Breast cancer – about | Mate pukupuku ūtaetae

Breast cancer (mate pukupuku ūtaetae) is a harmful growth that starts in your breast tissue. It is the most common cancer among New Zealand women, affecting 1 in 9 women over their lifetime.

On this page, you can find the following information:

On average, 8 New Zealand women will hear the news today that they have breast cancer. Most will live for 5 years or longer if the cancer is detected early enough, but more than 600 women die of the disease every year. 

Men can develop breast cancer, though this is rarer, adding up to about 1% of all breast cancers.

Key points:

  • Breast cancer can occur at any age but is most common in women between 50 and 70 years old. You are more at risk if you have a family history of breast cancer.
  • Treatment is usually more successful if breast cancer is found at an early stage.
  • For this reason, women are advised to have a free mammogram every two years from 45 to 69 years old.
  • By the time you can feel a breast cancer, it is about the size of a cherry or walnut, while mammograms can pick up breast cancers that are as small as a grain of rice.
  • If you find a breast lump, see your doctor to have it checked.

What are the causes of breast cancer?

Cancer is caused when some of the cells in our body start to grow out of control. These cells keep multiplying and form a lump called a tumour.

Some breast cancers grow very slowly, while others grow much faster. Breast cancer can spread to the lymph glands and to other parts of the body, such as the bones and liver.

The causes of breast cancer are not clear, but many risk factors are known. The main factors that influence your risk include being a woman and getting older. Most breast cancers are found in women who are 50 years old or older. Read more about risk factors for breast cancer.

What are the symptoms of breast cancer?

Breasts undergo changes throughout a woman's life, particularly the normal changes experienced during the menstrual cycle.  

Some breast changes may be early signs of breast cancer, including:

  • a lump or lumpiness
  • thickening of the tissue
  • nipple changes, such as skin dimpling
  • a blood-stained discharge from one nipple
  • an inverted nipple (unless the nipple has always been turned in)
  • a rash on a nipple
  • a change in breast shape
  • a painful area
  • a rash or red marks that appear only on your breast.

If you have any of these changes. You don’t necessarily have breast cancer, but you should see your doctor to get your breasts checked.

Most breast cancers begin in the milk ducts (ductal cancers), while a small number start in the milk sacs or lobules (lobular cancers). Within these two groups there are different subtypes of breast cancer.

How is breast cancer diagnosed?

Your doctor will talk to you about your medical history and symptoms and will do a physical examination.

You may them be referred to a specialist for a mammogram and/or ultrasound scans. Further testing, such as taking a sample of cells from the lump, biopsy or removal of the lump, and laboratory testing on any breast tissue samples may be required.

Find out more about each of these diagnostic methods for breast cancer.

How is breast cancer treated?

Breast cancer is treated by four different methods: surgery, radiation treatment (radiotherapy), chemotherapy and hormone treatment. Find out more about each of these types of treatment for breast cancer

Which treatment or combination of treatments is used depends on the type and size of the breast cancer and whether or not it has spread, and the age, general health and personal choice of the woman with breast cancer.

Understand your options

Before any treatment begins, make sure you have discussed the options with your doctor. Your doctor may advise that one method of treatment is better than another. Make sure you understand the reasons for this advice. Ask for a second opinion if you want one.

You may find it useful to have your husband or partner or another friend with you when you talk to the doctor. You may also find it helpful to make a list of questions before your visit. 

Your treatment team

If you are diagnosed with breast cancer, you will be cared for by one or more of a team of health professionals, including:

  • your family doctor
  • a breast surgeon who specialises in breast diseases, and sometimes a plastic (reconstructive) surgeon
  • a pathologist (a doctor who diagnoses disease by studying cells and tissues under a microscope)
  • a radiation oncologist (a doctor who specialises in the use of radiation in the treatment of cancer)
  • a medical oncologist (a doctor who specialises in the use of drug treatments for cancer)
  • a radiation therapist, who prepares you and gives you your radiation treatment
  • oncology nurses and breast care nurses, who help you through all stages of your cancer treatment
  • dietitians, who recommend the best foods to eat
  • social workers, physiotherapists and occupational therapists, who advise you on the support services available and help you get back to normal activities.

In some areas, not all means of diagnosis and treatment are available.

What happens after breast cancer treatment?

After your treatment is finished, you will have regular check-ups. Your doctor will decide how often these are needed. They will gradually become less often if you have no further problems. 

You should also regularly examine your breasts, or remaining breast and mastectomy area. Tell your doctor about any unusual breast symptoms or general health symptoms.

Many people worry that any pain or illness is a sign the cancer is coming back. This is usually not the case, but if you are worried, talk to your doctor about what you are experiencing.  

Cancer recurrence

Sometimes, breast cancer can come back. This is called a recurrence. Most recurrences appear within five years after the initial treatment. 

Treatment of recurrent breast cancer may be by surgery, radiation treatment, chemotherapy or hormone treatment or a combination of these. Treatment aims to control the disease. 

Successful treatment of recurrent breast cancer allows many women to continue leading normal lives. 

Common concerns following breast cancer treatment

Following breast cancer treatment, it is natural to have many questions and concerns that reach beyond whether the initial cancer has been cured.

Your recent experiences mean you may need access to good advice on how to best cope with the physical, emotional and psychological upheaval breast cancer has had on your life.  

Find out about common concerns after breast cancer treatment

Support and personal stories

Breast Cancer Support Inc. One-on-one calls, support, groups, step by step support pack and more.
Personal stories (English and Maori) National Screening Unit, NZ
What can you do for someone who is diagnosed? NZ Breast Cancer Foundation, 2013
Support for positive lives with secondary breast cancer Sweet Louise, NZ
Look good feel better Free Feel Better Class for any cancer patient with any cancer
More breast cancer support groups

Learn more

NZ Breast Cancer  NZ Breast Cancer Foundation, 2013
NZ Breast Cancer facts and statistics  NZ Breast Cancer Foundation
Breast cancer  NHS Choices, UK, 2014
Living with breast cancer  NHS Choices, UK, 2014


  1. Breast Cancer Foundation NZ, 2017 
Credits: Original content from Cancer Society. Latest update April 2016. Reviewed By: Andreea Dumitru, Senior RN from CCDHB, SIDU - Capital & Coast & Lower Hutt