As women who have had breast cancer before are at higher risk of developing another new breast cancer, it is recommended in both Australia and New Zealand that these women are followed up closely to diagnose new cancers early. Current guidelines for follow up are generalised and do not take into account factors that may influence whether a second breast cancer develops. A more personalised approach may lead to a less intense schedule of testing for patients without compromising on early detection of new cancers.
This study aimed to understand differences between women diagnosed with a new breast cancer after previous breast cancer treatment and women diagnosed for the first time. This would be the first step in determining more personalised follow up guidelines. The research used data from the BreastSurgANZ Quality Audit (BQA) and included women in Australia and New Zealand diagnosed between June 2023 and December 2024. Of 11,474 women diagnosed with breast cancer in the study, about 14% had previously had breast cancer surgery.
The study found:
- Women with a previous breast cancer were generally older, and their new breast cancers were often smaller, less likely to have spread to lymph nodes, and more often found before symptoms appeared.
- Women diagnosed with breast cancer for the first time were more likely to have breast-conserving surgery (i.e. where only part of the breast is removed) than a mastectomy (i.e. removal of whole breast) (around 71% vs 29%).
- For women diagnosed with a second breast cancer, treatment decisions often depended on their previous treatment, including whether the first cancer was in the same breast and whether they had radiotherapy.
- Immediate breast reconstruction was slightly more common in women having treatment for their first breast cancer (27% vs 21%).
In summary, the current study confirms that second breast cancers diagnosed after previous breast cancer treatment are found earlier and tend to be smaller and less advanced. As the current study did not include data on the first breast cancer for those who had been diagnosed with a second, further research is required. Further research should investigate factors that contribute to developing a second breast cancer and the length between first and second diagnosis. Such research could be used to create more personalised follow up guidelines which take into account a patient’s risk factors and treatment choices.
Reference:
Shepherdson, M., Edwards, S., & Bochner, M. (2026). Characteristics and management of women with a new breast cancer diagnosis after previous breast cancer in Australia and New Zealand. European Journal of Surgical Oncology, 52(4), 111732. https://doi.org/10.1016/j.ejso.2026.111732