New breast cancer diagnoses and treatments 2020

This report looks at breast cancer diagnoses in 2020 for women aged 45 to 69 across New Zealand. It includes cases found through BreastScreen Aotearoa (BSA), other types of screening, and those diagnosed without screening. The report helps show how outcomes differ between women screened through the national programme, screened elsewhere, or not screened at all.

The data for this report comes from Te Rēhita Mate Ūtaetae – Breast Cancer Foundation National Register, managed by the Breast Cancer NZ Register Trust. Every effort has been made to check and confirm the accuracy of the data. The results in this report may be slightly different from BreastScreen Aotearoa reports because of differences in definitions and eligibility rules.

The Register regularly checks and updates its data to make sure it is accurate and complete, so figures may change over time. This report is based on data from July 2023. A later check in May 2024 found some small differences (greater than 2% in some cases) after further data cleaning. These changes did not affect the overall findings. The main change was that 98 breast cancer cases were found to have been incorrectly recorded as not screened by BSA. When corrected, the proportion of cases screened by BSA rose from 53.4% to 56.8%.

Although great care has been taken to prepare this report, the Breast Cancer NZ Register Trust cannot guarantee it is completely free from error. The Trust is not responsible for any loss or damage from using the information. If you find any possible errors or have questions about the data, please contact breastcancerregister.org.nz.