New breast cancer diagnoses and treatments 2020

This report analyses 2020 breast cancer diagnoses nationally for women aged 45 to 69, across all referral sources: BSA or other screening, and non-screened diagnoses. This gives a valuable insight into the differences in outcomes between population-based screening, opportunistic screening, and women who have not been screened.

The Breast Cancer NZ Register Trust has supplied data from Te Rēhita Mate Ūtaetae - Breast Cancer Foundation National Register, and the analysis for this report. All reasonable efforts have been made to verify and validate this report. The data presented in this report may vary from BreastScreen Aotearoa reports due to differences in technical definitions, patient eligibility and other rules (e.g. diagnosis type). The Register conducts regular data audits to enhance the data's accuracy, completeness, and quality, therefore data may change over time. This report is based on data extracted on 21 July 2023. Prior to publication, a check on this report was conducted using data extracted May 2024, following an additional data audit and remediation between data sets. This identified some instances where there was an absolute change greater than two percent between this report and data extracted post-audit in May 2024. However, the post-audit data changes to counts or percent differences (>2%) did not materially impact the key findings in the 2020 report. Of note, 98 records of breast cancer cases where the referral source was BSA screened were misclassified as either non-BSA screened (24 cases) or symptomatic/other (73 cases) or unknown (1 case). This increased the proportion of total cases where the referral source was BSA screened by 3.4% overall in the post audit analysis from 53.4% to 56.8%.

While all care and diligence has been used in processing, analysing, and extracting data in this publication, The Breast Cancer NZ Register Trust makes no warranty it is error free and will not be liable for any loss or damage suffered by the use directly, or indirectly, of the information in this publication. If you notice any potential errors or have any concerns about the data or information presented, then please email breastcancerregister.org.nz