 21,000 people were diagnosed with breast cancer in 2024. Men are also affected by breast cancer, but the rates of diagnosis are much lower, with approximately 220 men diagnosed in Australia in 2024.  

There are multiple risk factors for breast cancer – some that we can't change (non-modifiable), such as inherited genes (ie, BRCA1 and BRCA2) and others that we can (modifiable), such as exercise and diet. 

Some other risk factors that are non-modifiable include:

• Increasing age

• Dense breast tissues

• A family history of breast or ovarian cancer

• Early onset of periods or late onset of menopause 

• Having your first child over the age of 35 years or never having children

Risk factors that we can modify include:

• Alcohol consumption – with the risk being higher the more you drink

• Smoking 

• Leading a sedentary lifestyle 

• Having a diet low in fibre (a reminder to eat those fruit and veg!)

• Being overweight or obese

There has long been anxiety that the use of hormonal contraception and menopause hormone therapy increases the risk of breast cancer.

However, up-to-date evidence shows that this risk is low compared with the other risk factors noted above – this is nicely outlined in a factsheet from the British Menopause Society.

The most accurate way to work out your own individual risk is through an online tool such as iPrevent, which is available free through the Peter MacCallum Cancer Centre.

This online tool takes about 30 minutes to complete and provides a report which is easily printable so that you can take it to your GP to discuss. Some women who are at a higher risk of breast cancer may need more regular screening or referral to a specialist breast service for advice. 

What are the most common breast cancer symptoms?

Some women will have no symptoms of breast cancer and their diagnosis will be made through a screening mammogram and subsequent tissue biopsy.

Other women do find new onset breast symptoms which should always prompt a visit to a GP for an examination and further investigation. These may include:

• Changes to the nipple include ulcers, discharge or inversion

• New lumps to the breast, particularly if on one side only

• Any breast pain or tenderness that is not related to your menstrual cycle

• Change to the skin such as dimpling, redness, rashes or scale-like plaques

• Swelling or pain in the armpit

• Weight loss for no known reason

• Persistent fatigue despite being well rested 

• Night sweats or fevers

• Nausea or loss of appetite

• Yellowing of the skin or eyes

• Bone pain including back pain

What is a breast self-exam, and how often should I be doing one?

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A breast self-exam is an opportunity for you to get to know your breasts – how they look and how they feel.

Everyone's breasts are different, so it's important to get to know yours. By knowing what your breasts look and feel like at baseline, you will be able to more easily detect any changes such as lumps, nipple changes, or any difference to the skin texture.  

There is no particular technique you need to follow for a self-check. It is recommended to start by looking in the mirror and checking both breasts, nipples and armpits for any notable changes.

The next step is to feel your breast tissue from the collarbone down to the underside of your breasts, as well as into each armpit. The easiest way to do this is in the shower, so your hand can glide over the skin more easily.

It is recommended checking your breasts every month so that you get to know them well.

What do I do if I find a lump or other breast symptoms?

Any new breast symptom, or even if you're not sure if it's new or different, should be raised with your GP for further review. Your GP will do a breast examination, which forms the first step of the triple test – the recommended diagnostic approach for a new breast symptom. 

The next step of the triple test is imaging – this will be a mammogram or an ultrasound of the breasts, or both. 

The final step of the triple test is a biopsy of the lump, either a fine needle aspiration (FNA) or a core biopsy, which is usually completed under ultrasound guidance. This is a required step even if the imaging results show that the breast lump is likely benign (such as a fibroadenoma). 

What is breast screening, and when am I eligible?

Breast screening in Australia involves a mammogram every two years from the age of 50 – 74 years.

All states and territories in Australia offer breast screening from the age of 40 years, but you will not be actively invited until the age of 50 years. Appointments can be booked online with each state and territory service without referral from your doctor. 

What's the good news?

The good news is that breast cancer survivability has increased in recent years.

Cancer Australia data shows that breast cancer has a 5-year survival of 92%, which has improved dramatically over the last two decades with increased screening, early detection and new treatment options. 

The key is to check your breasts regularly, attend your mammogram when eligible, assess your own personal risk with available calculators online and to see your GP early with any breast concerns you may have.

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