Surgical treatment of early stage breast cancer in the Auckland and Waikato regions of New Zealand

Background The aim of this study was to understand the factors influencing the use of surgical options by New Zealand women with newly diagnosed breast cancer. Methods Using data from the Auckland and Waikato breast cancer registers, we included 11 798 women diagnosed with stage I–III breast cancer from June 2000 to May 2013. The characteristics of women receiving different surgical treatments and having immediate breast reconstruction following mastectomy were examined. A logistic regression was used to estimate the odds ratio of having breast‐conserving surgery (BCS) versus mastectomy and immediate post‐mastectomy reconstruction. Bilateral breast cancer cases and women with unilateral breast cancer, but who had bilateral surgery, were also identified. Results Fifty‐two percent of women received BCS and 44% had mastectomy over the study period. Key influences associated with BCS were age, mode of diagnosis, socio‐economic status and public or private treatment. Just under half of the women who underwent bilateral surgery did not have bilateral cancer. Nineteen percent of women undergoing mastectomy underwent immediate reconstruction. Implant use increased slightly over the study period but there was a decrease in the use of autologous flap procedures. Conclusion Surgical management of women with localized breast cancer was generally in line with guidelines, but with potential to further increase the use of breast conservation and immediate reconstruction in suitable cases