Breast cancer: signs, symptoms, and treatments

Updated October 2024 | 5 min read
Expert contributor Dr Belinda Kiely, medical oncologist and breast cancer specialist
Words by Trudie McConnochie

Breast cancer is the most common cancer in Aussie women, but with frequent self-examinations, regular screenings and some lifestyle changes, you can reduce your risk.  

Cancer was the last thing on Barbe’s mind when she was diagnosed with the disease at the age of 39. There was no family history and she thought she’d reduced her risk by breastfeeding three children, not smoking and leading a healthy lifestyle.

But in 2002, Barbe was diagnosed with HER2 positive cancer, a type of breast cancer where cells have high levels of HER2 receptors on their surface which makes it easier for cancer cells to form. While the cancer hadn’t spread, it was aggressive, and she had to undergo surgery, chemotherapy and radiotherapy. 

Barbe isn't the only person to misunderstand their risk of breast cancer. Despite it being the most common cancer among Australian women, misconceptions about the likelihood of breast cancer persist, says medical oncologist and breast cancer specialist Dr Belinda Kiely. Most of the patients she treats with breast cancer have no family history and no risk factors.

“It’s a misconception that you can only get breast cancer if you have a family history,” she says. “One in seven women develop breast cancer in their lifetime and most of these women have no obvious risk factors. So essentially all women are at risk of breast cancer.”

Another misunderstanding Dr Kiely encounters is the idea that breast cancer only occurs in women.

“Breast cancer is much rarer in men, but men can still develop it,” she explains. “Approximately one in 700 men will develop breast cancer over their lifetime.”

While survival rates for breast cancer have improved significantly thanks to advances in treatment, more than 3,300 Australians died from the disease in 2023 (including as many as 33 men). That equates to around nine people every day.

Here’s what you need to know about your risk of breast cancer, the symptoms to look out for and the common forms of treatment.

What is breast cancer?

Breast cancer happens when cells lining the breast lobules or ducts grow in an abnormal way and have the potential to spread elsewhere in the body.

The different types of breast cancer are classified according to the presence of proteins or receptors on their surface. There are three main types: hormone receptor positive, HER2-positive and triple negative.

Each form of breast cancer is also given a stage from I to IV, explains Dr Kiely, with Stages I and II being early stage, Stage III being “locally advanced” within the breast and surrounding lymph nodes, and Stage IV where the cancer has spread to other parts of the body.

“Breast cancer staging is based on tumour size, the extent that cancer has spread to other parts of the body, the receptors and the grade,” says Dr Kiely.

Risk factors for breast cancer

There’s no single cause of breast cancer, says Dr Kiely. With that said, she adds, there are several known risk factors including being a woman, being over 50, having a family history of breast cancer, having dense breasts, being overweight or obese, drinking alcohol and lack of exercise.

You may also be at increased risk of breast cancer if you:

• smoke
• take certain medicines
• carry certain gene mutations (like the BRCA1 or BRCA2 genes)
• have a family or personal history of ovarian cancer
• started your period early
• reached menopause late
• didn’t have children
• didn’t breastfeed.

“[Contrary to popular belief] there is no evidence that deodorant nor hair dye increase the risk of breast cancer,” Dr Kiely says.

To help reduce the risk of breast cancer, doctors recommend that you:

• quit smoking
• maintain a healthy weight
• be physically active on a regular basis – aim for at least 30 minutes of moderate exercise a day
• avoid or minimise alcohol
• breastfeed your baby if possible.

Breast cancer symptoms, screening and diagnosis

Many people don’t experience breast cancer symptoms, and their cancer is detected through a routine screening, so it’s important to get regular mammograms if they’re recommended for you and to make sure you check your breasts regularly. If you notice any abnormality or have any concerns, it’s vital to speak to a health professional as soon as you can.

Breast cancer signs can include changes in the:

• size or shape of the breast
• nipple – like sores, discharge, turning in or changes in shape
• skin – like dimpling or a rash
• texture – like new lumps or thickening
• armpit – including pain or swelling
• breast sensation – i.e. pain or swelling, especially if it’s in one breast only and doesn’t change with your menstrual cycle.

Free mammograms are available every two years to Australian women aged 54 to 74 (free mammograms are also available if you’re aged 40 to 49 or over 74, but you should talk to your doctor first). This is part of the government’s BreastScreen Australia Program and is designed to find breast cancers early, before they can be seen or felt.

During a mammogram, each breast is pressed between two x-ray support plates. This allows the breast tissue to be spread out evenly so breast cancer can be detected at an early stage. The process can be uncomfortable, but it only lasts for 20 seconds.

The breast cancer diagnosis process may involve either a physical examination by a GP followed by tests and/or a mammogram, as well as an ultrasound, MRI and/or biopsy. In addition, CT scans, bone scans and PET scans may also be used to check if cancerous cells have spread in the body.

It can be a stressful time leading up to, and just after, a diagnosis from a specialist; there are a range of services and support groups throughout Australia who you can contact for help. An extensive range can be found on the Breast Cancer Network Australia website.

Checking your breasts

Early detection makes a big difference in breast cancer outcomes, so checking your breasts at home is vital.

“There is no right or wrong way to check your breasts. The main thing is to get used to the normal look and feel of your breasts and see your doctor if you notice any changes,” says Dr Kiely.

The National Breast Cancer Foundation recommends:

• knowing how your breasts normally look and feel through regular activities (like showering, looking in the mirror and getting dressed)
• looking at and feeling your breasts (and the area up to your collarbone) every month
• noticing any unusual changes (like a new lump, thickening, changes to the shape or size of the breast or nipple).

Breast cancer treatments

Since Barbe was diagnosed, breast cancer treatment has become more targeted to match both the tumour and the patient. “It’s really important that from when I was diagnosed to now, we have a more personalised approach,” she says.

As a result, doctors are now able to give less chemotherapy to breast cancer patients, and in some cases, avoid it entirely, says Dr Kiely.

The main forms of treatment for breast cancer include:

• surgery – to remove either the tumour or the entire breast (mastectomy)
• radiation therapy – a controlled dose of radiation is used to kill or damage cancer cells, usually via X-ray beams
• chemotherapy – medications to kill or slow the growth of cancer cells are put into your bloodstream
• hormone therapy – the use of medications to reduce or block oestrogen, to help slow the growth of cancers that are hormone-receptor positive
• targeted therapy – medications that target particular markers on cancer cells (eg HER2) that are used to destroy or damage them.

Thankfully for Barbe, her days of treatment and hospital appointments are now in the past.

“I just have regular check-ups with my GP now, I don’t need to go to an oncologist unless I have symptoms that I think need to be looked at (like a persistent cough). Otherwise, I like to think of myself as having the same risk of breast cancer as everybody else.”

For more information about hospital visits for breast cancer treatment can be found in HCF’s Breast Cancer Preparing for Hospital guide.

A nurse’s experience with breast cancer

When Royal Flying Doctor Service nurse Belinda booked a “run of the mill” mammogram, she didn’t expect a follow up. Belinda had always had regular check-ups and she hadn’t noticed any symptoms.

However, after her mammogram Belinda was asked to come back for a second appointment and was advised to bring a friend. A diagnosis of Stage II breast cancer followed, leaving Belinda shocked.

“It was really strange to me because I didn’t feel sick. To me, you shouldn’t feel as good as what I did,” Belinda says.

Within weeks the Broken Hill-based nurse had surgery to remove the cancer and was booked to undergo radiation in Melbourne to complete the treatment.

“Everyone at work was great. I had to have time off and when I came back, they said ‘no heavy lifting, no doing this, no doing that’,” Belinda says. “It was great to have that support.”

A year later, after successful radiation, Belinda now wears pink scrubs when working as a nurse embroidered with “check your boobies” and uses her experience to encourage patients.

“I ask patients [about mammograms] and if they can’t say when they last had one, I’ll say to them ‘you need to be quick’,” Belinda says, stressing the importance of early diagnosis.

Belinda’s message is simple; “get checked regularly” and she encourages friends and family to do the same.

Do you need to check a symptom with a GP?

It’s vital to talk to your GP about any abnormal symptoms or risk factors. And if you’d like a second opinion about a diagnosis, eligible members can connect to a network of independent, Australia-based medical specialists for a free second opinion on a health condition they're worried about^*. So you can confidently make the best decision for your health.