Surgical management of breast cancer in Victoria: A state-wide audit

The Victorian Tumour Summits are an initiative of the Victorian Integrated Cancer Services to engage clinicians and consumers in identifying unwarranted variations in cancer care across the state. From the analysis presented at the Victorian Breast Tumour Summit in 2021, this study provides a state-wide overview of epidemiology and surgical care of breast cancer in Victoria to outline any variations in care across the state, and limitations in data reporting, which impacts the understanding of breast cancer burden and service planning.

A retrospective analysis of Victorian breast cancer patients diagnosed between 2016 and 2018 was performed using a linked data set provided by the Department of Health. The linked data sources include Victorian Cancer Registry, Victorian Admitted Episodes Dataset and Victorian Radiotherapy Minimum Data Set, from which patient demographic details, tumor characteristics and treatment records were extracted. Pearson's chi-squared test was used to determine the statistical significance of relationships between various categorical parameters. Variables including demographics, types of surgery (breast-conserving vs. mastectomy), rates of neoadjuvant chemotherapy, and time to surgery were examined.

One thousand nine hundred thirty-seven patients with ductal carcinoma in situ and 13,375 patients with invasive breast cancer (IBC) were included. Of 11,351 patients with stages I-III IBC (85%, N = 13,375) 66% underwent breast-conserving surgery (BCS), and 31% underwent mastectomy. The ratio of mastectomy to BCS increased with increasing disease stage. Neoadjuvant chemotherapy was utilized in 11% of early IBC patients who were surgically treated. Eighty-three percent of patients undergoing upfront breast surgery were treated within 5 weeks of diagnosis, with a significant difference in the median time to surgery between public and private sectors. Breast reconstruction was performed in 37% of mastectomy patients, of whom 83% underwent immediate breast reconstruction, and 17% underwent delayed breast reconstruction.

Victorian breast cancer data show a high quality of surgical care coordination. Significant gaps in our data warrant future improvements in the Victorian breast cancer notification system and access to pharmaceutical data for an enhanced understanding of the breast cancer treatment pathways and care delivery.