About Mammograms


Mammograms are very low dose breast tissue x-rays. They are used to pick up breast changes, in particular, breast cancer. Mammograms bring forward the detection time of a breast cancer, as they can detect breast changes (lump/thickenings) which are so small they cannot be felt. 

The risk of breast cancer increases as you get older, so the NZBCF recommends women consider starting regular screening from age 40.  Screening mammograms cannot prevent breast cancer, but they can reduce the risk of dying from the disease by approximately a third.

The Foundation recommends mammograms:

·         40 – 49 years: consider screening every year

·         50 years onwards: every two years

·         70+: in discussion with your doctor 

BreastScreen Aotearoa

BreastScreen Aotearoa is New Zealand's National Breast Screening Programme. They provide free mammograms every two years for eligible women 45 - 69 years.

You can have a free screening mammogram ever two years through BSA if:

  • you are aged 45 to 69 years of age
  • you have no symptoms of breast cancer
  • you have not had a mammogram in the last 12 months
  • you are not pregnant
  • you are eligible for public health services in New Zealand.

To enrol with BreastScreen Aotearoa Freephone 0800 270 200


If you are not eligible for free screening and you have no symptoms, having a mammogram through a private x-ray clinic or breast clinic is your only option. The price may vary (approximately $180). However, if your doctor is concerned about your symptoms, you can get referred to a public hospital at not cost or choose to pay for a mammogram from a private breast clinic.

Find out more details in 'Mammograms - The Facts' (PDF, 162Kb)

Watch Anne's mammogram here

For women with symptoms:

A diagnostic mammogram is performed on a woman (or man) who has any breast signs and/or symptoms that require further investigation, e.g. lump, thickening, skin changes, etc, or a woman who is considered at high-risk for the development of breast cancer.

A NZ citizen or resident is entitled to:
o A free diagnostic mammogram - at any age – at a District Health Board (DHB) provided mammography service if she has significant signs and/or symptoms of breast cancer; a GP referral is required.
o A free annual diagnostic mammogram - at any age - at a DHB-provided mammography service if she has no symptoms of breast cancer, but is considered at high-risk for the development of breast cancer; a GP referral is required.
* Remember, 9 out of 10 breast lumps are not cancerous (benign).

Accuracy of Mammograms
Screening mammograms are not perfect; they do have their limitations. However, they are the best method presently for finding a breast cancer early enough so as to increase the chance of survival. Screening mammograms are 85% effective in detecting unsuspected cancers in women over 50, and 75% effective in women under 50. The reason for only a 75% detection rate in women under 50 is due to their breast tissue being relatively dense which can make it more difficult for a radiologist to see a breast cancer on a mammogram x-ray image. As a result, some breast cancers are not seen, and thus go undetected. As some breast cancers may not be detected, it is important for all women to continue to be ‘Breast Aware’ between their mammograms (look and feel for any new or unusual breast changes).

The benefit of a screening mammogram (early detection and treatment of breast cancer) far outweighs any risk to a woman from the very small amount of radiation exposure received from a screening mammogram. The amount of radiation exposure is considered to be a similar dose to what women would naturally be exposed to, in the environment, over a 7 week timeframe1.

What happens during a mammogram?
Your breast is briefly pressed between two plates of the x-ray machine. This is to spread the tissue apart and get a good image of the breast. Some women may find this uncomfortable or painful, but it is only for a short time. Let the radiographer (the person doing your mammogram) know if it is too uncomfortable. Afterwards, the images of your breast are checked by a radiologist (specialist doctor).

1. Gregory, M. (2014). Current Screening Issues: Are we making a difference? Auckland: Auckland Breast Conference  (27 June 2014)