International publication of major New Zealand study on breast cancer mortality

A major study of breast screening through New Zealand’s nationally organised BreastScreen Aotearoa programme has been published in the British Journal of Cancer.

“The study shows a reduction in mortality of a third in women ever screened by BreastScreen Aotearoa between 1999 and 2011 when compared with those never screened in the programme over this period.” Says Dr Marli Gregory, Clinical Leader of BreastScreen Aotearoa.

The study was based on individual data from all New Zealand women aged 45 years and older, and related mammography screening through the programme with subsequent breast cancer mortality. Following appropriate adjustments, the analysis showed:

• For women ever screened by the programme, the death rate from breast cancer is reduced by about a third, compared to women never screened by the programme.
• For women who take part in regular screening by the programme, there is an even greater reduction in the rate of breast cancer deaths.
• For women with a screen-detected cancer, outcomes are more favourable, as the cancer is found earlier.

“The reductions in the rate of death from breast cancer seen in the programme are consistent with findings demonstrated in international research,” says Professor Richard Taylor from the University of New South Wales (UNSW Sydney).

The study was commissioned by the National Screening Unit at the New Zealand Ministry of Health and carried out by researchers from the UNSW Sydney, University of South Australia and Otago University, in collaboration with the National Screening Unit.

Reference: Mammography service screening and breast cancer mortality in New Zealand: a national cohort study 1999-2011. British Journal of Cancer. In Press 2017.