While screening does not stop you getting breast cancer, it does reduce your chances of dying from it.

If you are under 50, screening reduces your chance of dying from breast cancer by about 20 percent. If you are between 50 and 65, screening reduces your chance of dying from breast cancer by about 30 percent. For women aged 65-69, it is reduced by about 45 percent.

The risk of breast cancer increases as you get older. Of those women who get breast cancer, three-quarters are 50 years and over.
Most women who develop breast cancer have no close relative with the disease. Even among women with a family history of breast cancer, only a very small number will be at high risk of getting breast cancer.
The chance of a New Zealand woman getting and dying from breast cancer for every 10,000 women is shown in the table below.  Because there are effective treatments available for breast cancer, most women who get breast cancer do not die from it.

Chance of developing or dying from breast cancer	Age
For every 10,000 women	45-49	50-54	55-59	60-64	65-69
The chance of developing breast cancer is	18	25	29	33	30
The chance of dying from breast cancer each year without screening is	4	5	7	7	9
The chance of dying from breast cancer each year with screening is	3	4	5	5	5

Source: NZHIS: data are averages for 1997-2002 (incidence) and 1996-2000 (mortality)

All BreastScreen Aotearoa facilities have to meet the BreastScreen Aotearoa National Policy and Quality Standards.  These are independently checked.  BSA monitoring reports can be viewed here.