National breast cancer audit: overview of invasive breast cancer in New Zealand

Abstract

Aim: The National Breast Cancer Audit collects data on the care of early breast cancer patients in Australia and New Zealand. An overview of invasive breast cancer in New Zealand is presented with emphasis on comparing the screened population with symptomatic referrals. Method: All New Zealand data in the National Breast Cancer Audit with a diagnosis date of 2008 have been included in the report. Data was analysed with an aim to compare the presenting features and management of screen detected invasive cancer with symptomatic referrals in New Zealand. Results: There were 2371 cases of breast cancer, 52% of which were symptomatic referrals, 37% of which were BreastScreen Aotearoa referrals. Higher breast conservation rates were reported in the screening population. 3% of patients had involved margins after surgery. Almost two-thirds (62%) of BreastScreen patients underwent a sentinel node biopsy without further axillary surgery. 72% of screening patients and 86% of symptomatic patients who were high risk did not receive post mastectomy radiotherapy. A larger proportion of symptomatic patients received chemotherapy. Endocrine therapy was prescribed to 81% of hormone receptor positive patients. Conclusion: Patients with early invasive breast cancer in New Zealand were managed appropriately according to audit performance indicators and clinical guidelines. The numbers of high risk patients not receiving post mastectomy radiotherapy and the lack of endocrine treatment in some patients with hormone receptor positive tumours may warrant further investigation.